Phylogeny and divergence of Chinese Angiopteridaceae based on chloroplast DNA sequence data (rbcL and trnL-F)

Marattioid ferns are an ancient lineage of primitive vascular plants that first appeared in the middle Carboniferous. Extant members are almost exclusively restricted to tropical regions, and the spe- cies-rich family Angiopteridaceae are limited in their distribution to the eastern hemisphere; relation- ships within the group are currently vague. Here the phylogenetic relationship between Angiopteris Hoffm. and Archangiopteris Christ et Gies. was evaluated based on the sequence analysis of chloro- plast rbcL gene and trnL-F intergenic spacer with MEGA2 and MrBayes v3.0b4. On the basis of the phy- logenetic pattern and fossil record, we further estimated the divergence time for the two genera. The phy- logenetic trees revealed that all species of Angiopteris and Archangiopteris in this study formed a monophyletic group with strong statistical support, but the relationship between the two genera re- mained unresolved based on individual sequence analysis. On the other hand, the sequence analyses of combined data set revealed that Archangiopteris species diverged first, indicating that Archangiop- teris may not be a direct derivative as traditionally assumed. The clade of Angiopteris and Archan- giopteris appears to have diversified in the late Oligocene (≈26 Ma) based on the molecular estimate. Thus, the evolutionary history of extant Angiopteris and Archangiopteris has been characterized by ancient origin and recent diversification, and these groups are not relic and endangered lineages as traditionally considered.

From the Himalayan region or the Malay Archipelago:Molecular dating to trace the origin of a fern genus Phymatopteris(Polypodiaceae)

Phymatopteris Pic.Serm.,a derived polypodiaceous fern,is one of the many fern genera that still suffer from nomenclatural confusion.Its generic circumscription and phylogenetic relationships with other selligueoid ferns have been controversial,and its geographic origin,whether in the Himalayan region of continental Asia or in Malay Archipelago,is still unknown.A phylogeny of all selligueoid ferns based on 4 cpDNA(rbcL,trnL-F,rps4 and rps4-trnS) regions indicates that Phymatopteris is not monophyletic.Phymatopteris species are distributed in 5 well-supported clades that can be distinguished with frond-shape and frond-margin characters.All early-divergent species are from the Malaysian Archipelago,while the remaining species are all from the Himalayan region and form a recently diverged group that is largely unresolved,most likely having resulted from an explosive radiation.Divergence-time estimation suggests that the first diversification of selligueoid ferns occurred at ca.27 Ma in the Malaysian Archipelago,followed by migration into the Himalayan region around 20 Ma.The radiation of the Himalayan species occurred mostly within the last 20 million years,within the period of recent major uplifts of the Qinghai-Tibetan Plateau(between the early Miocene and the Pleistocene) and late-Cenozoic global cooling.Our evidence leads us to propose that the Malaysian Archipelago is the ancestral area for Phymatopteris.

Factors acting on the distribution region of Carlemanniaceae:Rainfall,temperatureand the plants' biological characteristics

在东亚和热带亚洲的家庭 Carlemanniaceae，包括二个类， Carlemannia 和 Silvianthus，主要沿着 Himalaya 山的南部的脚和云南高原的西方、南部的接口被散布。为 Carlemannia 四角形的主要繁殖过程一被授粉实验在这个工作作为自花受粉验证。为两 C 的种子的萌芽率。当种子在二个月以后是镇定的时， and Silvianthus bracteatus 能百分之百到达的四角形，当率减少了到 25% 时当收集发生在上一年时。种子没有休眠阶段，这被发现，并且他们的种子银行具有短暂土壤类型。在地观察，为水果的裂开地位证明他们的种子不能被囊为疏开有效地逐出。在从年分析温度和降雨数据以后 1971～2000 ，它被看那年度降雨，最低吝啬的月刊一年里的温度，和在一个月内的极端最低温度在 Carlemanniaceae 的分发范围上有大效果，当吝啬的年度温度有更小的效果时。Carlemanniaceae 的狭窄的分发范围被多重因素影响，例如短花粉疏开距离和短暂土壤种子银行。Carlemanniaceae 的人口尺寸被降雨的水平，不是由任何单个变量容易也影响。