Studies On Conservation Biology Of Dysosma Versipelis (Hance) M.Cheng

Dysosma versipelis (Hance) M.Cheng is an important, medicinal ,perennial herb. It is also an endangered plant that is distributed only in China. Five populations of D. versipelis were sampled from both the middle and lower reaches of the Yangtze River Valley for conservation study. D. pleiantha, a congener of D. versipelis, was used as the outgroup for this study. It was sampled from one population in Zhejiang Province. The studies were carried out by life history analysis, breeding system analysis, morphological analysis, allozyme analysis and ISSR analysis. The results are as follows.1. The life history of D. versipelis lasts for eight months, from February to October. Flowering is from February to April. The growth rhythm of the JX population is the earliest and the SN population is the last, which is obviously related to the altitude of each population. The life history of the EM population is unusual in that there are evergreen plants throughout the year because new plants will grow out until October.2. The stamens and pistil of D. versipelis mature before the flowers open, which shows that Dysosma versipelis may be autogamous. D. versipelis produce few fruits. Ovaries of D. versipelis seldom develop in nature, but will develop after being pollinated with pollen of another plant. All these factors indicate that autogamy is a poor strategy, leading to a reproductive barrier. D. versipelis also reproduces by vegetative progagation with rhizomes.3. The morphological character analysis of D. versipeli indicates that there are some differences among populations: the color of stem bottom is purple in the SN population and the TP population, but green in the JX population and the EM population ; both colors have been found in the TT population. Leaves of all populations except TP are green; only TP plants are colored. Pubescence is found only in the SN population on the surface of veins.D. versipeli and D. pleiantha differ not only in location of flowers, but also in the colorand shape of their petals: the petals of D. versipeli are purple and rough, whereas D. pleiantha has red and smooth petals.4. The level of genetic diversity within D. versipelis is low and the level of genetic differentiation among populations is high. The results of allozyme analysis is P =15. 54%, ,4=1.16, Fst=0. 468. The results of ISSR analysis is PPB=66.67%, h=0.2089, i=0.3172. Genetic diversity of ISSR is higher than that of allozymes.Genetic diversity of D. pleiantha is higher than D. versipelis. The result of allozyme is P =55. 6%, the result of ISSR is ppb=70.83 %,h=0.2383, i=0.3576.5. The tree based on the results of allozyme and ISSR data shows that D. pleiantha is on one branch distinguished from all populations of D. versipelis. This indicates that there has been distinct genetic differentiation between the two species.6. It is suggested that there are three factors related to the endangered status of D. versipelis. The first is human disturbance and destruction of habitats. The second is the low capability of breeding. The last is its low level of genetic diversity.7. It is proposed that the habitats of D. versipelis should be protected. Meanwhile, numbers can be increased by artificial propagation. Most populations should be sampled so as to retain as much of the genetic diversity of the species in ex situ preservation as possible.