Development Of The Blast-resistant Rice By Molecular Marker-assisted Selection Of The Pi5Gene And Genetic Transformation Of The Sporamin Gene

Blast disease is one of the three most devastating diseases on rice, affecting the quality and quatity of rice heavily in China and other rice production areas in the world. So it’s important to create new rice materials resistant to rice blast. Many new resistant materials have been cultivated by traditional breeding combining with the modern molecular breeding technology until now and have been used widely.This study aims at cultivating new rice blast material by marker-assistant selection and trangenic technology. On the one hand we transfer the resistant gene Pi5from high and durable blast resistant culticar, Guyou12, to the female parent, photosensitive (temperaturesensitive) restorer lines921082, by marker-assistant selection. On the other hand, we hope to get improved material with high reisitance to blast by transferring sporamin and Chitinase to the susceptive cultivation, Nipponbare, with transgenic technology. The main results are as follows:(1) We design3pairs specificity primer, Pi5-1/-2、Pi5-3/-4and Pi5-5/-6, according to DNA sequence differences between Pi5and the Pi5loci in Nipponbare. We find that we can get the expected PCR bands in Guyoul2with the primers, while there is no amplified bands in921082, which suggests that there is complete Pi5in Guyou12.(2) We get9individualplants and2individualplants in BC1F1and BC2F1respectively, with the forementioned markers selecting the backcross progeny whose parents are Guyoul2and921082, while921082is the recurrent parents. In the process of background selection, we find that there are2individualplants,3-4and3-5, of the9individualplants in BC1F1with higher background recovery rate,80.18%and83.33%respectively. There are two individualplants, Y294-1and Y294-8, with complete Pi5in BC2F1, and the background recovery rates are90.09%and92.34%respectively. Then we inoculate PO6-6to Y294-1and Y294-8, and they show resistant to PO6-6.(3) We transfer sporamin and Chitinase to susceptible cultivation Niponbare with agrobacterium-mediated transformation, and we get50trangenic pure lines finally. In Enshi blast nursery we find that four trangenic materials show more than5levels of resistance.