Allozyme heterozygosity and homeostasis in germinating seeds of jack pine

The concept of phenotypic stability used in plant breeding was employed to test the relationship among allozyme heterozygosity, growth rate, and homeostasis, using seed germination as a model, in 51 open-pollinated families of jack pine. The seeds were germinated in petri dishes in nine variably stressful environments. Mean radicle length per individual in each family germinated in a specific environmental stress was then correlated with the amount of allozyme heterozygosity of the respective family. A significant positive relationship between mean radicle length and allozyme heterozygosity was found in three out of nine environments. Phenotypic stability values had a significant positive relationship with mean radicle length, but showed no relationship with allozyme heterozygosity. We conclude that environmental variation may be partially responsible for the strength of relationship between allozyme heterozygosity and growth rate; which is consistent with the notion that genotype-environment interactions are important determinants in the expression of heterosis.