Table 1_Genetic diversity and population structure of Kudouzi (Sophora alopecuroides) in Northwest China revealed by SNP markers and seed phenotypic traits.docx

IntroductionSophora alopecuroides L., a perennial leguminous herb native to northwest China, holds medicinal, ecological, and forage value. However, intensified human activities have caused a sharp decline in its wild populations and genetic diversity.
MethodsTo assess its genetic structure and diversity, we analyzed 65 wild populations using SNP markers and seed phenotypic traits.
ResultsThe coefficient of variation for eight seed traits ranged from 2.87% to 7.94%, with diversity indices (H) from 1.639 to 1.767, indicating rich phenotypic variation. Clustering based on phenotypic traits and SNP data both divided populations into two main groups. Genetic diversity was relatively low (He = 0.22; Ho = 0.17; Pi = 0.19), and AMOVA showed that variation was mainly among individuals (132.83%), with low population differentiation (FST = 0.00-0.04). Redundancy analysis revealed that phenotypic traits were largely influenced by mean temperature of the driest quarter and annual wind speed, while genetic diversity was shaped by precipitation and thermal variables.
ConclusionsOur results provide a foundation for understanding the genetic variation of S. alopecuroides, offering valuable insights for its conservation and breeding programs.

引言 苦豆子（Sophora alopecuroides L.）为原产于中国西北的多年生豆科草本植物，兼具药用、生态与饲用价值。然而人类活动强度加剧导致其野生种群数量与遗传多样性急剧下降。
材料与方法 为评估其遗传结构与遗传多样性，本研究采用单核苷酸多态性（Single Nucleotide Polymorphism, SNP）标记与种子表型性状，对65个野生种群展开分析。
结果 8个种子性状的变异系数介于2.87%至7.94%之间，多样性指数（H）取值范围为1.639至1.767，表明该物种存在丰富的表型变异。基于表型性状与SNP数据的聚类分析均将供试种群划分为两大类群。该物种遗传多样性相对较低（期望杂合度（Expected Heterozygosity, He）=0.22；观测杂合度（Observed Heterozygosity, Ho）=0.17；核苷酸多样性（Nucleotide Diversity, Pi）=0.19），分子方差分析（Analysis of Molecular Variance, AMOVA）结果显示，遗传变异主要来源于种群内个体间（132.83%），种群分化程度极低（遗传分化系数（Fixation Index, FST）=0.00~0.04）。冗余分析（Redundancy Analysis, RDA）结果表明，种子表型性状主要受最干季平均气温与年风速影响，而遗传多样性则受降水与温度变量调控。
结论 本研究结果为阐明苦豆子的遗传变异奠定了理论基础，可为该物种的保护与育种工作提供重要参考依据。