Genetic Diversity Evaluation and Core Germplasm Construction of Camellia fascicularis

doi:10.7525/j.issn.1673-5102.2025.06.008

Abstract

Abstract:

Camellia fascicularis，as a National Class II Key Protected Plant and a wild plant with extremely small populations in Yunnan Province， scientific guidance is urgently required for its population reconstruction and conservation. In this study， simplified genome sequencing method using Hyper-seq technology was used to evaluate and analyze the genetic diversity， population genetic structure and screen core germplasm among 133 accessions collected from three wild populations（Hekou， Mengzi and Maguan） and two ex situ conservation populations（Kunming Arboretum and Wenshan Arboretum）. The results revealed that genetic diversity of C. fascicularis was high， an average expected heterozygosity（H_E） was 0.232 6， an average observed heterozygosity（H_O） was 0.365 9， and an average nucleotide diversity（P_i） was 0.372 5. The genetic diversity of the ex-situ conservation populations（KMSMY and WSSMY） was slightly lower than that of the MG population and higher than those of the MZ and HK populations， but the H_E， H_O and P_i values of both ex-situ conservation populations did not reach 90% of the species-level benchmark. Genetic structure analysis showed that 133 individuals from five populations were categorized into four clusters， the MG and KMSMY populations showed more complex genetic structure and backgrounds. Population genetic differentiation showed that the degree of genetic differentiation among populations was very high（F_st=0.410 3）. In conclusion， 27 core germplasms were extracted from 133 germplasms based on genetic distance， which effectively represented the genetic diversity of C. fascicularis. This study first analyzed the genetic characteristics of C. fascicularis at the genomic-level， providing crucial theoretical foundations for formulating in situ conservation strategies， optimizing the ex situ preservation protocols and implementing scientific population reconstruction for this endangered species.

Key words: plant species with extremely small populations, Camellia fascicularis, genetic diversity, population genetic structure, core germplasm, population reconstruction

CLC Number:

Q346

Shanshan ZHANG, Sunmei RUAN, Wenzhong YANG. Genetic Diversity Evaluation and Core Germplasm Construction of Camellia fascicularis[J]. Bulletin of Botanical Research, 2025, 45(6): 909-918.

Figures/Tables 9

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种群 Population	类型 Type	样本量 Sample size	期望杂合度 H_E	观测杂合度 H_O	核苷酸多样性 P_i	近交系数 F_is
MG	野生种群 Wild population	46	0.292 5	0.406 7	0.449 8	0.090 1
HK		2	0.142 3	0.273 4	0.270 5	-0.004 3
MZ		5	0.206 7	0.349 1	0.352 6	0.006 1
KMSMY	迁地保护种群 Ex situ population	50	0.292 4	0.443 1	0.437 5	0.005 5
WSSMY	迁地保护种群 Ex situ population	30	0.229 4	0.357 4	0.352 0	0
物种水平 Species level		133	0.397 3	0.502 2	0.559 5	0.143 8