ACCUMULATION OF PHYTATE IN VEGETABLE-TYPE SOYBEAN GENOTYPES HARVESTEDAT 4 DEVELOPMENTAL STAGES

A total of 17 vegetable-type soybean (Glycine max [L.] Merr) genotypes were planted in four-row plots arranged in a randomized complete bloc k design in 1988 and 1989 at Petersburg, Virginia. Each genotype was h arvested at four developmental stages and evaluated for phytate conten t. Highly significant differences for phytate content were observed am ong the stages of harvest and genotypes, and there was an interaction between genotype x stage of harvest. The significant differences obser ved for phytate content among genotypes indicated that genetic variati on exists among the tested genotypes for selection and improvement thr ough hybridization. Among the genotypes, 'Kingston' and PI423852 had t he highest phytate content in most stages of harvest while PI 416771, 'Emperor', and PI416982 had the lowest phytate values. A heritability estimate of 81 percent was observed for phytate content. This high her itability value indicates that selecting genotypes for lower phytate c ontent would be effective. Significant correlations were observed for phytate content among genotypes harvested at R6, R7, R8, and overall. The magnitude of association of R6 with the overall phytate mean was e specially high. These results illustrate that determining the phytate content of genotypes at the R6 growth stage would be a good predictor of the overall genotypic performance.