I mproving Blast Resistance of Rice Restorer R288 by Molecular Marker -Assisted Selection of Pi9 Gene

To improve blast resistance of rice restorer line R288,an inner -gene functional marker Clon2 -1 was designed based on DNA sequence of the cloned broad -spectrum blast resistance gene Pi9,and molecular marker -assisted breed-ing was implemented.The main results were as the follows:Clon2 -1 is a co -dominant marker and showed obviously and stable polymorphism between Pi9 gene donor parent 75 -1 -127 and the receptor R288,and selection efficiency of Clon2-1 marker genotype for rice blast resistance phenotype reached 100%.The BC6 F3 population harboring Pi9 with R288 background was developed through consecutive backcross and self -pollination,and thereupon a resistant homozygous line R288 -Pi9 was bred.The hybrid produced by R288 -Pi9 and the photo -thermal sensitive genic male sterile line Peiai 64S,also showed high -level blast resistance.