基于SRAP分子标记的不同种壳厚度油棕种质资源遗传多样性分析

Genetic diversity analysis of oil palm germplasm resources with different seed shell thicknesses based on SRAP molecular marker

【目的】分析不同种壳厚度油棕种质资源的遗传多样性及群体结构,为油棕种质资源的有效利用及新品种选育提供理论依据。【方法】选取厚壳种BM8和无壳种L2T对288对SRAP引物组合进行筛选,从中筛选出扩增条带清晰、稳定及多态性好的SRAP引物组合,利用其对46份不同种壳厚度的油棕种质材料进行多态性扩增,基于扩增结果,利用NTSYS 2.1的非加权组平均法(UPGMA)计算遗传相似系数并构建聚类图,利用POPGENE 1.32计算遗传多样性指数。【结果】从288对引物组合中共筛选出15对SRAP引物,利用其对46份油棕种质材料进行PCR扩增,共扩增出303条条带,其中多态性条带183条,平均每条引物扩增出12.2条,多态比率为60.4%。46份油棕种质材料的观测等位基因数(Na)为1.0982~1.3264,平均1.6024;有效等位基因数(Ne)为1.1092~1.15976,平均1.4803;Nei’s基因多样性指数(H)为0.0572~0.1093,平均0.1937;I为0.0927~0.1648,平均0.3115。薄壳种油棕的遗传多样性指数与无壳种油棕较接近,且二者均高于厚壳种油棕,说明薄壳种和无壳种油棕的遗传多样性高于厚壳种油棕。厚壳种油棕与无壳种油棕的遗传一致度最小(0.7728),但二者间的遗传距离最大(0.2556)。厚壳种油棕与薄壳种油棕间的遗传一致度最大,(0.8396),且二者间的遗传距离最小(0.1748)。在遗传相似系数为0.59时,46份供试油棕种质被分为4个类群,其中,厚壳种油棕种质材料均分布在第I类群,薄壳种油棕种质材料(除Eg14分布在第I类群外)和无壳种油棕种质材料均分布在II、III和IV类群。【结论】46份油棕种质材料的遗传多样性整体较丰富,其中薄壳种油棕和无壳种油棕的遗传多样性较厚壳种油棕丰富,二者可作为优良育种材料进行亲本选配,选育出高产油率的油棕新品种。

【Objective】To study the population structure and genetic diversity of oil palm germplasm resources with different shell thicknesses and provide theoretical basis for the effective utilization of oil palm germplasm resources and the selection of new varieties.【Method】A total of 288 SRAP primer pairs were selected with BM8(thick shell)and L2 T(shellless).The 46 oil palm germplasm materials with different shell thicknesses were amplified using the SRAP primer with clear,stable and polymorphic.unweighted pair-group method with arithmetic mean(UPGMA)of NTSYS 2.1 was used to calculate genetic similarity coefficient and construct cluster graph,POPGENE 1.32 was used to calculate genetic diversity index.【Result】A total of 15 primer pairs with clear amplification and rich polymorphism were selected from 288 pairs,and 303 clear bands were amplified totally from 46 oil palm germplasm materials by PCR,of which 183 were polymorphism sites with an average of 12.2 bands by each primer,and the polymorphic ratio was 60.4%.Observed number of alleles(Na)of 46 oil palm germplasm materials was from 1.0982 to 1.3264,with an average of 1.6024,the effective number of alleles(Ne)was from 1.1092 to 1.15976,with an average of 1.4803,Nei’s gene diversity(H)was from 0.0572 to0.1093,with an average of 0.1937,Shannon’s information index(I)was from 0.0927 to 0.1648,with an average of0.3115.The genetic diversity index of thin shell oil palm was close to that of shellless oil palm,and both of them were higher than that of thick shell oil palm,indicating that the polymorphism of thin shell and shellless oil palm were higher than that of thick shell oil palm.The genetic consistency between the thick shell and shellless oil palm was the lowest(0.7728),but the genetic distance between them was the largest(0.2556).The genetic consistency between thick shell and thin shell oil palm was the highest(0.8396),and the genetic distance between them was the smallest(0.1748).When the genetic similarity coefficient was 0.59,46 oil palm germplasms were divided into 4 subgroups.Among them,thick shell materials were all distributed in subgroup I,thin shell materials(except Eg14 distributed in subgroup I)and shellless materials were distributed in subgroups II,III and IV.【Conclusion】The genetic diversity of 46 oil palm germplasm materials is relatively rich,among which thin shell and shellless oil palm have more genetic diversity than the thick shell oil palm.They can be used as excellent breeding materials for parent selection and breeding new oil palm varieties with high oil yield.