GENETIC STRUCTURE AND BREEDING SYSTEM OF A RARE UNDERSTORY HERB, DYSOSMA VERSIPELLIS (BERBERIDACEAE), FROM TEMPERATE DECIDUOUS FORESTS IN CHINA
GENETIC STRUCTURE AND BREEDING SYSTEM OF A RARE UNDERSTORY HERB, DYSOSMA VERSIPELLIS (BERBERIDACEAE), FROM TEMPERATE DECIDUOUS FORESTS IN CHINA
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DOI：
10.3732/ajb.0900160
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发表时间：
2010-01-01
影响因子：
3
通讯作者：
Comes, Hans Peter
中科院分区：
文献类型：
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作者：
Guan, Bi-Cai;Fu, Cheng-Xing;Comes, Hans Peter
为了评价第四纪避难所隔离在东亚温带森林生物群异地(初始)物种形成中的作用，我们对八角莲的扩增片段长度多态(AFLP)和繁育系统进行了分析。研究表明，该属植物大多自交不亲和，在种群水平上高度分化和退化(如Phi(St)=0.572/H-E=0.083)，花粉-种子迁移率较低(r约为4.0.)。后一种结果可能反映了低种子传播器中的花粉流动有限，该传播器假想的“嗜腐肌型”花朵经历了稀少、低效且可能是由小天牛进行的专门异花授粉，而不是之前假设的腐肉苍蝇。结果表明，粉锈菌的座果受到强烈的花粉限制。我们的AFLP数据支持西部和中东部种群之间基因流动长期停止的假设，这与之前的叶绿体DNA数据一致。这种系统地理格局支持四川盆地作为分隔中国-喜马拉雅森林亚国和中日森林亚国的植物区系边界的作用。我们的浮萍的遗传数据还表明，该盆地西部和东部的温带落叶森林元素对第四纪气候变化的反应不同，这可能已经触发或正在导致异地(初始)物种形成。
To evaluate the role of Quaternary refugial isolation in allopatric (incipient) speciation of East Asian temperate forest biotas, we analyzed amplified fragment length polymorphisms (AFLPs) and the breeding system in Dysosma versipellis. The study revealed that D. versipellis is mostly self-incompatible, genetically highly subdivided and depauperate at the population level (e.g., Phi(ST) = 0.572/H-E = 0.083), and characterized by a low pollen-to-seed migration ratio (r approximate to 4.0). The latter outcome likely reflects limited pollen flow in a low-seed disperser whose hypothesized "sapromyophilous" flowers undergo scarce, inefficient, and likely specialized cross-pollination by small Anoplodera beetles, rather than carrion flies as assumed previously. In consequence, fruit set in D. versipellis was strongly pollen-limited. Our AFLP data support the hypothesis of a long-standing cessation of gene flow between western and central eastern populations, consistent with previous chloroplast DNA data. This phylogeographic pattern supports the role of the Sichuan Basin as a floristic boundary separating the Sino-Himalayan vs. Sino-Japanese Forest subkingdoms. Our genetic data of D. versipellis also imply that temperate deciduous forest elements to the west and the east of this basin responded differently to Quaternary climate change, which may have triggered or is leading to allopatric (incipient) speciation.