Studies On Conservation Genetic Of Geodorum Eulophioides

Geodorum eulophioides (Orchidaceae), an endangered species endemic to Yachang Orhid Nature Reserve in Guangxi Province G. eulophioides has already become a vulnerable species due to the destruction of habitats.Using SSR markers, the genetic diversity and population differentiation in 4 natural populations of G. eulophioides from Yachang Orhid Nature Reserve were analyzed to explore the genetic diversity and endangered mechanism at molecular level and to formulate conservation strategy. The main results are as follows:1.18 polymorphic microsatellite primers were obtained by using the method of enrichment through magnetic beads.The alleles in each locus ranged from 2 to 10, the average allele in each locus was 5.The observed heterozygosity and expected heterozygosity in each locus ranged from 0 to 1 and from 0.3551 to 0.8279, with a average 0.732 and 0.5957, respectively. The test for Hardy-Weinberg equilibrium showed that all loci departed from the equilibrium,and the test for linkage disequilibrium between primers indicated that the primers weren’t linked to each other.Based on the above results,the 18 primers could be used to analysis the population genetic structure of G. eulophioides.The obtained primers developed for G. eulophioides could get 83.33% and 100% amplification rate in its sibling species G.dendiflorum and G.recurvum, respectively,these loci can be used to analysis the genetic structure of these species.2.84 individuals from 4 populations were amplified using the polymorphic primers,at the species level the observed heterozygosity and expected heterozygosity were 0.7797 and 0.6968,but at the population level the observed heterozygosity and expected heterozygosity were 0.7834 and 0.6519, which indicated the genetic variations were higher at the spices level rather than population level, yc 3 population showed the highest level of genetic variation was found.For the future conservation of G. eulophioides, the population with a relatively high genetic diversity should be paid more attention and priority.The genetic differention (Fst) between population were 0.1116,which indicated 11.16% of the total genetic diversity resided among populations and the main genetic diversity resided in populations.3. The SSR analysis indicated a relatively high genetic diversity in G. eulophioides, and the genetical variations were higher at the spices level rather than population level. The gene flow among the populations by SSR markers analysis were 1.9895, which demonstrated a moderate level of gene flow among populations in G. eulophioides.The habitat of G. eulophioides was destroyed heavily in recent years, and the population was in decline.But the loss of genetic diversity due to the habitat destruction and population decline didn’t show timely in a short time, the remanet populations still holded a high genetic diversity, the results we get at present were historical diversity and gene flow, not contemporary.4. The reason causing the species endangering probably are habitat destruction, pollinator affected by human activities and low ability of recruitment.Conservation strategies were put forward based on them, such as strengthening law management, protecting pollinator, strengthening habitat restoration, ex-situ protection.