DNA Genetic Diversity Of Genus Epimedium L. And Its Phylogeny

Barrenwort, a plant in genus Epimedium (Berberidaceae), comprises about 55 species in the world. Among them, 80% of barrenwort species are native to China. Guizhou, Sichuan, and Hubei are the variational centre of genus Epimedium L. In this study, 18 species of Epimedium natived to Sichuan and Guizhou etc. are studied by means of morphology, interspecific hybridization, RAPD, PCR-RFLP, in order to provide some new clues on phylogeny, taxonomy, genetic diversity, and modernization of Chinese traditional medicine.Morphological analysis showed that most species have continuous variation of morphological characteristics, leading to many difficulties of identification. It is the first time to discover that: The length of flower calcar shorter than the inner sepal may be controlled by partly-dominant gene, and the leaf shape of hybrid F1 progenies are the middle type between the parents. At the same time, the colour of the inner sepal and flower calcar in E. acuminatum is dominant.The results of reproductive biology suggested that Epimedium is largely a self-incompatible cross-pollination plant by anemophily. Although most of interspecific crosses can produce normal seeds, there are great variation of the interspecific crossability. E. wushanense and E. lishihchemii are widely affinitive pollen receptors, fit for female parent on interspecific hybridization. E. myrianthum is widely affinitive pollen donors, fit for male parent on interspecific hybridization. E. acuminatum and E. pubescense are widely affinitive pollen donor and receptor, fit for female or male parent on interspecific hybridization. These results are useful on interspecific hybridization, variety improvement, and their phylogeny study on Epimedium.On the basis of RAPD and PCR-RFLP, the RAPD fingerprints and the phylogenic map of Epimedium species were established. It is clear that there are some relationships of the genetic property with its geographic distribution. These results provide new data for the taxonomy, species identification, phylogeny of Epimedium.All above results showed that Chinese species of Epimedium can be grouped into the large-flower type and the small-flower type and reclassified according to the definition of biological species as follow: (1)certain biological species: E. davidii,E. pauciflorum,E. chlorandrum,E. acuminatum in the large-flower type of barrenwort species and E. ecalcaratum, E. myrianthum,E. sagittatum,E. pubescense in the small-flower type of barrenwort species. (2) incorporated species: E. simplicifolium into E. acuminatum, E. luodianense into E. leptorrhizum,E.lishihchemii into E. wushanense, E. pudingense into E. sagittatum. (3)uncertain species: The two E. acuminatum populations, AC5 and AC6 native to Sichuan, may be the natural hybrid F1 progenies of E. acuminatum and E. chlorandrum. E. dolichostemon may be the natural hybrid F1 progenies of E. acuminatum and one species in the small-flower species. And E. shuichengense may be natural hybrid F1 progenies between the large-flower species and the small-flower species. It need further study whether these species are reclassified as biological species.