Sex expression and sex dimorphism in sporophytic populations of the desert moss Syntrichia caninervis.

摘要: Ten sporophytic populations of Syntrichiacaninervis contained an average 22 individualscm−2, with a sex ratio 7.9 Female:1 Male: 3.1 Nonexpressing(N = 300). In each the populations, female individuals outnumberedmale individuals. A representative population size 50 × 25cm was estimated to contain 27,250 organically distinct individualplants. Given wide disparity in reproductive investment this dioeciousspecies, sex-specific traits were investigated at level individualinbiomass, total stem length, number ramets, branches, length ofannual growth interval, longest ramet, age, inflorescences,number ramets expressing sex, and consecutive seasons expression. Theonly significant dimorphism recorded sexexpression, nonsporophytic exhibiting higherfrequencythan males. However, nonexpressing had lower biomass, shorter totalstem fewer than males females, andfewer When biomass maleindividuals controlled for inflorescence number, no differencesbetween sexes found. There appears be threshold sizefor expression, all above 2.0 mg dry weightexpressing (N 108). Biomass are strongpositive correlates (r 0.88), individual is betterpredictor inflorescences produced per stemlength 0.85 vs. r 0.69, respectively). Independent stemlength, positive relationship withinflorescence number; however, independent lengthwas not associated number. Overall expression 0.74(individual level) 0.65 (ramet level). The functional wasassessedat level, ranged from 9.7♀:1♂, to14.9♀:1♂ over most recent four years. Fertilization frequencywas 0.69 (individual 0.34 (perichaetial Over last threeyears, 63% fertilized perichaetia resulted abortivesporophyte.