Relation of Respiratory and Enzymatic Activity to Corn Seed Viability.

Abstract

Changes in respiratory capacity and in activity of malic and alcohol dehydrogenases and cytochrome oxidase of corn embryos were measured during the early stages of germination. These metabolic indices at the 18 hr. stage also were compared with germination %, tetrazolium test, vigor test, and cold test of 31 lots of corn of varying viability: Malic dehydrogenase activity was more closely correlated with germination % and respiratory capacity than that of the other 2 enzymes. It was doubtful whether inactivation of these 3 enzymes was a . major cause of loss of viability, but dehydrogenase activity appeared to be more closely correlated with tetrazolium test than germination %. Variation in respiratory indices did not explain differences between germination % and cold test and vigor ratings.