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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVEMENT OF PEST RESISTANCE AND QUALITY TRAITS OF SOYBEAN

Location: Corn, Soybean and Wheat Quality Research Unit

2010 Annual Report


1a.Objectives (from AD-416)
1. Identify novel quantitative trait loci (QTL) for soybean cyst nematode (SCN) resistance. 2. Develop soybean germplasm with resistance to soybean aphids and map soybean aphid resistance genes. 3. Identify QTL for partial resistance of soybean to Bean pod mottle virus (BPMV). 4. Develop soybean germplasm with high seed-protein content.


1b.Approach (from AD-416)
Genes involved in disease and insect resistance and other target traits will be identified through molecular mapping. Segregating mapping populations will be developed for all target traits. The genes will be tagged with DNA markers to permit incorporation into advanced soybean germplasm. Molecular markers will be identified to facilitate marker-assisted selection of enhanced germplasm. Appropriate methods and technology will be identified or developed to facilitate gene identification and mapping. Soybean germplasms with resistance or tolerance to soybean aphid and high-protein will be developed through a combination of the conventional and marker assisted plant breeding approaches. Virus identification and detection procedures will be developed, and sources of partial resistance to bean pod mottle virus will be identified by greenhouse and laboratory screenings of plant introductions.


3.Progress Report
Most objectives of this project are fully met or ahead of schedule. We will complete development of soybean aphid resistant line ahead of schedule by releasing germplasm by 2011. The aphid resistant germplasm is high-yielding and have no yield drag associated with the resistance gene. The BC4F4 lines with Rag2 gene are being field tested at multiple locations in 2010 for the second year. Mapping of soybean aphid resistance genes in PI 567301B and PI567324 are also are ahead of schedule. High-protein high-yield soybean lines are being tested in multiple locations in Ohio one year ahead of schedule. These lines show 2-4% increase in protein without any associated loss of yield indicating a break though in the historical negative association between protein content and seed yield of soybean. Fine mapping of the Rag2 gene has started 3 years ahead of schedule. Going beyond our objectives, we have mapped a new powdery mildew resistant gene named Pmd_PI243540 (published two manuscripts) and fine mapped it into an interval of <100 kb. This research will allow cloning of the powdery mildew resistance gene soon. Five candidate genes have been identified. We have also started proteomic and transcriptomic studies on the Rag2 gene in collaboration with University of Missouri. Developed hundreds of SSR and SNP markers for molecular studies of the soybean aphid and published a paper on genomics of the soybean aphid. Much of this has been possible due to various support and productive collaborations from various institutes we have received during 2010.


4.Accomplishments
1. High-protein and high-yield soybean lines. More than 10 soybean lines have been developed with 3- 4% higher protein with no associated yield reduction. These high-protein soybeans will add value to improve animal and human nutrition and food security.

2. A new gene for powdery mildew resistance. Identified and mapped a new gene (named Rmd_PI243540) for powdery mildew resistance of soybean. This new gene will contribute to environmentally sustainable control of the powdery mildew disease of soybean to increase profitability of soybean growers in USA.

3. SSR markers for soybean aphids. Soybean aphid is the number one insect pest of soybean in the USA. We have developed more than 400 SSR markers for genetic study of soybean aphids. These SSR markers will enable researchers to conduct molecular and genetic studies of the soybean aphids and create an aphid biotypes distribution map of the USA. Such a map is critical for growers to decide which aphid resistant soybean cultivars to grow in their farms.


5.Significant Activities that Support Special Target Populations
Contacted West Virginia State University for mutual visits and research presentations to initiate collaboration with this historically black college on pest resistance of agronomically important crops and graduate training. First visit is scheduled in September 2010.


Review Publications
Michel, A.P., Mian, R.M., Olivas, N.D. 2010. Detached Leaf and Whole Plant Assays for Soybean Aphid (Aphis glycines) Resistance Show Differential Reponses among Resistance Sources and Biotypes. Journal of Economic Entomology. 103:949-957.

Michel, A.P., Zhang, W., Mian, R.M. 2010. Genetic Diversity and Differentiation among Laboratory and Field Populations of the Soybean Aphid, Aphis glycines. Bulletin of Entomological Research. 27:1-8.

Michel, A.P., Zhang, W., Jung, J., Kang, S., Mian, R.M. 2009. Cross-Species Amplification and Polymorphism of Microsatellite Loci in the Soybean Aphid, Aphis glycines. Journal of Economic Entomology. 102:1389-1392.

Michel, A.P., Zhang, W., Jung, J., Kang, S., Mian, R.M. 2009. Population Genetic Structure of the Soybean Aphid, Aphis glycines. Environmental Entomology. 38:1301-1311.

Bai, X., Wei, Z., Orantes, L., Jun, T., Mittapalli, O., Mian, R.M., Michel, A.P. 2010. Combining Next-Generation Sequencing Strategies for Rapid Molecular Resource Development from an Invasive Aphid Species, Aphis glycines. PLoS One. 5(6): e11370. doi:10.1371/journal.pone.0011370.

Sung-Taeg, K., Mian, R.M. 2010. Genetic Map of the Powdery Mildew Resistance Gene in Soybean PI 243540. Genome. 53(5):400-405.

Last Modified: 4/18/2014
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