斑块大小对油松授粉期花粉量以及结实的影响  

Effect of patch size on available pollen amount during reproductive season and on seed production of Chinese pine,Pinus tabulaeformis

作　　者：鲍蕾[1] 杨明博[1] 王红芳[1] 

机构地区：[1]北京师范大学生命科学学院,北京100875

出　　处：《生态科学》2015年第6期1-8,共8页Ecological Science

基　　金：国家自然科学基金青年基金项目(31200328)

摘　　要：景观破碎化随着人类活动的增强而日益严重,因此理解其对物种的影响程度显得尤为重要。选取北京城市种植的14个不同大小和隔离度的油松斑块,通过斑块内花粉量观察、结实量分析并佐以自交率的分析,回答斑块大小和隔离度对花粉量的影响,以及花粉量对结实和自交率的影响。研究发现花粉量随着斑块增大而显著升高,但与隔离度没有显著关系。花粉量大的斑块中每个球果得到的总种子数和饱籽率趋于更多。5个斑块的自交率分析表明大斑块具有很低的自交率,而小斑块的自交率取决于花粉量,花粉量大的斑块具有较高的自交率,而花粉量小的斑块以异交以及斑块间花粉流为主。研究表明小斑快具有花粉量限制和自交率升高的双重风险,并因此导致繁殖适合度的下降。在森林物种保护和管理中,这些小斑块值得特殊关注。The problem of landscape fragmentation is enhanced with human activity. Hence, it is important to understand the influence of landscape fragmentation on the fate of species. In this study, we selected 14 planted Chinese pine （Pinus tabulaeformis） patches with different patch size and isolation between patches. To understand the effect of patch size and isolation on pollen dynamics during reproductive season, the amount of available Chinese pine pollen was measured and compared between patches. In addition, seed production and mating pattern were measured to analyze the effect of available pollen within patch on mating success. The results revealed that the available pollen within patch was increased significantly with patch size, but not the isolation. Moreover, more available pollen within patch tended to have more seeds per cone and more viable seeds per cone. Mating pattern analysis of five patches indicated extreme low selfing rate in big patches, while the selfing rate in small patch depended on the available pollen within patch. More available pollen in small patch resulted in higher selfing rate, while small patches with less pollen were dominated with outcrossing mating and pollen emmigration from other patches. Our study revealed double risk of reduced reproductive fitness in small patches due to pollen restriction and/or increasing selfing rate, which deserved special focus in forest management and conservation.

关 键 词：景观破碎化 油松 斑块花粉量 结实 父本分析 叶绿体微卫星 

分 类 号：Q948[生物学—植物学]