Variations in antinutritional factors at different development stages in seed of Phaseolus vulgaris and Erythrina americana

Variation in the antinutritional factor (ANF) content of Phaseolus vulgaris , cv. Jamapa and Erythrina americana seed was studied at different developm ent stages. The highest concentration of ANFs, in both species, was in the seed. Trypsin inhibitors decreased markedly during germination (90 %) and w ere absent in seedlings, flowers and string beans. During germination lecti ns were present at the same level as in dry seed but they were absent in se edlings, flowers and string beans. They reappeared at the ripe bean stage. Alkaloids in E. americana were present at all growth stages. However, flowe rs had the lowest alkaloid concentration. Non-protein nitrogen decreased du ring seed development in inverse proportion to protein nitrogen at the same stage. The ANFs play a protective role against predators in addition to th eir important role in the physiological changes that occur during the devel opment of a new plant from seed.