Christianson J A, Rimmer S R, Good A G, Lydiate D J
Department of Biological Sciences, University of Alberta, Edmonton, Canada.
Genome. 2006 Jan;49(1):30-41. doi: 10.1139/g05-085.
Blackleg disease of crucifers, caused by the fungus Leptosphaeria maculans, is a major concern to oilseed rape producers worldwide. Brassica species containing the B genome have high levels of resistance to blackleg. Brassica juncea F2 and first-backcross (B1) populations segregating for resistance to a PG2 isolate of L. maculans were created. Segregation for resistance to L. maculans in these populations suggested that resistance was controlled by two independent genes, one dominant and one recessive in nature. A map of the B. juncea genome was constructed using segregation in the F2 population of a combination of restriction fragment length polymorphism (RFLP) and microsatel lite markers. The B. juncea map consisted of 325 loci and was aligned with previous maps of the Brassica A and B genomes. The gene controlling dominant resistance to L. maculans was positioned on linkage group J13 based on segregation for resistance in the F2 population. This position was confirmed in the B1 population in which the resistance gene was definitively mapped in the interval flanked by pN199RV and sB31143F. The provisional location of the recessive gene controlling resistance to L. maculans on linkage group J18 was identified using a subset of informative F2 individuals.
由真菌大茎点菌（Leptosphaeria maculans）引起的十字花科黑胫病是全球油菜籽生产者主要关注的问题。含有B基因组的芸苔属物种对黑胫病具有高度抗性。创建了芥菜型油菜F2和首次回交（B1）群体，这些群体对大茎点菌PG2分离株的抗性呈分离状态。这些群体中对大茎点菌抗性的分离表明，抗性由两个独立的基因控制，一个在本质上是显性的，一个是隐性的。利用限制性片段长度多态性（RFLP）和微卫星标记组合在F2群体中的分离情况构建了芥菜型油菜基因组图谱。芥菜型油菜图谱由325个位点组成，并与之前的芸苔属A和B基因组图谱进行了比对。基于F2群体中抗性的分离情况，将控制对大茎点菌显性抗性的基因定位在连锁群J13上。在B1群体中证实了这一位置，其中抗性基因最终被定位在pN199RV和sB31143F侧翼的区间内。利用一部分信息丰富的F2个体确定了控制对大茎点菌抗性的隐性基因在连锁群J18上的临时位置。
