| Rice blast is one of the major diseases affecting rice growth,which poses a great threat to the growth of rice.In order to achieve the purpose of controlling rice blast,breeders have introduced rice blast resistance genes into rice,resistance transformation,making it resistant to rice blast.As the physiological races of Magnaporthe grisea are susceptible to mutations,the newly promoted disease-resistant varieties often lose their resistance to disease soon after planting,resulting in the loss of their value.Therefore,quickly and effectively discover and use of fine varieties of resistance to rice blast has been the research focus at home and abroad.In this study,ten rice blast fungi and rice cultivars,ZYQ8 and JX17,were used as experimental materials,combined with genetic loci,population genetic analysis and bioinformatics analysis.To identify and screen the candidate genes for rice blast,followed by rice transformation,to verify its resistance to disease.The main results of this study are as follows:1.There were 254 NBS-LRR genes in 10 QTL loci of rice blast fungus and the total number of NBS-LRR genes was 468,accounting for 54.3% of the total number of NBS-LRR genes.The total length of the 10 QTL loci was 46,526,191 bp,accounting for 10.8% of the total length of the whole genome of rice,indicating that the ten QTL loci we located were located in the enrichment area of NBS-LRR gene.2.There are 119 genes in six QTL locating areas of ZYQ8 anti-JX17 susceptible.Among which there are 33 genes which are true genes in indica rice and pseudogenes in japonica rice.There are 69 genes in indica and japonica are both true genes.The former were screened out according to the criteria of Pi-indica / Pi-japonica greater than 20,and the latter two genes were screened according to the criteria of Pi-indica / Pi-japonica greater than 5.At last,five genes were used as ZYQ8 anti-candidate genes.3.There are 135 genes in four QTL locating areas of JX17 anti-ZYQ8 susceptible,among which there are 30 genes which are true genes in japonica rice and pseudogenes in indica rice.There are 84 genes in indica and japonica are both true genes.The former selected one gene according to the standard of Pi-indica / Pi-japonica less than 0.5,and the latter selected 5 genes according to the standard of Pi-indica/Pi-japonica less than 0.5.At last,six genes were used as JX17 anti-candidate genes.4.Through the above method,there were 11 candidate genes for rice blast resistance,distributed in eight QTL locating areas.Among them,there were five candidate genes for ZYQ8 resistance,located in four ZYQ8 resistant QTL locating areas;there were six candidate genes for JX17 resistance,located in four JX17 resistant QTL locating areas.5.We successfully constructed five genes complementary carriers for ZYQ8 resistance JX17 susceptible,and six genes knockout carriers for ZYQ8 susceptible JX17.These carriers are all successfully constructed and transferred into JX17 for agrobacterium-mediated rice transformation.6.At present,there are four genes that have been knocked out successfully on the T0 generation of transgenic plants,and a gene has been obtained for T1 generation of transgenic plants.A part of T1 generation of transgenic plants resistance testing has been completed,there are two transgenic plants showing obvious susceptibility and control of JX17 showed resistance,we initially thought that Os11g47780 is likely to the rice blast resistance gene we are looking for.7.At present,there are two genes that have successfully obtained the transgenic plants of the complementary carries,and the four transgenic plants of one gene have been tested for resistance.We found that three transgenic plants showed resistance and the control of the JX17 showed susceptibility.We initially thought that Os09g09490 is likely to be the rice blast resistance gene we are looking for. |
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