Matsuo Ayumi, Tomimatsu Hiroshi, Suzuki Jun-Ichirou, Saitoh Tomoyuki, Shibata Shozo, Makita Akifumi, Suyama Yoshihisa
Field Science Center, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi 989-6711, Japan Faculty of Bioresource Sciences, Akita Prefectural University, Akita 010-0195, Japan
Department of Biology, Yamagata University, Yamagata 990-8560, Japan.
Ann Bot. 2014 Oct;114(5):1035-41. doi: 10.1093/aob/mcu176. Epub 2014 Sep 15.
Although many studies have reported that clonal growth interferes with sexual reproduction as a result of geitonogamous self-pollination and inbreeding depression, the mating costs of clonal growth are expected to be reduced when genets are spatially intermingled with others. This study examined how clonal growth affects both female and male reproductive success by studying a population of a mass-flowering plant, Sasa veitchii var. hirsuta, with a high degree of clonal intermingling.
In a 10 × 10 m plot, genets were discriminated based on the multilocus genotypes of 11 nuclear microsatellite loci. The relationships between genet size and the components of reproductive success were then investigated. Male siring success and female and male selfing rates were assessed using paternity analysis.
A total of 111 genets were spatially well intermingled with others. In contrast to previous studies with species forming distinct monoclonal patches, seed production linearly increased with genet size. While male siring success was a decelerating function of genet size, selfing rates were relatively low and not related to genet size.
The results, in conjunction with previous studies, emphasize the role of the spatial arrangement of genets on both the quantity and quality of offpsring, and suggest that an intermingled distribution of genets can reduce the mating costs of clonal growth and enhance overall fitness, particularly female fitness.
尽管许多研究报告称，由于同株异花授粉和近亲繁殖衰退，克隆生长会干扰有性繁殖，但当无性系植株在空间上与其他植株混合生长时，克隆生长的交配成本预计会降低。本研究通过对一种大量开花植物——毛枝赤竹（Sasa veitchii var. hirsuta）的种群进行研究，探讨了克隆生长如何影响雌雄两性的繁殖成功率，该种群具有高度的克隆混合现象。
在一个10×10米的样地中，根据11个核微卫星位点的多位点基因型来区分无性系植株。然后研究无性系植株大小与繁殖成功各组成部分之间的关系。使用亲权分析评估雄性授精成功率以及雌雄两性的自交率。
总共111个无性系植株在空间上与其他植株充分混合。与之前对形成明显单克隆斑块的物种的研究不同，种子产量随无性系植株大小呈线性增加。虽然雄性授精成功率是无性系植株大小的递减函数，但自交率相对较低且与无性系植株大小无关。
这些结果与之前的研究共同强调了无性系植株空间排列对后代数量和质量的作用，并表明无性系植株的混合分布可以降低克隆生长的交配成本并提高整体适合度，尤其是雌性适合度。
