不同遗传背景下稻瘟病菌致病性对比分析

摘要

稻瘟病是黑龙江省水稻生产中的主要病害之一,造成重大产量损失。本文为明确不同遗传背景下4个稻瘟病菌株群致病性及其寄主品种的抗性改良情况,以中国鉴别品种、日本清泽鉴别品种、水稻单基因系品种和当地水稻品种为鉴定体系,以各群菌株为研究靶标,通过喷雾接种方式,结合联合抗病性和基因聚合方式完成改良分析得出下列结论：(1)在中国鉴别品种体系下,源自空育131、垦稻12、上育397和哈9811的菌株分别被划分为10个、6个、6个和9个生理小种,源自哈9811的菌株的优势小种为 ZF1,其他3个类群菌株的优势小种均为 ZG1。(2)在日本清泽鉴别品种体系下,源自空育131、垦稻12、上育397和哈9811的菌株分别被划分为19个、11个、13个和14个生理小种,其致病率平均值分别为54.17%、46.21%、41.67%和59.90%。(3)在水稻单基因系品种体系下,源自空育131、垦稻12、上育397和哈9811的菌株分别被划分为20个、11个、12个和16个致病型,其致病性相似系数分别介于0.20~0.87、0.25~0.90、0.25~1.00和0.31~0.88。(4)在当地水稻品种体系下,源自空育131、垦稻12、上育397和哈9811的菌株分别被划分为12个、7个、9个和13个致病型,其最佳抗性品种分别为龙盾104、松粳6号、松粳9号和龙稻7号。(5)从抗性改良角度分析,应用联合抗病性方式,其联合抗病性系数和联合致病性系数平均值分别介于0.71~0.92和0~0.08,效果较好；应用基因聚合方式,对源自空育131、垦稻12、上育397和哈9811的菌株表现免疫的基因组合分别有2个、2个、5个和7个。综合分析,以水稻单基因系品种为体系进行稻瘟病菌株致病性分析效果较好；2种抗性改良方式效果都较好,但也各有利弊。%Rice blast is one of the most serious rice diseases in Heilongjiang province, resulting in high incidence and yield reduc-tion. In order to definite the pathogenicity of P. oryzae isolates and resistance improvement of nurse varieties under different ge-netic backgrounds, the experiment was conducted using four groups of Pyricularia oryzae (P. oryzae) isolates and rice varieties including Chinese differential varieties, Japanese differential varieties, monogenic rice lines and landrace. Using the method of spraying inoculation and associational resistance and gene pyramiding analyses, the main results were as follows: (1) Under the Chinese differential varieties system, the P. oryzae isolates from Kuiku 131, Kendao 12, Shangyu 397, and Ha 9811 were divided into ten, six, six, and nine physiological races respectively, and predominant physiological race of P. oryzae isolates from Ha 9811 was ZF1 while the predominant physiological races of the other three groups of P. oryzae isolates were all ZG1. (2) Under the Japanese differential varieties system, the P. oryzae isolates from Kuiku 131, Kendao 12, Shangyu 397, and Ha 9811 were divided into 19, 11, 13, and 14 physiological races respectively, furthermore, the average disease incidence was 54.17%, 46.21%, 41.67%, and 59.90%, respectively. (3) Under the monogenic rice lines system, the P. oryzae isolates from Kuiku 131, Kendao 12, Shangyu 397 and Ha 9811 were divided into 20, 11, 12, and 16 pathogenic types respectively, additionally, their similarity coefficient of pathogenicity was 0.20–0.87, 0.25–0.90, 0.25–1.00, and 0.31–0.88, respectively. (4) Under the landrace system, the P. oryzae isolates from Kuiku 131, Kendao 12, Shangyu 397, and Ha 9811 were divided intotwelve, sever, nine and thirteen pathogenic types respectively, with the best blast-resistance varieties of Longdun 104, Songjing 6, Songjing 9, and Longdao 7. (5) Using the method of associational resistance, the average associational resistance coefficient and associational pathogenicity coefficient were 0.71–0.92 and 0–0.08, respectively; Using the method of gene pyramiding, the number of immunity gene combination to the P. oryzae isolates from Kuiku 131, Kendao 12, Shangyu 397, and Ha 9811 were two, two, five and seven. In conclusion, using monogenic rice lines to research the pathogenicity of P. oryzae is better than using other appraisal systems. And good effects can be get from two resistance improvement methods, but both of them have their advantages and disadvantages.