Progress 10/01/07 to 09/30/12
Outputs
OUTPUTS: The University of Illinois soybean breeding program developed new experimental lines and tested lines for yield, agronomic traits and disease and pest resistance during 2012. The program grew over 3,100 4-row yield test plots, 11,000 2-row yield test plots, and 14,000 plant row plots. These plots were planted in field locations that include the main South Farm on the University of Illinois campus, the Northern Illinois Agronomy Research Center near Shabbona, IL, the Brownstown Agronomy Research Center near Brownstown, IL and on land rented from farmers near Pontiac, IL and Arthur, IL. The most advanced lines from the program were evaluated in regional tests in locations throughout soybean growing regions in the north central and eastern U.S. Data from these tests have been analyzed and selections are being made to decide what lines to test in experiments planned for 2013. Those lines with the greatest yield and resistance over the past few years were selected and three new varieties and ten germplasm lines were released from the program. The released varieties are LD07-3419, LD07-4530, and LD06-7620. The three varieties are conventional (nonGMO) and were released because they combine high yield potential with resistance to soybean cyst nematode (SCN), which is the most important soybean disease in Illinois and across the U.S. LD07-3419 and LD07-4530 are both maturity group (MG) III varieties which are suitable for production in central Illinois and other regions with similar latitude. LD06-7620 is a MG IV variety suitable for production in southern Illinois and other regions with similar latitude. These varieties have been licensed for commercial production. Two germplasm lines were released because of their novel combinations of SCN resistance genes which make them useful as SCN resistance sources in breeding programs. The first germplasm line is LD09-30463 and it carries two SCN resistance genes bred from PI 468916 and combined with the SCN resistance gene rhg1 from PI 88788. The second germplasm line is LD09-30523 and it carries the same two SCN resistance genes from PI 468916 as the first germplasm line, but these genes are combined with rhg1 and Rhg4 from PI 437654. The other eight released germplasm lines carry the soybean rust resistance genes Rpp1, Rpp1-b, Rpp(Hyuuga), and Rpp5 in both a MG II and a MG IV genetic background. These rust resistant lines will be a good resource for the Midwestern U.S. soybean breeding community because these genes all originate from backgrounds that are not adapted to this region. Results from the breeding program were disseminated in a number of ways. The varieties developed from the research program were included in the University of Illinois Variety Tests and results from the tests are made available to the public through the test website and publications. A new project started in 2012 is the development of nanotechnology based moisture sensors that can be used in greenhouse research. These sensors will be used to monitor conditions in disease resistance testing in greenhouses and should help us obtain more precise greenhouse test results. The sensors are currently being fabricated by collaborators. PARTICIPANTS: Individuals: PI - Brian Diers. Partner Organizations: USDA-ARS, United Soybean Board, Illinois Soybean Association, North Central Soybean Association. Training was provided to four graduate students, two post doctoral research associates and several undergraduate students as part of the project. TARGET AUDIENCES: The target audiences of the research are the soybean breeding research community and soybean growers in the U.S. During the past year, talks were given to both grower and scientific audiences and results were published in scientific journals. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
There are a number of outcomes to report from the past year. The breeding program identified several new high yielding experimental lines that will be retested in 2013 and based on results from these tests, may be released as new varieties. During the year we completed a study focused on understanding the agronomic impact of the soybean aphid resistance allele Rag2 in fields that have no or limited aphid infestations. This is important to know because Rag2 originates from an exotic soybean line and when genes are introgressed into varieties from exotic sources, linked genes with a negative impact on agronomic performance will frequently be introgressed along with the target gene. Our research showed that across environments of testing in Illinois, the Rag2 resistance allele was significantly associated with 256 kg ha-1 less yield than those lines with the susceptibility allele in a MG III genetic background. The introgression of the Rag2 allele in a MG II genetic background did not show a significant effect across environments, but the Rag2 lines did have significantly less yield across three environments in 2011 than the susceptible lines. This research shows that we need to identify recombination events close to Rag2 in an attempt to break the association between the resistance allele and lower yield. Research progress has been made in fine mapping the genetic location of a major gene that controls protein concentration in soybean. This gene was originally mapped as a quantitative trait locus (QTL) over 20 years ago and efforts have continued since that time to identify the DNA sequence of this gene. Recent efforts have resulted in narrowing the interval where the gene is located from five million base pairs (bp) to 300,000 bp. Within this 300,000 bp region, there are 12 candidate genes shown on the Williams 82 genome sequence. The next step will be to start testing the functions of these genes to determine which is the actual gene that controls protein concentration.
Publications
- Valdes-Lopez, O, Thibivilliers, S., Qiu, J., Xu, W.W., Nguyen, T., Libault, M., Le, B., Goldberg, R., Hill, C.B., Hartman, G.L., Diers, B. and Stacey, G. 2011. Identification of quantitative trait loci controlling gene expression during the innate immunity response of soybean. Plant Physiology, 157:1975-1986.
- Kim, K.S., Unfried, J.R., Hyten, D.L., Frederick, R.D., Hartman, G.L., Nelson, R.L., Song, Q. and Diers, B.W. 2012. Molecular mapping of soybean rust resistance in soybean accession PI 561356 and SNP haplotype analysis of the Rpp1 region in diverse germplasm. Theor. Appl. Genet., 125:1339-1352.
- Kim, K.S., Diers, B.W., Hyten, D.L., Rouf Mian, M.A., Shannon, J.G. and Nelson, R.L. 2012. Identification of positive yield QTL alleles from exotic soybean germplasm in two backcross populations. Theor. Appl. Genet., 125:1353-1369.
- Cook, D.E., Lee, T.G., Guo, X., Melito, S., Wang, K., Bayless, A., Wang, J., Hughes, T.J., Willis, D.K., Clemente, T., Diers, B.W., Jiang, J., Hudson, M.E. and Bent, A.F. 2012. Copy number variation of multiple genes at Rhg1 mediates nematode resistance in soybean. Science, 338:1206-1209.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: This is a report of the progress of the University of Illinois soybean breeding and genetics research program. During 2011, the soybean breeding program developed new experimental lines and tested lines for yield, agronomic traits and disease and pest resistance. The program grew 4,759 4-row yield test plots, 9,369 2-row yield test plots, and 17,112 plant row plots. These plots were planted in field locations that include the main South Farm on the University of Illinois campus, the Northern Illinois Agronomy Research Center near Shabbona, IL, the Brownstown Agronomy Research Center near Brownstown, IL and on land rented from farmers near Pontiac, IL, and Arthur, IL. The most advanced lines were evaluated in regional tests in locations throughout soybean growing regions in the north central and eastern U.S. Those lines with the greatest yield and resistance were selected in these tests and three new varieties were released from the program. The released varieties are LD05-1540, LD06-8970, and LD06-7609. The three varieties are conventional (nonGMO) and were released because they combine high yield potential with resistance to soybean cyst nematode (SCN), which is the most important soybean disease in Illinois and across the U.S. LD05-1540 is a maturity group (MG) II variety which is suitable for production in northern Illinois and other regions with a similar latitude. LD06-8970 and LD06-7609 are both MG IV varieties which are suitable for production in southern Illinois and other regions with a similar latitude. These varieties were licensed for commercial production. Research is continuing on developing new high-yielding experimental lines that carry the aphid resistance genes Rag1 and or Rag2. Varieties carrying Rag1 have been released from the program. High yielding experimental lines were identified that have Rag2 and a line carrying this gene may be released this year. Many aphid resistant lines were tested in 2011 and these tests show that we can breed these genes into high yielding genetic backgrounds. Our genetic markers linked to aphid resistance genes and our aphid resistant germplasm is being licensed to private companies and is being used in their variety development programs. Another activity of the program is the organization of uniform testing of SCN resistant experimental lines from public soybean breeders. The 2011 tests included 215 experimental lines evaluated in 47 environments through a collaboration with soybean breeders located in states in the northern U.S. and southern Canada. During 2011, agronomic, composition, and SCN resistance results from the 2010 tests were summarized and published in a book that was distributed to public and private soybean breeders throughout the U.S. Work on summarizing the 2011 tests is underway. Results from the breeding program were disseminated in a number of ways. The varieties developed from the research program were included in the University of Illinois Variety Tests. These results are made available to the public through a website and publications. Information was also disseminated through talks given to both scientific audiences and to grower groups. PARTICIPANTS: Individuals: PI - Brian Diers. Partner Organizations: USDA-ARS, United Soybean Board, Illinois Soybean Association, North Central Soybean Association. Training was provided to four graduate students, two post doctoral research associates and several undergraduate students as part of the project. TARGET AUDIENCES: The target audiences are the soybean breeding research community and soybean growers in the U.S. During the past year, talks were given to both grower and scientific audiences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
There are a number of outcomes to report from the past year. The breeding program identified several new high-yielding experimental lines that will be retested in 2012 and based on results from these tests, may be released as new varieties. Progress was made in research focused on fine mapping the genetic locations of two genes that confer resistance to soybean cyst nematodes (SCN) from the wild soybean plant introduction (PI) 468916. Mapping genes conferring resistance to SCN is important because it is estimated to cause the greatest yield loss in the U.S. of any soybean pest or disease. The genes being fine mapped from wild soybean are likely novel and could be useful in increasing the genetic diversity for resistance genes in soybean varieties. Research during the past year has resulted in fine mapping a resistance gene from PI 468916 on chromosome 18 to a 146 thousand base pair interval and the gene on chromosome 15 to an 800 thousand base pair interval. Having these genes mapped to small genetic intervals is important for plant breeders because it provides information on what genetic markers they can use to select these genes in their variety development programs. This information can also be used in cloning these resistance genes which will help researchers understand how these genes function to confer resistance to SCN. Research was done to test the effects of soybean sudden death syndrome (SDS) resistance genes on chromosomes 17 and 19 in four different genetic backgrounds. These genes were previously mapped; however, it is important to test these genes in multiple genetic backgrounds to determine their effect across backgrounds. Although only low levels of SDS symptoms were observed in these tests, we were able to detect the effect of the two genes in two of the four genetic backgrounds, suggesting that these genes can be useful in new genetic backgrounds.
Publications
- Kim, M., Hyten, D.L., Niblack, T.L. and Diers, B.W. 2011. Stacking resistance alleles from wild and domestic soybean sources improves soybean cyst nematode resistance. Crop Sci. 51:934-943.
- Woody, J.L., Severin, A.J., Bolon, Y.T., Joseph, B., Diers, B.W., Farmer, A.D., Weeks, N., Muehlbauer, G.J., Nelson, R., Grant, D., Specht, J.E., Graham, M.A., Cannon, S.B., May, G.D., Vance, C.P. and Shoemaker, R.C. 2011. Gene expression patterns are correlated with genomic and genic structure in soybean. Genome. 54:10-18.
- Hesler, L.S., Dashiell, K.E., Prischmann, D.A., Diers, B.W. and Scott, R.A. 2012. Evaluation of putatively resistant soybean selections against the soybean aphid. J. Crop Improvement. (In Press).
- Tinsley, N.A., Steffey, K.L., Estes, R.E., Heeren, J.R., Gray, M.E. and Diers, B.W. 2011. Field-level effects of preventative management tactics on soybean aphids (Aphis glycines Matsumura) and their predators. J. Appl. Entomol. doi: 10.1111/j.1439-0418.2011.01656.x.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: This is a report of the progress of the University of Illinois soybean breeding and genetics research program. During 2010, the soybean breeding program developed new experimental lines and tested lines for yield, agronomic traits and disease and pest resistance. The most advanced lines were evaluated in regional tests which resulted in the evaluation of the lines across several locations in many states. Those lines with the greatest yield and resistance were selected in these tests and five new varieties were released from the program. The released varieties are LD06-16721, LD06-30504Ra, LD06-30505Ra, LD04-11056H, and LD04-13265. All five varieties have resistance to soybean cyst nematode (SCN), which is the most important soybean disease in Illinois and across the U.S. LD06-16721 is a conventional (nonGMO) maturity group (MG) II variety that combines high yield with the aphid resistance gene Rag1. LD06-30504Ra and LD06-30505Ra are both MG II varieties that have the Roundup Ready herbicide resistance gene combined with high yield and the soybean aphid resistance gene Rag1. LD04-11056H, and LD04-13265 are MG III varieties that were released because they combine high yield with SCN resistance. These varieties were licensed to a commercial company which will market them to soybean producers. Research is continuing on developing new high yielding experimental lines that carry the aphid resistance genes Rag1 and or Rag2. Many aphid resistant lines were tested in 2010 and these tests show that we can breed these genes into high yielding genetic backgrounds. Our genetic markers linked to aphid resistance genes and our aphid resistant germplasm is being licensed to private companies and is being used in their variety development programs. Another activity is the organization of uniform testing of SCN resistant experimental lines from public soybean breeders. This test in 2010 includes 175 experimental lines tested in 44 environments through a collaboration with soybean breeders throughout the northern U.S. and southern Canada. Agronomic, composition, and SCN resistance results from these tests were summarized and published in a book that was distributed to public and private soybean breeders throughout the U.S. Results from this work were disseminated in a number of ways. The varieties developed from the research program were included in the University of Illinois Variety Tests. These results are made available to the public through a website and publications. Information was also disseminated through talks given to both scientific audiences and to grower groups. PARTICIPANTS: Individuals: PI - Brian Diers. Partner Organizations: USDA-ARS, United Soybean Board, Illinois Soybean Association, and the North Central Soybean Association. Training was provided to four graduate students, two post doctoral research associates and several undergraduate students as part of the project. TARGET AUDIENCES: The target audiences of the research are the soybean breeding research community and soybean growers in the U.S. During the past year, talks were given to both grower and scientific audiences. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
There are a number of outcomes to report from the past year. We made progress in fine mapping the SCN resistance gene rhg1 from the resistance sources PI 88788 and PI 437654. These two sources have been shown to have different functional alleles at rhg1 and there have been questions regarding whether they have a resistance allele at the same locus or closely linked loci. We fine mapped rhg1 from PI 88788 to a 67 thousand base pair (kb) interval that contains 11 protein-coding genes that could each potentially be rhg1. From PI 437654, we mapped rhg1 to a 93 kb interval that overlaps the location of rhg1 from PI 88788. These results are consistent with both sources having rhg1 at the same locus. We are collaborating with other researchers in cloning the rhg1 resistance gene from both resistance sources which will allow us to prove whether the resistance genes from these sources are allelic. We completed research on the effectiveness of combining SCN resistance genes from different SCN resistance sources. Two SCN resistance genes from wild soybean PI 468916 were combined with rhg1 from PI 88788 and rhg1 and Rhg4 from PI 437654. SCN resistance tests of populations segregating for these genes showed that improved resistance can be achieved through combinations of genes from these different resistance sources. For example, when the population segregating for the resistance genes from wild soybean and PI 88788 were tested with the SCN isolate PA5, lines that had only the resistance allele at rhg1 had a female index (FI) of 55.1, whereas lines with rhg1 and the two G. soja alleles had a FI of 14.4. The FI index is a measure of SCN resistance and a FI of 100 equals complete susceptibility and a FI of 0 equals complete resistance. In another research project, we organized a study to evaluate the genetic gain of soybean varieties released over the past 80 years. This study included a set of MG II, a set of MG III, and a set of MG IV soybean varieties that were released from the 1920's to the present time. Across tests in six Illinois locations, we observed an average yield increase across time of 0.35 bushels/acre/year (or in metric units, 21 kg/hectare/year). This means that over this period, every three years there was slightly more than a 1 bushel/acre yield increase. The varieties were also tested in blocks within fields that followed continuous corn or a corn-soybean rotation. The soybeans grown after continuous corn yielded about 4 bushels/acre greater than those grown after the corn-soybean rotation. Interestingly, the yield trends across years were the same after the corn-soybean rotation or continuous corn. This means that breeders have not been successful in breeding to overcome the causes of reduced yields after a corn-soybean rotation compared to continuous corn.
Publications
- Kim, K., Bellendir, S., Hudson, K.A., Hill, C.B., Hartman, G.L., Hyten, D.L., Hudson, M.E. and Diers, B.W. 2010. Fine mapping the soybean aphid resistance gene Rag1 in soybean. Theor. Appl. Genet. 120:1063-1071.
- Diers, B.W., Cary, T., Thomas, D., Colgrove, A. and Niblack, T. 2010. Registration of LD00-2817P soybean germplasm line with resistance to soybean cyst nematode from PI 437654. J. of Plant Registrations. 4:141-144.
- Mikel, M., Diers, B., Nelson, R. and Smith, H. 2010. Genetic diversity and agronomic improvement of North American soybean germplasm. Crop Sci. 50:1219-1229.
- Delheimer, J.C., Niblack, T., Schmidt, M., Shannon, G. and Diers, B.W. 2010. Comparison of the effects in field tests of SCN resistance genes from different resistance sources. Crop Sci. 50:2231-2239.
- Melito, S., Heuberger, A.L., Cook, D., Diers, B.W., McGuidwin, A.E. and Bent, A.F. 2010. A nematode demographics assay in transgenic roots reveals no significant impacts of the Rhg1 locus LRR-Kinase on soybean cyst nematode resistance. BMC Plant Biology. 10:41.
- Severin, A.J., Woody, J.L., Bolon, Y.T., Joseph, B., Diers, B.W., Farmer, A.D., Muehlbauer, G.J., Nelson, R.T., Grant, D., Specht, J.E., Graham, M.A., Cannon, S.B., May, G.D., Vance, C.P. and Shoemaker, R.C. 2010. RNA-Seq Atlas of Glycine max: A guide to the soybean transcriptome. BMC Plant Biology 10:160.
- Kim, K., Hill, C.B., Hartman, G.L., Hyten, D.L., Hudson, M.E. and Diers, B.W. 2010. Fine mapping of the soybean aphid resistance gene Rag2 in soybean PI 200538. Theor. Appl. Genet. 121:599-610.
- Bolon, Yung-Tsi, Joseph, B., Cannon, S.B., Graham, M.A., Diers, B.W., Farmer, A.D., May, G.D., Muehlbauer, G.J., Specht, J.E., Tu, Z.J., Weeks, N., Xu, W.W., Shoemaker, R.C. and Vance, C.P. 2010. Complementary genetic and genomic approaches help characterize the linkage group I seed protein QTL. BMC Plant Biology. 10:41.
- Kim, M., Hyten, D.L., Bent, A.F. and Diers, B.W. 2010. Fine mapping of the SCN resistance locus rhg1-b from PI 88788. Plant Genome 3:81-89.
- Perez, P.T., Diers, B.W., Lundeen, P., Tabor, G.M. and Cianzio, S.R. 2010. Genetic analysis of new sources of soybean resistance to brown stem rot. Crop Sci. 50:2431-2439.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: During the past year, the breeding program developed new experimental lines. These lines were evaluated for yield and some were evaluated for disease and pest resistance. Those lines with the greatest yield and highest level of resistance were selected. The experimental lines LD02-4485, LD01-7323, LD01-7222, LDXG05241R-1-2 and LD05-16657 were released as varieties from the program in 2009 because they combined high yield with resistance to soybean cyst nematode (SCN). In addition to the SCN resistance, both LDXG05241R-1-2 and LD05-16657 also carry the aphid resistance gene Rag1. These represent the first aphid resistant soybean varieties released by the public sector in the northern U.S. There is great interested in aphid resistant soybean varieties because soybean aphid continues to be an important pest resulting in the application of insecticides on hundreds of thousands to millions of acres of soybean in the U.S annually. The variety LD01-7323 was released in part because it has yellow hilum and above average protein content which makes it a good variety for use in soy food production such as tofu. The released lines are being licensed to seed companies for commercialization. Research is continuing on developing new high-yielding experimental lines that carry the aphid resistance genes Rag1 and or Rag2. Many aphid resistant lines were tested in 2009 and yield test results show that we can breed these genes into high yielding genetic backgrounds. Our genetic markers linked to aphid resistance genes and our aphid resistant germplasm is being licensed to private companies and is being used in their variety development programs. Progress has been made in developing backcross lines that carry resistance to soybean rust. An experimental line adapted to southern Illinois and a line adapted to northern Illinois have been developed through four backcrosses that carry the rust resistance genes Rpp1 and Rpp2 (Hyuuga). These lines could be useful sources of rust resistance if soybean rust becomes a disease problem in the Midwest. Another activity is the organization of uniform testing of experimental lines from public soybean breeders throughout the northern U.S. This test in 2009 included 245 experimental lines tested in 44 environments through a collaboration with these northern breeders. Agronomic, composition, and SCN resistance results from these tests were summarized and published in a book that was distributed to public and private soybean breeders throughout the U.S. In addition to the research, the program is mentoring four Ph.D. students. PARTICIPANTS: Individuals: PI - Brian Diers. Partner Organizations: USDA-ARS, United Soybean Board, Illinois Soybean Association, and the North Central Soybean Association. Training was provided to four graduate students, three post doctoral research associates and several undergraduate students as part of the project. TARGET AUDIENCES: The target audiences of the research are the soybean breeding research community and soybean growers in the U.S. During the past year, I gave talks to both farmer and scientific audiences. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Outcomes in a number of research areas were generated during the past year. During the year we made progress in fine mapping the soybean cyst nematode (SCN) resistance gene rhg1. Plants with recombination close to this gene were selected using markers on either side of the gene. Progeny from these selected plants were then evaluated in a greenhouse for SCN resistance and new genetic markers were developed close to the gene. These efforts resulted in mapping the gene to a genetic interval of less than 336 kilobases (kb). Further research is in progress that promises to reduce the size of this genetic region even further. Research has progressed in fine mapping the soybean aphid resistance genes Rag1 and Rag2. Like with the mapping of the SCN resistance gene rhg1, plants were identified with recombination close to the resistance gene, progeny of these plants were tested for aphid resistance, and new genetic markers were developed close to the resistance gene. This research resulted in the mapping of Rag1 to a 115 kilobase (kb) genetic region that contains two candidate resistance genes on the Williams 82 DNA sequence. The Rag2 resistance gene was mapped to a 54 kb genetic interval that contains one candidate resistance gene on the Williams 82 DNA sequence. This work should result in the eventual identification of the DNA sequence of these resistance genes which will improve our understanding of how disease resistance to nematodes and aphids works. This is also resulting in the identification of better markers that will help us improve our marker-assisted selection for these resistance genes. Research was done in an attempt to identify new soybean aphid resistance genes. To do this, four populations that each segregate for soybean aphid resistance from a different resistance source were tested for soybean aphid resistance and genetic markers in the intervals where aphid resistance genes are known to be located to determine if they have known resistance genes. The resistance sources tested so far all have known aphid resistance genes suggesting that they don't have new resistance genes to contribute to soybean breeding programs.
Publications
- Farias Neto, A.L., Schmidt, M., Hartman, G.L., Li, S. and Diers, B.W. 2008. Inoculation methods under greenhouse conditions for evaluating soybean resistance to sudden death syndrome. Pesq. Agropec. Bras. 43:1475-1482.
- Chakraborty, N., Curley, J., Frederick, R.D., Hyten, D.L., Nelson, R.L., Hartman, G.L. and Diers, B.W. 2009. Mapping and confirmation of a new allele at Rpp1 from soybean PI 594538A conferring RB lesion type resistance to soybean rust. Crop Sci. 49:783-790.
- Hill, C.B., Kim, K., Crull, L., Hartman, G.L. and Diers, B.W. 2009. Inheritance of resistance to the soybean aphid in soybean PI 200538. Crop Sci. 49:1193-1200.
- Kim, K. and Diers, B.W. 2009. The associated effects of the soybean aphid resistance locus Rag1 on soybean yield and other agronomic traits. Crop Sci. 49:1193-1200.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: During the past year, the breeding program developed experimental lines. These lines were evaluated for yield, and some were evaluated for disease and pest resistance. Those lines with the greatest yield and highest level of resistance were selected. The experimental lines LD01-5907 and LD00-2817 were released from the program during 2008 because they combined resistance to soybean cyst nematode (SCN) from plant introduction (PI) 437654 with good yield potential. This PI has more broad based SCN resistance than PI 88788, the most commonly used source of SCN resistance in the Midwestern U.S. One of the lines is being licensed to seed companies and seed from it was increased during 2008 and the other line was released as a parent for other breeders to use. Both lines have been widely used as a parent by both private and public sector soybean breeders. The experimental lines LDXG05241R-1-2 and LD05-16657 were licensed to seed companies in 2008 because they combine good seed yield, the soybean aphid resistance gene Rag1, and SCN resistance. Commercial production of LDXG05241R-1-2 is expected in 2009 and this will be one of the first soybean aphid resistant cultivars marketed in the U.S. In addition to releasing lines developed by the Illinois breeding program, the soybean aphid resistance genes Rag1 and Rag2 are being licensed to breeders in private industry. These genes are being licensed to these companies after they have been bred into Midwest adapted genetic backgrounds, which makes it faster for companies to incorporate them into their cultivars. Research was completed on the identification of a new Asian Soybean Rust resistance allele. Through genetic mapping, a rust resistance allele was mapped from PI 594538A that is a different allele at Rpp1. This allele should be useful to breeders because it provides resistance to isolates of rust that are not controlled by Rpp1. This new gene from PI 594538A was given the official gene designation Rpp1b. Information on breeding lines developed by the program was distributed to public and private industry soybean breeders through uniform testing programs. In these uniform tests, lines developed by the program were tested together with lines developed by breeders at other institutions. The results from these tests are then distributed to interested public and private breeders. In addition, the best breeding lines from the program were evaluated in the commercial soybean variety test organized by the University of Illinois. The results from the testing of the best lines from the program together with commercial cultivars are then distributed to soybean farmers in the state. PARTICIPANTS: Individuals: PI - Brian Diers, Partner Organizations: USDA-ARS, United Soybean Board, Illinois Soybean Association, North Central Soybean Association. Training was provided to three graduate students, four post doctoral research associates and several undergraduate students as part of the project. TARGET AUDIENCES: The target audiences of the research are the soybean breeding research community and soybean growers in the U.S.A. During the past year, I gave talks to both farmer and scientific audiences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Outcomes in a number of research areas were generated during the past year. In one project, new combinations of soybean cyst nematode (SCN) resistance genes from different resistance sources were tested to determine if these new combinations provide an increased level of resistance. We found that two SCN resistance genes from the wild soybean G. soja PI 468916 contributed to increasing levels of SCN resistance in both the PI 88788 and PI 437654 backgrounds. This suggests that it would be useful for breeders to incorporate these genes from G. soja into SCN resistant backgrounds if they wish to make resistance more broad based. New experimental lines are being developed that carry either the Rag1 or Rag2 soybean aphid resistance genes. These genes are continuing to be bred into high yielding backgrounds. Initial tests done during 2008 in cages in the field that were highly infested with soybean aphids indicate that both genes are effective, but Rag2 had lower aphid infestation levels than Rag1. This indicates that the Rag2 gene is more effective in providing aphid resistance than Rag1 and increased effort will be placed on breeding Rag2 into new cultivars. In an effort to clone the aphid resistance gene Rag1, the fine mapping of this gene is being done. By screening almost 2,000 segregating plants and developing new genetic markers close to these genes, Rag1 has now been mapped to an approximately 115,000 base pair genetic region. This information has allowed us to develop new genetic markers that are very tightly linked to this gene. Fine mapping is also being done for the major SCN resistance gene Rhg1 from PI 88788. The screening of segregating plants has resulted in the mapping of this gene into about a 300,000 based pair region.
Publications
- Kim, K.S., Hill, C.B., Hartman, G.L., Rouf Mian, M.A. and Diers, B.W. 2008. Discovery of soybean aphid biotypes. Crop Sci. 48:929-932.
- Kopisch-Obuch, F.J., Koval, N.C., Mueller, E.M., Paine, C., Grau, C.R. and Diers, B.W. 2008. Inheritance of resistance to alfalfa mosaic virus in soybean plant introduction PI 153282. Crop Sci. 48:933-940.
- Vuong, T.D., Diers, B.W. and Hartman, G.L. 2008. Identification of QTL for resistance to Sclerotinia stem rot (Sclerotinia sclerotiorum) in soybean PI 194639. Crop Sci. 48:2209-2214.
- Kaczorowski, K., Kim, K., Diers, B.W. and Hudson, M.E. 2008. Microarray-based genetic mapping using soybean near-isogenic lines and generation of SNP markers in the Rag1 aphid resistance interval. The Plant Genome 1:89-98.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: During the past year, breeding experiments were conducted in an effort to improve soybean germplasm. This includes planting, maintaining, taking notes on, and harvesting over 11,000 yield plots and 4,900 plant rows. In addition, new crosses were made and populations were advanced to develop new experimental lines. A major focus of these efforts include identifying new sources of disease and pest resistance, determining the genetic basis of this resistance, and breeding this resistance into high yielding, Illinois adapted experimental lines. Research during the past year includes experiments focused on improving resistance to soybean cyst nematodes (SCN), soybean sudden death syndrome (SDS), soybean rust, and soybean aphids. For SCN, genes from different resistance sources were combined in an effort to determine whether these gene combinations will result in an overall greater level of resistance. Experimental lines were tested that segregate for the major SCN resistance gene
rhg1 in the field to study the effect of this resistance gene on yield, plant height, date of maturity, SCN reproduction in the soil, and resistance to other diseases. In addition, uniform tests of experimental lines that carry SCN resistance are being coordinated with soybean breeders throughout the northern U.S. soybean production region. This effort includes soliciting experimental lines from soybean breeders throughout the region, organizing these experimental lines into tests and summarizing results from these tests. The SDS research includes efforts to confirm SDS resistance genes that were previously mapped by my laboratory and the breeding of these genes into new genetic backgrounds to determine their effect in the diverse backgrounds. The soybean rust research includes efforts to map genes from newly identified rust resistance sources that confer soybean rust resistance. The genes being mapped are both genes that confer qualitative and quantitative resistance. For aphid
resistance, genes that confer resistance to this pest are being mapped and bred into high yielding genetic backgrounds. During the past year, I taught one half of an introductory genetics course to approximately 90 undergraduate students both spring and fall semesters. I advised three graduate students and three post doctoral research associates and I have been on the committees of five graduate students who are advisees of other faculty. I have given four talks to farmer groups and six talks to scientific audiences. Soybean germplasm that my program has developed was requested for use as a parent by breeders in both the public and private breeding sector. This includes experimental lines that have been developed with aphid resistance that have been licensed by several soybean breeding companies.
PARTICIPANTS: Individuals: PI - Brian Diers. Partner Organizations: USDA-ARS, United Soybean Board, Illinois Soybean Association, North Central Soybean Association.
TARGET AUDIENCES: The target audiences of the research are the soybean breeding research community and soybean growers in the U.S. During the past year, I gave four talks to farmer groups and six talks to scientific audiences.
Impacts
A number of significant outcomes have resulted from research during the past year. Germplasm that was developed by combining three SCN resistance genes from two different sources of resistance were tested for resistance to an isolate of SCN that can overcome both resistance sources. All three resistance genes were found to act additively to increase resistance and those lines that carry all three resistance genes had good levels of resistance to this SCN isolate. This shows that combining these three resistance genes could be useful for obtaining broad based SCN resistance. An SDS resistance quantitative trait loci (QTL) on soybean linkage group (LG) L that we previously mapped from the variety Ripley was confirmed in a near isogenic line population in a greenhouse test. This is the second SDS resistance QTL that was confirmed from Ripley using greenhouse tests. These resistance QTL will be useful in the development of new soybean germplasm with a high level of SDS
resistance. A new allele for the rust resistance gene Rpp1 was identified from PI594538A. We know this is a new allele because we mapped it using an isolate of soybean rust that can overcome the previously identified rust resistance allele at Rpp1. Two new QTL were mapped from PI 84674 that confer partial resistance to rust. These QTL confer partial (slow) rusting resistance and should provide resistance to a broader array of rust isolates than qualitative rust resistance genes. Progress has been made in backcrossing the rust resistance genes Rpp1 and Rpp Hyuuga into the backgrounds of two Illinois adapted germplasm lines. F1 plants developed through three backcrosses that carry these genes are growing in a greenhouse. Progress is being made in breeding for resistance to soybean aphids. Illinois adapted experimental lines have been developed that carry the aphid resistance gene Rag1. Seed of one line is being increased this winter with the target for releasing it as a variety in 2009.
Breeding was initiated to develop varieties with a second aphid resistance gene which has been tentatively named Rag2. This gene is being crossed into Illinois adapted genetic backgrounds and experimental lines that carry this gene will be grown in the field during 2008. The eventual production of aphid resistant varieties carrying Rag1, Rag2, or both genes will reduce the amount of insecticide applications by soybean farmers.
Publications
- Guzman, P.S., Diers, B.W., Neece, D.J., St. Martin, S.K., LeRoy, A.R., Grau, C.R., Hughes, T.J. and Nelson, R.L. 2007. QTL for increased yield in three backcross-derived populations of soybean. Crop Sci. 47:111-122.
- Li, Y., Hill, C.B., Carlson, S.R., Diers, B.W. and Hartman, G.L. 2007. Soybean aphid resistance genes in the soybean cultivars Dowling and Jackson map to linkage group M. Mol. Breeding. 19:25-34.
- Farias Neto, A.F., Hashmi, R., Schmidt, M., Carlson, S.R., Hartman, G.L., Li, S., Nelson, R.L. and Diers, B.W. 2007. Mapping and confirmation of a new sudden death syndrome resistance QTL on linkage group D2 from the soybean genotypes PI 567374 and Ripley. Mol. Breeding. 20:53-62.
- Nichols, D.M., Lianzheng, W., Pei, Y., Glover, K.D. and Diers, B.W. 2007. Variability among Chinese Glycine soja and Chinese and North American soybean genotypes. Crop Sci. 47:1289-1298.
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Progress 01/01/06 to 12/31/06
Outputs
The objective of the project is to improve soybean through plant breeding and genetics research. This work is being done because soybean farmers need new varieties with improved disease resistance and greater yield. Work in the breeding program has continued during the past year with crosses made between high yielding, disease resistant experimental lines and varieties. From crosses made in past years, new experimental lines were developed and tested for yield and disease resistance. We are considering releasing during the next year LD00-2817, an experimental line which we developed. This line has high yield and broad based resistance to soybean cyst nematode (SCN). The release of this line would be an important contribution to the soybean industry because it has SCN resistance from a source different than almost all other SCN resistant soybean varieties in the Midwest. The new SCN resistance genes in LD00-2817 would control SCN populations that are developing in
fields that can overcome the resistance genes in currently used SCN resistant varieties. Progress is being made in developing varieties with resistance to soybean aphids and in studying the genetic basis of this resistance. Soybean aphid has recently become a major soybean pest in the Midwestern U.S. In collaboration with Glen Hartman's research program, we mapped the major aphid resistance gene Rag1. This gene was backcrossed into several different genetic backgrounds and high yielding Roundup Ready and conventional experimental lines have been developed that carry this resistance. After one more year of testing, we will make a final decision on whether we will release one or more of these experimental lines. We also are mapping the precise location of Rag1. By identifying plants that have recombination very close to the resistance gene, we have been able to map the gene to a genetic interval of less than 4 map units. A study was recently completed in which we mapped the locations of
soybean sudden death syndrome (SDS) resistance quantitative trait loci (QTL). From the resistance sources Ripley and PI 567374, a total of five QTL were mapped using resistance tests in both the field and greenhouse. One QTL that was common to both resistance sources has been confirmed in two new populations. These new resistance genes are now being bred into high yielding varieties and they should be useful in increasing the SDS resistance level of soybean varieties.
Impacts
The goal of this project is to improve soybean through breeding and genetics research. During the past year, there has been impact in a number of areas. Our development of varieties with sources of SCN resistance other than PI 88788, the source most commonly used by soybean breeders, is important for broadening the diversity of SCN resistance genes in varieties. SCN is evolving in a way that is allowing it to overcome the resistance from PI 88788 and we are countering this by developing a high yielding experimental line with new SCN resistance genes from a different SCN resistance source. This new variety is already impacting soybean breeding as we have made it available to many other soybean breeders in the public and private sector and they are using it as a parent in their breeding programs. Our past work on SCN also is impacting the development of soybean varieties. For example, we showed that PI 88788 and PI 437654 have different resistance alleles at the SCN
resistance gene rhg1. This knowledge is helping soybean breeders make better decisions about which of the two alleles they need to select in their programs. Our development of experimental lines with the aphid resistance gene Rag1 is impacting the soybean industry. We provided seed of our experimental lines that carry this gene to breeders from 13 companies and 9 public institutions and they are now breeding this resistance gene in their varieties.
Publications
- Kopisch-Obuch, F.J. and Diers, B.W. 2006. Segregation at the SCN resistance locus rhg1 in soybean is distorted by an association between the resistance allele and reduced field emergence. Theor. Appl. Genet. 112:199-207.
- Kabelka, E.A., Carlson, S.R. and Diers, B.W. 2006. Glycine soja PI 468916 SCN resistance loci associated effects on soybean seed yield and other agronomic traits. Crop Sci. 46:622-629.
- Diers, B.W., Cary, T.R., Thomas, D.J. and Nickell, C.D. 2006. Registration of LD00-3309 soybean. Crop Sci. 46:1384.
- Nichols, D.M., Glover, K.D., Carlson, S.R., Specht, J.E. and Diers, B.W. 2006. Fine mapping of a seed protein QTL on soybean linkage group I and its correlated effects on agronomic traits. Crop Sci. 46:834-839.
- Wang, D., Diers, B. and Boyse, J. 2006. Registration of Skylla soybean. Crop Sci. 974-975.
- Diers, B.W., Kopisch-Obuch, F.J., Hoffman, D., Hartman, G.L., Pedersen, W.L., Grau, C.R. and Wang, D. 2006. Registration of A X N-1-55 soybean germplasm with partial resistance to Sclerotinia stem rot. Crop Sci. 46:1403-1404.
- Farias Neto, A.F., Hartman, G.L., Pedersen, W.L., Li, S. and Diers, B.W. 2006. Irrigation and inoculation methods that increase the severity of soybean sudden death syndrome in the field. Crop Sci. 46:2547-2554.
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Progress 01/01/05 to 12/31/05
Outputs
The objective of the project is to improve soybean through plant breeding and genetics research. This work is being done because soybean farmers need improved varieties with greater disease resistance and yield. A new germplasm line, AXN-1-55 was released from the program during 2005. This line was released because it has a high level of resistance to Sclerotinia stem rot. In testing across 11 environments that had sufficient disease to rate disease responses, AXN-1-55 had significantly less disease than Syngenta S19-90, a line that has been used as a partially resistant check for the last 15 years. A new cultivar, LD00-3309, also was released from the program during 2005. This cultivar was released because of its high yield potential and resistance to soybean cyst nematode and soybean sudden death syndrome. Rapid progress was made in crossing the Rag1 gene into the backgrounds of several soybean varieties. The Rag1 gene confers resistance to soybean aphid, which has
become a major soybean pest in the Midwestern U.S. The Rag1 gene was discovered in a variety that is not adapted to the Midwest. To make the gene available to soybean growers in the Midwest, Rag1 was backcrossed four times (BC4) into the backgrounds of five adapted soybean lines and backcrossed two times into the backgrounds of four additional lines. Preliminary analysis of the backcross lines showed that Rag1 was not associated with reduced agronomic performance, which indicates that we should be able to transfer the gene into varieties without deleterious effects. A study to test the association between two major soybean cyst nematode (SCN) resistance genes from wild soybean (Glycine soja) and yield was completed. These resistance genes were identified by my program a number of years ago and since this discovery, we backcrossed the genes into the background of a soybean line and a backcross population segregating for these genes was developed. The population was evaluated in field
sites with moderate SCN population levels. Under these conditions, both resistance alleles were associated with significantly greater yield than the susceptibility alleles. These results are promising because often genes introgressed from wild relatives of crop species carry unfavorable alleles through genetic linkages. We completed a study to fine map the location of a major gene that increases seed protein concentration. To do this, populations that segregated for different chromosomal regions near the location of the protein gene were developed and tested. These tests resulted in the mapping of this gene to a 3 centi-Morgan region. Unfortunately, the allele of the gene that gave greater protein concentration also resulted in lower yields.
Impacts
The goal of this project is to improve soybean through breeding and genetics research. During the past year, there has been impact in a number of areas. One area of impact is the release of AXN-1-55, a germplasm line with a high level of resistance to Sclerotinia stem rot, an important disease that kills soybean plants in the Midwestern U.S. This line was requested and sent to 19 private industry soybean breeders. These breeders are using this line as a parent in their breeding programs which should help them increase the level of Sclerotinia stem rot resistance in their varieties. The variety LD00-3309 was also release by the program during the past year. This release will have an impact to soybean growers as they can directly grow this variety. It was one of the highest yielding non Roundup Ready varieties in tests of commercial varieties in Southern Illinois during 2004-2005. This variety will give soybean farmers more choices of non Roundup Ready varieties. Our
development of varieties with soybean aphid resistance will have a major impact on soybean production in the Midwest through the reduction of insecticide usage, which will benefit the environment and reduce production costs to farmers. In 2003, an estimated seven million acres of soybean were sprayed in the Midwest with insecticides to control the aphid. We hope to have our own varieties with the aphid resistance gene to the market by 2008 or 2009 and we have licensed our aphid resistant germplasm to seed companies and they are currently developing their own aphid resistant varieties.
Publications
- Kopisch-Obuch, F.J. and Diers, B.W. 2005. Segregation distortion at the SCN resistance locus rhg1in soybean is at least partially caused by reduced field emergence associated with the resistance allele. Theor. Appl. Genet. (Online at DOI 10.1007/s00122-005-0104.2).
- Brucker, E., Niblack, T., Kopisch-Obuch, F.J. and Diers, B. 2005. The effect of rhg1 on reproduction of Heterodera glycines in the field and greenhouse and associated effects on agronomic traits. Crop Sci. 45:1721-1727.
- Brucker, E., Carlson, S., Wright, E., Niblack, T. and Diers, B. 2005. Rhg1 alleles from soybean PI 437654 and PI 88788 respond differentially to isolates of Heterodera glycines in the greenhouse. Theor. Appl. Genet. 111:44-49.
- Diers, B.W., Arelli, P.R., Carlson, S.R., Fehr, W.R., Kabelka, E.A., Shoemaker R.C. and Wang D. 2005. Registration of 'LDX01-1-65' soybean. Crop Sci. 45:1671.
- Kabelba, E.A., Carlson, S.R. and Diers, B.W. 2005. Marker saturation and the localization of two soybean cyst nematode resistance loci from Glycine soja PI 468916. Crop Sci. 45:2473-2481.
- Kopisch-Obuch, F.J., McBroom, R.L. and Diers, B.W. 2005. Association between SCN resistance loci and yield in soybean. Crop Sci. 45:956-965.
- Patzoldt, M.E., Carlson, S.R. and Diers, B.W. 2005. Characterization of resistance to brown stem rot of soybean in five accessions from central China. Crop Sci. 45:1092-1095.
- Patzoldt, M.E., Grau, C.R., Stephens, P.A., Kurtzweil, N.C., Carlson, S.R. and Diers, B.W. 2005. Localization of a quantitative trait locus providing brown stem rot resistance in the soybean cultivar Bell. Crop Sci. 45:1241-1248.
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Progress 01/01/04 to 12/31/04
Outputs
The objective of the project is to improve soybean through plant breeding and genetic research. This work is being done because soybean farmers need improved varieties with greater disease resistance and yield. A new germplasm line, LDX01-1-65 was released from the program during 2004. This line was released because it has two soybean cyst nematode (SCN) resistance genes backcrossed into it from wild soybean (Glycine soja). These genes map to regions when SCN resistance genes in current varieties are not located, showing that the line should be a source of new SCN resistance genes. For genetics research, my program has made progress in studying resistance to SCN, brown stem rot (BSR), and soybean aphid. We have recently completed studies on rhg1, the major SCN resistance gene in varieties. We studied the effect of rhg1 on resistance, yield, emergence, and for allelic differences. To determine these effects, a series of near isogenic line populations, which are
genetically fixed for most of the genome except for the region surrounding the gene, were developed. These studies have shown that rhg1 has a very large impact on resistance, increases yields and reduces SCN populations in infested fields, has limited or no impact on yield in fields with little SCN infestion, and is associated with reduced seedling emergence. Finally, we recently showed that rhg1 alleles from two SCN resistance sources have different functional alleles based on resistance phenotype. This is the first report of more than one resistance allele at a soybean resistance QTL. I recently tested five populations that were each developed by crossing a different BSR resistant PI to a susceptible cultivar. Unfortunately, the resistance in all of these populations was mapped to the same genetic region where all other mapped BSR resistance genes are located. Because we have been unable to identify soybean lines that carry resistance genes on other linkage groups, we initiated the
screening of additional soybean lines for BSR resistance. We evaluated BSR resistance levels on a set of over 600 PIs that were recently introduced from China. From this group, we identified ten with a high level of resistance. Crosses were made with some of these PIs to find resistance genes that map to other locations in the genome. In collaboration with Glen Hartman, a USDA-ARS pathologist at UI, we have studied the genetic basis of aphid resistance. This collaboration has led to the mapping of a major aphid resistance gene. Because resistance is conferred by a major gene that we mapped, this resistance is being backcrossed into elite soybean varieties and experiment lines. We plan to start field testing aphid resistant lines in 2005 and hope to have varieties to farmers by 2008.
Impacts
The goal of this project is to improve soybean through breeding and genetics research. During the past year, impact has been made in a number of areas. One area that the program has had impact is in the release of LDX01-1-65, a germplasm line that has two soybean cyst nematode (SCN) resistance genes backcrossed into it from wild soybean (Glycine soja). These genes map to regions where SCN resistance genes in current varieties are not located, showing that the line should be a source of new SCN resistance genes. This line was requested and sent to breeders from 13 soybean breeding companies. These breeders are using this line as a parent in their breeding programs. The genes from G. soja will have an impact on the soybean breeding industry by broadening the diversity of SCN resistance genes in varieties, which should slow the process of SCN overcoming resistance. The identification of a soybean aphid resistance gene will have a major impact on soybean breeding since
this is the first soybean aphid resistance gene reported and it has the potential for controlling the pest and reducing insecticide usage. In 2003, an estimated seven million acres of soybean were sprayed in the Midwest with insecticides to control the aphid. This aphid resistance gene is being licensed to soybean breeders in the public and private sector and varieties should be available to growers in a few years with the gene. The deployment of this resistance could have a large positive environmental impact through eliminating the spraying of millions of acres with insecticides.
Publications
- Vuong, T.D., Hoffman, D.D., Diers, B.W., Miller, J.K., Steadman, J.R. and Hartman, G.L. 2004. Utilization of the cut stem inoculation method to evaluate soybean, dry bean, and sunflower for resistance to Sclerotinia sclerotiorum. Crop Sci. 44:777-783.
- Kabelka, E.A., Diers, B.W., Fehr, W.R., LeRoy, A.R., Baianu, I.C., You, T., Neece, D.J. and Nelson, R.L. 2004. Putative alleles for increased yield from exotic soybean germplasm. Crop Sci. 44:784-791.
- Glover, K.D., Wang, D., Arelli, P.R., Carlson, S.R., Cianzio, S.R. and Diers, B.W. 2004. Near isogenic lines confirm a soybean cyst nematode resistance gene from PI 88788 on linkage group J. Crop Sci. 44:936-941.
- Diers, B.W., Cary, T.R., Thomas, D.J. and Nickell, C.D. 2004. Registration of 'LN97-15076' soybean. Crop Sci. 44:1483.
- Concibido, V.C., Diers, B.W. and Arelli, P.R.. 2004. A decade of QTL mapping for cyst nematode resistance in soybean. Crop Sci. 44:1121-1131.
- Hughes, T.J., Kurtzweil, N.C., Diers, B.W. and Grau, C.R. 2004. Resistance to brown stem rot in soybean germ plasm with resistance to soybean cyst nematode. Plant Dis. 88:761-768.
- Hill, C., Hartman, G., Li, Y., Diers, B. and Carlson, S. 2004. Soybean gene for resistance to Aphis glycines. Provisional application 60/581,501 filed with the U.S. Patent and Trademark Office.
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Progress 01/01/03 to 12/31/03
Outputs
The objective of the project is to improve soybean through plant breeding and genetics research. This work is being done because soybean farmers need improved varieties with greater disease resistance and improved yield. A new germplasm line, LN97-15076, was released from the program during 2003. This is a high yielding, maturity group IV line. For genetics research, my program completed a study of methods used to obtain a high level of sudden death syndrome (SDS) foliar symptoms in the field on a consistent basis. In a large, multi-year study, we identified two inoculation methods that increased the level of SDS symptoms in field tests. These methods include planting the soybean seed with sorghum or popcorn seed that is infected with the fungus that causes SDS, or placing the infected seed directly below the soybean seed. We also found that the more irrigation treatments that we apply to the field, the more SDS symptoms we will observe. Overall, we found that by
using our best inoculation methods together with irrigating the field, we can consistently obtain SDS symptoms in the field. We made progress in increasing our understanding of the effect of two soybean cyst nematode (SCN) resistance genes from PI 88788. These genes are rhg1 and a second gene on linkage group (LG) J. Using populations of near isogenic lines, which segregate for only a small portion of the genome, we found that lines homozygous for the resistance allele at rhg1 had a female index that was 123 less than lines homozygous for the susceptibility allele. The difference between these homozygous groups was 13 for the LG J gene. In some environments with a high SCN pressure, the rhg1 resistance allele was associated with greater yield and a reduction in SCN reproduction.
Impacts
The goal of this research is to improve soybean through breeding and genetics. During the past year, progress was made in a number of areas. A new maturity group IV germplasm line was released from the program that has high yield. This line was released to private and public soybean breeders for use as a parent in their programs. We identified methods that show promise as a way to increase the level of sudden death syndrome (SDS) disease in the field. This could greatly help soybean researchers increase their efficiency in screening for SDS resistance because in most SDS trials, little disease is observed and ratings can not be taken from plants. We obtained better information on the effect of two soybean cyst nematode (SCN) resistance genes mapped from PI 88788, the most commonly used source of SCN resistance. One gene was found to have a very large effect on SCN reproduction in the greenhouse, whereas, the second was found to have a minor effect. The gene with the
large effect on greenhouse SCN reproduction was found to be associated with a significant yield increase and a reduction in SCN reproduction in field sites with a high SCN pressure. This information will help breeders better understand the effects of these genes and improve their methods of breeding for SCN resistance.
Publications
- Patzoldt, M., Chen, W. and Diers, B.W. 2003. Plant introductions with resistance to brown stem rot. Plant Health Progress. On line journal at www.plantmanagementnetwork.org/php/default.asp.
- Wang, D., Graef, G.L., Procopiuk, A.M. and Diers, B.W. 2003. Identification of putative QTL that underlie yield in interspecific soybean backcross populations. Theor. Appl. Genet.
- Wang, D.J., Shi, J., Carlson, S.R., Cregan, P.B., Ward, R.W. and Diers, B.W. 2003. A low-cost, high-throughput polyacrylamide gel electrophoresis system for genotyping with microsatellite DNA markers. Crop Sci. 43:1828-1832.
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Progress 01/01/02 to 12/31/02
Outputs
The objective of the research is to improve soybean through plant breeding and genetics research. This work is being done because soybean farmers need improved varieties with greater disease resistance and improved yield. For the breeding program, varieties and experimental lines were crossed to form breeding populations, populations were advanced several generations, and breeding lines were derived. The yield and disease resistance levels of breeding lines were determined by testing in field locations throughout Illinois. In addition, lines were further tested for disease resistance levels in greenhouse evaluations. Breeding lines with high yield and disease resistance were identified and these lines will be tested in the field again next year. Progress recently was made in identifying lines with a high level of resistance to the fungus that causes the disease white mold. For genetics research, during the past year an experiment was completed in which genes that
control yield were genetically mapped. This mapping was done in a population developed from a cross between a U.S. variety and a line of exotic origin. In this population, 14 genetic regions were identified that contained putative genes that control seed yield. For 9 of these genes, the yield improving allele had an exotic origin. The yield improving allele originated from the elite variety for the remaining five. Some of these genetic regions were associated with agronomic traits such as date of maturity or plant height. In these cases, we may not have mapped yield genes but instead genes that indirectly control yield through a direct effect on other traits. The mapped genes that have an exotic origin could potentially be used to improve the yield of North American soybean varieties. Progress also was made during the past year toward the precise mapping of a gene that controls protein content. This gene is responsible for increasing protein content by about 5% (20 g/kg seed). Through
the use of near-isogenic lines, which are genetically identical except for defined regions near the protein gene, we have now mapped this gene to approximately a 2 cM genetic region.
Impacts
The goal of this research is to improve soybean through breeding and genetics research. During the past year, progress was made in a number of areas. Breeding lines with a high level of resistance to white mold have been identified. These lines may be directly released to farmers or to seed companies for use in their breeding programs. The locations of genes controlling yield and a number of agronomic traits were also identified. Most of the alleles that increase yield were from an exotic source. These exotic alleles will be retested in other genetic backgrounds and crossed into high yielding genetic backgrounds. These genes could potentially be used to improve the overall yield of elite soybean varieties. In addition, the fine mapping of the gene that increases protein content should help in the cloning of this gene, which will improve our understanding of how improvements in protein content can be made.
Publications
- Hoffman, D.D., Diers, B.W., Hartman, G.L., Nickell, C.D., Nelson, R.L., Pedersen, W.L., Cober, E.R., Dorrance, A.E., Graef, G.L., Steadman, J.R., Grau, C.R., Nelson, B.D., Helms, T., Poysa, V. , Rajcan, I. and Stienstra, W.C. 2002. Selected soybean plant introductions with partial resistance to Sclerotinia sclerotiorum. Plant Disease (In Press).
- Procopiuk, A.M., Nelson, R.L. and Diers, B.W. 2001. Increasing yield of soybean cultivars through backcrossing with exotic germplasm. In Agron. Abstr., CD ROM computer file, Madison, WI.
- Kabelka, E., Diers, B.W., Nelson, R.L., Neece, D., Fehr, W. and Leroy, A. 2001. QTL analysis for yield in a soybean population derived from exotic germplasm. In Agron. Abstr. CD ROM computer file. Madison, WI.
- Glover, K.D., Carlson, S.R. and Diers, B.W. 2001. Fine-mapping protein and yield QTL on linkage group I of soybean. In Agron. Abstr., CD ROM computer file, Madison, WI.
- Kirsch, M.E., Grau, C.R., Stephens, P.A. and Diers, B.W. 2001. Co-Inheritance of BSR and SCN resistance from soybean PI 88788. In Agron. Abstr., CD ROM computer file, Madison, WI.
- Diers, B.W. and Carlson, S.R. 2001. Marker assisted selection in soybean: promises realized? In Agron. Abstr., CD ROM computer file, Madison, WI.
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Progress 01/01/01 to 12/31/01
Outputs
The objective of this research is to improve soybean through plant breeding and genetics. This research is being done because soybean farmers need better varieties with greater yield potential and disease resistance. Many aspects of breeding research were done during the past year. This includes the crossing of varieties and experimental lines to form populations, the advancement of other populations to further generations, and deriving new breeding lines. The performance of the lines was determined by testing them in field locations in Illinois. Lines were also selected for disease resistance by directly screening them with the pathogen and by genetic marker evaluations. A new variety named `Loda' was released from the program during 2000. Loda is a high-yielding, maturity group II variety with resistance to soybean cyst nematode (SCN). Genetic research was done in the areas of resistance to soybean diseases and increasing the protein content of soybean. During the
past year, we confirmed the location of a major brown stem rot (BSR) resistance gene in the variety Bell, which has SCN resistance. Using greenhouse tests, we confirmed that Bell has a BSR resistance gene very close to a minor SCN resistance gene. These results are in agreement with our previous field test results and should help breeders do a better job of selecting for both traits simultaneously. Additionally, our research provided more information on the location of a gene or group of genes that are responsible for increasing protein content by about 5% (20 g/kg seed). Our genetic analysis showed that the protein gene(s) are in about a 15 cM region on soybean linkage group I. This work has also provided evidence that we may have at least partially broken the association between high protein content and low seed yield in this material. More work is needed to further confirm this finding. New sources of SCN resistance were identified during the past year. We screened a number of wild
soybean (Glycine soja) lines and identified four lines that have a high level of resistance to SCN race 3. Further research is being done to test their resistance to other SCN races.
Impacts
The goal of this project is to improve soybean through breeding and genetics research. During the past year, we have made progress in a number of areas. We released a new high yielding maturity group II variety that has resistance to soybean cyst nematode (SCN). This variety can be directly grown by soybean farmers to help them profitably produce soybean in SCN infested fields. In addition, we made progress in more basic genetics research. This includes detailed mapping of the locations on chromosomes of genes that provide resistance to brown stem rot and increase the protein content of seed.
Publications
- WANG, D., ARELLI, P.R., SHOEMAKER, R.C. and DIERS, B.W. 2001. Loci underlying resistance to Race 3 of soybean cyst nematode in Glycine soja plant introduction 468916. TAG 103:561-566.
- NICKELL, C.D., NOEL, G.R., CARY, T.R., THOMAS, D.J. and DIERS, B.W. 2001. Registration of 'Loda' soybean Crop Sci. 41:589-590.
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Progress 01/01/00 to 12/30/00
Outputs
The objective of the research is to improve soybean through plant breeding and genetics. This work is being done because soybean farmers need better varieties with greater yield and more disease resistance. During the past year, varieties and lines were crossed to form populations, populations were advanced generations, and breeding lines were derived. The yields of lines were determined by testing them in field locations in Illinois. Lines were also selected for disease resistance through direct resistance testing and through marker evaluations. Breeding lines with high yield and disease resistance were identified and these lines will be evaluated in the field again next year. Genetic research is being conducted to identify the locations on chromosomes where disease resistance genes are located. During the past year, we confirmed the locations of new genes that confer resistance to soybean cyst nematode (SCN). These resistance genes are from the wild soybean species
Glycine soja and they should be useful for improving the diversity of SCN resistance in varieties. We also have identified the location of a major brown stem rot (BSR) resistance gene from a source of SCN resistance. This identification will help us select for both SCN and BSR resistance at the same time. We have continued with the evaluation of plant introductions (PIs) to identify better sources of resistance to white mold. PIs were identified with a high level of resistance and these are being used as parents in the breeding program to develop new varieties with a high level of white mold resistance.
Impacts
The goal of this project is to improve soybean through breeding and genetics research. During the past year, we have made progress in identifying the locations of important genes that provide resistance to soybean cyst nematodes and brown stem rot. We have also made progress in identifying soybean breeding lines that have a high level of resistance to white mold.
Publications
- Kim, H.S. and Diers, B.W. 2000. Inheritance of partial resistance to sclerotinia stem rot in soybean. Crop Sci. 40:55-61.
- Sebolt, A.M., Shoemaker, R.C. and Diers, B.W. 2000. Analysis of a quantitative trait locus allele from wild soybean that increases seed protein concentration in soybean. Crop Sci. 40:1438-1444.
- Kim, H.S., Hartman, G.L., Manandhar, J.B., Graef, G.L., Steadman, J.R. and Diers, B.W. 2000. Resistance of soybean cultivars to sclerotinia stem rot in field, greenhouse, and laboratory evaluations. Crop Sci. 40:665-669.
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Progress 01/01/99 to 12/31/99
Outputs
Project just started 10/1/99. No results to report at this time.
Impacts
(N/A)
Publications
- No publications reported this period
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