QUANTITATIVE-ANALYSIS OF SEXUAL DIMORPHISM IN ASPARAGUS

In the dioecious perennial Asparagus oficinalis, female function, esti mated by the number of berries per plant and seeds per berry, was posi tively correlated with stem diameter and height and negatively correla ted with stem number. In contrast, male function, estimated by the mea n production of pollen per flower and by the number of male flowers pe r ramet, was positively correlated with stem number and negatively cor related with stem diameter and height. These correlations, which are c alculated between mean values per genotype, are in accordance with sex ual dimorphism in this species: male plants produce more but thinner s tems than female plants. We propose that morphological constraints at the plant level could have favoured the evolution of dioecy in this sp ecies.