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.是亚洲水稻种植区最严重和最具破坏性的害虫之一。在本研究中，我们报告了来自印度水稻品种ADR 52的高抗褐飞虱的遗传基础。以ADR 52与感病品种台中65杂交的F_2群体为材料，进行了QTL分析。结果表明，该F_2群体对褐飞虱的高抗受多个基因位点控制。进一步利用携带ADR 52抗性基因的近等基因群体进行连锁分析，发现一个新的抗褐飞虱基因bph 20（t）定位在第6染色体短臂的远端，另一个基因bph 20（t）定位在第6染色体短臂的远端，Bph 21（t）定位于水稻第12染色体长臂上。其特征是形成水状损害，导致产卵部位的卵死亡。 关于我们 我们发现，苯甲醇苯甲酰转移酶（BEBT）的表达增加产卵后3小时的白背飞虱对近等基因系携带杀卵QTL，除了杀卵基因。褐飞虱产卵后，水稻植株中除了BEBT基因的表达外，还积累了肉桂酸-4-羟化酶（C4 H）。菌株进行了使用差异品种和携带BPH抗性基因的近等基因系。对1966年至2005年在日本收集的褐飞虱菌株进行了评价，使用9个不同品种携带不同的抗褐飞虱基因。结果表明，1989-BPH、1999-BPH和2005-BPH对Mudgo（携带Bph 1）有强毒力，1999-BPH和2005-BPH对ASD 7（携带bph 2）有强毒力。Bph 1和bph 2抗性基因在1989年和1999年之前已被分离。此外，根据成虫存活率和产卵量，我们发现1999-BPH和2005-BPH对bph 2C（t）和Bph 21（t）都有毒性，但对bph 20（t）和Bph 21（t）的组合系没有毒性。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