Reproductive trade-offs in genetically distinct clones of Vaccinium macrocarpon, the American cranberry

Abstract

Patterns of resource allocation to growth, current reproduction, and potential future reproduction were quantified in six genetically distinct cultivars of Vaccinium macrocarpon. For all cultivars (genotypes), vegetative size if positively correlated with some measures of current reproduction (fruit and flower number) but negatively correlated with others (seed number per fruit, seed weight per fruit). Vegetative growth in the current year is significantly related to the production of reproductive terminal buds, a measure of the potential for reproduction in the following year. Stems with low levels of current reproduction lower flower number, fruit number, and seed weight were more likely to form reproductive terminal buds than stems with higher levels of current reproduction. Individual genotypes differed significantly for vegetative size, fruit number, fruit weight, seed number, and seed weight, as well as for the frequency of fruiting stems and reproductive terminal buds produced. Genotypes were segregated in principal component space, indicating overall differences between them in allocation to the suite of variables measured. These results indicate the possibility of fitness differences among cultivars due to genetically determined allocation strategy, which has implications for fitness differences among genotypes within natural populations.