致病疫霉超级生理小种遗传多样性分析.docVIP

 致病疫霉超级生理小种遗传多样性分析# 徐小虎，杨志辉，朱杰华，张维宏** （河北农业大学植物保护学院 保定 071001） 5 10 15 20 25 30 35 40 45 摘要：【目的】通过分析致病疫霉超级生理小种菌株的遗传多样性，揭示超级生理小种的遗 传变异规律和特征，为马铃薯抗病品种策略制定和生产上晚疫病的防控提供指导。【方法】 对本实验室所保存的致病疫霉超级生理小种菌株进行了交配型、甲霜灵抗性测定以及线粒体 DNA 单倍型、SSR 和 AFLP 基因型分析。【结果】被测 40 个菌株发现了 A1、A2 和自育 3 种不同类型的交配型。其中，A1 和自育型菌株数量多，分别为 21 株和 14 株，而 A2 交配 型仅 5 株。甲霜灵抗性测定检测出高抗菌株 26 株，敏感菌株 14 株。线粒体 DNA 单倍型测 定出 Ia 型和 IIa 型两种，比例接近 1:1。基于 5 个基因座被测 40 个超级生理小种菌株共鉴定 出了 7 种 SSR 基因型。利用 6 对荧光引物共检测到 258 条 AFLP 谱带，其中多态性谱带 204 条，多态性为 79.1%。将供试的 40 个菌株划分为 38 个基因型，几乎每个菌株都为 1 个特有 基因型。我国南方和北方超级生理小种群体存在着明显的遗传差异。本研究结果揭示了我国 致病疫霉超级生理小种具有丰富的遗传多样性。【结论】致病疫霉中的任何小种都可在多个 抗病基因的强大选择压力下，在短时间内通过与之对应的无毒基因快速突变而成为超级生理 小种。当前对致病疫霉生理小种的鉴定及监测对生产上利用抗病品种防控晚疫病的指导意义 不大。 关键词：致病疫霉；超级生理小种；交配型；甲霜灵抗性；线粒体 DNA 单倍型；SSR；AFLP 中图分类号：S435 Genetic Diversity of the Super Physiological Race in Phytophthora infestans XU Xiaohu1, YANG Zhihui1, ZHU Jiehua2, ZHANG Weihong2 (1. College of Plant Protection, Agricultural University of Hebei, Baoding, 071001; 2. College of Plant Protection, Agricultural University of Hebei, Baoding 071001) Abstract: 【Objective】 The analysis of the genetic diversity of the super physiological race in Phytophthora infestans could reveal its rule of genetic variation and character, which would give the directions for the strategy of resistant varieties breeding and the management of late blight disease on potato planting.【Method】The phenotypic characteristics such as mating type and metalaxyl resistance in combination with the genotypes such as mtDNA haplotypes, SSR and AFLP of the super physiological race of P. infestans isolates collected by our laboratory were analyzed systematically. 【Result】The results showed that 21 strains were A1 mating type, 14 self-fertile and only 5 A2 mating type among the 40 tested isolates. The numbers of high resistant and sensitive isolates to metalaxyl were 26 and 14, respectively. The mtDNA haplotype test showed a nearly 1-to-1 ratio between Ia and IIa. Among 40 isolates of the super physiological race,