芒果^(60)Co-γ、EMS诱变及SC-SSR分子标记遗传多样性分析

Genetic Diversity Analysis of SC-SSR Molecular Markers in Mango Irradiated by^(60)Co-γand EMS Mutagenesis

诱变育种是短时间内增加物种遗传多样性和表型变异的最有效方法之一。为探明诱变创制芒果突变体基因库可行性,本研究以凯特芒果为试验材料,通过^(60)Co-γ射线辐射枝条和EMS溶液浸泡种子创制诱变群体材料,利用SC-SSR分子标记进行遗传多样性分析。结果表明:^(60)Co-γ射线辐射半致死剂量为31.37 Gy,0.2%EMS溶液浸泡半致死时间为5.9 h;利用16对SC-SSR引物分析100份诱变材料和1份凯特材料的遗传多样性,共检测出117个多态性位点,引物多态性条带百分比、多态性信息含量(PIC)、观测等位基因数(Na)、有效等位基因数(Ne)、Nei’s基因多样性指数(H)和Shannon’s信息指数(I)平均值分别为93.18%、0.610、1.923、1.583、0.334和0.493;试验材料间遗传相似系数在0.373~0.984之间,平均为0.779。诱变增加了芒果遗传信息,其中EMS诱变种子变异更大,本研究结果为芒果诱变育种提供了理论依据。

Mutation breeding is one of the most promising approaches for increasing genetic and phenotypic variability in a short period of time.In order to explore the feasibility of creating a mango mutant gene library through mutagenesis.The study used Keitt mango as test materials,irradiated branches with^(60)Co-γray and soaked seeds in EMS solution to create a mutagenesis population,and analyzed the Genetic diversity by SC-SSR molecular markers.The results indicated that the seemi-lethal dose of^(60)Co-γray radiation is 31.37 Gy,and the semi-lethal time of immersion in 0.2%EMS solution is 5.9 hours.The genetic diversity of 100 mutagenized materials and Keitt material was analyzed through 16 pairs of SC-SSR primers,and a total of 117 polymorphic sites were detected.The average values of sexual locus,primer percentage of polymorphism bands,polymorphism information content(PIC),number of observed alleles(Na),number of effective alleles(Ne),Nei's gene diversity index(H)and Shannon's information index(I)were 93.18%,0.610,1.923,1.583,0.334 and 0.493,respectively.The genetic similarity coefficient among test materials ranged from 0.373 to 0.984,with an average of 0.779.The study indicated that mutagenesis significantly enhanced genetic diversity in mango,among which EMS mutagenesis seed variation was greater,and the results lay a solid theoretical foundation for mango mutation breeding.