关键词: 马蔺, 花性状, 变异性, 繁殖适合度

Abstract: Plant Flower diversity is largely thought to be subject to pollinator-mediated natural selection. This study aimed to explore adaptation of floral traits and possible selective mechanisms of Iris lactea by detecting the correlations between floral traits and reproductive fitness in a natural population in the alpine grasslands in Tianzhu County. The results showed that the coefficients of variation for stamen-to-stigma distance and stigma height were the largest among the I. lactea flower traits,with 44% and 29%,respectively,while the degree of variation for inflorescence height and flower size was intermediate,and the degree of variation for exoperigon size was the smallest. There were highly significant positive correlations (P < 0.001) between inflorescence height,flower size,exoperigon size and stigma height and seed number and seed set;significant positive non-linear relationships (P<0.05) between stamen-to-stigma distance and seed set and significant negative non-linear relationship (P<0.05) between stigma height and seed set;there was a and significant positive correlation (P < 0.05) between the two combinations of the traits of stigma height and exoperigon size and both seed number and seed set. The analyses showed that there was a significant effect of floral trait variability in I. lactea on its reproductive fitness,and its floral structural trait combinations had specific fitness contributions,so there was a tendency towards functional integration to improve its pollination efficiency and reproductive success.

Key words: Iris lactea, Floral traits, Variability, Reproductive fitness