|其他摘要||Ellisiophyllum pinnatum is the only species in the Genus Ellisiophyllum. The distribution range of the genus covers India, Bhutan, Nepal, Japan, Philippines, Papua New Guinea and China. In China, it distributes in Yunnan, western Sichuan, Chongqing, southeastern Guizhou, western Guangxi, southern Xizang, southern Gansu, southern Hebei, western Hubei and Taiwan. Thorough study on its phylogeography and genetic diversity were made based on preliminary study on biological habits and preliminary observation on pollination of E. pinnatum, and genetic diversity, genetic structure at population level and the factors influencing them were revealed. The comprehensive studies, phylogeographical analysis based on DNA sequence and genetic diversity analysis based on molecular marker (AFLP), were also carried out on E. pinnatum. Finally, the correlation between the distribution of some associated species including E. pinnatum and Yunnan ancient planation surface was briefly discussed here. The main results were as follows:
1. Biological habits and preliminary observation on pollination
E. pinnatum is perennial herb, stoloniferous, distributed from alt. 850 m to 2800 m. The results of anthecology of SL(Shilin) population showed that E. pinnatum was pollinated by insects and wind. Both self-pollination and cross-pollination can bear fruit. What’s more, it also can bear fruit without any pollinators. The main insects recorded as flower-visitors were from the Order Diptera and the Order Hymenoptera. The anthesis of single flower, pistil and stamen were 3-4 d, 2.5-3.5 d, and 1-2 d respectively.
Based on trnS-trnG and trnT-trnL sequences data of 15 populations of E. pinnatum, the study of phylogeography revealed that E. pinnatum had high genetic diversity (hT=0.971) and high genetic differentiation (GST=1) among populations, with no differentiation within population. There were 13 haplotypes in 15 populations. WS, FM and LS shared one haplotype while the others had their own unique haplotype, which indicated that the haplotypes were highly structured. Meanwhile, the geographic distance between LC population and XZ population was far whereas the differentiation in haplotype evolution was insignificant. The following reasons are proposed to explain the phylogeographic pattern: 1) E. pinnatum is an ancient species with long evolutional history; 2) the pattern of seed dispersion was inefficient; 3) random factors likely contributed to long distance dispersion.
3. Genetic analysis based on molecular marker (AFLP)
Amplified Fragment Length Polymorphism (AFLP) analysis of 147 individuals from 15 populations showed that this species had high genetic diversity. Long evolutional history and wide distribution might make important contribution to its high genetic diversity. E. pinnatum was highly differentiated with GST=0.6656. The main reasons for the high differentiation were as follows: 1) population isolation caused by long distance and topographic condition; 2) important role of self-cross in its breeding system; 3) habitat fragmentation resulting from the climatic vicissitudes of the Quaternary period.
4. Correlation between the distribution of E. pinnatum with related species and Yunnan Acient Planation Surface
Based on the principle of Eco-physiology, the distribution altitude of plants will decline with the increase of latitude. However, the distribution of many species in Yunnan is inconsistent with the principle. Their distribution in Yunan is similar to the distribution of Yunnan Ancient Planation Surface. That is to say, there is a positive correlation between the altitude and the latitude of its distribution. But as the range of the species exceed the Yunnan plateau, its distribution is still consistent with the principle of Eco-physiology, such as the E. pinnatum and some spices of Scrophulariaceae. This indicated that the species’ distribution in Yunnan had been extremely influenced by the Yunnan Ancient Planation Surface. At last, the origin of the characteristic elements should be earlier than the uplift of Yunnan Ancient Planation Surface according to the principle of formation of the distribution area. More knowledge about the distribution of the E. pinnatum is needed to get the correlation of the E. pinnatum and the Yunnan Ancient Planation Surface.|