Singh Harish Chandra, Tiwari Vandana, Kumar Narender, Rana Tikam Singh
Molecular Systematics Laboratory, Plant Diversity Systematics and Herbarium Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, Uttar Pradesh, 226001, India.
School of Studies in Botany, Jiwaji University, Gwalior, Madhya Pradesh, 474011, India.
Biochem Genet. 2025 Feb 7. doi: 10.1007/s10528-025-11032-3.
Betula utilis subsp. jacquemontii (Spach) Ashburner & McAll. is a medicinally and ecologically important tree species in the Western Himalayan Region (WHR) of India. Estimation of genetic variability and population structure of 11 populations of B. utilis subsp. jacquemontii in the WHR were carried out using 15 ISSR and 10 DAMD markers. The cumulative analyses of the markers (ISSR + DAMD) revealed a moderate level (49.47%) of polymorphism at the species level. Khilanmarg, Gangotri, and Khaliya top populations showed the highest polymorphism, while the Bhyundar Valley and Chatru-Kaza road populations showed the lowest polymorphism across 11 populations. Mantel test revealed a positive correlation between pair-wise genetic and geographical distances in wild populations of B. utilis subsp. jacquemontii in the WHR. The AMOVA analysis showed that majority of variation of the species exists among populations (54%), followed by within populations (20%). The clustering pattern obtained from UPGMA, PCoA, and STRUCTURE analyses revealed that 11 natural populations of B. utilis subsp. jacquemontii separated into two distinct genetic clusters. The genetic differentiation is notably high (G = 0.74) among populations with a low gene flow (Nm = 0.16), which could be attributed to geographic isolation, high mountain ranges, regional climatic conditions, and habitat destruction in the WHR. The genetically diverse populations recognized in this study could be a valuable genetic resource for conservation and management of this important timberline tree species.
喜玛拉雅桦亚种（Betula utilis subsp. jacquemontii (Spach) Ashburner & McAll.）是印度西喜马拉雅地区（WHR）一种具有重要药用和生态价值的树种。利用15个ISSR标记和10个DAMD标记对西喜马拉雅地区11个喜玛拉雅桦亚种种群的遗传变异性和种群结构进行了评估。对这些标记（ISSR + DAMD）的累积分析表明，该物种水平的多态性处于中等水平（49.47%）。在11个种群中，基兰马尔格、甘戈特里和卡利亚托普种群表现出最高的多态性，而比云达尔山谷和查特鲁 - 卡扎公路种群的多态性最低。Mantel检验显示，西喜马拉雅地区野生喜玛拉雅桦亚种种群的成对遗传距离和地理距离之间存在正相关。AMOVA分析表明，该物种的大部分变异存在于种群之间（54%），其次是种群内部（20%）。从UPGMA、PCoA和STRUCTURE分析获得的聚类模式表明，11个喜玛拉雅桦亚种自然种群分为两个不同的遗传簇。种群间遗传分化显著较高（G = 0.74），基因流较低（Nm = 0.16），这可能归因于地理隔离、高山山脉、区域气候条件以及西喜马拉雅地区的栖息地破坏。本研究中识别出的遗传多样的种群可能是保护和管理这种重要的林线树种的宝贵遗传资源。
