Improvement Of The Fungal Blast Resistance Of T1007 And The Bacterial Blight Resistance Of Hua201S Through Molecular Marker-assisted Selection

The heterosis utilization is the effective way to increase the yield potential of rice in our country. However, many of hybrid varieties are susceptible to bacterial blight and fungal blast, which are two of the most serious diseases in rice production worldwide, and cause great yield loss. Developing new varieties with resistant to bacterial blight and fungal blast is an effective method economically in rice breeding program. Huazhong Agricltural University has developed two early two-line rice hybrids, Hua-Liangyoul03 and Hua-Liangyoul05, and one medium two-line rice hybrid, Hua-Liangyoul206. They were certifercated in Jiangxi and Hubei Province in recent years, respectively. Hua-Liangyou103 and Hua-Liangyoul05 were susceptible to fungal blast, and Hua-Liangyou1206 was susceptible to bacterial blight. The aim of this study was to improve the fungal blast disease resistance of T1007, which is the male parent of Hua-Liangyou103 and Hua-Liangyoul05, by introgressing fungal blast resistance gene Pi-2, and the bacterial blight disease resistance of Hua201S, which is the female parent of Hua-Liangyou1206, by introgressing bacterial blight resistance genes; Xa7, Xa2\, through MAS and embryo culture in the process of backcross-selfcross. The follows are the main results:1. Through MAS and embryo culture in the process of backcross-selfcross, 12 homozygous introgressing lines were obtained from T1007, the receptor parent which was highly susceptible to fungal blast. The resistance level in some lines was improved.2. The results of evaluating to main agronomic charateristics showed that five breeding lines, VE6203, VE6213, VE6222, VE6228 and VE6235, were similar to the original parent T1007. Other five lines, VE6202, VE6205, VE6208, VE6217 and VE6235 had some differences comparing with T1007 in seed-setting and 1000-seed weight.3. 12 breeding lines with introgressing pi-2 were tested with Hua102S, and the combinations were compared with Hua-Liangyou103. The results indicated that VE6283 was as same as Hua-Liangyou103. VE6279, VE6281, VE6286, VE6288 had more tillers/plant, longer panicle, more grains/panicle and higher 1000-seed weight than the contrast.4. 12 breeding lines with introgressing Pi-2 were tested with Hua103S, and the combinations were compared with Hua-Liangyou105. The results showed that the plant types, plant height, panicle length, 1000-grain weight in the combinations were...