Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: PROGRESS: 2008/10 TO 2009/09 OUTPUTS: INSECT RESISTANT TOMATOES Part of the tomato program is focused on genetic control of acylsugar-mediated broad spectrum of insects, and for important viral diseases vectored by insects. Last year, several tomato breeding lines that are homozygous for S. pennellii introgressions that support production of moderately high levels of acylsugars were released to seed companies. This year a series of additional acylsugar producing tomatoes lines were released to seed companies. These lines have modifications to their introgressions to reduce their size, thereby improving horticultural type, or have additional introgressions, to raise acylsugar levels and increase insect control. MEETINGS AND OUTREACH: 1. The current status of the projects in the tomato breeding program were presented to tomato breeders and related professionals at the Tomato Breeders Roundtable meeting, Sacramento, Ca, July 2009. 2. Current status of the fungal disease resistance work within the tomato breeding program were presented to plant pathologists and related professionals at the Tomato Disease Workshop, University Park, PA, Nov, July 2009. 3. The annual Vegetable Breeding Field Day was held in Ithaca NY late August 2009 for seed company breeders and other seed company representatives to view the current materials in the tomato program in field and greenhouse plantings, to see materials being released, and to discuss progress and future plans of the tomato breeding program. 4. Information on the progress of the tomato program and on materials being released is presented in written VBI annual reports provided to seed companies each January, along with instructions on how companies can submit requests for germplasm. 5. The summer 2009 results were also presented to NY State extension agents at the annual In Service training session, Nov. 2009, in Ithaca NY. PARTICIPANTS: PARTICIPANTS: Martha Mutschler (Professor and PI) Department of Plant Breeding Peter Hyde (Technician and M.S. Graduate student on the employee degree program working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca. Assists in tomato crosses, planting, harvests, and disease evaluations. Darlene DeJong (Technician working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca Performs acylsugar assay on insect resistant tomatoes, and marker analysis for introgressions associated with acylsugars and for virus resistance genes, and other characteristics Stephen Southwich, (Technician working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca. Assists in tomato crosses, planting, harvests, and disease evaluations. Christina Westerling. (Technician working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca Assists in tomato crosses, planting, harvests, and disease evaluations. COLLABORATORS: Tom Zitter (Professor Department of Plant Pathology, Cornell University, Ithaca and CoPI on SLS, LB, EB project) Charles Bornt Cooperative Extension Educator, Cornell Cooperative Extension, Cooperating in SLS, LB, EB project field trials Barbara Liedl, Gus R. Douglass Institute, Agricultural and Environmental Research Station West Virginia State University, Institute, WV; Cooperator on SLS, LB, EB project Steve Rideout, Steve Rideout, Dept. of Plant Pathology, Virginia Tech - Eastern Shore AREC, Painter, VA; Cooperator on SLS, LB, EB project Kelly Ivors, Department of Plant Pathology, NC State University, Mountain Hort. Crops Research & Extension Center, 455 Research Drive, Mills River, NC 28759 Cooperator on SLS, LB, EB project Peter Hanson provided germplasm with TY1, Ty2, and Ty3 resistance genes, and is testing insect resistant materials in Asia and Africa Jay Scott provided germplasm with TY3 resistance gene Mikel Stevens provided germplasm with SW7 resistance gene and is interacting with our effort to map SW7 as we are combining it with insect resistance. PARTNER ORGANIZATIONS AVRDC is cooperating with this program on insect/virus resistance by providing virus resistant lines to combine with insect resistance, testing materials in Asia and Africa, and providing funds through a subcontract of a Gates Foundation grant. Nunhems Seed Company has cooperated with this program on insect/virus resistance by testing and gift funds. OPPORTUNITIES FOR TRAINING OR PROFESSIONAL DEVELOPMENT Two postdoctoral fellows are currently working within the tomato program. Dr. Stella Zitter is working on the SLS/LB/EB triple resistant tomato project. Dr. Brian Leckie is working on the insect resistant/virus resistant tomato project. TARGET AUDIENCES: TARGET AUDIENCES One target audience are the national and international seed companies, which use the tomato germplasm produced by this program, as well as the methods developed by this program, to develop commercial tomato varieties with improved performance and disease and or insect resistance. A second target audience are the US and international tomato growers, who will use the varieties resulting from the germplasm produced by this program to improve tomato production and quality, and reduce their use of fungicides and insecticides. Though our cooperation with international agencies, this includes small and subsistence growers as well as commercial tomato production operations. A third target audience are Extension staff, who are trained in the yearly IN SERVICE training sessions, at which the results of this program are presented and discussed. A fourth target audience are rural agricultural communities and the rural environment, which benefit from reduction of chemical use when tomato pests and diseases are controlled by genetic resistance, rather than chemical sprays. A fifth target audience are tomato consumers, who benefit from improved quality and availability of tomatoes as well as from reduction of chemical usage and thereby the reduction of risk of residue in food. Efforts Practicum experiences: the program is part of a practicum course providing graduate students outside of the program with opportunities for experience in vegetable breeding. Internships: The programs frequently has interns. In summer 2009, an undergraduate summer intern from France (Daphne Bonduelle) was hosted in the tomato and onion programs to gain experience. She will return spring of 2010 to continue her internship. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
CONTROL OF THREE FUNGAL DEFOLIATING DISEASES. Three diseases defoliate tomato in moist temperate regions, late blight or LB caused by Phytophthora infestans, early blight or EB caused by Alternaria tomatophila, and Septoria leaf spot or SLS, caused by Septoria lycopersici. The recent creation and testing of tomato inbred lines possessing LB resistance and EB tolerance provided a partial solution. However, once LB/EB resistant cultivars are deployed, the susceptibility of these cultivars to SLS will be the limiting factor to reduction of pesticide use. Work started in 2008 and largely completed in 2009 sought to add strong SLS resistance to create lines with genetic control of all three diseases. Work characterizing newly established SLS resistant lines demonstrated that the resistance is strong in homozygous lines, and almost but not quite as strong in heterozygous F1 hybrids. It also demonstrated that SLS resistance results in substantial reduction in lesion size, and in considerable reduction in the number of pycnidia per lesion and pycnidiaspores per pycnidia, limiting reproduction and spread of SLS. Additional work in spring 2009 resulted in selection of plants possessing Ph2 and Ph3 genes for LB resistance, as well as the EB tolerance and SLS resistance. Work in summer of 2009 determined which populations were homozygous for all of these genes, and selected the subset of plants with the best fruit and plant characteristics. This resulted in the creation of the first tomato lines with genetic resistance to all three diseases. To facilitate this work, new PCR based markers were also created for the Ph2 and the Ph3 genes. CONTROL OF INSECTS AND INSECT VECTORED VIRUS. 1. Work in 2009 has nearly completed the creation of dual resistant plants, by adding single virus resistance genes into lines producing acylsugars for insect resistance. The virus resistance genes being transferred include Ty1, Ty2 and Ty3 genes for resistance to TYLCV, and Sw5 and Sw7 genes for resistance to SWV. Existing markers for the TY genes or Sw5 were used to assist the transfer of these genes. Since the location of the Sw7 gene within a 10cM introgression is not yet known, a series of markers was used, and plants with introgressions shortened by recombination were identified to provide material needed to finer map the location of Sw7. 2. Prior work identified QTL that affect acylsugar level. A mapping population analyzed in 2009 has identified QTL associated with alteration in acylsugar structure, modifying either the sugar moiety, or the fatty acid side chains of the acylsugar structure. The genetic control of both of these facets of acylsugar production involves epistatic genetic systems, with 3 QTL interacting to affect sugar moiety and multiple QTL affecting different aspects of the fatty acid side chains. The information will be very useful in generating different types of acylsugar producing lines to optimize insect control.
Publications
- Martha Mutschler, Stella Zitter, Stephen Southwick, Darlene DeJong, Jessica Drennan, Tom Zitter, 2009, Late Blight/Early Blight/Septoria Leaf Spot Program, 2008 Report of the Vegetable Breeding Programs, Vegetable Breeding Institute, pp 55 to 63.
- Martha Mutschler, Darlene DeJong, Stephen Southwick, Peter Hyde, Christina Westerling, Brian Leckie, 2009, Insect and Virus Control Program, 2009, 2008 Report of the Vegetable Breeding Programs, Vegetable Breeding Institute, pp 64 to 78.
- Mutschler, M.A., Zitter, S.M., and Zitter, T.A. 2009. Combining resistance to Septoria leaf spot, late blight and early blight in tomato for joint control of defoliating diseases. Phytopathology 99:S91. http://apsjournals.apsnet.org/doi/pdf/10.1094/PHYTO.2009.99.6.S1
- Mutschler, M.A., Zitter, T.A., and Bornt, C.H. 2009. Benefits of early integration of interdisciplinary work for tomato improvement. Phytopathology 99:S91. http://apsjournals.apsnet.org/doi/pdf/10.1094/PHYTO.2009.99.6.S1
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: OUTPUTS: MATERIALS BEING RELEASED: ACYLSUGAR PRODUCING LINES FOR RELEASE. The acylsugar breeding program has been working since 1990 to transfer acylsugar-mediated multiple-pest resistance to tomato. The initial acylsugar line, 97FL, produces high levels of acylsugars and shows significant reduction of insect infestation in prior field trials. However, its genome is 73% tomato and 27% S. pennellii. The introgression of so much of the S. pennellii genome had detrimental effects on plant type, with the large introgressions associated with negative traits, including reduced and/or delayed fruit set, small fruit size, lack of seed set, reduced plant size, and poor germination. To eliminate the negative traits, the breeding program used populations derived from crossing 97FL and elite tomatoes, and a combination of molecular markers and acylsugar screens to select acylsugar producing plants within reductions in the number of sizes of introgressions. A subset of the acylsugar lines with the better fruit set is being released in 2008 to seed companies, so that they can start the transfer of this trait to their lines and hybrids. The release of some of these lines had been intended for late 2007, however had to be delayed until late 2008 due to seed issues. In addition to the lines intended for release in 2007, some additional refined acylsugar lines are also being released. A smaller subset of the total lines, with the best levels of acylsugar production and plant/fruit characteristics, are being recommended to seed companies for use in applied breeding. The other lines are intended for more basic research, as they will be useful in biochemical/genomic studies of acylsugar production and action on insects. MEETINGS AND OUTREACH: Current status of tomato breeding program was presented to tomato researchers and public and private tomato breeders at the Tomato Breeders Roundtable, held at Pennsylvania State University Park, PA Nov. 2008. Formalized presentations covering the Septoria Leaf Spot and the Blight project were made at a Tomato Disease Workshop held in Raymond, MS. Nov of 2008. In-service training of extension educators was held in Ithaca, NY, NY in November of 2008, with presentations made for tomato disease resistance studies, and use of resistant materials for disease control. The current status, and especially the new lines being released, were presented to Seed Company representatives at the annual Vegetable Breeding Field Day, Aug 2008 in Ithaca, NY NY, and presented in written reports in the annual report Dec. 2008/Jan 2009, along with instructions on how companies can submit requests for germplasm. PARTICIPANTS: PARTICIPANTS: Martha Mutschler (Professor and PI) Department of Plant Breeding, Cornell University, Ithaca, NY Stella Zitter, Post Doctoral Fellow, Department of Plant Breeding, , Cornell University, Ithaca, NY Working on the Septoria leaf spot program, and on the blight program. Brian Leckie Post Doctoral Fellow, Department of Plant Breeding, Cornell University, Ithaca, NY. Working on the insect resistance program Peter Hyde (Technician and M.S. Graduate student on the employee degree program working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca, NY. Darlene DeJong (Technician working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca, NY Performs acylsugar assay on materials in insect resistance program, and also marker analysis on tomatoes in blight project, Septoria Leaf spot project, and insect resistance project, develops new markers for use in tomato program Stephen Southwich, (Technician working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca, NY. Assists in tomato growth in greenhouse and field, crossing to produce tomato seed, handling of tomato seed, assists in tomato disease screens Christina Westerling. (Technician working for Mutschler) Dept. of Plant Breeding, Cornell University, Ithaca, NY Assists in onion planting, harvests, and grading. COLLABORATORS: Tom Zitter (Professor Department of Plant Pathology, Cornell University, Ithaca, NY and CoPI on Blight project and Septoria Leaf Spot project) Jessica Drennan (Plant Pathology, Cornell University, Ithaca, NY technician working for Tom Zitter; assisting with Blight project, including inoculation production, inoculation, evaluation of disease tests) A. Daniel Jones (Professor Dept. of Biochemistry & Molecular Biology and Dept. of Chemistry Michigan State University East Lansing, MI, collaborating on Acylsugar insect resistance program for biochemical characterization of acylsugars. Feng Shi (a graduate student in Dr. Jones lab, Dept. of Biochemistry & Molecular Biology Michigan State University East Lansing, MI, chemical analyses of chemical composition of acylsugars) George Kennedy (Dept. of Entomology, NCSU, Raleigh, NC, collaborating on control of thrips and spotted wilt using tomato lines with acylsugar production and virus resistance genes) Peter Hanson (Plant Breeder and Global Theme Leader-Breeding, AVRDC. TAIWAN, ROC, collaborating on transfer of Acylsugar production into virus resistant tropical tomato for Africa.) PARTNER ORGANIZATIONS Syngenta Seed Company: Providing gift funds and cooperating in acylsugar insect resistance project Nuhems Seed Company: Provides gift funds and cooperating in acylsugar insect resistance project Asian Vegetable Research and Development Center (AVRDC) Directing a Vegetable production program in Africa and Asia, which is cooperating with the acylsugar insect resistance project, to use the insect resistance in Africa. The AVRDC project, which is funded by the Gates Foundation, provides funding to the acylsugar insect resistance project through a subcontract. TARGET AUDIENCES: OPPORTUNITIES FOR TRAINING OR PROFESSIONAL DEVELOPMENT Two post doctoral fellow are current training and working in the tomato program. Dr. Stella Zitter is working on the Septoria Leaf Spot project, (see NYC-149484) and Dr. Brian Leckie (see NYC-149312) is working on the acylsugar insect resistance project. A summer intern (Frank Lutz) who is an current undergraduate at West Virginia State University, was hosted in the lab and worked part time in the onion program and the tomato program to gain experience in vegetable breeding. A graduate student, Feng Shi, who is in the lab of A Daniel Jones, MSU, is also working in conjunction with this project as part of the collaboration with her adviser, Dr. Jones. TARGET AUDIENCES Vegetable seed companies who will use the germplasm produced, to transfer disease and insect resistance into new elite commercial hybrids Extension staff, who are trained in the yearly IN SERVICE training sessions, at which the results of this program are presented and discussed. Tomato growers in temperate growing regions, who will use the varieties with resistance to Septoria Leaf Spot, early blight and late blight resulting from the germplasm produced, Tomato growers in semitropical and tropical production areas, which are subject to insects and insect vectored virus, and so will benefit from insect/virus resistant germplasm. Rural communities, which benefit from reduction of chemical usage when diseases and insects are controlled by genetic resistance instead of chemicals. Consumers in developed countries, who benefit from reduction of chemical usage though reduction of risk of residue in food, Consumers in developing countries which and benefit from improved food quality greater availability and lower cost when tomato crop can be produced without heavy loss to insect vectored virus. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
INCREASE OF ACYLSUGAR LEVEL IN CROSS WITH 97FL In 2007, the hybrid 071026 x 97FL had acylsugar levels that were significantly higher than that 071026 itself. In 2008, the F2 population derived from selfing this F1 hybrid had significantly higher (P< 0.0001) levels of acylsugar than that of 071026. Marker analysis indicated that highest acylsugar levels were associated with presence small segments of the introgressions on chromosomes 3 and 5, confirming these two QTL. Plants fixed for these two regions, with the better fruit set of 071026, were saved to establish a new acylsugar line superior to either parent. CONTROL OF THRIPS AND SPOTTED WILT VIRUS (TSWV). The interaction among the virus, insect vector, and plant will determine the degree to which acylsugars can control virus. In 2008, a test in NC, in coop Dr. George Kennedy, of acylsugar lines without virus resistance genes showed that higher levels of acylsugars will be needed to control thrips. However the entry with the highest level of acylsugars (379.6 mol/gm dry tissue) showed a sharp decrease in the numbers of thrips as well as reduction in detection of TSWV to 50% of the tomato control. This is very encouraging for the prospect of suppression of thrips and TSWV through use of lines that possess high levels of acylsugars and one or more virus resistance gene. COMBINING VIRUS RESISTANCE GENES AND ACYLSUGAR PRODUCTION FOR DUAL PROTECTION AGAINST INSECT TRANSMITTED VIRUS We are combining the TSWV resistance genes SW5 and SW7 to acylsugar lines to form a dual layer control of this pest and virus combination. F2 populations segregating for both virus resistance and acylsugar production are being used to select for lines possessing both traits. Combination of insect control and virus resistance could provide better control of viral diseases than either single control alone. The virus resistance genes being transferred include TY1 and TY3, and Sw5 and SW7. The most advanced transfer is that of SW5. Plants with high acylsugar levels that are fixed for SW5 were selected in summer 2008; however the selections were still heterozygous for one or two acylsugar introgressions. Through marker selection of their progeny, we should have generated lines fixed for both SW5 and acylsugar introgressions by April 2009. BREAKING INTROGRESSIONS TO ELIMINATE NEGATIVE GENES. Some of introgressions in acylsugar lines are large, and carry genes that are detrimental to horticultural characters. In its original form, the introgression on chromosome 3 is ca. 90cM long and is associated with poor fruit set, late maturity, small fruit size, and yellow fruit. From an F2 population in the SW5/acylsugar project we isolated a plant heterozygous for a rare triple recombinant form of this introgression that has greatly increased fruit set, fruit size, earlier maturity, and is red fruited. F3 self progeny of this plant has confirmed the impact of this recombination to eliminate the negative traits. This will allow production of greatly improved acylsugar lines.
Publications
- Publications WILLIAMSBURG, VA meeting of the 22nd Tomato Disease Workshop, Oct 25, 2007 http://www.cpe.vt.edu/tdw/ Zitter, T. A., Zitter, S. M., and Drennan, J. L. 2007. Evaluation of lite fungicides for early blight and Septoria leaf spot control and pyramiding fungicides with genetic resistance.
- RAYMOND, MS meeting of the 23rd Tomato Disease Workshop, Oct 16, 2008 http://conference.ext.msstate.edu/tomato_disease_workshop/ Zitter, S. M., Zitter, T. A., Southwick, S., and Mutschler, M. A. 2008. Expression and genetic control of resistance to Septoria leaf spot in tomato.
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: CONTROL OF SILVERLEAF WHITEFLY (SLW) IN ACYLSUGAR LINES The trials of acylsugar lines were performed in Florida in coop with Dr. David Schuster of University of Florida, IFAS, Gulf Coast Research & Education Center in spring of 2007. SLW infestation data were collected of eggs, first instar, second and third instar, fourth instar. Acylsugar samples were collected in late May. A range of acylsugar levels is represented by the acylsugar lines in the trial, with 97FL having a uniquely high level, close to 47 umol/ug dry leaf tissue, and the other lines having acylsugar levels ranging from 10 to 20 umol/ mg dry leaf tissue. Within these lines, the lines 06.6245.2, 06.6116.9, 06.6066.4, 06.6041.9 had the higher range of acylsugar levels (15 to 20 umol/ mg dry leaf tissue), and the lines 06.6059.2, 06.6076.8, 05.5019.140, 06.6046.6 had significantly lower acylsugar levels (9 to 10 umol/ mg dry leaf tissue). This allowed an initial determination of the affect of acylsugar level on
the degree of control. The lowest levels of SLW infestation, across developmental stages of this pest, were on 97FL, the line with the highest acylsugar level. Significant reductions in SLW were found across all stages assayed for 97FL and also for the higher acylsugar producers, 06.6066.4, 06.6116.9, and 06.6041.9. However reduction of acylsugar level to less than that of lines 06.6066.4 and 06.6041.9 may result in reduced pest control. ACYLSUGAR LINES. 31 acylsugar lines was evaluated for acylsugar production and other traits. A total of 24 of the 31 acylsugar lines have total acylsugar levels significantly higher than that of the tomato controls, and the top 14 or 16 lines have acylsugar at levels expected to control insects based on the prior trials in Florida. ACYLSUGAR HYBRIDS A series of hybrids were created by crossing acylsugar lines with other acylsugar lines. The hybrids of the control cross, tomato x 97FL, has levels of acylsugars that are only slightly higher than that of
tomato. The acylsugar levels of all of the hybrids created by crossing an acylsugar line with 97FL are much higher than that of the tomato x 97FL controls, ranging from 29 to 43 umol/ mg dry leaf tissue. The crosses to 97FL have higher acylsugar levels than all of the there acylsugar line x acylsugar line hybrids. A series of hybrids was also made using S. pennellii LA 716 as the male parent. The cross of tomato and S. pennellii LA 716 produces a moderate level of acylsugars similar to some of the acylsugar lines, and roughly 1/8 of that of S. pennellii LA 716 itself. The cross of acylsugar lines with S. pennellii LA 716 results in markedly higher acysugar levels, up to 2/3 that of S. pennellii LA 716. Most of the acylsugar lines created to date produce almost entirely acylsucroses. This is in marked contrast to S. pennellii LA 716, which produces acylsugars that are more than 95% acylglucoses. Crosses of acylsugar lines with S. pennellii LA 716 result in production of acylsugars that
are 33 to 40% acylglucoses.
PARTICIPANTS: Martha Mutschler (Professor and PI)Department of Plant Breeding Stella Zitter (Post Doctoral Fellow working for Mutschler) Dept. of Plant Breeding Peter Hyde (Technican and working for Mutschler) Dept. of Plant Breeding Darlene DeJong (Technican working for Mutschler) Dept. of Plant Breeding Stephen Southwich, (Technican working for Mutschler) Dept. of Plant Breeding Tom Zitter (Professor and CoPI on EB/LB/SLS project) Jessica Drennan (Technican working for Zitter)
Impacts
MEETINGS AND PRESENTATIONS: Current status of tomato breeding program was presented to tomato growers and related horticultural professionals at the Annual Vegetable Meetings, Feb. 2007, in Syracuse NY. The summer 2007 results were also presented to NY State extension agents at the annual In Service training, Nov. 2007, in Ithaca NY. Acylsugar information was presented to international tomato breeders at the Tomato Breeders Roundtable meeting, Nov 2007. An article will be published in the proceedings of this meeting sometime in 2008. The current status, and especially the new lines being released, were presented to Seed Company representatives at the annual Vegetable Breeding Field Day, Aug 2007 in Ithaca NY, and presented in written reports in the annual report Dec. 2007. CONCLUSIONS ON CONTROL OF SLF BY ACYLSUGARS. The results of testing a control of SLW by acylsugar producing lines indicate that moderate levels of control are possible with lower levels of acylsugar
(comparable to lines 06.6066.4 and 06.6041.9), and that nearly no insects were found on 97FL, which had the highest levels of acylsugars. However reduction of acylsugar level to less than that of lines 06.6066.4 and 06.6041.9 may result in reduced pest control. CONCLUSIONS ON ACYLSUGAR MODULATION: Comparison of acylsugar production by hybrids of tomato and acylsugar lines and acylsugar line x acylsugar line crosses demonstrates the impact on acylsugar level of homozygousity for some of the introgressions. The acylsugar levels in acylsugar line x 97FL hybrids shows that 97FL has at least one region not possessed by any of the other lines used in acylsugar x acylsugar crosses, or some combination of interactive introgressions not present in any of the other lines, so that it is unique in its high acylsugar level as a line and as a parent of hybrids. The acylsugar produced by the acylsugar line x S. pennellii LA716 hybrids shows homozygousity for some region(s) carried in the acylsugar
lines is important for the production of higher acylsugar levels in these hybrids. That the acylsugar level is so much higher than that of 97FL indicates that at least one region NOT carried in 97FL but present in S. pennellii LA 716 exists, and that this region(s) acts in the heterozygous condition to substantially raise acylsugar level. The fact that the hybrids of acylsugar lines crossed with S. pennellii LA 716 produce acylsugars that are 40% acylglucoses indicates that at least one region present in S. pennellii LA 716 but NOT carried in 97FL acts in the heterozygous condition to allow production of acylglucoses. TOMATO LINES RELEASED. Trials of experimental hybrids of freshmarket tomatoes homozygous for Late Blight (LB) and early blight (EB) resistance demonstrated that the best hybrids were those with the Cornell lines 07-1002, 07-1008, 07-1009 or 048143-7 as the female parent. Trials of experimental hybrids of freshmarket plum tomatos possessing LB and EB resistance in
addition to several other resistances showed that the best hybrids were those with the Cornell lines CU 05A21 and CULBPT 04-5 as the female parent. We are releasing seed of these 6 tomato lines to seed companies.
Publications
- Mutschler, M., Zitter, T. A., and Bornt, C. 2006. Effectiveness of genetic resistance and lite fungicides for disease control. Proceedings 21st Annual Tomato Disease Workshop, Asheville, NC. (online) http://cherokeereservation.ces.ncsu.edu/fletcher/programs/plantpath/2 006-11-tomato-disease/TDW06proceedings.pdf
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Progress 01/01/06 to 12/31/06
Outputs
Acylsugars confer a safe non toxic resistance to a broad range of pests in wild tomato. The acylsugar breeding program is focused on the transfer of this resistance to cultivated tomato and the determination of the best combination of level and type of acylsugar for good pest control. The first acylsugar producing tomato line, 97FL, produced in 1999 is progenitor of all newer improved lines. To confirm that all introgressions has been detected, additional marker analysis was performed in 2006. The resulting 10cM map confirms that 97FL has 8 introgressions from S. pennellii, which when combined cover ca. 25 percent of the tomato genome. Breeding work from 2002 through 2005 produced a series of newer acylsugar producing tomato lines and the identified numerous new modifications of introgressions carried in these lines to improve plant type. Trials run in Florida spring of 2006 tested the acylsugar levels of the subset of five of these lines, under moderate pest
pressure. Although those lines produced only moderate levels of acylsugars, they reduced infestation by Silverleaf Whitefly by approximately 90 percent compared to standard tomato control. Therefore, this trial provides partial information regarding acylsugar level vs. the control of Silverleaf whitefly, and provided a trial run of protocols to be used in more complete acylsugar/whitefly trials planned for the coming year. Two types of populations were trialed in Ithaca, NY summer of 2006. Populations segregating for only one or two introgressions were assayed for homozygousity of the introgressions using molecular markers and for acylsugar productions, and resulting in the production of about 6 more lines. Trials in Ithaca, NY summer of 2006 of all of 18 lines fixed as of April 2006 characterized those lines for acylsugar level, and fruit and seed set characteristics. There was a 10 fold range of acylsugar levels represented by these lines. Analysis of the fruit and seed set data,
alone and in conjunction with the genotypes of these lines across introgressions, is still continuing. None of the lines has all of the modifications needed to restore all desired plant and fruit characters. However problems with pollen fertility and fruit/seed set have been eliminated in about half of the lines, facilitating additional work needed to complete the creation of lines with acceptable plant and fruit type. Lines with complementary sets of modified introgressions are being intermated to combine these modified introgressions to recover fully improved plant type. Seed production is underway to generate hybrids possessing both acylsugar mediated pest resistance and resistance to one or more insect vectored virus.
Impacts
Tomatoes have numerous pests and diseases that cause losses directly through feeding and indirectly through the transmission of plant viruses, resulting in reduction in yield and fruit quality. A large part of tomato production costs are spent on pest management. Acylsugars confer resistance to a broad range of pests in wild tomato, including but not limited to Potato aphid, Green peach aphid, Silverleaf whitefly, Fruitworm, Armyworm, Leafminer, Tomato Psyllids, Tomato fruitborer, Spider mites. Tomato cultivars producing acylsugars would have resistance to many pests, and could be used within the framework of a balanced IPM program for pest control. Incorporation of this safe, natural, broad based pest resistance would result in substantially reductions in losses of crop or crop quality, as well as reductions in production cost, the risk of chemical residue in food, the risks to agricultural workers, and the release of chemicals to the environment. With reduced use of
pesticides, the selection for pesticide resistant pests may also be reduced. Tomato cultivars producing acylsugars would also reduce damage and loss of crop and crop quality due to pests in global regions where farmers are not able to afford pesticides. Acylsugar-mediated pest resistance may also reduce losses due to insect vectored virus. Hybrids combining acylsugar-mediated pest resistance and genetic resistance to virus would have complementary dual control for insect vectored viral diseases that could be particularly advantageous.
Publications
- Kim, M.K. and M.A. Mutschler. 2006. CULBPT-A46 and CULBPT-A48 Series of Late Blight Resistant Processing Tomato Breeding Lines HortSci. 41: 263-265
- Kim, M.K. and M.A. Mutschler. 2006 Characterization of late blight resistance derived from Solanum pimpinellifolium L3708 against multiple isolates of the pathogen, Phytophthora infestans Journal of the American Society for Horticultural Sciences 131: 637-645
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Progress 01/01/05 to 12/31/05
Outputs
Acylsugars have been shown to confer resistance to a broad range of pests in wild tomato. The system is safe and non toxic. There is also preliminary evidence that insect resistance could reduce the spread of virus vectored by the insects. Trials combining an acylsugar assay, PCR based marker analysis of pennellii introgressions, and measures of horticultural characteristics have permitted rapid and substantial improvement of acylsugar lines in the BC6 generation. Trials run in the spring and summer seasons of 2005 resulted in the establishment of more than 21 additional acylsugar producing lines and the identification of numerous new modifications of introgressions to improve plant type. The new lines have a range of acylsugar levels, most of which are within the range expected to provide good pest control. The genomes of these plants have from 85 to 90 percent tomato DNA, an approximately 50 percent reduction in their S. pennellii DNA content. One very interesting
line has an internal portion of the introgression 3 removed, removing a previously identified small fruit QTL, increasing fruit ca. 2.5 times that of sibling plants. Combining the greater than 30 acylsugar lines currently on hand, there are 3 to 5 modifications of each of the long introgressions on chromosomes 3, 5, 8, and 10. The long chromosome 6 introgression is eliminated from most lines. There is also one variant of the short introgression on chromosome 4. Transferal to tomato of acylsugar mediated insect resistance has been a long and arduous job, but it is very close to completion. We are very close to generation of the type of lines that will permit the use of acylsugar mediated resistance in cultivated tomato. The methods and strategies developed have proven their efficacy and power to improve plant type. We have produced a series of hybrids using the newer acylsugar lines for trials of acylsugar production, horticultural type and insect controls in spring 2006 in Florida.
Impacts
Tomatoes have numerous pests and diseases that cause losses directly through feeding and indirectly through the transmission of plant viruses, resulting in reduction in yield and fruit quality. A large part of tomato production costs are spent on pest management. Incorporation of this safe, natural, broad based pest resistance would result in substantially reductions in losses of crop or crop quality, of production cost, as well as reduced risk of chemical residue in food, reduce risk to agricultural workers, and reduce release of chemicals to the environment. Preliminary data indicate that the resistance may also reduce losses due to insect vectored virus. The results of the 2005 trials provided substantial progress on creation of usable pest resistant tomatoes. The methods and strategies developed combining acylsugar/field/molecular markers have proven their efficacy and power to rapidly improve plant type. If we can continue perform this work with appropriately
large populations, this would allow us to attain our goal in the lowest number of generations. We have produced a series of hybrids using the newer acylsugar lines and are proceeding to trials of efficacy of control of insect pests and of cultivar-quality.
Publications
- Zitter, T.A., Drennan, J.L., Mutschler, M.A., and Kim, M.J. 2005. Control of early blight of tomato with genetic resistance and conventional and biological sprays. Acta Hort 695: 181-190.
- Kim, Min-Jea and Mutschler, M.A. 2005. Transfer to Processing Tomato and Characterization of Late Blight Resistance Derived from Solanum pimpinellifolium L. L3708 Journal of the American Society for Horticultural Sciences 130 877-884
- Kim, Min-Jea, Federer, W., Mutschler, M.A. 2005. Using half-normal probability plot and regression analysis to differentiate the disease response of resistant and susceptible tomato genotypes to multiple isolates of Phytophthora infestans Theor. And Applied Genet. 112: 21 - 29
- Kim, M.K. and Mutschler, M.A. 2006. CULBPT-A46 and CULBPT-A48 Series of Late Blight Resistant Processing Tomato Breeding Lines HortScience 41: 263-265
- Mutschler, M.A. and Wintermantel, W. 2006. Reducing Virus Associated Crop Loss Through Resistance To Insect Vectors. Natural Resistance Mechanisms of Plants to Viruses, Gad Loebenstein and J.P. Carr. eds. Springer, Dordrecht
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Progress 01/01/04 to 12/31/04
Outputs
Acylsugars produced by the wild tomato L. pennellii mediate resistance to many important pests of tomato. This resistance is being transferred to horticulturally acceptable tomato lines. Backcross 5 tomato lines, which produced good acylsugars levels and controlled pests well under field conditions. However these lines genomes also had 25 and 30 percent pennellii DNA in 8 and 9 introgressions, respectively, and the plants possessed several negative traits linked to the larger of these introgressions. Small fruit and poor pollen were associated with chromosome 3, delayed germination and seedling abnormalities associated with chromosome 5, and reduced fruit set, and seed production with chromosome 10. Shortening introgressions on Chr 10, 3 and 5: In 2003, an acylsugar producing BC6F3 plant, 033001-81, was found to have a recombination of the chromosome 10 introgression eliminating the central portion of the introgression. This plant was far more normal in vine
appearance than its acylsugar-producing sibs, was 15 percent higher in number of fruit produced, 53 percent higher in weight/fruit, 670 percent greater in seeds/fruit. This plant was also heterozygous for the critical introgressions on chromosomes 3 and 5. In 2004 the self and progeny of 033001-81included many plants with high acylsugar, improved seed set and germination. DNA analysis revealed recombinations on Chromosomes 3 and 5. Selections were made of progenies to grow for isolation of homozygous plants with desired combination of traits. Plant 033001-71, a sibling of plant 033001-81, also showed improved seed set. In the genome of 033001-71 the chromosome 3 introgression was altered such that the top fourth was eliminated, the second fourth homozygous for L. pennellii, and the lower half was heterozygous, and the chromosome 10 introgression was homozygous for the top fourth, and the rest of the introgression was eliminated. The genome of 033001-71 (population 044008) was only
heterozygous for introgression 5 and parts of introgression 3. In 2004, 9 selections were made of progenies of 033001-71 with seed production of 250 to 560 seeds, and acylsugar production of 24 to 44 umol/gm dried leaf. Germination tests and molecular marker work were run to further narrow the list of population to be used in the 2005 season. Other BC6F3 and cross progenies grown in 2004 included additional plants with desired improvements in plant type and acylsugar production, and generated 3 new acylsugar fixed lines which sharply reduced percentage of L pennellii DNA in their genomes. Seed of these lines and hybrids made with them is being produced to allow further testing in 2005. The results of the 2004 trials show that combining the acylsugar assay with molecular marker screens allows us to reduce the number and size of introgressions in a targeted manner, while maintaining acylsugar production. The 2004 season identified a number of selections with shortened introgressions
that could resolve shortcomings of the prior acylsugar lines. In 2005, the best selections will be progeny tested, to confirm the effect of new recombinations in eliminating linkage drag, and to identify more advanced fixed lines.
Impacts
The results of the 2004 trials provided substantial progress on creation of usable pest resistant tomatoes. The shortened Chromosome 10 introgression identified in a single plant in 2003 was demonstrated to increase fecundity. Additional unrelated recombinations on chromosome 10 found in 2004 also appear to improve fecundity. Recombinations shortenting the chromosome 3 and 5 introgressions were identified in 2004, and will be persued in 2005 to determine if they will provide the needed improvements in seed set and germination. If we can perform this work with appropriately large populations, this would allow us to attain our goal in the lowest number of generations, and to proceed to trials of efficacy of control of insect pests and of insect vectored virus using cultivar-quality acylsugar producing lines. Tomatoes have numerous pests and diseases that cause losses directly through feeding and indirectly through the transmission of plant viruses, resulting in
reduction in yield and fruit quality. A large part of tomato production costs are spent on pest management. Incorporation of this safe, natural, broad based pest resistance would result in substantially reductions in losses of crop or crop quality, of production cost, as well as reduced risk of chemical residue in food, reduce risk to agricultural workers, and reduce release of chemicals to the environment. Preliminary data indicate that the resistance may also reduce losses due to insect vectored virus.
Publications
- Mutschler M. A and Wintermantel, W. 2005. Reducing Virus Associated Crop Loss Through Resistance To Insect Vectors. IN Natural Resistance Mechanisms of Plants to Viruses G. Loebenstein ED Kluwer Academic
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Progress 01/01/03 to 12/31/03
Outputs
Acylsugars produced by the wild tomato L. pennellii mediate resistance to many important pests of tomato. This acylsugar-mediated pest resistance is being transferred to horticulturally acceptable tomato varieties. Backcross 5 derived tomato lines, which had 25 to 20 percent pennellii DNA in 8 to 9 introgressions, possess several negative traits. Examination of a BC6F2 populations showed that small fruit and poor pollen were associated with chromosome 3, delayed germination and seedling abnormalities associated with chromosome 5, and reduced fruit set, and seed production with chromosome 10. Selection within the BC6F2 and examination of the selected BC6F3 populations identified plants with elimination of introgressions, or most importantly, recombinations shortening introgressions so that acylsugar production was maintained but negative traits associated with the introgressions were eliminated. In 2003, the chromosome 10 introgression successfully modified as follows.
The full introgression carries the agt gene, the last gene in the acylsugar biosynthetic pathway, but also includes a region severely affecting seed set, and a region causing segregation distortion for region that makes isolation of recombinations altering the introgression very difficult. In late 2002, one acylsugar producing BC6F2 plant, code B03, was found with an alteration that theoretically could eliminate the segregation distortion issue. In 2003, the selfed progeny of this plant provided a BC6F3 population which included one acylsugar producing plant, 033001-81, with a recombination of the chromosome 10 introgression that eliminated the central portion of the introgression. This plant was far more normal in vine appearance than all of its acylsugar-producing siblings, was 15 percent higher in number of fruit produced, 53 percent higher in weight/fruit, 670 percent greater in seeds/fruit. Although this plant did not also have the necessary recombinations for the introgressions
on the chromosomes 3 and 5 introgressions, its genome is still heterozygous for the critical parts of those introgressions. Most fortunately, this plant is already homozygous for the introgressions required for acylsugar production but not associated with negative traits. Therefore, the selfed progeny of 033001-81 will provide the ideal population for targeting recombinations of the chromosome 3 and chromosome 5 introgressions, to eliminate their negative traits. This will be the goal in 2004. A cooperative project testing the materials in Florida and California will also proceed, if funding is obtained.
Impacts
The results of the 2003 trials, particularly the BC6F3 populations, were extremely exciting. The survey of the BC6 populations shows that combining the former breeding methods with the use of molecular screens allows us to reduce the number and size of introgressions in a targeted manner, while maintaining acylsugar production. With the advances made in the BC6 populations, we also have extremely large seed lots from elite plants, such as 033001-81, to rapidly reach our goal of improved plant type in high acylsugar lines. If we can perform this work with appropriately large populations, this would allow us to attain our goal in the lowest number of generations, and to proceed to trials of efficacy of control of insect pests and of insect vectored virus using cultivar-quality acylsugar producing lines Tomatoes have numerous pests and diseases that cause losses directly through feeding and indirectly through the transmission of plant viruses, resulting in reduction in
yield and fruit quality. A large part of tomato production costs are spent on pest management. Incorporation of broad based pest resistance would result in substantially reductions in losses of crop or crop quality, of production cost, as well as reduced risk of chemical residue in food, reduce risk to agricultural workers, and reduce release of chemicals to the environment.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
Acylsugars produced by the wild tomato L. pennellii mediate resistance to many important pests of tomato. This acylsugar-mediated pest resistance is being transferred to horticulturally acceptable tomato varieties. The genomes of backcross 5 derived tomato lines are 75 to 80% tomato in origin. The lines have 6 introgressions in common, three of which are very large. These lines still possess the negative traits, late flowering and reduced fruit set, which have been maintained, probably through linkage drag, in lines producing high level acylsugars. Some of these negative traits are associated with the very large introgression on Chr 3. Primers were created so that PCR analysis could be used to facilitate selection to eliminate linkage drag. BC6F2 plants were characterized for acylsugars, fruit and seed set, and for genotypes at 18 markers within 8 introgressions. Fecund acylsugar-producing plants with reductions in the size and/or number of introgressions were
selected. It is very encouraging that plants were obtained with moderate to high levels of acylsugars and also substancially reduced numbers and/or sizes of introgressions and increased fecundity. When the progeny of the selected plants are screened to select for homozygousity at all of the introgressions, the genomes of the resulting plants should be ca. 85 to 90% tomato in origin, and several negative traits should be eliminated. A patent application is in preparation. Three publications are in preparation, and, with the submission of the patent, should also all be submitted spring 2003. A cooperative project testing the materials in Florida and California will proceed, if funding is obtained.
Impacts
Tomatoes have numerous pests and diseases that cause losses directly through feeding and indirectly through the transmission of plant viruses, resulting in reduction in yield and fruit quality. A large part of tomato production costs are spent on pest management. Incorporation of broad based pest resistance would result in reduced losses, lower production cost, and improved crop quality. It would also reduce risk of chemical residue in food, reduce risk to agricultural workers, and reduce release of chemicals to the environment.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
Acylsugars produced by the wild tomato L. pennellii mediate resistance to several important pests of tomato. This acylsugar-mediated pest resistance is being transferred to horticulturally acceptable tomato varieties. Three lines fixed for high levels of acylsugar production were derived after 5 backcrosses to tomato. RFLP analysis of these lines indicates that their genomes are 75 to 80% tomato. The lines have 6 introgressions in common, indicating that some subset of up to 6 of these introgressions is necessary for acylsugar production. These lines still possess the negative traits, late flowering and reduced fruit set, which have been maintained, probably through linkage drag, in lines producing high level acylsugars. Some of these negative traits are associated with a very large introgression on Chr 3. Reduction of this introgression size to 25% of the original size has eliminated most of the negative traits associated with that introgression, resulting in a far
more normal vine type and improved fruit set and size. Reductions of two other large introgressions are still needed to obtain further improvements in plant type. Primers have been created so that PCR analysis can be used to facilitate selection for reduced size in these introgressions.
Impacts
Tomatoes have numerous pests and diseases that cause losses directly through feeding and indirectly through the transmission of plant viruses, resulting in reduction in yield and fruit quality. A large part of tomato production costs are spent on pest management. Incorporation of broad based pest resistance would result in reduced losses, lower production cost, and improved crop quality.
Publications
- No publications reported this period
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Progress 01/01/00 to 12/31/00
Outputs
Acylsugars produced by the wild tomato L. pennellii mediate resistance to several important pests of tomato. This acylsugar-mediated pest resistance is being transferred to horticulturally acceptable tomato varieties. A set of sibling lines fixed for acylsugars was identified. These self-progenies and experimental hybrids from them were tested for insect control in Florida, and for acylsugar level and fruit production in New York. The resulting F1 and self-progenies were effective in controlling silverleaf whitefly and leaf in the Florida trials. The hybrids tested in Ithaca produced low to moderate levels of acylsugars, depending on the genotype of the second parent used in the cross, and whether the hybrid was homozygous or heterozygous for acylsugar-related genes. These hybrids also varied for fruit set and fruit weight. This will allow us to create a series of related experimental hybrids in identical backgrounds, but with predictable variations in acylsugar level
and structure. These materials will be useful in determining the levels and types of acylsugars for the most efficient control of pests while having the best horticultural type. A second set of fixed lines is nearly developed. These are resulting from progenies in which linkage between acylsugar genes and genes with deleterious effects on plant growth and fruit set and color have been broken. These lines may be completed in the 2001 field season.
Impacts
Tomatoes have numerous pests and diseases that cause losses directly through feeding and indirectly through the transmission of plant viruses, resulting in reduction in yield and fruit quality. A large part of tomato production costs are spent on pest management. Incorporation of broad based pest resistance would result in reduced losses, lower production cost, and improved crop quality.
Publications
- S Doganlar, S. D. Tanksley and M. A. Mutschler. 2000. Identification and molecular mapping of loci controlling fruit ripening time in tomato . Theor. Appl. Genet. 2: 249-255
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Progress 01/01/99 to 12/31/99
Outputs
The wild tomato L. pennellii LA 716 is resistant to many tomato pests, including whiteflies, spider mites, lepodopterous spp., aphids spp., and thrips spp. We have show that acylsugars exuded from foliar trichomes are responsible for resistance of L. pennellii to these pests, and that this resistance is largely due to deterrence, rather than toxicity. Acylsugars are not found in cultivated tomato, but the tomato breeding program recently developed advanced tomato lines fixed for acylsugar production. These lines had significantly less infestation by silverleaf whitefly than unprotected tomato controls under heavy pressure in field trials in southern Florida. Work is continuing to determine the effects of differences in the levels and/or types of acylsugars and of trichome number on the efficacy of acylsugar-mediated control of a series of important pests. We are also examining the effects, if any, of the transferal of acylsugar production to tomato on horticultural
quality of field grown tomatoes.
Impacts
This research will lead to the development and deployment of tomato cultivars resistant to most of the important pests of this crop, reducing the dependence on synthetic chemicals for insect control.
Publications
- Blauth, S.L., J.C. Steffens, G.A. Churchilll, and M.A. Mutschler 1999 QTL analysis of acylsugar fatty acid constitutents using an using intraspecific populations of the wild tomato Lycopersicon pennellii. Theoretical and Applied Genetics. 99:373-381.
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Progress 01/01/98 to 12/31/98
Outputs
Acylsugars produced by the wild tomato L. pennellii mediate resistance to several important pests of tomato. This acylsugar-mediated pest resistance is being transferred to horticulturally acceptable tomato varieties. The acylsugar program has maintained levels of acylsugars in each of the past 5 BCF2 generations to one to three times that of the interspecific F1 control, and recovered even higher acylsugar levels in selections derived from the BCF3 and BC4 generations. Progenies of the summer 1997 selections were grown during winter/early spring 1998 in a greenhouse in Woodland CA with cooperation from Hunt's and tested for acysugar production. The greenhouse data suggested that the acylsugar trait is fixed in several of the populations. Ca. 70% of the plants selected acylsugar production set fruit and seed. Progenies of the winter selections were included in the summer 1998 plantings in Ithaca. Four lines were confirmed to be fixed for acylsugar production at levels
of 1.5 to 3 times that of the interspecific F1 positive control. Self seed were collected from selections within these rows, and crosses have been made with these selections and both processor and freshmarket tomato. The resulting F1 and self progenies will be used winter 1998 in Florida to test the efficacy of different varied levels of acylsugars against infestation by insect pests under field conditions.
Impacts
(N/A)
Publications
- Blauth, S.L., G.A. Churchill, and M.A. Mutschler. 1998. Identification of QTL associated with acylsuagar accumulation using intraspecific populations of the wild toamto Lycopersicon pennellii. Theoretical and applied genetics.96:458-467.
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Progress 01/01/97 to 12/31/97
Outputs
Acylsugars produced by the wild tomato L. pennellii mediate resistance to several important pests of tomato. This acylsugar-mediated pest resistance is being transferred to horticulturally acceptable tomato varieties. The acylsugar program has maintained levels of acylsugars in each of the past 5 BCF2 generations to one to three times that of the interspecific F1 control, and recovered even higher acylsugar levels in selections derived from the BCF3 and BC4 generations. Nonfecundity was the major obstical problem in transfer of this pest resistance to tomato. The breeding strategy was shifted in 96 and 97, resulting in production of populations combinbing full fruit set and acylusgar production. Self progenies of these popoulations will be screened to find populations fixed for both traits for further evalution of the pest resistance and breeding. An earliness trait from an old cherry tomato cultivar functions by shortening the time of fruit development between
anthesis and fruit ripening. Transfer of the earliness trait to fresh market tomatoes is progressing. The chief difficulty in the process was recovering fruit type - size, shape, smoothness, firmness, as well as the earliness trait.. CA. a doze cherry tomato inbreds contaiining this earliness trait were released in the past 3 years, and 4 more are being released 2/98, completing the work in cherry tomato. The first two freshmarket lines and six processing tomato lines incorporating this earliness trait are being released 2/98.
Impacts
(N/A)
Publications
- MCNALLY, K.L. and M.A. MUTSCHLER 1997. Use of introgression lines and zonal mapping to identity RAPD markers linked to QTL. Molecular Plant Breeding:3:202-212.
- LAWSON DARLENE and M.A. MUTSCHLER. 1997. Marker-assisted transfer of acylsugar-mediated pest resistance from the wild tomato, Lycopersicon pennellii, to the cultivated tomato, Lycopersicon esculentum. Molecular Breeding 3:307-317
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Progress 01/01/96 to 12/30/96
Outputs
1) Acylsugars produced by the wild tomato L. pennellii mediate resistance to several important pests of tomato. This acylsugar-mediated pest resistance is being transferred to horticulturally acceptable tomato varieties. The acylsugar program has maintained levels of acylsugars in each of the past 5 BCF2 generations to one to three times that of the interspecific F1 control, and recovered even higher acylsugar levels in selections derived from the BCF3 and BC4 generations. Nonfecundity remains a problem in selections producing high levels of acylsugars. The non-fecundity may be a combination of very late set and very reduced set. The reduction in fruit set appears partially dominant , and is also found in numerous sibs that do not accumulate acylsugars. The trait appears to be due to a gene or genes which are tightly linked to one of the genes necessary for acylsugar accumulation. We are shifting more of our effort to breaking the linkages. 2) An earliness trait from
an old cherry tomato cultivar functions by shortening the time of fruit development between anthesis and fruit ripening. Transfer of the earliness trait to fresh market tomatoes is progressing. The chief difficulty in the process is recovering fruit type - size, shape, smoothness, firmness, as well as the earliness trait.. Several families were found to be fixed for the earliness trait. These populations generally average TFD of 40 to 45 days, compared to 52 to 60 days for normal checks and parental lines.
Impacts
(N/A)
Publications
- Liedl, B. E. , D. M. Lawson, K. K. White, J. A. Shapiro, D. E. Cohen, W. G. Carson, J. T. Trumble, and M. A. Mutschler. 1995 Acylglucoses of the wild tomato Lycopersicon pennellii (Corr.) D'Arcy alters settling and reduces oviposition of B
- Liu S.-C., B. E. Liedl, and M. A. Mutschler 1995 Alterations of the manifestations of hybrid breakdown in Lycopersicon esculentum x L. pennellii F2 populations containing L. esculentum versus L. pennellii cytoplasm. Sexual Plant Repro
- Mutschler, M. A., R. W. Doerge, J. Liu, J. P. Kuai, B. Liedl, Y. Shapiro 1996 QTL analysis of pest resistance in the wild tomato, Lycopersicon pennellii.: QTL controlling acylsugar level and composition. Theor. Appl Genet. 92:709-718
- Liedl, B. E., S. McCormick and M.A. Mutschler 1996 Unilateral incongruity in crosses involving Lycopersicon pennellii and L. esculentum is distinct from self-incompatibility in expression, timing and location. Sexual Plant Reproduction 9:.
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Progress 01/01/95 to 12/30/95
Outputs
An earliness trait from the old cherry tomato cultivar 'Early Cherry' functions by shortening the time of fruit development between anthesis and fruit ripening. The trait was incorporated in the development of elite inbred lines, which were used to create experimental hybrids. In field trials in 1994 and 1995, the earliness trait results early marketable yields up to 2.5 times that of the commercial control varieties, without reduction in plant or fruit size. Five inbred early cherry lines are being released in 1995, bringing the total number of early cherry parent lines released since 1993 to 14. Information regarding the performance of hybrids possible using these parents is also being released in 1995. 2) Work in the prior two years suggested that some, but not all, of the Early Blight tolerant lines developed at Cornell also appear to have reduced susceptibility to Late Blight. A trial was run through a cooperation with W. E. Fry of the Department of Plant
Pathology shwed that two recent releases had reduced susceptability to tomato (1994) and potato (1995) strains of the pathogen. It is unclear whether the level of reduced susceptibility to late blight is of practical use in fields using appropriate horticultural practices to control blight.
Impacts
(N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs
1) Acylsugars produced by the wild tomato L. pennellii mediate resistance to several important pests of tomato. The goal of the tomato pest resistance is the transfer of acylsugar-mediated pest resistance to horticulturally acceptable tomato varieties. Field tests are required to show whether acylsugar-mediated resistance will hold up in field, and levels of acylsugars required to control pests under field conditions. Surveys done in 1994 at Bradenton Fl with the cooperation of Dave Schuster in the observation of acylsugar-mediated resistance to leaf miner and silverleaf whitfly (SLW). The levels of acylsugars produced by the interspecific F1 were not sufficient for control of SLW, but acylsugars of the F5 and BC1F4 breeding lines severely limited infestation by SLW at a range of larval stages. The 1994 trial also indicated that acylsugars might provide control of and an additional pest, pinworm. 2) An earliness trait from an old cherry tomato cultivar functions by
shortening the time of fruit development between anthesis and fruit ripening. The trait was incorporated into several elite inbred lines, used to create experimental hybrids. The earliness trait results in a marked increase in early marketable yield, without reduction in plant or fruit size. Three of the hybrids produced an early harvest that was up to 2.4 times that of the commercial control varieties, and were were also noted for superior fruit flavor and crack resistance.
Impacts
(N/A)
Publications
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Progress 01/01/92 to 12/30/92
Outputs
1.) Acylsugars were found to mediate feeding deterrence to green peach aphids (M. persicae), and sweetpotato whitefly (B. tabaci), ovipositions and adult feeding deterrence to leafminer (L. trifolii), and feeding deterrence and reduced growth/survival of larvae of beet armyworm (S. exigua) and fruitworm (H. zea). Summarizing over pests, the acylglucoses levels of 50 to 70 ug/cm(superscript 2) provided high level of control of all of these pests under lab conditions. A preliminary field trial Spring 1992 at Bradenton Florida showed that infestation of the acylsugar-producing line 905464 by sweetpotato whitefly and leafminers was substantially reduced compared to that of the tomato control. 2.) Earliness from the old cherry cultivar Early Cherry functions by shortening the time of fruit development between anthesis and fruit ripening. We have the trait in lines which combine most of the horticultural characteristics needed for either home or commercial cherries. These
lines are about 1.5 weeks earlier in maturity than most cherry lines used today. Since the earliness trait is nearly dominant in expression, the lines ready for release could readily be used in crosses with other lines to produce early F(subscript 1) hybrids. Work is in progress to transfer the earliness trait to fresh market tomatoes.
Impacts
(N/A)
Publications
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Progress 01/01/88 to 12/30/88
Outputs
Lines homozygous for alc have extended shelf line, but poor fruit quality. To obtain a fair assessment fruit of 10 experimental hybrids heterozygous for alc were compared in a 2 year blind survey with their homozygous parents. Lines homozygous for alc produced fruit which were firmer and had more than a 100% increase in shelf life over normal lines. However, the homozygous alc fruit were paler and less red, with a mean a/b color ratio of 0.16, compared to a 0.57 ratio for normal fruit. The F1 hybrids had a 60% increase in fruit storability over normal lines, and had nearly the same color ratio (0.55) as normal fruit. This demonstrates the potential use of heterozygotes for tomato with extended shelf life. The homozygous alc lines used to create the best F1 hybrids have been released. An atrazine resistant (ATR) cauliflower line was created by the fusion of protoplasts from a atrazine suceptible persistant-white cauliflower line and a B. campestris line carrying the
chloroplast mutation for ATR. The resistant cauliflower has the nucleus of the cauliflower parent line, and the mitochondrial and chloroplast genomes of the campestris parent. The ATR cauliflower line withstands very high levels of atrazine under field conditions, but has a later maturity than the normal cauliflower parental line. The ATR cauliflower is about to be released.
Impacts
(N/A)
Publications
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Progress 01/01/87 to 12/30/87
Outputs
BRASSICA IMPROVEMENT: 1. A cytoplasmically triazine-resistant cauliflower line was field tested against 0 to 4 kg/hc of atrazine. Plants from the resistant lines survived all these treatments, however, they grew slower and produced smaller heads than untreated normal control plants. 2. A superior, early maturing cauliflower line was identified in a somaclonal variation study. The line, derived from the self progeny of a plant regenerated from protoplast, is a firm headed persistent white line. INSECT RESISTANCE: Each of the sugar esters isolated from the trichome-exudate of pennellii plants and tested in aphid chambers effectively inhibited aphid breeding. None of the esters was significantly more effective than the others. The sugar esters exuded by trichomes of F1 plants (L. esculentum x L. pennellii) differ in composition from those produced by the resistant pennellii parent. There is a significant negative correlation between the presence/level of sugar esters and
aphid susceptibility in segregating F2 populations.
Impacts
(N/A)
Publications
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Progress 01/01/86 to 12/30/86
Outputs
BRASSICA IMPROVEMENT: One cauliflower plant carrying the cytoplasmically controlled trait triazine resistance has been derived via protoplast fusion. The line established from this plant is of good horticultural type, and will be tested in herbicide trials summer 1987. A survey of the self progeny of cauliflower plants regenerated from protoplasts has identified plants with altered leaf color and maturities. Further tests are required to determine the nature of the alterations producing these traits. PEST RESISTANCE IN TOMATO: The extent of aphid resistance in L. pennellii (Lp) and in the F1 progeny of tomato and Lp was measured using leaf cage assays. The resistance in the F1 is considerable, but not as strong as in the Lp. Its effects on aphid feeding were demonstrated by use of trichome extracts in artificial feeding chambers and by electro-feeding monitoring. GC and GC/MS studies identifies the class of 9 related compounds present in the trichome exudate. We are
completing assays of the effectiveness of each of the compounds using the artificial feeding chambers. Two BC1F4 lines carrying a single dominant gene for resistance to Fusarium race 3 were also identified and released. The source of the resistance gene is the pennellii accession being used for the insect resistance work.
Impacts
(N/A)
Publications
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Progress 01/01/85 to 12/30/85
Outputs
Over 45 accessions of l. esculentum have been screened for resistance to Alternaria solani, the pathogen causing Early Blight in tomatoes. Five lines were identified which were as early as 'New Yorker', with smaller or as large fruit as 'New Yorker', but with 6-15% defoliation due to blight vs. 60% defoliation in New Yorker. These lines are being genetically analyzed to determine the source of the tolerance, and whether any alone or in combination can provide a useful tolerance. A series of horticulturally acceptable lines homozygous for the alc ripening mutant have been developed. These have been crossed to acceptable normal lines to create F1 hybrids heterozygous for alc. The hybrids will be tested for acceptability of their fruit characteristics commercial and consumer. Work concerning the use of L. pennellii as a source of insect resistance is continuing. Two BC1F2 populations from the cross New Yorker x L. pennellii were identified which include a high
proportion of aphid resistant plants. Self cross progeny of these plants have been saved for further study.
Impacts
(N/A)
Publications
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Progress 01/01/84 to 12/30/84
Outputs
Work on the alc tomato mutant has been summarized in two 1984 publications (see below). A non-storable dark-red fruited plant was isolated from a alc population. Genetic studies indicate that this spontaneous mutant is dominant to alc, and may be allelic to alc. Further tests on the nature of the revertent are underway. A series of tomato lines isogenic for visual (d, sp, j, u) or disease resistance (Ve, I, Tm2a) genes in the cultivars Gardener or Vendor were released. Seed of the disease resistance isogenic lines was requested by 3 labs, where they have now begun to use the lines in studies of the mechanism of the disease resistance genes. The line VFT Vendor has also been adopted as a cultivar by at least 1 seed company. Work is continuing in backcrossing a tomato nuclear genotype into L. pennellii cytoplasm. Use of ovule culture has facilitated this work. Development is now nearly complete of a series of lines created using Backcross-Self and 2 modified
Backcross Self methods. Analysis of these lines will start in 1985 to determine the usefuleness of these breeding methods in tomato improvement.
Impacts
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Publications
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Progress 01/01/83 to 12/30/83
Outputs
An early determinate uniform Verticillium race 1 resistant alc line (Cornell 111) was released fall 1983 for use as an alc source in breeding programs. The recommendation is made to use alc only with uniform lines. Progress continues in developing alc stocks with improved horticultural type. A VFTMV resistant stock of Vendor was also released. Work is progressing on use of L. pennellii as a source of insect resistance. Field and growth chamber tests have shown L. Pennellii and F(1) materials to be resistant to potato aphid and green peach aphid, respectively, but to be susceptible to Colorado potato beetle. The cross L. pennellii x (L. esculentum x L. pennellii) was successfully made, and 17 plants were recovered using ovule culture. This cross has not previously been successful. This material is being further backcrossed to create material with L. Pennellii cytoplasm with an L. esculentum nucleus. A uniform, self-compatible stock of B.campestris was developed
for use in mutagenesis and in vitro research. The mutagenesis work has begun.
Impacts
(N/A)
Publications
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