紫苞鸢尾的开花物候特征与生殖特性

Flowering Phenology and Reproductive Characteristics of Iris ruthenica

为研究紫苞鸢尾(Iris ruthenica)开花物候特征与生殖特性,本文对草甸草原和林下生境的紫苞鸢尾在种群、个体以及单花水平上分析开花日期、相对开花强度和同步性等开花物候特征及其与坐果数的相关性进行分析。结果表明:草甸草原生境中,种群花期为4月末至5月中旬,而林下生境的花期在5月中旬至6月初。草甸草原生境中,种群、个体以及单花水平持续时间分别为18 d、12.95±0.64 d和3.88±0.15 d,林下生境为16 d、11.35±0.62 d和4.47±0.12 d。草甸草原生境中,紫苞鸢尾种群的开花振幅呈现出“双峰”曲线,而林下生境呈“单峰”曲线。草甸草原种群的该物种个体在10%~30%具有较高的开花强度,偏斜率为0.55。林下种群具有两个较高分布频度的开花强度范围,分别为20%~40%以及60%左右,其偏斜率为1.29。该物种在草甸草原和林下生境中均具有较高的开花同步指数(0.75和0.79)。林下生境该物种的坐果数与开花数达到极显著正相关关系,与花期持续时间呈正相关关系;而草甸草原种群的坐果数与花期持续时间、开花数均呈负相关关系。可见不同种群紫苞鸢尾的开花物候与生殖特性不仅受遗传因子影响,还受所处环境因子的影响。

To study the flowering phenology and reproductive characteristics of Iris ruthenica by analyzing the flowering course of each individual and inflorescence including the first flowering date,duration,mean flowering amplitude and last flowering date and the correlation between fruit setting numbers.The results showed that:In meadow steppe habitat,the flowering period was from late April to mid-May,while in understory habitat,the flowering period was from mid-May to early June.In meadow steppe habita,the flowering span of the population,individual and single flowering was approximately18 d,12.95±0.64 d and 3.88±0.15 d.The synchrony index was 0.75.The relative flowering intensity showed one major peak from 10%to 30%and the skewness was 0.55.The understory habitat was 16 d,11.35±0.62 d and 4.47±0.12 d.The synchrony index was 0.79.The relative flowering intensity had two major peaks from 20%to 40%and 60%and the skewness was 1.29.In meadow steppe habitat,the flowering amplitude of I.ruthenica population showed a‘double peak’curve,and the understory habitat showed a‘single peak’curve.Correlation analysis showed that the number of fruit setting and flowering of this species in understory habitat had a very significant positive correlation,and a positive correlation with flowering duration.The fruit number of meadow steppe population was negatively correlated with flowering duration and flowering number.This study showed that the flowering phenology and reproductive feature of different populations of I.ruthenica were affected by genetic factors,and also affected by the environmental factors.