The evaluation of the genetic diversity of breeding populations and construction of a core collection of Cunninghamia lanceolata
[Objective]A core collection of germplasm construction and assessing on the dynamic evolution of genetic diversity over generations of Chinese fir was studied in Hunan province in order to provide theoretical basis and material support for the next generation genetic improvement and germplasm utilization.[Method]A total of 137 samples from 3 different generations of Chinese fir breeding population were displayed substantial genetic diversity analyzed by PCR with 21 polymorphic SSR primers.The Gene Marker software was used for genotyping,and GenAlex software was employed to estimate population genetic parameters,assess Hardy-Weinberg balance,and execute molecular variance analysis,GENEPOP software for frequency of invalid alleles estimation;FSTAT software for genetic distance evaluation between pairs of breeding populations;STRUCTURE software for genetic structure of populations analysis;Darwin software for Neighbor-Joining(NJ)phylogeny construction;and Core-hunter software for construction of core collection;and t-test and principal coordinates analysis(PCoA)were used to verify the validity and representativeness of the core collection.[Result]The whole breeding populations of Hunan province Chinese fir displayed substantial genetic diversity(HO=0.541,HE=0.630),and three breeding populations of different generations showed heterozygotes loss,which highly significant difference or significantly difference deviated from Hardy-Weinberg equilibrium;the germplasm in the whole breeding population was clustered into two groups,genetic relationships exist among the collection;genetic differentiation among different breeding populations was minimal(FST between 0.01 and 0.014),the core collection constructed with 40%sampling ratio had 14.55%homology and 100%allelic coverage,the genetic parameters of the population were not significantly different from that of the whole breeding population,and the core collection are evenly distributed in the principal coordinates of reserved collection.[Conclusion]The multi-generation genetic improvement strategy of Chinese fir in Hunan province is scientific and rational.High genetic diversity has been maintained across all breeding populations generations without decline through the genetic improvement process.The constructed 55 core collection retain all alleles of the whole breeding population,effectively limit the homology and meet the requirements of the construction of biological core collection,which can supply superior germplasm materials for germplasm innovation,efficient resource utilization and high-generation seed orchard construction of Chinese fir in Hunan province.
万方数据
维普
