The Study On Genetic Diversity Of Paeonia Qiui Native To Xunyang

Paeonia qiui is an important ornamental flower in China and it belongs to one member of Paeonia Sect.Moutan,Paeoniaceae.All the wild species of peony trees are distributed in the territory of China.Among them,the ecological environment of P.qiui has suffered various degrees of damage.Its population quantity and distribution area are gradually diminishing,and it is quite endangered currently.Therefore,the research on genetic diversity of P.qiui is fairly essential for protection of wild germplasm resources.Xunyang,located in the qinling mountain area,there are the wild populations of P.qiui.This study 178 half wild and wild strain and P.ostii for material,In this experiment,the phenotypic traits analysis and molecular marker technology were used to study genetic diversity of different wild populations and a Xunyang population under semi-artificial habitat of P.qiui.The fatty acid content of seed oils from the plants of various populations was measured.The main results were shown as follows:1.The clustering results of 33 phenotypic trait indexes indicated that all materials of peony trees were divided into three groups.The first group included 2 ‘Feng Dan' plants as control.The second group consisted of various populations of wild P.qiui.The third group was mainly the P.qiui population under Xunyang semi-artificial habitat and classified into 4 subgroups.2.The results by ISSR molecular markers suggested that the range of plant genetic diversity(H)of the population under Xunyang semi-artificial habitat was 0.013~0.5,with average value being 0.288.Number of Effective alleles(Ne)was 1.013~1.999,with an average of 1.591.Allele frequency(Pi)was 0.035~0.622,with a mean of 0.426.Shannon-Wiener index(I)was 0.039~0.649,with an average of 0.493.Polymorphism loci percentage of plants from P.qiui population was over 50%,and PIC value was 0.403.According to the molecular level,genetic variation of this population was abundant compared with other wild populations,suggesting that the intraspecific genetic diversity of P.qiui was quite variable.From the molecular level shows that compared with other wild population,the population genetic variation are abundant.3.The clustering results of stripe data from ISSR molecular markers demonstrated that GS value of P.qiui populations was 0.58~0.94.Specifically,GS value between Xunyang semi-artificial population and Xunyang Yangshan wild population was 0.77,indicating a close genetic relationship between the two populations.At the genetic similarity coefficient of 0.65,163 P.qiui materials tested were divided into 4 groups.The first group included 2 ‘Feng Dan' plants as control.The second group consisted of various populations of wild P.qiui,including Baokang wild population,Shennongjia wild population,and Xunyang Bailiu wild population.The third group included Xunyang Yangshan wild P.qiui population and 97 population plants from semi-artificial habitat,and phenotypic consistency within this group was relatively high.The fourth group was composed of the majority of materials from 65 collecting areas.The samples of this group were obviously different from other population plants and wild species in the aspects of leaf shape and plant height.For example,the leaf shapes of plants in the fourth group were mainly lanceolate.In the terms of geographical location,the straight-line distance between Xunyang Yangshan wild population and Xunyang semi-artificial habitat population was shortest.Thus,we concluded that Xunyang Yangshan wild population was involved in the formation of semi-artificial habitat population.4.Total content of five main fatty acids in seed oils of P.qiui from various populations was significantly different.The maximum total content of five main fatty acids from the plants of Xunyang Yangshan wild population was 49.9g/100 g,while the lowest total content of five main fatty acids from the plants of Hubei Baokang wild population was 47.03g/100 g.Total content of five main fatty acids from other plants ranged from 47.85g~49.22g/100 g.Total fatty acid content of Hubei Baokang wild population and Shennongjia wild population was lower than other materials.Total fatty acid content of plants from Yangshan,Bailiu,and semi-artificial habitat populations in Xunyang had weak differences.Total content of five main fatty acids from three plant materials in the same population didn't have significant differences.Moreover,content of each fatty acid component didn't have obvious changes.