Improvement Of The Bacterial Blinght, Rice Blast And Brown Planthopper Resistance Of Rice Restorer Lines Xianhui207 By Pyramiding Genes

Rice is an important food corp. Bacterial blight(BB), rice blast(BL), brown planthopper(BPH) are three of the most serious diseases and insect-pests, which seriously limit rice production of high yield, stable yield and high quality. In 2014, 96 million hm2 rice suffered from diseases, which became more serious than previous years. Developing and planting new resistant varieties control of diseases and insect pests effectively. The molecular markers assisted selection technology easily to choose the plant which have target gene, will greatly improve the efficiency of breeding.In the present experienct, Huahui1437 with two bacterial blight resistance genes Xa7, Xa21 which was from the genetic background of Xianhui207 by backcrossing, molecular marker assisted selection(BMAS). 75-1-127 harboing a rice blast resistance genes Pi9 and B5 possesing two brown planthopper resistance genes Bph14, Bph15 were used for pyramiding multi-resistance genes. More than 20 breeding lines with double resistance(BB and BL or BB and BPH) were developed. Some of them were used to testcross with a CMS line Jin23 A. We evaluated the resistance identification, the agronomic traits and rice quality traits of breeding lines and their derived hybrids. The main results showed as follows:1. Twenty-one breeding lines carrying genes Xa7, Xa21 and genes Pi9 under the genetic background of Xianhui207 were selected. Of them, eleven lines were testcrossed with Jin23 A. Two strains of Xanthomonas oryzae pv.Oryzae, GD1358 and ZHE173 were inoculated to breeding lines and eleven combinations for identifying the bacterial blight resistance. The results showed that twenty-one breeding lines were resistant against two Xoo strains, the eleven combinations were resistant or medium resistant to two Xoo strains. The results of evaluation at Yuan’an where is the rice blast prevalent areas, showed that breeding lines and combinations were resistant or medium resistant against blast.Two priming combinations, Jin23/YJQ1301-32-1 and Jin23/YJQ1313-1 were selected. They were resistant against BB and BL. The agronomic traits and rice quality are similar to Jinyou207.2. Twenty-five breeding lines carrying genes Xa7, Xa21, Bph14, Bph15 and two breeding lines carrying genes Xa7, Xa21, Bph15 or Xa7, Bph14, Bph15, respectively, were selected. Twelve of them were testcrossed with Jin23 A. The evaluation results of bacterial blight showed that all breeding lines and twelve combinations were resistant agains two Xoo strains. The results of BPH resistance identifications at seedling stage showed that eight lines were highly resistant against BPH, sixteen lines were resistant against BPH and three lines were moderately resistant against BPH. But hybrid combinations weren’t resistant to BPH. These results implied that when the restorer lines carrying BPH resiatance genes, but sterile line didn’t carry BPH resistance genes, their hybrid combinations were not resistant to BPH. The results of main agronomic traits test and rice quality analyses showed that only one hybrid combinations, Jin23A/YJQ1339 were similar as Jinyou207.