AGRONOMIC PERFORMANCE OF SOYBEAN RECOMBINANT INBREDS IN NORTHERN USA AND CHILE

Winter nurseries are widely used by soybean [Glycine mar CL.) Merr.] breeders for generation advancement. Limited research has shown that oh-season facilities can also be used to select for agronomic traits. Our objective was to determine the relationship In performance between soybeans grown in northern USA and those in central Chile for days to maturity (R8), plant height, lodging, seed protein and oil concentration, and seed weight and yield. For this purpose, 284 recombinant inbred lines of soybean (RIL) ranging from Maturity Group 00 to I, their parents, 'Minsoy' and 'Noir 1', and 10 check cultivars were evaluated in Minnesota, USA, and central Chile during 2 yr using a randomized complete-block design with three replications. There were highly significant differences among RILs for all traits. Estimates of heritability (h(2)) on an entry mean in the USA ranged from 0.65 for protein concentration to 0.89 for R8 and plant height, whereas in Chile they ranged from 0.74 for oil concentration to 0.93 for plant height. Across countries, h(2) ranged from 0.69 for oil concentration to 0.93 for plant height. Moreover, the phenotypic (and rank) correlations for performance between central Chile and northern USA were high, positive, and highly significant (P < 0.01): 0.89 (0.90), 0.89 (0.90), 0.79 (0.85), 0.68 (0.62), 0.67 (0.62), 0.78 (0.80), and 0.72 (0.70) for R8, plant height, lodging, seed protein and oil concentration, and seed weight and yield, respectively. The same correlations for the 10 check cultivars confirmed these results. We concluded that selection for these traits in off-season winter nurseries in central Chile should also be effective in identifying genotypes that perform similarly in the northern USA.