李海伦 魏环宇 杨伟 李成云 刘永胜 王云月 王扬 谢勇

摘要 ‘月亮谷是云南元陽梯田种植面积最大的地方籼稻品种，种植历史逾百年仍保持对稻瘟菌较稳定的田间抗性，我们猜测其原因与‘月亮谷-稻瘟菌的群体互作有关。为此，本研究采用群体遗传学研究方法，利用稻瘟菌16 对 SSR 引物，对从‘月亮谷不同单粒传纯系、‘月亮谷自然群体、现代品种‘合系 22-2及云南元阳哈尼梯田环境中分离到的稻瘟菌进行遗传多样性分析，以了解不同‘月亮谷纯系对稻瘟菌群体遗传结构的影响。结果显示，来源于梯田环境的稻瘟菌与不同水稻品种（系）的稻瘟菌群体遗传结构差异明显，梯田环境：Ht=0.160 3，I=0.323 8;水稻寄主群体：Ht=0.092 9，I=0.200 9。而且，分离自不同水稻品种（系）的稻瘟菌群体遗传结构差异也较大，Shannons 遗传多样性指数、Nei 基因多样性指数和 PIC 的总体趋势是：‘月亮谷感病纯系（L4、L3）>‘月亮谷自然群体（G5）> ‘月亮谷抗病纯系（L1、L2）>‘合系 22-2（H6）。基于 neighbor-joining 的聚类分析发现，从环境（Y）中挑选的 30 株稻瘟菌和 6 个不同水稻寄主材料上分离到的稻瘟菌群体在相同相似系数下的遗传宗谱的数量变化趋势为：Y>L4>G5>L3>L1>L2>H6，说明现代品种对田间稻瘟菌群体产生的选择压力最大。水稻地方品种的抗病纯系群体对环境中稻瘟菌群体也产生了与现代抗性品种相类似的正向选择作用，而感病纯系和自然群体有利于稻瘟菌群体的稳定性选择。

关键词 水稻地方品种;单粒传;稻瘟病菌;群体遗传;定向选择

中图分类号： S435.111.41

文献标识码： A

DOI： 10.16688/j.zwbh.2021194

Abstract ‘Acuce， an indica landrace with the largest planting area in Yuanyang terrace of Yunnan province， has been planted for more than a hundred years and still maintain relatively stable resistance to Magnaporthe oryzae in the field. We hypothesized that this phenomenon might be related with the population interaction between ‘Acuce and M.oryzae. In order to understand the effects of ‘Acuce SSD lines on population genetic structure of M.oryzae， the genetic diversity of M.oryzae isolated from air in Hani terrace environment， ‘Acuce SSD lines， ‘Acuce natural population and modern variety ‘Hexi 22-2 were analyzed using 16 pairs of SSR primers based on population genetic methodology. The results showed that the genetic structure of M.oryzae population from terraced field environment was significantly different from that from different rice varieties （lines）： for the isolates from terraced field environment， Ht=0.160 3， I=0.323 8， and for the isolates from rice host population， Ht=0.092 9， I=0.200 9. Moreover， the population genetic structure of M.oryzae was also significantly different among different rice varieties （lines）. The general trend of Shannons genetic diversity index， Nei gene diversity index and PIC from high to low were as followed： susceptible line （L4， L3）， natural population （G5）， resistant line （L1， L2）， and ‘Hexi 22-2 （H6）. Based on the neighbor-joining clustering analysis， it was observed that the quantitative variation trend of genetic genealogy of 30 M.oryzae populations selected from the environment （Y） and six different rice host materials under the same similarity coefficient from high to low was as followed： Y， L4， G5， L3， L1， L2， and H6， which indicated that modern varieties had the greatest selection pressure on M.oryzae populations in the field. Similarly， the resistant SSD line also imposed positive selection on the population of M.oryzae， while the susceptible SSD line and natural population were conducive to the stable selection of M.oryzae population.1B464F7B-5FE0-4E50-B08C-3B7275142D42

Key words rice landrace;single seed descent;Magnaporthe oryzae;population genetic;directional selection

稻瘟病是全球危害最大、流行最广的水稻真菌病害之一，严重威胁水稻的生产[1-2]。稻瘟菌Magnap……