福建省稻瘟病菌致病性及其无毒基因分析

Pathogenicity and avirulence genes analysis of Magnaporthe grisea Barr. from rice in Fujian Province of China

利用41个已知抗性基因水稻品种测定2003—2006年从福建省闽东、闽南、闽西、闽北和闽中5个主要稻区采集分离的87个稻瘟病单孢菌株的致病性。结果表明,福建省稻瘟病菌群体含有与所有测试抗病基因相应的无毒基因,其中66.67%的稻瘟病菌株表现较强致病力。病菌群体对水稻抗病基因Pi-d2、Pi-k(1)、Pi-km、Pi-kh、Pi-1(1)、Pi-z5(1)、Pi-z5(2)和Pi-1(2)的毒力频率均低于10%,提示这些抗病基因在福建省可作抗源使用。2003—2006年福建省稻瘟病菌群体中分别出现了40、37、36和38个无毒基因,其中有34个无毒基因在各年份均有分布,有30个无毒基因在5个主要稻区均有分布,Avr-a(2)、Avr-3(2)、Avr-ks、Avr-4b、Avr-b、Avr-kp(C)、Avr-km(C)、Avr-ta(C)、Avr-11(C)、Avr-19(t)、Avr-t和Avr-a(1)无毒基因的出现频率均低于30%,提示与之相对应的抗病基因在福建省水稻品种抗稻瘟病育种中应慎用。含有17、14、23、18和16个无毒基因组合的病菌较多,其组合频率分别为13.79%、10.34%、9.20%、8.05%和8.05%。

In order to know virulence of Magnaporthe grisea Bart. from rice in Fujian Province of China, pathogenicity of 87 M. grisea single spore isolates from 5 rice growing regions of Mindong, Minnan, Minxi, Minbel and Minzhong during 2003 to 2006 in Fujian Province was studied against 41 rice varieties known resistance genes. The results indicated that all the avirulence genes, which corresponding to the resistance genes, were detected in Fujian isolates, 66.67% of isolates had stronger pathogenicity. The virulence frequency of the isolates group to resistance gene Pi-d2, Pi- k （ 1 ）, Pi-k^m, Pi-k^h, Pi-1 （ 1 ）, Pi-z^5（1）, Pi-z^5（2） and Pi-l（2） was all below 10%, which suggested that these resistance gene could be used as resistance resources in rice breeding in Fujian Province. 40, 37, 36 and 38 avirulence genes were detected in isolates from 2003 to 2006 respectively, 34 avirulence genes were detected in each year, and 30 avirulence genes were detected in all five rice growing regions, avirulence genes Avr-a （2） , Avr- 3（2）, Avr-k^s, Avr-4b, Avr-b, Avr-k^p（ C） , Avr-km（ C） , Avr-ta （C）, Avr-ll （C）, Avr-19 （t） , Avr-t and Avr-a（ 1 ） occurred at a frequency of below 30% , it suggested that resistance genes corresponding to these avirulence genes would not be suitable to apply in rice breeding of resistance for control of M. grisea in Fujian Province. Most of isolates contained 17, 14, 23, 18, 16 avirulence genes with combination frequencies of 13.79% , 10.34%, 9.20%, 8.05% and 8.05% respectively.