Development Of Brown Plant Hopper Resistant Rice Photo-Thermo-Sensitive Genic Male Sterile Lines

Brown planthopper (BPH)(Nilaparvata lugens Stal) is one of the most widespread and destructive rice pests which decrease rice yield. In recent years two-line hybrid rice has become an important type in rice production in China. However, most sterile lines are lacking in BPH resistance genes and the hybrid combinations for BPH resistance are mainly rely on the restorer lines. So developing rice sterile lines with BPH resistance can strengthen the resistance to BPH for combinations and is very significant for our country rice production.In this research, Two BPH-resistance genes, Bphl4and Bphl5, coming from B5were introgressed into the sterile line C815S, Guangzhan63-4S and Hua328S by crossing, backcrossing and molecular marker-assisted selection (MAS). Several new PTGMS breeding lines were developed through identification of BPH resistance, fertility alteration, analysis of main agronomic traits, rice quality and crossing tests. The main results are as follows:1. Eight PTGMS breeding lines were developed, they were desinated as Hua1054S, Hua1141S, Hua1164S (with background of C815S), Hua1053S, Hua1143S, Hua1155S, Hua1165S (with background of Guangzhan63-4S) and Hua1212S (with background of Hua328S).2. The results of BPH resistance identification showed that eight PTGMS breeding lines were moderately or highly resistant against BPH.Among which, Hua1054S, Hua1155S, Hua1212S and Hua1165S were resistant against BPH.3. The results of identification under23℃water in the growth chamber showed that the pollen sterilities of eight breeding TGMS lines were higher than99.5%, indicating that their fertility alteration caritical point located on23℃. The stable sterility durations was longer than thirty days.4. The analysis results of main agronomic traits and rice quality showed that some of lines were better than controls. Among which the main agronomic traits and rice quality of Hua1165S were better than Guangzhan63-4S, except its small stems.5. The results of cross-testing showed that the yield combining ability of Hua1164S was better than C815S, but other breeding PTGMS lines were lower than contrasts. It is necessary to improve combining ability of new developed PTGMS lines in future.