Genetic mapping of host plant resistance genes against rice planthopper species and monitoring the breakdown of the host plant resistance in rice

褐飞虱（Nilaparvata lugens Sal）。是水稻最严重和最具破坏性的害虫之一，在亚洲的水稻种植区随处可见。在本研究中，我们报道了来自印度水稻品种ADR52的BPH高抗性的遗传基础。以ADR52与敏感品种台中65杂交获得的F_2群体为材料，进行了数量性状位点（QTL）分析。结果表明，该F_2群体对BPH的高抗性由多个基因座控制。进一步的连锁分析表明，携带ADR52抗性基因的近等基因群体在6号染色体短臂远端定位了一个新的bph20(t)抗性基因，在12号染色体长臂上定位了另一个Bph21(t)抗性基因。水稻对白背飞虱（WBPH）的杀卵反应的特点是形成水样损伤，导致产卵部位的卵死亡。结果表明，在除杀卵基因外，还携带杀卵qtl的NILs上，产卵3小时后，苯甲醇苯甲酰转移酶（BEBT）的表达增加。除了BEBT的表达外，肉桂酸-4-羟化酶（C4H）在WBPH产卵后也在水稻植株中积累。利用携带褐飞虱抗性基因的差异品种和NILs，对褐飞虱（BPH）、褐飞虱（Nilaparvata lugens）菌株的毒力进行了长期监测。用9个携带不同抗性基因的品种对1966 ~ 2005年在日本采集的白斑病品系进行了鉴定。结果表明，1989- bph、1999-BPH和2005-BPH菌株对携带Bph1的Mudgo有毒力，1999-BPH和2005-BPH菌株对携带bph2的ASD7有毒力。耐药基因Bphl和bph2分别在1989年和1999年之前被分解。此外，我们发现1999-BPH和2005-BPH对bph2C(t)或Bph21(t)都有毒力，但对bph20(t)和Bph21(t)的组合系没有毒力，基于BPH成虫存活率和产卵量。少

The brown planthopper (BPH), Nilaparvata lugens Sal. is one of the most serious and destructive pests of rice that can be found throughout the rice growing areas in Asia. In the present study, we report a genetic basis of high resistance to BPH derived from an Indian rice cultivar, ADR52. An F_2 population derived from a cross between ADR52 and a susceptible cultivar, Taichung 65 was used for quantitative trait loci (QTL) analysis. The result showed that multiple loci controlled the high resistance to BPH in this F_2 population. Further linkage analysis using nearly isogenic populations, which carry resistance genes transferred from ADR52,revealed that a new BPH resistance gene, bph20(t) was mapped on distal end of the short arm of chromosome 6 and another one, Bph21(t) was mapped on the long arm of chromosome 12.Rice ovicidal response to whitebacked planthopper (WBPH) is characterized by the formation of watery lesions which result in the death of the eggs at the ovipositional sites. … More We revealed that the expression of benzyl alcohol benzoyl transferase (BEBT) increased three hours after oviposition of the WBPH on NILs carrying ovicidal QTLs in addition to the ovicidal gene. In addition to the expression of BEBT, cinnamic acid-4-hydroxylase(C4H) was also accumulated in the rice plant after oviposition of the WBPH.Long-term monitoring of the virulence of the brown planthopper (BPH), Nilaparvata lugens (Stal.) strains was carried out using differential cultivars and NILs carrying the BPH resistance genes. The BPH strains collected between 1966 and 2005 in Japan were evaluated using nine differential cultivars carrying different resistance genes against the BPH. The results showed that the1989-BPH, the 1999-BPH and the 2005-BPH strains were virulent to Mudgo (carrying Bph1) and the1999-BPH and the 2005-BPH strains were virulent to ASD7 (carrying bph2). It is appeared that the resistance genes, Bphl and bph2 had been broken down before 1989 and 1999, respectively. In addition, we revealed that the 1999-BPH and the 2005-BPH were virulent to either bph2C(t) or Bph21(t), but not against the combined line of bph20(t) and Bph21(t) based on the adult survivorship and oviposition of the BPH. Less