Study on Genetic Diversity and Genetic Structure of Four Torreya Species Based on SSR Markers

Ma Changle; Zhang Jinli; Yang Jianxin; Li Jing; Yue Liangliang; Zhou Bingjiang

doi:10.14083/j.issn.1001-4942.2026.01.005

Abstract：To unveil the genetic diversity and structure of Torreya plants and lay a theoretical foundation for evaluating,protecting and utilizing germplasm resources,a total of 295 samples from 4 Torreya species were used as materials.After selection,15 pairs of selected primers were employed for SSR-PCR amplification across all samples,and the amplification products were analyzed by capillary electrophores detection to explore their genetic diversity and structure,and cluster analysis was conducted.The results revealed the following in-sights:(1)Based on the effective allele,the genetic diversity from high to low was Torreya fargesii(P=87.50%,He=0.396,I=0.740),Torreya taxifolia(P=86.67%,He=0.342,I=0.596),Torreya parvifolia(P=73.33%,He=0.285,I=0.480),and Torreya yunnanensis(P=57.57%,He=0.194,I=0.332).(2)The average Fis value of 21 Torreya populations was 0.174,the average Fst value was 0.490,and the Nm was 0.260,indicating that gene exchange occurred infrequently.The Fit value of Torreya populations was greater than the Fis value,suggesting that the heterozygous level between populations was higher than that within pop-ulations.(3)The results of the analysis of molecular variance indicated that the genetic variation of Torreya plants mainly originated among populations with a variable coefficient of 58%.The Nei's standard genetic dis-tance among 21 populations ranged from 0.018 to 2.453 with an average of 0.609.Overall,the genetic distance was positively correlated with the geographical distance(r=0.759,P<0.05),while there was no significant correlation between the genetic distance and geographical distance in T.yunnanensis and T.fargesii.(4)Ge-netic similarity coefficients among the 21 populations were ranged from 0.403 to 0.983.Using a threshold of 0.12,the populations were grouped into 2 major categories with T.taxifolia forming one category and the re-maining 20 populations of the other three species another.At a threshold of 0.58,they could be divided into 4 major categories.