C. Damgaard et V. Loeschcke, GENOTYPIC VARIATION FOR REPRODUCTIVE CHARACTERS, AND THE INFLUENCE OFPOLLEN-OVULE RATIO ON SELFING RATE IN RAPE SEED (BRASSICA-NAPUS), Journal of evolutionary biology, 7(5), 1994, pp. 599-607
The variance component for genotypic effects and covariable plant vigo
r were estimated for pollen production, number of ovules, the weight o
f the flower without anther sacs and pistil, and the gender of the who
le plant, in the rape seed variety Topas. There was a significant effe
ct of the genotype for all measured characters. We did not find any tr
ade-off between the male and female functions. Small plants were relat
ively more male-biased than large plants. The weight of the flower wit
hout anther sacs or pistil was positively correlated with pollen produ
ction. The selfing rates of the lines were positively correlated with
the pollen-ovule ratio, suggesting that the selfing rate of individual
plants is positively correlated with pollen-ovule ratio, thus support
ing the ''mass-action'' model. It is proposed that the observed increa
se in the population selfing rate during the flowering season for some
species, including rape seed, can be caused by an overall decrease in
male investment.