Creating Of Rice Resources With Multiple Resistance

Rice (Oryza sativa L.) is one of the most important and the oldest crops in the world. Rice blast, stem borers, leaf roller, drought and other factors are the most important factors which seriously affect the rice production and restrict the sustainable agricultural development in China. Nowadays, the chemical pesticides are the most popular methods to solve these problems. However, what’s more, it causes severe environment pollution and other problems which are harmful for human health. Therefore, breeding new rice lines which are broad and durable resistance to the abiotic and biotic stress is one of the best ways to obtain the stable and high yield, promote sustainable development of agriculture and ensure food security in China.In this study, the donor materials and basic rice materials which contain the blast resistance genes have been crossed with the rice materials which contain the insect and drought resistant genes for the purpose to obtain some hybrid varieties which contain different kinds of resistant genes. Taking the advantages of molecular markers, the elite genes have been aggregated and the plants with good agronomic traits have been selected, which greatly reduced the risk of losing any single resistant gene and overcomed the long breeding period, poor predictability, lower efficiency, and reproduction isolation between species. Finally, the new materials have been obtained with broad spectrum, multi-resistance, high-stable-yield and good application prospect.By molecular markers, the homologous fragments of Pi40and Pi9in R498, the homologous fragments of Pikh, Pib, Pi9and Piz in Kang Hui1, the homologous fragments of Pi40, Pi9, Pikm and Piz in R06, the homologous fragments of Pikh、Pita、Pi9、Pikm and Piz in R1088, the homologous fragments of Pikh、Pita、Pi9、Pikm and Piz in R727and the homologous fragments of Pi40、Pi9、Pikm and Piz in R820have been detected.By full-length PCR, re-sequencing and specific molecular markers, five blast resistance genes homologous sequences in the receptor material R498have been detected. The result showed there were a9-bp fragment insertion at695bp in the coding region and a single base pair deletion at1071bp in the coding region. These mutations lead to early termination of translation at1145bp. Since the same SNPs of Pi9between R498and Nip in chr6sections 10386515-10388650, it was supposed that Pi9has the same sequence in R498and Nip. R498contained pita and did not have full Pikh sequence and Pid3has the same sequence both in R498and9311.Through traditional hybridization and marker-assisted selection,168insect-resistant materials,76drought resistance materials and28insect-drought-resistant materials have been obtained. Finally, the insect-resistant transgenic plants were identified by using inoculation both in laboratory and field. The results showed both the B21-1and B23were more resistant, the field withered heart rate were6.3%and1.9%respectively, the chilo simplex mortality were90%and93.33%, respectively.