AGRONOMIC PERFORMANCE OF SOYBEAN RECOMBINANT INBREDS IN NORTHERN USA AND CHILE

Winter nurseries are widely used by soybean [Glycine mar CL.) Merr.] b reeders for generation advancement. Limited research has shown that oh -season facilities can also be used to select for agronomic traits. Ou r objective was to determine the relationship In performance between s oybeans grown in northern USA and those in central Chile for days to m aturity (R8), plant height, lodging, seed protein and oil concentratio n, and seed weight and yield. For this purpose, 284 recombinant inbred lines of soybean (RIL) ranging from Maturity Group 00 to I, their par ents, 'Minsoy' and 'Noir 1', and 10 check cultivars were evaluated in Minnesota, USA, and central Chile during 2 yr using a randomized compl ete-block design with three replications. There were highly significan t differences among RILs for all traits. Estimates of heritability (h( 2)) on an entry mean in the USA ranged from 0.65 for protein concentra tion to 0.89 for R8 and plant height, whereas in Chile they ranged fro m 0.74 for oil concentration to 0.93 for plant height. Across countrie s, h(2) ranged from 0.69 for oil concentration to 0.93 for plant heigh t. Moreover, the phenotypic (and rank) correlations for performance be tween central Chile and northern USA were high, positive, and highly s ignificant (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, l odging, seed protein and oil concentration, and seed weight and yield, respectively. The same correlations for the 10 check cultivars confir med 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.