Location: Corn Insects and Crop Genetics Research2009 Annual Report
1a. Objectives (from AD-416)
Objective 1: Identify and utilize fertility/sterility mutants in a phenotypic recurrent selection program for insect-mediated cross-pollination to increase hybrid seed production. Objective 2: Identify phenotypes/genotypes that can be characterized and molecularly mapped that contribute to insect-pollinator attraction and reward.
1b. Approach (from AD-416)
Soybean accessions in the USDA germplasm collection will be crossed with known cytoplasmic restorer lines to identify cytoplasmic male sterile cytoplasms. Sterility mutants (nuclear) obtained via gene tagging from the w4-mutable system will be characterized genetically. Both the cytoplasmic and nuclear sterility mutants will be used in a phenotypic recurrent selection system, with insect-mediated cross-pollination, to increase hybrid seed production. The plant factors that contribute to the increased attraction/reward of the insect pollinators will be identified, characterized, and molecularly mapped.
3. Progress Report
The search for cytoplsmic male sterility in the USDA soybean germplasm was initiated in summer 2008. Hail destroyed approximately 90% of the hybrid pods. These crosses were repeated in summer 2009, plus 200 additional cross-pollinations with plant introductions were made. Advanced populations of fertility/sterility mutants were evaluated by molecular mapping. Fertility/sterility mutants previously identified were added to the allelism tests. The second population for studying insect-pollinator attraction and reward was planted at Texas and Nebraska. A CRADA is being finalized on the identification, characterization, and molecular mapping of insect-pollinator attraction traits in soybean.
1. Hybrid soybean - one way to increase yield and profits for the farmers. Two-temperature sensitive male-sterile mutants were identified. The objectives were to determine if 1) the mutants were the same or different genetically and 2) if they could be used to produce hybrid seed. The two mutants were mapped to different linkage groups and, therefore, are different mutants. The two mutants differed in their fertility/sterility response to high and low temperature. Because of the wide fluctuations in temperature during the flowering (reproductive) period, the mutant lines would not be useable for commercial hybrid soybean seed production.
Healy, R.A., Palmer, R.G., Horner, H.T. 2009. Multicellular Secretory Trichome Development on Soybean and Related Glycine Gynoecia. International Journal of Plant Science. 170(4):444-456.