横断山区湿地优势植物水葱种子繁殖性状对环境变化的响应

选择对环境变化较为敏感的横断山区纳帕海湿地、拉市海湿地以及滇池流域为采样地点,研究这些区域的湖滨带优势植物水葱(Schoenoplectus tabernaemontani)种子繁殖性状,包括穗长、小穗数、每穗种子产量、种长、种宽以及种长/种宽等指标对环境变化的响应及适应策略。结果显示:除种宽外,上述水葱种子繁殖性状在不同采样地点间均存在显著差异。逐步回归模型分析表明,年均气温和最暖月均气温的变化是影响水葱种子繁殖性状的主要原因,其中穗长主要受年均气温和最暖月均气温的共同影响,小穗数和种长主要受年均气温的影响,每穗种子产量和种长/种宽主要受最暖月均气温的影响,而种宽与本研究所有环境因子间的相关性均不显著。温度是影响横断山区湿地植物种子繁殖过程的重要环境因子,而降水和饱和大气压差对这一过程的影响相对较小。

Responses of Seed Reproduction Traits of A Wetland Dominant Plant Schoenoplectus tabernaemontani to Environ-mental Changes in Hengduan Mountains

With three wetlands,Napahai Wetland, Lashihai Wetland and Dianchi basin in Hengduan Mountains, belonging to the environmental-sensitive region,and a lakeside dominant species(Schoenop lect us ta bernaemontani)of this region as our target species,we studied response differences and adaptive strategies of the species reproductive traits including spike length, spikelets number, spike seeds number, seed length, seed width, and seed length/seed width to environmental changes.All the reproductive traits were significantly different among the studied sites except for seed width.By the step-wise regression model analysis,the variation of annually mean temperature and monthly mean temperature of the warmest month were the main factors affecting the reproductive traits.The spike length was affected by both types of temperature, the number of spikelets and seed length were mainly affected by the annually mean temperature,seed yield per panicle and seed length/seed width were mainly influenced by monthly mean temperature of the warmest month,and there were no sig-nificant correlations between seed width and all environmental factors.Temperature was an important environmental factors affecting seed reproduction process of wetland plants in Hengduan Mountains,while the effect of precipitation and saturated atmospheric pressure on this process was relatively small.