水稻黑条矮缩病抗性QTL分析

Detection of QTL for Resistance to Rice Black-Streaked Dwarf Viral Disease

利用珍汕97B/明恢63的重组自交系群体,采用自然发病鉴定的方法,以穴发病率为表型值,对各株系进行黑条矮缩病抗性鉴定。群体的穴发病率偏向于抗病亲本,且呈连续性分布,表明水稻黑条矮缩病抗性受数量性状基因控制。利用WinQTLcart2.5软件对黑条矮缩病抗性QTL进行分析,共检测到6个QTL,其中第6、11染色体上各有2个,第7、9染色体各有1个。第6、7、9染色体上的4个QTL在两个地点都能检测到,是稳定表达的QTL,尤其是第6染色体上的2个QTL,LOD值分别为12.09和9.77,贡献率分别为20.20%和18.68%,是主效QTL,能在分子标记辅助选择育种中加以利用。

The rice black-streaked dwarf viral disease （RBSDV）, transmitted by the planthopper Laodelphax striatellus Fallèn, was one of the most serious diseases in rice in south China. Breeding of RBSDV resistance variety using marker-assisted selection was effective measure to reduce the disease damage. For achieving this aim, QTL mapping of resistance to RBSDV was studied using a recombinant inbred line （RIL） population from the cross between Zhenshan 97B and Minghui 63. Reactions of 242 RILs to RBSDV were investigated by natural infection method in Agricultural College of Yangzhou University and Lixiahe Agricultural Research Institute, and scored by the incidence of RBSDV. The trait of RBSDV incidence was normally distributed and marked bias towards the resistant parent, which implied that they were controlled by quantitative trait loci. Six QTLs for resistance to RBSDV were detected by WinQTLcart 2.5 software. Two adjacent QTLs were mapped on chromosome 6, two on chromosome 11, one on chromosomes 7 and 9, respectively. Four QTLs on chromosomes 6, 7, and 9 could be detected in two locations, and were stably expressed across the two environments. There had not been any reports about location of QTL for resistance of rice stripe virus and planthopper, which suggested that six QTLs in this study were really resistant to RBSDV. Two QTLs on chromosome 6 were with main effect, and their contributions to the total variation were 20.20% and 18.68% with LOD scores of 12.09 and 9.77 respectively, moreover, they had high value for study on genetics of RBSDV and should be useful in marker-assisted selection for resistance to RBSDV.