| Rice(Oryza sativa L.)is one of the four major food crops consumed by humans worldwide.Magnaporthe oryzae(Magnaporthe oryzae;asexuality: Pyricularia oryzae)is one of the three most difficult to control diseases in the world.Proved by longterm production practice,the most economically feasible and safest method for controlling the disease is to cultivate and rationally use disease-resistant varieties.However,the resistance of disease-resistant varieties can only be maintained for 3 to 5 years in actual production.Therefore,it is of great significance to dig out and create new types of diseaseresistant genes to cultivate more durable and broad-spectrum disease-resistant varieties.Most of the resistance alleles Pik,Pik-m,Pik-p,Pik-s,Pik-h,Pi1,Pik-x,Pik-g,Pi7,etc.of the Pik locus of rice blast have broad-spectrum and lasting resistance.Therefore,discovering from gramineous plants and using gene-directed mutagenesis to create a new type of Pik gene,and then confirming its resistance function through transgenic technology,is of great significance for further enriching and using the Pik family in disease-resistant breeding programs.This research carried out the following work,and the main results obtained are as follows:(1)Resistance inheritance of transgenic offspring of the new Pik family of gramineous plantsArtificial inoculation with rice blast strain CHL346 and analysis of specific molecular markers,the progeny of the new Pik family genes Pik-sb,Pik-bd,Pik-bg,and Pik-eg of gramineous plants were phenotyped/co-segregation analysis of genotypes,the results showed that the resistance of new Pik family disease resistance genes in grasses can be inherited stably;at the same time,isolates/individuals without selection marker and carrying the target gene,or those carrying the selection marker and target gene and stably expressing the resistance pure By combining strains/individuals,a visual phenotype/genotype co-segregation analysis chart of related strains is obtained,which is further used as resistance source material for resistance spectrum identification and disease resistance breeding.(2)The inheritance of resistance in the transgenic offspring of the new Pik family by site-directed mutation of the broad-spectrum durable disease resistance gene Pi1Artificial inoculation with rice blast strain CHL346,the resistant gene Pi1 is sitedirected mutation of new Pik genes Pi1-M1,Pi1-M2,Pi1-M3,Pi1-M4,Pi1-M12,Pi1-M13,Pi1-M14 of T2 and T3 of the transgenic plants were phenotyped and the results showed that the resistance of the Pi1 site-directed mutation of the new Pik family disease resistance genes can be stably inherited.Genotype identification of T2 and T3 progeny of 7 new Pik gene transgenic plants using specific molecular markers,the results showed: Pi1-M1,Pi1-M2,Pi1-M3,Pi1-M12,Pi1-M13 transgenic plants T2 and T3 progeny Individual specific SNP sites were successfully mutated,but Pi1-M4,Pi1-M14 all or part of the individual related SNP sites were not successfully mutated;at the same time,isolates/individuals without selection markers and carrying the target gene were screened out,or carrying selection markers and the resistance homozygous strain/individual that can stably express the target gene and obtain the visual phenotype/genotype co-segregation analysis chart of the related strain,which can be further used as the resistance source material for the identification of resistance spectrum and disease resistance breeding. |
