目的 采用iPBS分子标记技术，分析32份不同地区矩唇石斛Dendrobium linawianum种质资源的遗传多样性及分化关系。方法 构建“0，1”矩阵，通过NTSYS-pc 2.10e计算遗传相似系数（G_s）并构建UPGMA聚类树状图，利用Popgene 1.32计算各项遗传多样性指数。结果 6条iPBS引物共扩增出84条清晰条带，其中多态性条带76条，多态性比率90.48%，平均多态信息含量（polymorphism information content，PIC）0.46；G_s变化范围为0.547 6～0.965 5，平均值为0.766 8，G_s为0.732时，32份种质分为4个类群；居群平均观测等位基因数（observed number of alleles，N_a）、平均有效等位基因数（effective number of alleles，N_e）、Nei’s基因多样性指数（Nei’s gene diversity index，h）、Shannon多样性信息指数（Shannon information index，I）分别为1.631 0、1.381 6、0.219 0、0.326 7；居群遗传结构分析显示，基因多样度（total genetic diversity，H_t）、各居群基因分化系数（gene diversity within population，H_s）、居群间遗传分化系数（coefficient of gene differentiation，G_st）分别为0.281 3、0.219 0、0.221 3，居群间遗传变异占总变异的22.13%，居群内遗传变异占总变异的77.87%，说明遗传变异主要来源于居群内。此外，基于6条引物的19个多态位点成功构建了32份种质的DNA指纹图谱，为矩唇石斛品种分类与鉴定提供了参考。结论 矩唇石斛居群内遗传多样性高于居群间，遗传变异以居群内为主，且种质资源的遗传分化特征与地理分布具有显著相关性。明确了矩唇石斛不同种质间的遗传关系及其居群遗传多样性特征，可为该物种种质资源的科学保护与可持续利用提供理论依据。

Objective This study employed iPBS molecular marker technology to analyze the genetic diversity and genetic differentiation relationships among 32 Dendrobium linawianum germplasm resources from different regions. Methods A “0, 1” matrix was constructed using Excel 2016, and the genetic similarity coefficient (G_s) was calculated using NTSYS-pc 2.10e to construct a UPGMA cluster dendrogram. Additionally, various genetic diversity indices were calculated using Popgene 1.32. Results A total of 84 clear bands were amplified from the six selected iPBS primers, including 76 polymorphic bands, with a polymorphism rate of 90.48% and an average polymorphism information content (PIC) of 0.46, indicating high polymorphism of the iPBS primers. The genetic similarity coefficients ranged from 0.547 6 to 0.965 5, with an average of 0.766 8. At a genetic similarity coefficient of 0.732, the 32 germplasm samples were classified into four populations. The average observed allele number (N_a), average effective allele number (N_e), Nei's genetic diversity index (h), and Shannon diversity information index (I) were 1.631 0, 1.381 6, 0.219 0, and 0.326 7, respectively. Genetic structure analysis revealed that the genetic diversity (H_t), gene differentiation coefficients (H_s) among populations, and genetic differentiation coefficients (G_st) were 0.281 3, 0.219 0, and 0.221 3, respectively. Genetic variation among populations accounted for 22.13% of total variation, while genetic variation within populations accounted for 77.87%, indicating that genetic variation was primarily derived from within populations. Furthermore, DNA fingerprinting of 32 germplasm resources was successfully constructed based on 19 polymorphic loci with six primers, which provided a reference for the classification and identification of D. linawianum. Conclusion The genetic diversity of D. linawianum was significantly lower between populations than within populations, and the genetic variation was mainly within populations. The genetic differentiation characteristics of germplasm resources are significantly correlated with their geographical distribution patterns. This study not only elucidates the genetic relationships among different germplasm of D. linawianum and the characteristics of population genetic diversity, but also provides an important theoretical basis for the subsequent scientific conservation and sustainable utilization of D. linawianum germplasm resources.

R282.12

广西重点研发计划项目（桂科AB21220056）；广西自然科学基金项目（2020GXNSFBA297021）；设施与休闲农业产业科技先锋队（桂农科盟202512）；广西特色作物试验站建设（TS202218）