Influence of growing environment on the biochemical composition and physical characteristics of soybean seed

The biochemical composition and physical appearance of soybean seeds determine the quality of various soy foods. A multi-locational field trial with seven Indian cultivars at four growing locations was conducted to study the influence of the growing environment on the biochemical and physical characteristics of soybean seed. Genotypic, locational and genotypic×locational interaction were found to be significant for protein, oil and unsaturated fatty acids, namely oleic acid, linoleic acid and linolenic acid ( P < 0.001 ). Phytic acid and heat-stable antinutritional factor in soybean seed showed significant ( P < 0.01 ) locational and genotypic×locational effects. Among climatic factors, latitude showed a significant positive correlation with oil ( P < 0.05 ) and a negative correlation with protein ( P < 0.01 ), while rainfall showed a negative correlation with protein content ( P < 0.001 ). Average daily mean temperatures during bean development showed a positive correlation with protein ( P < 0.05 ) and a negative one with oil and linolenic acid ( P < 0.05 ). Among physical characteristics, seed size showed a positive correlation with phytic acid and oleic acid, and a negative correlation with linolenic acid. Over four growing locations, the seed coat colour showed no variation, while light hilum colour cultivars responded differentially. The effect of various climatic factors on physical and biochemical composition of soybean seed as observed in our studies suggests the need for development of location-specific cultivars for food uses of soybean.