Studies On Genetic Diversity And Niche Of Community Dominant Species Of Goodyera Schlechtendaliana Rchb.f.

Goodyera schlechtendaliana Rchb.f.,a perennial herb of the genus Goodyera in Orchidaceae lives under the evengreen broad-leaves of thick humus in hillside and channel.The plant is used in the Chinese folk medicine as herbal drug against fever,pain,snake-bites and lung disease since time immemorial.Being ornamental,G.schleehtendaliana Rchb.f.has also aesthetic value.The present study is mainly deals with the plant genetic diversity and niche.The results collected for G schlechtendaliana Rchb.f.has been analyzed to develop a database for further study The major findings are as follows:1.The genetic variations of seven populations of G schlechtendaliana Rchb.f.was compared by using RAPD as below:a)Twelve primers were selected from 50 random primers amplified 160 fragments in 93 species of G schlechtendaliana Rchb.f.,where 159 segments were polymorphic.The rate of polymorphism was 99.38%;the ratio of the polymorphic loci of the single primer was from 0.626～1.000.It showed that the level of Genetic Diversity of G schlechtendaliana Rchb.f.is higher.b)According to the results of Nei's index,the genetic diversity within a population and among the populations was 69.53%and 30.47%respectively.The Shannon index was 59.69%and 40.31%. The findings showed that G schlechtendaliana Rchb.f.possessed a higher level of genetic diversity within the population than that among populations.c)The result of PopGen32 clustering showed a clustered pattern of population of this species, strictly following their geographical distance,which indicates that certain ecological factors could affect genetic diversity.2.In this paper,species niche and the relationships among G.schlechtendaliana Rchb.f.and other species;relationship between G.schlechtendaliana Rchb.f.communities and their environment was studied.The result showed the niche breadth of G.schlechtendaliana Rchb.f.was 0.9520,which indicates the species is widely distributed.G.schlechtendaliana Rchb.f.also found to have high niche,overlapping with other dominant species in the experimental communities,which showed that these dominant species have highly similar in their requirements to various resources.The more the niche breadth of the populations,the greater the ability to use resources.The higher value of the niche overlapping,the more similar the ecological characters and the greater the similarity of using resources.In other words,G schlechtendaliana Rchb.f.can coexist nicely with other dominant species in the studied communities and can maintain high species diversity as well as stabile relationship.3.The threatening factors were analyzed and several measures for effective measures for conservation of the species were also proposed,including in situ & ex situ conservation by transplanting plants in botanical garden,tissue culture laboratory etc.In order to protect this endangered species,further studies on reproduction and multiplication should be made. Simultaneously,launching of extension programme including active education and propaganda may be initiated.