Fine Mapping Of The Panicle Apical Abortion Gene In Rice

In rice,panicle apical abortion(PAA)often occurred in rice production.In this study,we reported a rice mutant Q179 with panicle apical,derived from the F4 generation pedigree from the cross of the Bobai B and RW11.In order to understand the genetic and phenotypic characteristics of panicle apical abortion mutant Q179.The morphological and physiological characteristics of the mutant were conducted by agronomic investigation and by DAB staining in spikelet.The genetic analysis and gene mapping controlling panicle apical abortion in Q179 were carried out by SSR and Indel analyses in BC2F2 population.The main results were as following:Phenotypic analysis found that the mutant panicle apical was dwarf and spikelets degeneration on the top panicle,less number per panicle,short and thin in flag leaf and less number panicle,resulted in reduction of the grain number and decreasing yield during the later period.Genetic analysis was conducted by two BC2F2 population derived from the crossed of Q179 mutant and Nipponbare.The result showed the proportion of the wild type to the panicle apical abortion type was 3.40:1 and 3.45:1,χ2=1.07 and 1.09(χ20.05=3.841).This is consistent with the proportion of 3 to 1 in Mendel’s genetic laws,and the panicle apical abortion controlled by a pair of recessive gene.The hydrogen peroxide in panicle was detected by DAB staining to the spikelet of mutant.Results showed that the oecurrence of gene is associated to excess accumulation of hydrogen peroxides.The fine mapping of the gene was conducted in BC2F2 population and new SSR and Indel markers were used in chromosome 10 for fine mapping.The gene paalO(t)was located in the region between the newly developed markers ID-36与 ID-16 with 11 kb and three Open Reading Frame.One of the three Open Reading Frame may be the candidate gene.