Genetic Diversity Analysis And Core Germplasm Construction Of Chinese Fir Populations In South Of Jiangxi

Cunninghamia lanceolata(Lamb.)Hook.is a very important fast-growing timber species in southern China.It is widely distributed in the subtropical regions of China's Qinling and Huaihe Rivers.Due to long-term natural selection and artificial selection,as well as obvious differences in climate,soil and landform in the distribution area,Chinese fir has different genetic phenotypic traits and different requirements for ecological environment.,such as red heartwood Chinese fir in the Luoxiao Mountains and the southwestern mountains of Jiangxi.Red heartwood Chinese fir is named after its chestnut-brown color and high ratio.It is a kind of Chinese fir germplasm resource with excellent material properties.The main results are as follows:(1)The genetic diversity of 174 materials from 11 Chinese fir populations in southern Jiangxi was analyzed by 24 SSR polymorphic primers.The results showed that the average allele number(Na),effective allele number(Ne)and Shannon's information index(I)of 11 Chinese fir populations in southern Jiangxi were 3.061,2.164 and 0.841,respectively.The genetic similarity coefficients among populations ranged from 0.760 to 0.948,with an average of 0.870.This indicates that the population of Cunninghamia lanceolata in southern Jiangxi has high genetic diversity.(2)Based on the data of heartwood red heart traits,43 Core Germplasms(24.7%)were selected from 174 samples of Cunninghamia lanceolata.The results of t-test of genetic diversity index of heartwood red heart traits showed that the primary core germplasm could better represent the genetic variation range of the initial red heart traits.(3)According to the results of SSR molecular markers,the method of "SM genetic distance + UPGMA clustering multiple clustering + site priority sampling" was used to construct the core germplasm of 174 initial provenance resources of Cunninghamia lanceolata,obtained 20 copies.The core collection of Chinese fir germplasm accounts for11.5% of the total.Compared with the initial germplasm,the core germplasm retained all the alleles of the initial germplasm,and the t-test results of each genetic parameter indicated that the core germplasm could better represent the initial germplasm.(4)Based on the red heart traits and SSR molecular markers of Chinese fir heartwood,the core collection of Cunninghamia lanceolata in southern Jiangxi containing 60 Chinese fir cultivars was constructed,accounting for 34.4% of the total.The constructed core germplasm can better represent the initial germplasm,achieve the effect on the phenotypic and genetic diversity preservation of the initial germplasm,and provide basic data and technical support for the construction of the ex situ conservation pool.