细叶云南松林大径木择伐后的遗传多样性动态及小尺度空间遗传结构  

Genetic diversity and fine-scale spatial structure of Pinus yunnanensis var.tenuifolia after selective logging of large-diameter trees

作　　者：黄春晖 白天道[1,2] 李远发[1,2] 黄厚宸 郑党斌 蒋维昕[1,2] HUANG Chunhui;BAI Tiandao;LI Yuanfa;HUANG Houchen;ZHENG Dangbin;JIANG Weixin(Guangxi Key Laboratory of Forest Ecology and Conservation,Guangxi University,Nanning 530004,Guangxi,China;College of Forestry,Guangxi University,Nanning 530004,Guangxi,China;Guangxi Zhuang Autonomous Region National Yachang Forest Farm,Baise 533000,Guangxi,China)

机构地区：[1]广西大学广西森林生态与保育重点实验室,广西南宁530004 [2]广西大学林学院,广西南宁530004 [3]广西壮族自治区国有雅长林场,广西百色533000

出　　处：《中南林业科技大学学报》2023年第10期60-69,共10页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金项目(32160381);广西自然科学基金项目(2018GXNSFBA281110)。

摘　　要：【目的】研究择伐对林分后续遗传多样性及空间遗传格局是否有显著影响。【方法】对大径木(DBH≥20 cm)强度择伐(1970年)后自然恢复49 a(2019年)的细叶云南松天然林样地内个体进行全站仪定位,并基于nSSR标记检测其遗传多样性,探究择伐后不同时期更新个体(以径级推算)的多样性变化。最后结合空间坐标及遗传关系分析其小尺度空间遗传格局。【结果】参试群体有较丰富的遗传多样性(期望杂合度He=0.641,Shannon’s指数I=1.209),但群体内存在一定程度的近/自交(固定指数F=0.234);比较不同径级组遗传多样性表明,群体内观测杂合度(Ho)、F随径级减小分别呈递增和递减趋势,He,I呈先下降后增加趋势,表明近/自交主要发生在伐后早期,并在一定程度上导致了林分遗传多样性的暂时下降。后期随着林分的自然更新,有效繁殖群体增大,遗传多样性逐步增加;空间遗传聚类表明,样方内个体可分为两组,组内个体呈现轻度聚集分布,但空间自相关分析未达显著水平,表明林分现有遗传格局可能受到了择伐造成的母树非随机分布、长距离基因流(种子/花粉)等因素的综合作用。【结论】以收获为主的大径木强度择伐对伐后初期细叶云南松林分的遗传多样性及空间遗传格局有负面影响,但随着林分的自然恢复,其所带来负面效应逐渐下降,表明细叶云南松林具备一定的遗传多样性自我修复能力。【Objective】To investigate whether selective logging had significant impact on the subsequent genetic diversity(GD)and spatial genetic structures(SGS)in stands.【Method】In a Pinus yunnanensis var.tenuifolia natural forest suffering from an intensive logging(DBH≥20 cm)49 years ago,the coordinates of individual trees in a sample plot(100 m×80 m)were positioned by total station.The individuals in the plot were genotyped based on nSSR markers,aiming to compare the GD of trees generated at three consecutive stages(arbitrarily group by DBH)after logging.Moreover,the SGS were analyzed at the fine-scale.【Result】The tested population was rich in GD(He=0.641,I=1.209),but there was a certain degree of inbreeding/selfing(F=0.234)within the population.The GD of three diameter classes showed that the observed heterozygosity(Ho)and fixed index(F)within the population increased and decreased with the decline of diameter class,respectively.The expected heterozygosity(He)and Shannon’s index(I)decreased firstly and then increased,indicating that inbreeding/selfing pollination mainly occurred in the early post-logging period,which led to the temporary decline of genetic diversity to some extent.With the natural regeneration of the stand,the size of effective reproduction population increased,and the GD gradually increased.The spatial genetic clustering showed that the trees can be divided into two groups,and the individuals within group present a slight aggregation distribution.However,the spatial autocorrelation analysis based on Moran’s I was not significant,implying that the existing genetic pattern was probably affected by the nonrandom distribution of mother trees caused by selective logging and the species nature of long-distance gene flow(seed/pollen).【Conclusion】The wood harvest through intensive logging has a negative impact on the genetic diversity and spatial genetic structure of P.yunnanensis var.tenuifolia stands in the early stage of post-logging.However,the negative effects were relieved with the

关 键 词：细叶云南松 择伐 自然恢复 SSR 空间遗传格局 

分 类 号：S791.257[农业科学—林木遗传育种]