Improvement Of The Rice Blast Resistance Of R2817 And Blast Resistance And Brown Plant Hopper Resistance Of Fengxianghui No.1

Rice blast which is a worldwide rice disease is one of the three major rice diseases(rice blast, bacterial leaf blight, sheath blight). Brown planthopper happened frequently in our country in recent years. Both rice blast and brown planthopper constraint the rice production. The use of molecular marker assisted selection for rice blast and brown planthopper resistance breeding is an effective measure to control plant diseases and insect pests.Fengxianghui No.1 and R2817 are two excellent rice restorer lines, the combinations in which they were used as male parent were widely used in the hybrid rice production. But they are not resistant to rice blast and brown planthopper. In this study, we introgressed blast resistance gene Pi9(from 75-1-127) into R2817 and introgressed blast resistance gene Pi9 and brown planthopper resistance genes Bph14、Bph15(from B5) into Fengxianghui No.1 with the using of marker-assisted selection technology, backcrossing and gene pyramiding. Several new restorer lines carrying gene Pi9 under the genetic background of Fengxianghui No.1 or R2817, carrying both Bph15 and Bph14 genes under the genetic background of Fengxianghui No.1, and carrying Pi9, Bph15 and Bph14 genes under the genetic background of Fengxianghui No.1 were selected. The resistance identification of Rice blast and brown planthopper, and the main agronomic traits, yield, rice quality traits were characterized. The main results were as follows:1.Twenty four new restore lines carrying Pi9 under the genetic background of R2817 have been selected. The rice blast identification of these lines and their hybrid combinations was conducted at Yichang in 2014. The results showed that six lines reached moderately resistance(MR), three lines showed moderately susceptible(MS), the other lines showed susceptible(S) or highly susceptible(HS). The leaf blast resistance of 24 lines were improved, but the composite index of resistance were increased a little. The blast resistance of the hybrid combination Hui34S/HWQ13033-3-2 riched moderately resistance(MR), the other seven hybrid combinations(including Hui34S/HWQ13032-11-2 、 Hui34 S /HWQ13032-11-3 、 Hui34 S /HWQ13033-1-1 、Hui34S/HWQ13033-1-2、Hui34S/HWQ13033-1-3、Hui34S/HWQ13033-3-1、Hui34S /HWQ13033-3-3) showed moderately susceptible(MS). The 1000-grain weight and grain weight per plant in these eight hybrid combinations are different from Fengliangyou No.4(the control), while the other main agronomic traits are similar with Hui34S/R2817. The yield per plant were over Fengliangyou No.4 by more than 10%.2. Twenty eight restore lines carrying Pi9 under the genetic background of Fengxianghui No.1 have been selected. The rice blast identification of these restore lines and their hybrid combinations was conducted at Yichang in 2014. The results showed that the resistance of HWQ13022-11 and HW12234 reached moderately resistance(MR), HWQ13022-7-3 and HW12166-2 showed susceptible(S), the other restore lines showed highly susceptible(HS). The leaf blast resistance of 28 restore lines were scored between 4 and 7, the leaf blast resistance were significantly improved. But the incidence of panicle blast and loss ratio of panicle blast were improved a little. The resistance of hyrid combination Guangzhan63S/HW12234 reached moderately resistance(MR).The seed setting rate and grain weight per plant in hybrid combination Guangzhan63S/HWQ13020-7-1 was significantly higher than Fengliangyouxiang No.1, while the other main agronomic traits are similar with Fengliangyouxiang No.1. The leaf blast resistance of HWQ13020-7-1 and its hybrid combination Guangzhan63S/HWQ13020-7-1 were scored as 5 and 6, showed moderately susceptible(MS).3. Thirty restorer lines carrying Bph14 and Bph15 under the genetic background of Fengxianghui No.1 have been selected. The brown planthopper identification of these restore lines and their hybrid combinations was conducted in 2014. The results showed that the brown planthopper resistance of restore lines HW12182-1, HW12182-2 and HW12197 reached level 3(R), while restore lines HWQ13006-20-3, HWQ13007-49-3 and HW12169-37 showed 5(MR). The resistance of hybrid combinations Guangzhan63S/HW12182-2 and hybrid combinations guangzhan63 S /HW12197 showed moderately susceptible(MS). The seed setting rate and grain weight per plant of hybrid combination Guangzhan63S/HWQ13007-49-3 were significantly higher than contrast, while the other main agronomic traits were similar with Fengliangyouxiang No.1. The growth period of Guangzhan63 S /HWQ13007-49-3 was significantly longer than the control, while the other main agronomic traits are similar with Fengliangyouxiang No.1.4. Nine restorer lines carrying Pi9, Bph14 and Bph15 under the genetic background of Fengxianghui No.1 have been selected. The resistance of leaf blast are between level 4(MR) and level 6(MS), but the composite index of resistance showed level 9(HS). The brown planthopper resistance of HWQ13017-11-16 and HWQ13017-11-231 showed level 9(HS), while other 7 restore lines showed level 7(MS).