Genetic Analysis of Ecotypic Differentiation Within an Annual Plant Species, Geranium carolinianum L., in Response to Sulfur Dioxide

Abstract

Infraspecific variation within G. carolinianum in response to SO2 is reported. Disparate responses in leaf SO2 resistance between selected lines contrasting in susceptibility are associated with the sensitivity of parental types. Maternal cytoplasmic inheritance is eliminated as a creditable hypothesis. Heritability in the narrow sense (hn2) is estimated statistically as 0.50 .+-. 0.14, and the mode of inheritance of SO2 susceptibility is quantitative. Neither resistance nor sensitivity exhibits dominance. The importance of existing genetic variation in SO2 susceptibility to the process of population differentiation in response to SO2 stress is discussed.