The extent of heterosis observed in a single cross hybrid has generally been reported to be a function of the genetic diversity of its inbred components. We used isozyme variability as an indicator of genetic diversity. Fifteen inbred lines of maize (Zea mays L.) were characterized for esterase, amylase, leucine aminopepridasc, catalase, alcohol dehydrogenase and peroxidase isozymes. Differences in these systems were used to calculate a diversity index (DI). The DI for an inbred pair represented the number of isozymes that were dissimilar in the two inbreds. Hybrids produced from inbred pairs with higher DI's outyielded those with low DI's. However, the correlation between grain yield performance of the single cross hybrids and DI was low (r = 0.09) and not significant. Hence, the DI, as used here, is of very limited predictive value.
Characterization of Photosynthetic Performance during Senescence in Stay-Green and Quick-Leaf-Senescence Zea mays L. Inbred Lines
