Response of soybean genotypes differing in yield structure to ecological changes and dif-ferentiative capacity of environment

Breeding for specific adaptability requires estimation of quantitative traits inputs into yield response to environment alterations. About 200 genotypes of early soybean MGs 00 and early 0 were studied for 7 years in Belarus. The stratified regression analysis of „yield - node number‟ and „yield - TSW‟ interrelations in the gradient of environments revealed extension of regression slopes and differentiative capacity as index of environment increased in both cases. Thus, increasing node number and TSW promotes specific adaptability to high-yielding locations within MG 00. Predicted yield gains from the optimization of these traits were estimated for different environments. Regression of yield on node number is likely to be non-linear: regression coefficient was more responsive to environment index over the range of environments 2 to 2.5 t ha-1. Best differentiative capacity for both yield and node number was observed in sparse crops (20 plants m-2). Obtained results may be used for optimizing breeding process for early soybeans.