摘要
无毒基因是病原物中决定寄主抗病性表达与否的功能基因,其功能的丧失导致毒性小种的产生。在先前的研究中,本研究小组从稻瘟病菌中分离了与无毒基因AVR-P ikm连锁的2个SCAR标记SCO12946和SCE121406。在本研究中,作者首先将这2个标记定位到稻瘟菌第1号染色体上;然后,利用稻瘟菌70-15全基因组草图序列和SSR技术,又分离了与无毒基因AVR-P ikm连锁的4个SSR标记:SSR47T34、SSR50CA24、SSR52TAGG18和SSR56A28。进一步分析表明:上述4个SSR标记位于与SCO12946和SCE121406相反的一侧,与AVR-P ikm位点的遗传距离分别为4.90、7.01、19.12和21.94 cM,无毒基因AVR-P ikm位于SCE121406和SSR47T34之间。本研究获得的稻瘟菌无毒基因AVR-P ikm的精细定位为通过染色体步移法克隆该基因奠定了基础。
Avirulence genes in pathogens are functional genes that determine if or not the race-specific resistance is expressed in host cultivars. Function lose of the genes results in generation of virulent races in pathogen population. In previous studies, two SCAR markers, SCO12946 and SCE121406 that are linked with the avirulence gene AVR-Pik^m in M. grisea were isolated. In this investigation, the two SCAR markers were mapped on the chromosome I by sequencing the end of the TAC clones and their comparison with the whole genome draft sequence of 70-15. On the basis of this result, four more DNA markers linked with AVR-Pik^m, SSR47T34, SSR50CA24, SSR52TAGG18 and SSR56A28, were identified utilizing the whole genome draft sequence of M. grisea 70-15 and SSR. Further analysis indicated that the four SSR markers lie on the side opposite to the two SCAR markers; the genetic distance between the four SSR markers and AVR-Pik^m is 4. 90,7.01, 19.12,21.94 cM, respectively. This mapping will facilitate isolation of AVR-Pik^m by chromosome walking.
出处
《植物病理学报》
CAS
CSCD
北大核心
2006年第2期116-122,共7页
Acta Phytopathologica Sinica
基金
"十五"国家重大科技专项基金资助项目(2002BA711A15)
国家"九七三"课题资助项目(G2000016201)
关键词
稻瘟病菌
SSR标记
无毒基斟
染色体定位
Magnaporthe grisea
SSR marker
avirulence gene
chromosomal location
