Genetic diversity and population structure analysis of Ghanaian and exotic cassava accessions using simple sequence repeat (SSR) markers
Genetic diversity and population structure analysis of Ghanaian and exotic cassava accessions using simple sequence repeat (SSR) markers
复制标题
DOI：
10.1016/j.heliyon.2019.e03154
复制
发表时间：
2020-01-01
期刊：
影响因子：
4
通讯作者：
Offei, Samuel Kwame
中科院分区：
文献类型：
--
作者：
Adjebeng-Danquah, Joseph;Manu-Aduening, Joseph;Offei, Samuel Kwame
遗传多样性在作物改良中具有根本的重要性，并为植物提供满足不断变化的环境需求的能力。本研究旨在评估木薯（Manihot esculenta Crantz）组合材料的多样性和遗传亲缘关系。我们对来自加纳和外来来源的89份木薯材料进行了微卫星标记分析。利用35个SSR （simple sequence repeat）标记对这些材料进行分析。从35个多态性标记中共检测到167个等位基因，平均每个位点有4.77个等位基因。等位基因频率在0.32 ~ 0.99之间，平均为0.62个。观察到的杂合度范围为0.03 ~ 0.97。多态性信息含量（PIC）变化范围为0.03 ~ 0.78，平均值为0.45，表明各种质间存在较高的多态性水平。与外来种质相比，本地种质的等位基因数量、基因多样性和观察到的杂合度均高于外来种质，表明本地种质具有丰富的遗传多样性。基于结构的种群结构分析鉴定出两个亚种群和大量杂合种群。基于邻居加入算法的聚类分析进一步将集合划分为7个子组，而不考虑地理来源。这表明在不同的物种中可能存在共同的基因组区域。不同种质间等位基因频率差异较大，杂合性较高。这些发现表明，种质资源具有显著的遗传变异，值得选择。
Genetic diversity is fundamentally important in crop improvement and provides plants with the capacity to meet the demands of changing environments. This work was carried out to assess the diversity and the extent of genetic relatedness among a number of assembled cassava (Manihot esculenta Crantz) accessions. We conducted a microsatellite marker analysis of 89 cassava accessions collected from Ghanaian and exotic sources. These accessions were assayed using 35 simple sequence repeat (SSR) markers. A total of 167 alleles were detected from 35 polymorphic markers with an average of 4.77 alleles per locus. High allelic frequency was detected across the accessions, ranging from 0.32 to 0.99 with an average of 0.62 per marker. Observed heterozygosity ranged from 0.03 - 0.97 across the accessions. Polymorphism information content (PIC) ranged from 0.03 to 0.78 with a mean of 0.45, indicating high level of polymorphism across the accessions. Comparatively, higher number of alleles, gene diversity and observed heterozygosity were detected among the local accessions compared with the exotic accessions indicating rich genetic diversity among them. Population structure analysis based on STRUCTURE identified two subpopulations and a large number of admixtures. Cluster analysis based on the neighbour joining algorithim further separated the collection into seven sub-groupings irrespective of geographical origin. This indicates the possible sharing of common genomic regions occurring across the accessions. High allelic frequency differences and levels of heterozygosity were observed among the germplasm. These findings indicated significant genetic variability in the germplasm to warrant selection.