文献类型：期刊文献

中文题名：北亚热带日本落叶松不同改良水平群体的遗传多样性

英文题名：Genetic Diversity of Larix kaempferi Populations with Different Levels of Improvement in Northern Subtropical Region

作者：杜超群[1,2] 孙晓梅[1] 谢允慧[1] 侯义梅[3]

第一作者：杜超群

通信作者：Sun, Xiaomei

机构：[1]林木遗传育种国家重点实验室,国家林业和草原局林木培育重点实验室,中国林业科学研究院林业研究所,北京100091;[2]湖北省林业科学研究院,武汉430075;[3]建始县林业科学研究所,建始445300

年份：2021

卷号：57

期号：5

起止页码：68-76

中文期刊名：林业科学

外文期刊名：Scientia Silvae Sinicae

收录：CSTPCD;;EI(收录号：20212910642686);Scopus;北大核心:【北大核心2020】；CSCD:【CSCD2021_2022】；

基金：中央级公益性科研院所基本科研业务费专项资金CAF(CAFYBB2018ZY001-4;CAFYBB2017ZA001-4);国家自然科学基金项目(31971652)。

语种：中文

中文关键词：北亚热带;日本落叶松;育种群体;SSR标记;遗传多样性

外文关键词：northern subtropical region;Larix kaempferi;breeding population;SSR markers;genetic diversity

分类号：S718.

摘要：【目的】利用EST-SSR标记比较和评价北亚热带亚高山区日本落叶松引种种源群体、一代育种群体和二代育种群体的遗传多样性及其变化趋势,为该区域日本落叶松高轮次遗传改良和持续利用提供依据。【方法】利用16个SSR标记分析日本落叶松3个群体共873份个体的遗传多样性,应用GenAlex 6.41软件进行遗传参数估算、遗传变异分析和主坐标分析。【结果】16对引物在全部样品中共检测到106个等位基因,平均等位基因数为6.7个,不同位点的多态性差异较大,其中中高度多态性位点有14个,说明这些标记能够较好地反映该群体的遗传多样性水平;3个群体的平均有效等位基因数(N e)为2.543,Shannon多样性指数(I)为0.979,多态性信息含量PIC值为0.480,具有较高的遗传多样性;引种种源群体、一代育种群体和二代育种群体的多样性指数I值分别为0.911、1.017和1.009,PIC值分别为0.432、0.484和0.488,说明一代和二代育种群体的遗传多样性参数略高于种源群体,但方差分析结果显示3个群体之间差异不显著;总体来说3个群体间的遗传距离较小,在0.006~0.075之间,其中,一代和二代育种群体间的距离最小,种源群体与一代和二代育种群体间的遗传距离逐渐增大;AMOVA分析结果也表明3个群体间分化较小,变异主要来源于群体内;等位基因频率比较及主坐标分析(PCoA)结果显示种源群体与一代和二代群体的遗传基础存在着明显的差异,将少量种源群体中差异较大的基因型引入二代育种群体中,可有效提高二代育种群体的遗传多样性水平。【结论】北亚热带日本落叶松育种群体的遗传多样性较高,改良代群体遗传变异水平并没有降低,说明目前该区域的育种策略对于维持遗传多样性是合适的。3个群体的材料来源差异、栽培与育种中的花粉污染以及高强度的定向选择,是造成种源群体与一代、二代群体遗传多样性参数及遗传组成上的差异的主要因素,适时地将原产地资源补充到育种群体中,这对日本落叶松这样的外来树种的高轮次育种群体构建尤为重要。
【Objective】In order to provide a basis for advanced-cycle genetic improvement and sustainable utilization of Larix kaempferi,genetic diversity and its variation trend of the introduced provenance population(IP),the first cycle breeding population(FP)and the second cycle breeding population(SP)of L.kaempferi in northern subtropical subalpine region were compared and evaluated using EST-SSR markers.【Method】16 SSR markers were used to analyze the genetic diversity of 873 individuals from three populations of L.kaempferi.Estimation of genetic diversity parameters,analysis of molecular variance(AMOVA)and principal coordinate analysis(PCoA)were carried out using GenAlex 6.41.【Result】A total of 106 alleles were detected at 16 pairs of primers in all the samples with an average of 6.7 alleles.The polymorphism of different loci was significantly different,among which 14 loci were moderately to highly polymorphic,indicating that these markers could well reflect the genetic diversity level of the population.The average effective allele number(N e),Shannon diversity index(I)and polymorphism information content(PIC)of the three populations were 2.543,0.979,and 0.480,respectively,indicating that all of the three populations had high level of genetic diversity.The diversity index I of IP,FP and SP were 0.911,1.017 and 1.009,and the PIC were 0.432,0.484 and 0.488,respectively.These indicated that the genetic diversity parameters of FP and SP were slightly higher than those of IP and there was no significant difference among the three groups.In general,the genetic distances among three populations were small,ranging from 0.006 to 0.075.The genetic distance between IP and FP was higher than that between IP and SP,while the genetic distance between FP and SP was the least.AMOVA analysis also showed that the differentiation among the three populations was small,and the variation mainly came from within the populations.Allele frequency comparison and PCoA analysis showed that the genetic basis of IP was obviously different from that of the other two populations.The genetic diversity level of SP could be effectively improved by introducing a small number of genotype with large differences from SP in IP.【Conclusion】The genetic diversity of L.kaempferi breeding populations in northern subtropical region were high and the level of genetic diversity of improved population did not decrease compared with the introduced introduced provenance population.It was suggested that current breeding strategies in the region were appropriate for maintaining genetic diversity.The differences of origins among the three populations,pollen contamination in breeding process and high intensity of directional selection were the main causes for the differences in genetic composition and genetic diversity between the introduced provenance population and the first and the second cycle breeding populations.Replenishing the original resources into the breeding population in time is particularly important for the construction of advanced-cycle breeding populations of exotic species like L.kaempferi.