您的位置:首页  > 论文页面

羊草种子生产、大小、萌发能力和幼苗生长对母体增温环境的响应

发表时间:2012-03-15  浏览量:1167  下载量:395
全部作者: 高嵩,王俊锋,张志静,郭继勋
作者单位: 东北师范大学草地科学研究所,植被生态科学教育部重点实验室;东北师范大学生命科学学院
摘 要: 以欧亚大陆草原带东端的主要建群种羊草为例研究母体在连续增温条件下对种子大小、发芽能力、幼苗生长等重要因素的影响,以期为阐明羊草种群变化和评估生态安全性提供有价值的信息。结果发现:增温能够显著降低单位面积的抽穗数量,增加每穗小花数、结实粒数,最终使单位面积的种子数减少。增温后小种子所占比例显著降低,而大种子所占比例显著增加,这使千粒重显著增加;小种子的发芽率、发芽速率和所产幼苗的生物量和根生物量均比对照有显著降低,而大种子的这些指标没有明显变化;综上,增温会减少单位面积可发芽的种子数量。结果同时显示:在温带半干旱地区,增温在不同季节对多年生禾草种子生产过程有着不同影响,在降雨稀少的季节有不利影响,但在降雨较多的季节对种子生产有促进作用。羊草种子生产能力的降低暗示着羊草种群的正常扩展在继续增温的条件下会受到限制,研究为评估欧亚大陆草原带东端的主要物种种群结构在全球变暖背景下的变化过程提供一些重要的参考信息。�
关 键 词: 生态学;温带草原;种子产量;发芽;幼苗生长
Title: Effect of seed production, mass, germinability and subsequent seedling growth on parental warming environment in Leymus chinensis
Author: GAO Song, WANG Junfeng, ZHANG Zhijing, GUO Jixun
Organization: Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University; School of Life Sciences, Northeast Normal University
Abstract: This study uses Leymus chinensis, a dominant perennial grass widely distributed in the eastern regions of the Eurasia grassland zone as a model to investigate the effect of warming on the factors including seed production, mass, germinability and subsequent seedling growth, so as to provide new information on new plant population establishment and find how the existing population is maintained in this region. There was a significant positive response in floret number and seed number per plant to warming. However, there were negative responses to warming in terms of the flowering plant number and seed number per unit area. Warming significantly decreased the proportion of light seeds, increased the proportion of heavy seeds, and led to a significant increase in the thousand seeds weight. Germination success and rate, together with the root: shoot ratio of light seeds was significantly reduced by warming, in contrast to the heavy seeds which did not seem to be affected by elevated temperatures. Finally, warming reduced the potential germinated seed number per square meter. Synthesis analysis indicated that warming had different effects on the seed production process in semi-arid regions depending on the season. There was a positive effect in high precipitation summers and cold springs, and a negative effect in low precipitation autumns. The reduction in the germinability of light seeds and the seed germination potential with increased temperature has implications for new population establishment. Furthermore, existing population maintenance that depends on the seeds is likely to be constrained by global warming and will have an effect on plant population dynamics in the eastern regions of the Eurasia grassland zone.�
Key words: ecology; temperate grassland; seed production; germination; seedling growth
发表期数: 2012年3月第5期
引用格式: 高嵩,王俊锋,张志静,等. 羊草种子生产、大小、萌发能力和幼苗生长对母体增温环境的响应[J]. 中国科技论文在线精品论文,2012,5(5):431-439.
 
0 评论数 0
暂无评论
友情链接