Photosynthesis in a half-sib family experiment in pitch pine

Abstract

Intraprovenance variation in the rate of photosynthetic CO 2 exchange was determined for 20 half-sib families of pitch pine. During early seedling development, rates of CO 2 uptake were comparable with those for highly productive crop plants and the highest yet reported for conifers. Differences among families were small but statistically significant. Genotype-environment interactions were relatively unimportant, i.e., patterns of photosynthetic response to temperature and light were the same for all families within the limits of error.