Progress 10/01/13 to 09/30/16
Outputs
Target Audience:One target audience reached this year 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. This is a critical target audience, since seed companies must successfully incorporate new traits into their hybrids for the traits to become available to growers, and thereby benefit consumers. The "Seed Company" target audience was reached through annual reports sent January of 2016, 2015, and 2016 to seed companies cooperating through the Vegetable Breeding Institute coordinated at Cornell, and by presentations at the annual field day presentations Aug 2014, 2015, and 2016, as well as the two presentations given at the 2014 tomato Breeders roundtable. They are also reached though papers published throughout the three year period, Based on all of these communications, seed companies request seed of lines produced by the Cornell program, and receive the seed under appropriate MTA. Commercial tomatoes resistant to Late blight and Septoria leaf spot, and tolerant to early blight, as a result of the Cornell breeding program, started in 2013 with the sale of Iron Lady by High Mowing Organic Seed Company and started again in 2016 with the sale of Stellar by PanAmerican Seed. Additional lines were licensed in 2016 by a different company, which will start sales of organic seed of another hybrid with similar resistance in early 2018. Other seed companies are using the Cornell released lines as germplasm to transfer these resistance to proprietary lines; hybrids from such lines would be coming to market in 2018 and thereafter. A second target audience reached this year are the US and international tomato growers, who will use the varieties resulting from the germplasm produced by this program. Tomato growers in temperate growing regions will use the varieties with resistance to Septoria Leaf Spot, early blight and late blight resulting from the germplasm produced, reducing their use of fungicides, to improve tomato production and quality, reduce risk of crop loss. These growers were have been using "Iron Lady", the first hybrid resistance to Septoria Leaf Spot, early blight and late blight, particularly for organic production. Growers are trialing the similar hybrid released in 2016, Stellar, as well for future adoption. A third target audience are home gardeners, who are also starting to use the blight resistant hybrids Iron Lady and Stellar. A fourth target audience reached are Extension staff who are trained in the yearly IN SERVICE training sessions, at presentations listed above, as well as the papers published this year, at which/ in which the results of this program are presented and discussed. Some cooperators on this project have extension components to their duties, and these cooperators assist with transfer of information to extension staff. These efforts are important, so that the extension staff are knowledgeable in the performance of new lines and hybrids, to better service the needs of their grower and home gardener communities. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? In year one, the graduate student working on breeding for QTL to alter structure of acylsugars had several opportunities for training and professional development. He has learned new methods in the course of this work (GC analysis, using machines to test acylsugar viscosity). He also gained experience in developing and delivery presentations: he created and presented a poster describing his results at a national meeting (2014 Plant Breeding meeting), presented his work to seed company representatives at our annual field day (August 2014) , and created and presented a talk at an international meeting (2014 Tomato breeders roundtable). This graduate student has also started participation in a one year (2014 to 2015) mentoring program, in which he (and graduate students at 5 other universities) are trained to be effective mentors, and in turn, gain experience by mentoring an undergraduate in their laboratory. In year one, a research associate in the PIs lab learned the process for genotype by sequencing, and has started the process for tomato line in both the fungal resistance project and the insect/virus resistance project. In year two, this research associate had also participated in the same mentoring program. The undergraduate student intern mentored by the research associate a Cornell junior, who worked on a project measuring changes in acylsugar level over time or in different parts of plants. A paper resulting from that work is in preparation for submission soon. In year two, the graduate student working on breeding for QTL to alter structure of acylsugars gained further experience in developing and delivery presentations: he gave an oral presentation of his results to seed company representatives at our annual field day (August 2015), and created and presented a talk at the10th International Symposium on Thysanoptera and Tospoviruses, Pacific Grove, CA MAY 16-20, 2015. This graduate student has also participated in a one year (fall 2014 to June 2015) mentoring program, in which he was trained to be an effective mentor and gained experience by mentoring an undergraduate in my laboratory. In year 2 the undergraduate student intern my graduate student mentored was a Cornell senior who performed an independent project spring/summer of 2015 testing the impact of new acylsugar producing tomato lines on fruit worm and armyworm larvae. This work has been continued and will be soon be submitted for publication by the graduate student and undergraduate student. In years 1, 2 and 3 The set of acylsugar lines that differ for acylsugar level, and the set of lines that differ for acylsugar type, are being used in 4 universities in 4 states, and are the basis of research being performed by4 graduate students and one post-doctoral fellow. How have the results been disseminated to communities of interest? Publications, listed elsewhere in this report Annual reports sent to seed companies Jan 2014, both describing progress of program, and listing germplasm available for request under MTA, and subsequent licensing, if desired. Presentations at the 2014 plant breeders meeting (July 2014), Presentations at the Tomato breeders roundtable (Sept 2014), Presentations at Tomato disease workshop (Oct 2014) 2014 annual vegetable breeding field day (Aug 2014) Annual reports sent to seed companies Jan 2015, both describing progress of program, and listing germplasm available for request under MTA, and subsequent licensing, if desired. The Report distributed Jan 2015 included 7 reports (listed elsewhere in this report) on different portions of the tomato program 2015 annual vegetable breeding field day (Aug 31/Sept 1 2015) A presentation by the PI at the 10th International Symposium on Thysanoptera and Tospoviruses, Pacific Grove, CA MAY 1620, 2015 dealing with materials developed by the portion of the program working on control of insect resistance, and the performance of these materials. Annual reports sent to seed companies Jan 2016, describing progress of program, and listing germplasm available for request under MTA, and subsequent licensing, if desired. The Report distributed Jan 2016 included 7 reports (listed elsewhere in this report) on different portions of the tomato program 2016 annual vegetable breeding field day (Aug 31/Sept 1 2016) What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Milestones for Fungal/Oomycete disease control Refine horticultural type of LB/EB/SLS tomato lines after an additional backcross and using genome wide selection Several 2nd generation LB/EB/SLS lines, carrying less donor DNA on chromosomes other 1 and 5, were created and characterized. Improved SLS markers (see 2) facilitated creation of 3rd generation LB/EB/SLS lines, in which the chromosome 1 and 5 introgressions carrying the SLS-1 and SLS-2 genes were reduced to <6 Mbp. Plants with recombinations to further reduce introgression sizes were also identified. The 2nd and 3rd generation lines were used to make seed of experimental hybrids. Field trials of LB/EB/SLS tomato lines 2015 and 2016 showed that increase in fruit size and fruit smoothness, and reduction in cracks were achieved through genomic and direct selections. The strongest negative impact on fruit size was associated with the chromosome 1 region that carries both SLS-1 and the gene for the WILTY. Field trials of The LB/EB/SLS tomato hybrids at 3 locations in 2015 and 2016 showed the superiority of several of hybrids. Based on these trials, one hybrid was recently licensed for commercial seed sales in 2018 Map the SLS resistance gene to create a PCR-based marker Plants with recombinations in the regions of SLS-1 and SLS-2 used to fine map these genes. SLS-1 is located within a 400,000 bp region of chromosome 1 that also contains Wilty. SLS-2 is located within an 800,000 bp region of chromosome 5. This advance provides closest possible linked markers for these genes. Map EB tolerance in current LB/EB/SLS and create a marker, and 4) Determine if other sources of EB tolerance are non-allelic, and could be combined to increase level of EB control We tested if select LB/EB/SLS populations could also be used to map the EB tolerance gene with little expense. However screens demonstrated that the populations did not provide the segregation needed. Mapping EB would have to be a separate project. Since funding was not sufficient to perform all of that additional work, this part of the program was held until additional funding is obtained. Milestones for Insect/virus control Refine horticultural type of acylsugar producing tomato lines by reducing size of introgressions The acylsugar tomato benchmark line CU071026 produces moderate levels of acylsugar that controls Bemisia whiteflies under high insect pressure. The major defect of CU071026 are reduced fruit set, very small fruit size, and reduced seed production. There are five introgressions in CU071026: four modest/small introgressions on chromosomes 2, 7, 10 and 10, and a very large introgression on chromosome 3. Focus on the smaller introgressions on chromosome 2, 7, 10, and 10 was testing impacts of their elimination on acylsugar production. This work showed that: Presence of the chromosome 2 introgression is crucial for acylsugar production, it can be reduced in size but not eliminated from acylsugar lines. Absence of either the chromosome 7 introgression or the lower chromosome 10 introgression does not impact acysugar levels; so these introgressions could be eliminated. The introgression on chromosome 3 is large (> 50Mbp of DNA). Multiple modifications of this introgression were created, including: A) reducing the introgression from the upper boundary, B) reducing the introgression from the lower boundary C) removing central sections of the introgression 4) using recombination to combine alterations listed in A, B, and C together in a single line. Some of the resulting lines also possess an additional small introgression on chromosome 8. The results of the field testing the lines, and hybrids made using the resulting lines, has helped define the location of important acylsugar genes on chromosome 3, and also of other QTL with negative impacts on fruit and seed set, and fruit size. This provides the information needed to further modify chromosome 3 to improve fruit set and size without lowering acylsugar level. Use current virus resistant acylsugar lines to pyramid resistance genes and test resulting lines (years 1-3) Field data of lines possessing a moderately large introgression carrying Ty-3 shows that the lines evoke the lack of fruit set fruit set evidenced by action of Cullin 1 gene on chromosome 6, as reported as (Li and Chetelat, 2010 Science 330: 1827-1830, Li and Chetelat, 2015 PNAS 112:4417-4422) This indicates that size of TY-3 introgression would have to be reduced to eliminate Cullen 1 or else the presence of Cullen 1 in the line would have to be "balanced" by the presence of an additional undefined introgression on chromosome 1. Therefore, it was determined that the work to combine Ty-3 with other virus resistance genes would be premature. Several acylsugar lines also possessing a large chromosome 12 introgression containing Sw-7 line were also generated and field tested against TSVW by a cooperator. Only one Sw-7/AS line shows the full resistance against TSWV as the Sw-7 source. It is possible that the source plant actually possess two resistance TSWV genes, one that is Sw-7 in the Chromosome 12 introgression, and another in an as of yet location in the genome. Determination of the second gene would be necessary before the Sw-7 genes are combined with other resistance genes, and into acylsugar lines with better fruit set/seed set/fruit size. Add additional QTL to acylsugar lines to alter levels of acylsugars and/or density of acylsugar producing trichomes (years 1-2) Work was completed on development of a full set of 4 acylsugar sister lines that have/do not have a chromosome 6 QTL that increases acylsugar level and trichome density, or an chromosome 10 QTL that affects acylsugar level but not trichome density, or both of these QTL, or neither of these QTL. This set of 4 lines was extended include 4 parallel sibling lines of the same type, regarding QTL6 or QTL10, but all of which also possess the Sw-5 gene for TSWV resistance. These eight lines were fully characterized for introgressions present, acylsugar level and type. Cooperating entomologists and plant pathologist in 4 states are testing these lines for their impacts on whiteflies and thrips and on likelihood that plants are infected by tomato spotted wilt virus or by tomato yellow leaf curl. The lines with optimal impact on insects will be the focus of further breeding and release. An additional acylsugar line was created that includes a large chromosome 9 introgression possessing green hypocotyl and TM2 gene for TMV resistance. This line also has increased acylsugar level, indicating the presence of an acylsugar QTL on chromosome 9. None of these lines have horticultural quality (since all of the lines possess the full large introgression on chromosome 3), however the lines are useful as germplasm and also as a platform for research on insect/ virus control. Add QTL to alter structure of acylsugars produced, and determine the impact of altered acylsugar structure on level of acylsugars produced and on insect and virus control. (Years 1-3). New acylsugar producing tomato lines were created into which was added one, two or all three of the fatty acid affecting QTL on chromosomes 2, 7, or 8; the resulting produce different types of acylsugars (due to altering the fatty acid moieties). All of these lines were fully characterized for acylsugar level and for acylsugar chemotypes using gas chromatograph analysis and liquid chromatography/mass spectrometry. An additional acylsugar line was created with a combination of 3 QTL that change the sugar component of acylsugars so that the line produces acylglucoses rather than acylsucroses. The lines tested by cooperating entomologists and plant pathologists in 4 states against whiteflies and thrips and on for the frequency which with the plants are infected by TSWV or by TYLCV. The lines producing the most effective acylsugar types and optimal impact on insects will be the focus of further breeding and release.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Leckie, BM, DeJong, DM, and MA Mutschler. 2013. Quantitative trait loci regulating sugar moiety of acylsugars in tomato. Molecular Breeding. 31 (4): 957-970
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Leckie, B.M., R Halitschke, D.M. De Jong, J.R. Smeda, A. Kessler, and M.A. Mutschler 2014. Quantitative trait loci regulating the fatty acid profile of acylsugars in tomato, Molecular Breeding: accepted
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Hansen, Z., I. Small, M.A. Mutschler, W. Fry, C. Smart. 2014: Differential Susceptibility of Thirty Nine Tomato Varieties to Phytophthora infestans Clonal Lineage US-23. Plant Disease 98, (12) 1666-1670
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Smeda John R., Anthony L. Schilmiller, Robert L. Last, Martha A. Mutschler. 2016 Introgression of acylsugar chemistry QTL modifies the composition and structure of acylsugars produced by high-accumulating tomato lines. Molecular Breeding. DOI 10.1007/s11032-016-0584-6
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Leckie, BM, D'Ambrosio, DA, Chappell, TM, Halitschke, R, De Jong, DM, Kessler, A, Kennedy, GG, Mutschler, MA 2016. Differential and synergistic functionality of acylsugars in suppressing oviposition by insect herbivores. PLOS ONE | DOI:10.1371/journal.pone.0153345
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:One target audience reached this year 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. This is a critical target audience, since seed companies must successfully incorporate new traits into their hybrids for the traits to become available to growers, and thereby benefit consumers. This target audience was reached through annual reports sent January 2015 January to seed companies cooperating through the Vegetable Breeding Institute coordinated at Cornell, and by presentations at the annual field day presentations which were held this year Aug 31/Sept 1, 2015 Another target audience reached in 2015 are the US and international tomato growers, who will use the varieties resulting from the germplasm produced by this program. Tomato growers in temperate growing regions will use the varieties with resistance to Septoria Leaf Spot, early blight and late blight resulting from the germplasm produced, reducing their use of fungicides, to improve tomato production and quality, reduce risk of crop loss. These growers were first able to access tomatoes resistant to Late blight and Septoria leaf spot, and tolerant to early blight, as a result of the Cornell breeding program, starting 2013 with the sale of Iron Lady by High Mowing Organic Seed Company. Additional lines were licensed by Pan American Seeds, which will start sales of a new hybrid (Stellar) with similar resistance in early 2016. A field trial of a series of new hybrids with fungal resistance located in eastern NYS summer of 2015 was also used as a demonstration plot for NYS tomato growers, to acquaint them with the new fungal resistant hybrids and best practices for their use in tomato production. A third target audience reached this year are Extension staff, who are trained in the yearly at presentations listed above at which the results of this program are presented and discussed, so that the extension staff are knowledgeable in the performance of new lines and hybrids, to better service the needs of their grower communities. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? In year two, the graduate student working on breeding for QTL to alter structure of acylsugars He also gained further experience in developing and delivery presentations: he gave an oral presentation of his results to seed company representatives at our annual field day (August 2015), and created and presented a talk at the10th International Symposium on Thysanoptera and Tospoviruses, Pacific Grove, CA MAY 16-20, 2015. This graduate student has also participated in a one year (fall 2014 to June 2015) mentoring program, in which he was trained to be an effective mentor and gained experience by mentoring an undergraduate in my laboratory. The undergraduate student intern my graduate student mentored was a Cornell senior who performed an independent project spring/summer of 2015 testing the impact of new acylsugar producing tomato lines on fruitworm and armyworm larvae. This work has been continued and will be soon be submitted for publication by the graduate student and undergraduate student. How have the results been disseminated to communities of interest? Publications, listed elsewhere in this report Annual reports sent to seed companies Jan 2015, both describing progress of program, and listing germplasm available for request under MTA, and subsequent licensing, if desired. The Report distributed Jan 2015 included 7 reports (listed elsewhere in this report) on different portions of the tomato program Two presentations at the 10th International Symposium on Thysanoptera and Tospoviruses, Pacific Grove, CA MAY 16-20, 2015. Both presentations dealt with materials developed by the portion of the program working on control of insect resistance, and the performance of these materials. 2014 annual vegetable breeding field day (Aug 31/Sept 1 2015) What do you plan to do during the next reporting period to accomplish the goals?Continue work as described in original proposal towards the goals listed.
Impacts
What was accomplished under these goals?
1. Year 2 progress on the Milestones for the Fungal/Oomycete disease control project: Refine horticultural type of LB/EB/SLS tomato lines after an additional backcross and using genome wide selection (years 1-3). Significant progress continued to be made towards this goal during year 2. In year 1 work, use of molecular markers allowed the production of 3rd generation LB/EB/SLS tomato lines, carrying less donor DNA on chromosomes other than those carrying the two SLS resistance genes, was created, as well as 3rd generation LB/EB/SLS tomato lines, carrying the SLS-1 and SLS-3 genes in introgressions over 90% reduced in size from the original introgressions, as well carrying less donor DNA on chromosomes other than those carrying the two SLS resistance genes, was created, characterized and used to make self-seed and seed of experimental hybrids for testing in field trials in summer of 2015. The field 2015 field tests of the lines at one location and the hybrids at 3 locations were largely successful despite the unusually cold wet summer. Comparison of lines with different modifications of the introgressions revealed the regions associated with negative traits, and thus helped advance the development of superior lines. Several of the hybrids tested show promise, and the hybrid trials will be repeated at three locations in 2016 field season. Map the SLS resistance gene to create a PCR-based marker (year 1-2). we continued the work using molecular markers to select plants recombinant for the introgression carrying SLS-1 Septoria resistance gene to further reduce the donor DNA on this chromosomes, then test the resulting progenies for presence of SLS-1 and of WILTY. This has substantially reduced the region within which SLS-1 is located, and has generated 2 selection with disease screen data on plant appearance that suggests that they are homozygous for SLS-1, and SLS-2) but heterozygous for WILTY. As soon as seed is harvested the progenies of these selections will be tested to determine if the single- plant data are correct, and if the desired selections homozygous for both the presence of SLS-1 and the absence of WILTY can be selected. Year 1 progress on the Milestones for the Insect/virus control project Refine horticultural type of acylsugar producing tomato lines by reducing size of introgressions Building on the results of 2014, a larger series of lines were generated with ireductions in the size of the chromosome 3 introgression size, which at originally > 50Mbp of DNA accounted for ca. 90% of the pennellii DNA in the current acylsugar producing tomato lines. These lines were then crosses to make hybrids that added additional introgressions on other to test for interations. Tests in 2015 field season showed that several of these hybrids had much more normal fruit and seed set, supporting the concept that the lack of normal fruit/seed set is due to the interaction of a region(s) on chromosome 3 with a region on another chromosome. The F2 self seed from the best hybrids were grown fall/winter to select balanced sets of progenies with all possible geneotype for the sets of regions segregating. The resulting lines will be tested Summer of 2016 to determine which genotypes provide improved fruit and seed set, Add QTL to alter structure of acylsugars produced, and determine the impact of altered acylsugar structure on level of acylsugars produced and on insect and virus control. (Years 1-3). Considerable progress has also been made in generating lines that produce acylsugars with different chemical structures (altering the sugar moiety and/or the fatty acid moieties). The creation of lines carrying QTL on chromosomes 2, 7, or 8, ore sets of 2 or 3 of these QTLs, was completed in year 1. The lines were then grown together with controls for full characterization of acylsugar level and acylsugar chemotypes. A publication on these lines is well into preparation, for submission early 2016. Work testing the impact of these lines against three species of insect was started in 2015, for completion during 2016.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Molecular Breeding: 34 (3) pp 1201-1213
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: One target audience reached this yearare 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. This is a critical target audience, since seed companies must successfully incorporate new traits into their hybrids for the traits to become available to growers, and thereby benefit consumers. This target audience was reached through annual reports sent to seed companies cooperating through the Vegetable Breeding Institute coordinated at Cornell, and by presentations at the 2014 annual field day presentations Aug 2014, as well as the 2014 tomato Breeders roundtable. They are also reached though paper published this year, A second target audience reached this year are the US and international tomato growers, who will use the varieties resulting from the germplasm produced by this program. Tomato growers in temperate growing regions will use the varieties with resistance to Septoria Leaf Spot, early blight and late blight resulting from the germplasm produced, reducing their use of fungicides, to improve tomato production and quality, reduce risk of crop loss. These growers were first able to access tomatoes resistant to Late blight and septoria leaf spot, and tolerant to early blight, as a result of the Cornell breeding program, starting 2013 with the sale of Iron Lady by High Mowing Organic Seed Company. Additional lines were licensed in 2014 by a different company, which will start sales of another hybrid with similar resistance in 2015 or early 2016. A third target audience reached this year are Extension staff, who are trained in the yearly IN SERVICE training sessions, at presentations listed above, as well as the papers published this year, at which/ in which the results of this program are presented and discussed, so that the extension staff are knowledgeable in the performance of new lines and hybrids, to better service the needs of their grower communities. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? 1. In year one, the graduate student working on breeding for QTL to alter structure of acylsugars had severalopportunities for training and professional development. Hehas learned new methods in the course of this work (GC analysis, using machines to test acylsugar viscosity). He also gained experience in developing and delivery presentations: he created and presented a poster describing his results at a national meeting (2014 Plant Breeding meeting), presented his work to seed company representatives at our annual field day (August 2014) , and created and presented a talk at an international meeting (2014 Tomato breeders roundtable). This graduate student has also started participation in a one year (2014 to 2015) mentoring program, in which he (and graduate students at 5 other universities) are trained to be effective mentors, and in turn, gain experience by mentoring an undergraduate in their laboratory. 2. The intern my graduate student is mentoring is a Cornell senior who has started an independent project testing the impact of new acylsugar producing tomato lines on fruitwork and armyworm larvae. 3. A research associate in my lab has learned the process for genotype by sequencing, and has started the process for tomato line in both the fungal resistance project and the insect/virus resistance project. 4. This research associate had also participated in the same mentoring program, in the 2013 to 2014 school year. The undergraduate student he mentored was a Cornell junior, who worked on a project measuring changes in acylsugar level over time or in different parts of plants. A paper resulting from that work is in preparation for submission in 2015. How have the results been disseminated to communities of interest? 1. Publications, listed elsewhere in this report 2. Annual reports sent to seed companies Jan 2014, both describing progress of program, and listing germplasm available for request under MTA, and subsequent licensing, if desired. 3. Presentations at meeting, including the 2014 plant breeders meeting (July 2014), the tomato breeders roundtable (sept 2014), Tomato disease workshop (Oct 2014,) 4. 2014 annual vegetable breeding field day (aug 2014) What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Year 1 progress on the Milestones for the Fungal/Oomycete disease control project: 1) Refine horticultural type of LB/EB/SLS tomato lines after an additional backcross and using genome wide selection (years 1-3). Significant progress was made towards this goal during year 1.A refined 2nd generation LB/EB/SLS tomato lines, carrying less donor DNA on chromosomes other than those carrying the two SLS resistance genes, was created, characterized and used to make seed of experimental hybrids, which will be evaluated in Field trials in 2015. Use of improved SLS markers (see 2 below) enabled us to create of 3rd generation LB/EB/SLS tomato lines, in which the introgressions carrying the SLS-1 and SLS-2 are substantially reduced (for further refinement of line horticultural type). These introgressions in the 2nd generation LB/EB/SLS tomato lines are both greater than 60 Mbp (most of their respective chromosomes). The introgressions in the 3rd generation LB/EB/SLS lines created by the end of year 1 are both less than 6 Mbp (a >90% reduction in size) and plants with additional recombinations that can further reduce the size of these introgressions were also identified. 2) Map the SLS resistance gene to create a PCR-based marker (year 1-2). The location of two SLS resistance gene were refined, so that SLS-1 has been located within a 500,000 base pair region of chromosome 1, and SLS-2 has been located within a 1 Mbp region of chromosome 5. This advance allows choice of the closest possible linked markers for these genes. b) Year 1 progress on the Milestones for the the Insect/virus control project 1) Refine horticultural type of acylsugar producing tomato lines by reducing size of introgressions Significant progress was made in year 1 in reducing introgression size, particularly the size of the chromosome 3 introgression (which at > 50Mbp of DNA accounts for ca. 90% of the pennellii DNA in the current acylsugar producing tomato lines). Characterization of these lines has helped refine the map location of important acylsugar genes, and also of different QTL with negative impacts on fruit and seed set, and fruit size. Furthermore, some of the resulting lines also show marked improvement in fruit/seed set (a problem in lines possessing the full-sized chromosome 3 introgression).The lines, and hybrids produced using them, will be used in 2015 trials. 3) Add additional QTL to acylsugar lines to alter levels of acylsugars and/or density of acylsugar producing trichomes (years 1-2) Work was completed on development of a full set of 4 acylsugar sister lines that have/do not either a chromosome 6 QTL that increases acylsugar level and trichome density, or an acylsugar 10 QTL that affects acylsugar level, but not trichome or both or neither of these QTL. Furthermore, this set is extended to include an additional set of 4 lines of the same type, but all of which also possess the Sw-5 gene for TSWV resistance. These lines are not of the horticultural quality needed for commercial use (since all of the possess the full sized large introgression on chromosome 3 discussed above), however they will be useful as germplasm and also as a platform for research testing insect/TOSPO virus control. 4) Add QTL to alter structure of acylsugars produced, and determine the impact of altered acylsugar structure on level of acylsugars produced and on insect and virus control. (Years 1-3). Considerable progress has also been made in generating lines that produce acylsugars with different chemical structures (altering the sugar moiety and/or the fatty acid moieties). The creation of lines carrying QTL on chromosomes 2, 5, 7, or 8, ore sets of 2 or 3 of these QTLs, either were completed in year 1, or have been advanced in year 1, with completion expected in year 2. Characterization of the lines for impact on acylsugar level, acylsugar type, and for impact of the change in acylsugars on insect control, has commenced.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Leckie, B.M., R Halitschke, D.M. De Jong, J.R. Smeda, A. Kessler, and M.A. Mutschler 2014. Quantitative trait loci regulating the fatty acid profile of acylsugars in tomato, Molecular Breeding: accepted
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
3. Hansen, Z., I. Small, M.A. Mutschler, W. Fry, C. Smart. 2014: Differential Susceptibility of Thirty Nine Tomato Varieties to Phytophthora infestans Clonal Lineage US-23. Plant Disease 98, (12) 1666-1670
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