The Studies Of Molecular Maker Pyramiding Genes For Resistant To The Serious Diseases And Insect Pests In Rice

Rice(Oryza stativa)is one of the most important cereal crop in the world,Rices lives with a multitude of plant diseases and insect pests throughout their lives.Bacterial blight(BB),rice blast disease,stripe stem borer(Chilo suppressalis)and brown planthopper(BPH),which are so called "two diseases two insects" in rice,are the major rice diseases and insect pests.The incorporation of resistance genes into cultivars is considered as the most economical and effective approach to control the diseases and pests,xa23,pi9 and bph14 are wide-spectrum and dominant rice resistant genes to BB,blast and BPH respectively,and molecular markers of xa23 and bph14 are EST C189and SSR MRG2329 respectively.Transgenic rice with cry1Ac/sck genes is resistance to stripe stem borer.Somes rice near-isogenic lines(NILs)with one or two resistance genes and materals with three or four resistance genes are developed by maker assisted selection(MAS)strategy.Main results are as follows:(1)By maker assistd backcross breeding,xa23,pi9,cry1Ac/sck and bph14 genes was introgressed into fifteen receptors(twelve rice restorers and three maintainer lines)respectively.Five NILs with pi9,nine NILs with xa23,seven NILs with cry1Ac/sck and the BC3F2 of four receptors harboring the resistance gene bph14 were gotten.(2)Rice NILs carrying xa23 and pi9 genes or cry1Ac/sck and bph14 genes were developed by maker assistd backcross breeding.So far,two NILs with xa23/pi9 and the BC3F2 of one receptor harboring the resistance gene cry1Ac/sck and bph14 were gotten.(3)Three homozygous lines with the three resistance gene xa23,pi9 and bph14 and three homozygous lines with the four resistance gene xa23,pi9,cry1Ac/sck and bph14 were cultivated by MAS.The BT(CrylAc) protein ELISA analysis showed the average percentage of the relative content of BT protein is 0.1254%,the highest 0.1381%in the individuals of the three homozygous lines with the four resistance gene xa23,pi9,cry1Ac/sck and bph14;inoculation test in greenhouse showed these lines have resistance to blast.