Floral distribution, clonal structure, and their effects on pollination success in a self-incompatible Convallaria keiskei population in northern Japan
Floral distribution, clonal structure, and their effects on pollination success in a self-incompatible Convallaria keiskei population in northern Japan
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DOI：
10.1007/s11258-006-9173-9
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发表时间：
2007-04-01
期刊：
影响因子：
1.7
通讯作者：
Ohara, Masashi
中科院分区：
文献类型：
--
作者：
Araki, Kiwako;Shimatani, Kenichiro;Ohara, Masashi
在植物物种中，当无性系生长产生斑片结构和开花分株聚集时，有助于繁殖成功的花粉量通常受传粉者效率和婚属制的调节。种群空间结构可能影响繁殖成功率。研究了日本北部一种昆虫传粉、自交不亲和无性系草本植物康伐兰（Convallaria keiskei）的无性系结构、分株空间分布及其对坐果的综合影响。在已建立的100 x 90 m研究地块中，每5 m网格点对1 m(2)样方的芽、花和果实数量进行计数。在所有有芽的样方中采集叶片样品进行同工酶分析。利用开花分株密度和基因型两个空间参数，构建了基于个体的坐果模型。共有236个样方含有芽，135个样方含有开花分株，表明该植物在整个样地的分布扩大，而芽、花和果实均呈聚类分布。282份样品的等位酶分析显示94个多位点基因型。最大的克隆延伸超过40米，而仅在一个样本中检测到56个基因型。几个大无性系和许多小无性系分布得很近。精细尺度空间模拟结果表明，不同基因型的邻近花数对坐果的影响大于本地基因或花的多样性，其中邻近花数的影响范围为14.5 m。这些结果表明，昆虫传粉媒介传播的亲和性花粉对香桐种群有性生殖有显著影响。因此，包括基因分布和分株克隆扩展在内的空间结构对传粉成功率有显著影响。
In plant species, when clonal growth produces a patchy structure and flowering ramets are clustered, the amount of pollen contributing to reproductive success is often regulated by pollinator efficiency and geitonogamy. The spatial population structure may influence reproductive success. We examined the clonal structure, the spatial ramet distribution, and their combined effects on fruit set in a natural population of the insect-pollinated, self-incompatible clonal herb, Convallaria keiskei, in northern Japan. The number of shoots, flowers, and fruits in 1-m(2) quadrats were counted at every 5 m grid point in an established 100 x 90-m study plot. From all the quadrats where shoots existed, leaf samples were collected for allozyme analysis. Using the two spatial parameters of flowering ramet densities and genotypes, we then constructed individual-based fruit-set models. A total of 236 quadrats contained shoots, and 135 contained flowering ramets, which indicated expanded distribution of this plant throughout the study plot, while shoots, flowers and fruits all showed clustering distributions. Allozyme analysis of 282 samples revealed 94 multilocus genotypes. The largest clone extended to more than 40 m, whereas 56 genotypes were detected in only one sample. Several large clones and many small clones were distributed close to each other. Fine-scale spatial modelling revealed that the neighbouring flower numbers of different genotypes, compared with local genet or flower diversity, more influenced fruit set, in which the range of the neighbour was 14.5 m. These findings indicate that the compatible pollen dispersed by insect pollinators has a significant effect on sexual reproduction, in this C. keiskei population. Consequently, the spatial structure, which includes both genet distribution and clonal expansion by ramets, had a significant effect on pollination success.