Karim Kumba Y, Ifie Beatrice, Dzidzienyo Daniel, Danquah Eric Y, Blay Essie T, Whyte Jim B A, Kulakow Peter, Rabbi Ismail, Parkes Elizabeth, Omoigui Lucky, Norman Prince E, Iluebbey Peter
1Sierra Leone Agricultural Research Institute, Tower Hill, Freetown, PMB 1313 Sierra Leone.
3West Africa Centre for Crop Improvement, College of Basic and Applied Sciences, University of Ghana, P.O. Box LG 30, Legon, Accra, Greater Accra Ghana.
Physiol Mol Biol Plants. 2020 Feb;26(2):317-330. doi: 10.1007/s12298-019-00740-x. Epub 2019 Dec 23.
Dearth of information on extent of genetic variability in cassava limits the genetic improvement of cassava genotypes in Sierra Leone. The aim of this study was to assess the genetic diversity and relationships within 102 cassava genotypes using agro-morphological and single nucleotide polymorphism markers. Morphological classification based on qualitative traits categorized the germplasm into five different groups, whereas the quantitative trait set had four groups. The SNP markers classified the germplasm into three main cluster groups. A total of seven principal components (PCs) in the qualitative and four PCs in the quantitative trait sets accounted for 79.03% and 72.30% of the total genetic variation, respectively. Significant and positive correlations were observed between average yield per plant and harvest index (r = 0.76), number of storage roots per plant and harvest index (r = 0.33*), height at first branching and harvest index (0.26*), number of storage roots per plant and average yield per plant (r = 0.58*), height at first branching and average yield per plant (r = 0.24*), length of leaf lobe and petiole length (r = 0.38*), number of leaf lobe and petiole length (r = 0.31*), width of leaf lobe and length of leaf lobe (r = 0.36*), number of leaf lobe and length of leaf lobe (r = 0.43*), starch content and dry matter content (r = 0.99***), number of leaf lobe and root dry matter (r = 0.30*), number of leaf lobe and starch content (r = 0.28*), and height at first branching and plant height (r = 0.45**). Findings are useful for conservation, management, short term recommendation for release and genetic improvement of the crop.
关于木薯遗传变异程度的信息匮乏，限制了塞拉利昂木薯基因型的遗传改良。本研究的目的是利用农艺形态学和单核苷酸多态性标记评估102个木薯基因型的遗传多样性及亲缘关系。基于定性性状的形态学分类将种质分为五个不同的组，而定量性状集则分为四个组。SNP标记将种质分为三个主要聚类组。定性性状集中共有七个主成分（PCs），定量性状集中有四个主成分，分别占总遗传变异的79.03%和72.30%。单株平均产量与收获指数之间存在显著正相关（r = 0.76），单株贮藏根数量与收获指数之间存在显著正相关（r = 0.33*），首次分枝高度与收获指数之间存在显著正相关（0.26*），单株贮藏根数量与单株平均产量之间存在显著正相关（r = 0.58*），首次分枝高度与单株平均产量之间存在显著正相关（r = 0.24*），叶裂片长度与叶柄长度之间存在显著正相关（r = 0.38*），叶裂片数量与叶柄长度之间存在显著正相关（r = 0.31*），叶裂片宽度与叶裂片长度之间存在显著正相关（r = 0.36*），叶裂片数量与叶裂片长度之间存在显著正相关（r = 0.43*），淀粉含量与干物质含量之间存在显著正相关（r = 0.99***），叶裂片数量与根干物质之间存在显著正相关（r = 0.30*），叶裂片数量与淀粉含量之间存在显著正相关（r = 0.28*），首次分枝高度与株高之间存在显著正相关（r = 0.45**）。研究结果对于该作物种质资源的保存、管理、短期推广建议及遗传改良具有重要意义。
