基于简化基因组技术的33份芒果品种遗传分析

Genetic Analysis of 33 Mango Varieties Based on Genotyping by Sequencing

芒果具有丰富的种质资源,目前关于芒果育种材料与抗病性遗传结构和亲缘关系相关性的研究较少。为分析探究不同抗、感细菌性角斑病芒果品种的遗传结构和亲缘关系,本研究采用GBS(Genotyping by sequencing)简化基因组测序技术对33份芒果材料进行测序,基于数据处理后的SNP信息进行系统进化树分析、主成分分析和群体遗传结构分析,分析芒果种质材料的遗传进化和亲缘关系,结合前期抗病性评价实验结果探究其遗传分化特点及与抗病性的相关性。结果表明,33份芒果品种可划分为7个类群,类群Ⅰ包含7个高、中抗品种中的5个;类群Ⅲ与类群Ⅳ遗传距离近,包含了4个高感品种中的3个;群体结构分析最佳分群数为9;主成分分析显示这些芒果品种整体没有产生特别明显的分组,但是各品种间的遗传距离远近关系和进化树结果基本一致;遗传多样性分析中,所有芒果品种的期望杂合度为0.3361,多态性信息含量(PIC)为0.2694,有效等位基因数1.5732个,Shannon信息指数为0.5041,表明芒果遗传多样性较低;且从高抗品种到感病品种的各项遗传多样性指标由高到低分别为中感>感病>中抗>高感>高抗,说明这些品种中高感品种、高抗品种相对其他抗感病梯度的品种,各自之间的遗传一致性较高,而中感品种的遗传多样性高。以上结果表明芒果高感品种与高抗品种之间遗传差异大,亲缘关系远;群体血统混合在一定程度上可能有助于提高品种抗病性。该研究结果为今后芒果杂交育种、种质创制、芒果种质资源开发利用等提供理论依据。

Mango has abundant germplasm resources,and there are few studies on the correlation between mango breeding materials and disease resistance genetic structure and genetic relationship.In order to analyze and explore the genetic structure and genetic relationship of different mango varieties resistant and susceptible to bacterial angular spot disease,this study used GBS(Genotyping by sequencing)simplified genome sequencing technology to sequence 33 mango materials based on the SNP information after data processing.Phylogenetic tree analysis,principal component analysis and population genetic structure analysis,analysis of genetic evolution and genetic relationship of mango germplasm materials,combined with the results of early disease resistance evaluation experiments to explore its genetic differentiation characteristics and the correlation with disease resistance.The results shows that 33 mango varieties can be divided into 7 groups,groupⅠcontains 5 of the 7 high and medium resistant varieties;groupⅢand groupⅣare close in genetic distance,including 3 of the 4 highly susceptible varieties;The optimal number of clusters for population structure analysis is 9;principal component analysis shows that there is no obvious grouping among these mango varieties,but the genetic distance and phylogenetic t ree results are basically the same.In the genetic diversity analysis,the expected heterozygosity(He)of all mango varieties is 0.3361,the polymorphic information content(PIC)is 0.2694,the effective numbers of alleles(Ne)is1.5732,and the Shannon information index(I)is 0.5041,indicating that the genetic diversity of mangoes is low.In addition,the genetic diversity indexes from high-resistant varieties to susceptible varieties were moderately susceptible>susceptible>moderately resistant>high susceptible>high resistant,indicating that the high susceptibility and high resistance of these varieties have higher genetic consistency than other susceptible varieties,while the genetic diversity of the moderately susceptible varieties is high.The susceptible cultivars have higher genetic consistency,while the moderately susceptible varieties have higher genetic diversity.The above results indicate that the genetic difference between the highly susceptible varieties and the highly resistant varieties is large and the genetic relationship is far;the population pedigree mixing may help to improve the disease resistance of the varieties to a certain extent.The research results provide theoretical basis for future mango hybrid breeding,germplasm creation,and development and utilization of mango germplasm resources.