Development Of Photo-thermo-sensitive Genic Male Sterile Lines And Two-line Hybrid Rice With Resistant Against Stemborer And Brown Plant Hopper

Brown planthopper(BPH)(Nilaparvata lugens) and stemborer are the major insect pests for the rice production, which can lead to great damage of the rice’s yield, quality and commercial value. Modern biotechnology and convential breeding technology were used to develop Photo-Thermo-sensitive Genic Male Sterile(PTGMS) rice lines with the resistance to BPH and stemborer. These PTGMS lines were used to develop two-line hybrid rice resisitant against insects. It can help to reduce the use of pesticides, protect environment, and has vital significance for the food security of our country.In this research, the methods of crossing, backcrossing, multicross and marker-assisted selection were used to introgress two BPH resistance genes Bph14 and Bph15 into Hua328 S, the BPH resistance gene Bph15 and insect-resistance gene cry1C* were introgressed into C815 S, and insect-resistance gene cry1C* was introgressed into Guangzhan63-4S. Several new insect-resistance PTGMS lines were developed. These new PTGMS lines and other Hua1165S(carrying Bph14, Bph15 and Pi2), Hua1228S(carrying Xa7, Pi2) were crossed with several male parents for developing two-line hybrid rice. The BPH and stemborer resistances, main agronomic traits and rice quality traits of the developed new PTGMS lines and their derived hybrid rice were evaluated in the past two years. The main results were as following:1. Four PTGMS lines carrying Bph14 and Bph15(desiged as Hua1301 S, Hua1302 S, Hua1303 S, Hua1305S)under the genetic background of Hua328 S, Hua1306 S carrying cry1C* under the genetic background of Guangzhan63-4S and Hua1307 S carring Bph15 and cry1C* under the background of C815 S were developed.2. The identification results in the plant growth chamber showed that the critical temperature point(CTP) of fertility-sterility alteration of Hua1306 S was ranged in 23.0-23.5℃ of daily mean temperature. The CPT of fertility-sterility alteration of other PTGMS lines were higher than 23.5℃ of daily mean temperature.3. The results of BPH-resistance identification, the field insect-resistance evaluation and main tested agronomic traits showed that Hua1301 S, Hua1302 S, Hua1303 S and Hua1305 S were resistant against BPH. Their plant height were significantly higher than Hua328 S, and other agronomic traits were similar as Hua328 S. Hua1307 S was moderately resistant against BPH and highly resiatant against stemborer. Its main agronomic traits were similar as C815 S. Hua1306 S was not damaged by stemborers in the field. Its main agronomic traits was similar as Guangzhan63-4S.4. The results of BPH-resistance identification of 95 hybrid combinations showed that 13 combinations were highly resistant against BPH, 15 combinations were resistant against BPH and 25 combinations were moderately resistant against BPH. These results were implying that both the female parent and the male parent have BPH-resistance genes, the BPH-resistance of hybridized combination can be improved significantly, but only one parent in combination has BPH-resistance gene, the hybridized combinations were not resistant against BPH. All of the combinations carrying cry1Ab/Ac or cry1C* genes were resistance to stemborers in the field. The percentage of damaged leaves by leaffolders of non-trangenic contrast Fengliangyou No.4 is 21.6%, the white head rate is 3.79%, and the leaffolder damage and white head rate of Jinyou207 are 19.42% and 4.43%, respectively.5. The identificant results of yield hetorosis showed that the yields of the combinations from Hua328 S and new developed PTGMS lines under the genetic background of Hua328 S were higher than the contral combination “Jinyou207”. Of them, the yields of Hua1302S/ZX11032-15, Hua1305S/ZX11520 and Hua328S/ZX11307 were significantly higher than contral combination, they can be considered as promising second crops. The growth duration of the hybrid combinations from Hua1306 S, Hua1307 S, Hua1165 S, and Hua1228 S used as the female parent were similar to Fengliangyou No.4. Hua1306S/ZX11057, Hua1165S/CHQ1318-1 and Hua1165S/CHQ1318-1with good insect-resistance and qulity can be considered as promising combinations for single crop.