Construction of a core collection of Cunninghamialanceolata in southern Jiangxi Province based on phenotypic traits and SSR markers

<bold>Objective</bold> The core germplasm of <italic>Cunninghamia lanceolata</italic> in southern Jiangxi was constructed based on phenotypic traits and SSR markers，laying a foundation for its effective management and utilization in subsequent studies. <bold>Method</bold> Phenotypic traits were investigated in 212 germplasms of <italic>C</italic>. <italic>lanceolata</italic> in southern Jiangxi Province，including the tree height，the diameter at breast height，individual tree volume，heartwood rate，wood basic density，and heartwood color，and the genetic diversity was analyzed by SSR markers.Based on the data of phenotypic traits and SSR markers，a core collection was constructed using allele number maximization strategy in conjunction with the principles of extreme phenotype and rare allele prioritization based on the data of phenotypic traits and SSR markers.Furthermore，the representativeness of the core collection was accessed by the <italic>t</italic>-test and principal coordinate analysis. <bold>Result</bold> The coefficient of variation of the 8 phenotypic trait in the germplasm of <italic>C. lanceolata</italic> in southern Jiangxi Province is 5.48%-64.20%，and the phenotypic diversity index（<italic>H'</italic>）is 1.924-2.090.A total of 108 alleles（<italic>Na</italic>）were detected in the 212 germplasms by 20 SSR markers.The means of the effective number of alleles（<italic>N_e</italic> ）observed heterozygosity（<italic>H_o</italic> ），expected heterozygosity（<italic>H_e</italic> ），Shannon’s information index（<italic>I</italic>），and locus polymorphism information content（PIC）were1.821，0.377，0.399，0.752，and 0.355，respectively.Finally，the core collection consisting of 57 germplasms was constructed，with the sampling ratio of 26.89%.The mean difference percentage（MD），variance difference percentage（VD），range coincidence rate（CR），and coefficient of variation coincidence rate（VR）were 2.04%，21.62%，100.00%，and 111.65%，respectively.There were no significant differences between the original collection and core collection in <italic>N_a</italic>，<italic>N_e</italic>，<italic>I</italic>，<italic>H_o</italic>，<italic>H_e</italic> and PIC，and the core collections are uniformly distributed throughout the original collection.Five SSR loci were selected to construct the DNA fingerprinting of the core germplasm.The DNA fingerprints of the core collections were constructed by 5 SSR marker. <bold>Conclusion</bold> There are rich phenotypic variations and genetic diversity in the germplasm of <italic>C. lanceolata</italic> in southern Jiangxi Province，and the 57 core collections can effectively represent the original collection of <italic>C</italic>. <italic>lanceolata</italic> in Southern Jiangxi Province.