|Lewers, K - IOWA STATE UNIVERSITY|
Submitted to: Genetics and Exploitation of Heterosis in Crops
Publication Type: Abstract Only
Publication Acceptance Date: August 21, 1997
Publication Date: N/A
Technical Abstract: Soybean is an important oilseed legume. Production of hybrid seed usually is done by manual cross-pollination. The use of genetic male-sterile, female-fertile plants with insect cross-pollination to produce hybrid seed is feasible. The pollen fertility locus, Ms6, is linked to flower color locus, W1 and recombination values in coupling phase for Ms6 - W1 were between 2.48 +/- 0.1 and 3.18 +/- 0.1. Use of the close-linked marker system for the production of hybrid seed for research purposes was termed the Cosegregation Method. Soybean lines included a Plant Introduction from Japan, Plant Introduction from the former S.R. and three commercial lines with greater than 25% exotic germplasm in their pedigrees. The sixth line used was the donor source of the ms6-w1 alleles. Two testers were used to evaluate the six lines. The testers were three near-isogenic lines each of cv Clark (Clark e2, Clark e2 Dt2, and Clark e2 S and cv Harosoy (Harosoy, Harosoy Dt2, and Harosoy S). Agronomic evaluations were made on replicate three-row plots at three locations for two years. The data were sorted by environment (year-location) and treatment. An analysis of variance was conducted to obtain genotypic means and error mean-square values for each agronomic trait. Significant levels of F1 midparent heterosis were found for every trait measured. Grain yield of the pod-parent lines were generally greater than that of the testers, only PI 384.474 yielded less than the testers. Midparent heterosis was significant and positive for PI 384.474, AG020, and CX155, and heterosis levels among these lines were not significantly different from one another.