2021年4月23日 星期五
山东鹊山省级自然保护区胡桃楸的居群结构及遗传多样性分析
Analyses on population structure and genetic diversity of Juglans mandshurica in Queshan Provincial Nature Reserve of Shandong
2020年 第29卷 第3期 页码[34-42]
摘要

 在实地调查基础上,在山东鹊山省级自然保护区山体下部、山体中部和山体上部样地中分别划分1、3和2个样方,采用径级代替龄级的方法编制静态生命表,分析胡桃楸(Juglans mandshurica Maxim.)居群的径级结构和居群特征,同时采用SRAP分子标记研究胡桃楸个体的遗传多样性和遗传关系,并据此探讨其致危原因。结果表明:6个样方的胡桃楸个体总数为135株,其中,Ⅰ级(DBH<2 cm)和Ⅱ级(2 cm≤DBH<5 cm)个体数占个体总数的58.5%,而Ⅵ级(20 cm≤DBH<25 cm)和Ⅶ级(25 cm≤DBH<30 cm)个体数仅占个体总数的6.0%;在各样地内幼苗和幼树的数量差异明显,其中山体下部样地缺失中高径级个体。由静态生命表可见:随径级增加,胡桃楸个体的存活数(ax)和期望寿命(ex)总体上逐级递减,而死亡率(qx)则呈先逐渐升高然后降低的趋势,但不同坡位的样地及居群的ax、ex和qx值略有差异,居群的qx值在Ⅴ级(15 cm≤DBH<20 cm)达到峰值;该居群的个体存活曲线总体符合Deevey Ⅱ型。SRAP分子标记结果显示:从供试的10份样本中共获得104个扩增位点,其中多态性位点51个,占扩增位点总数的49.0%;供试胡桃楸样本的遗传相似系数为0.654~0.904。UPGMA聚类分析结果显示:在遗传相似系数0.762处,供试的10份样本被分为3组2亚组,其中,栽培胡桃(J. regia Linn.)为一组,而9份胡桃楸样本聚为2组,其中采自同一地点(宋山)的3份胡桃楸样本聚为1个亚组。综合分析结果表明:该胡桃楸居群总体表现为增长型,径级结构相对完整;居群内个体间遗传变异较为丰富,且个体间的遗传关系与其地理分布有一定的关联。根据研究结果,认为人为干扰(山体下部样地)、环境筛选和种内竞争(山体中部和上部样地)是影响该胡桃楸居群更新的主要原因。

Abstract

Based on field investigation, 1, 3 and 2 quadrats were divided in plots at lower, middle, and upper parts of the mountain in Queshan Provincial Nature Reserve of Shandong, respectively, and diameter class structure and population characteristics of Juglans mandshurica Maxim. population were analyzed by making static life table with diameter class in place of age class, meanwhile, genetic diversity and relationship of J. mandshurica individual in this reserve were studied by using SRAP molecular marker, and its endangered reason was discussed on the basis. The results show that total number of J. mandshurica individuals in 6 quadrats is 135, in which, number of individuals of class Ⅰ (DBH<2 cm) and class Ⅱ (2 cm≤DBH<5 cm) accounts for 58.5% of the total number of individuals, while that of class Ⅵ (20 cm≤DBH<25 cm) and class Ⅷ (25 cm≤DBH<30 cm) does only 6.0% of the total number of individuals; numbers of seedlings and saplings in each quadrat are evidently different, in which, quadrat at lower part of the mountain lacks midhigh diameter class individuals. It can be seen from the static life table that with the increase of diameter class, survival number (ax) and life expectancy (ex) of J. mandshurica individuals decrease step by step in general, while their mortality rate (qx) shows a tendency of first gradually increase and then decrease, but ax, ex and qx values of plots and population at different slope positions are slightly different, and the peak of qx value of population appears at class V (15 cm≤DBH<20 cm); the survival curve of individuals of this population is of Deevey Ⅱ type in general. The SRAP molecular marker result shows that 104 amplification loci are obtained from 10 samples tested, in which, there are 51 polymorphic loci, accounting for 49.0% of the total amplification loci; the genetic similarity coefficient of J. mandshurica samples tested is 0.654-0.904. The UPGMA cluster analysis result shows that at the genetic similarity coefficient of 0.762, 10 samples tested can be classified into 3 groups and 2 subgroups, in which, cultivated J. regia Linn. is one group, while other 9 J. mandshurica samples cluster into 2 groups, in which, 3 J. mandshurica samples collected from the same location (Songshan) cluster into one subgroup. The comprehensive analysis result shows that this J. mandshurica population shows a growth type in general, and diameter class structure is relatively complete; genetic variations among individuals within population are relatively abundant, and there are some associations between genetic relationship among individuals and their geographic distribution. Based on the research result, artificial interference (plot at lower part of the mountain), environment selection and intraspecific competition (plots at middle and upper parts of the mountain) are considered as the main reasons affecting the regeneration of this J. mandshurica population.

关键词胡桃楸; 径级结构; 静态生命表; 存活曲线; SRAP分子标记; 遗传相似性
Key wordsJuglans mandshurica Maxim.; diameter class structure; static life table; survival curve; SRAP molecular marker; genetic similarity
作者张浩1, 胡德昌1, 解孝满2, 刘丹2, 张萍1, 王仲礼1
所在单位1. 鲁东大学生命科学学院, 山东 烟台 264025; 2. 山东省林木种质资源中心, 山东 济南 250014
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基金项目国家自然科学基金青年基金资助项目(31000308); 山东省自然科学基金资助项目(ZR2019MC055); 山东省林业科技创新项目(LYCX01-2018-01); 烟台市科技发展计划项目(2016ZH064); 山东省农业良种工程子课题(2019LZGC01805)