Genetic Diversity And Conservation Of The Endangered Species Opisthopappus Shih Plant

Opisthopappus Shih within the family Asteraceae,a rareendangered species, comprises two species,O.taihangensis (Ling）Shih and O.longilobus Shih .which is a perennial herb endemic toTaihang Mountain. The distribution very norrow in the junction ofthree province Shanxi,Henan and Hebei. Many grows in themountain slopes and the crevices of cliffs，which place’s altitudeclose to 1000m.Becouse of its speciality hardy,shade-tolerance,drought-tolerance,suitable for domsetic and garden cultural，hasvery high ornamental and economic valie.To investigate themechanism of endangering and to make corresponding steps forOpisthopappus Shih protection, we studied the genetic diversityand genetic structure of 13 population of Opisthopappus Shih inTaihang mountain,based on cpSSR and SRAP molecular marker .Theresults are as follows:cpSSR molecular marker shows that Opisthopappus Shihexhibits comparatively high genetic diversity at species level compair with population level.At species level,the geneticdiversity(ne=1.267；I=0.087；He=0.163；Ht=0.156).At populationlevel,the genetic diversity(ne=1.033；I=0.042；He=0.024；PPB=15.39%)is lower than the average level of other dicotyledonsits Population genetie diversity has been effeeted by habitatfragmentation and human activitie.It was revealed that total number of haplotypes was 13 in thepopulation of Opisthopappus Shih by cpSSR marker.It is showedfrom the that It was showed from statistical result that haplotypeH1 exist in all populations,and it is account for 75.8% as the maintype,and the Sharing rate was highest.The eight haplotype( H3、H7-H13) only existed in a special population so it is called thespecial haplotype of the population. The heterozygosity ofhaplotype in four population of O. longilobus Shih was higher thannine population of O. taihangensis (Ling）Shih,and showed that thedifferentiation between population in O. longilobus Shih was richerthan O. taihangensis (Ling）Shih.SRAP molecular marker shows that Opisthopappus Shih Atspecies level the genetic diversity (ne=1.620，na=1.862，I=0.486，H=0.397，PPB=63.72%).At population level the diversity (ne=1.329，na=1.472，I=0.148，H=0.188，PPB=40.69%).Same to show thatOpisthopappus Shih exhibits comparatively high genetic diversity at species level compair with population level。The result of low level genetic structure existed among thepopulation revealed by cpSSR and SRAP marker of OpisthopappusShih. AMOVA analyse show that 89% of genetic diversity existedamong the population，11% of genetic diversity existed in thepopulation The Nm between population based on cpSSR is 0.123based on SRAP is 0.36，The index of Nm<1，show that the genesflow was obstructed.Large differentiation existde inpopulation.Genes flow could not resist the populationdifferentiation caused by genetic drift.Above all We propose to rely mainly on in situ conservation，supplemented by ex situ conservatio，all individuals of naturalpopulation should be protected and the distribution region ofOpisthopappus Shih should be given sufficient attention and effortof protection.