Gene Mapping And Canidate Genes Cloning Of An Panicle Apical Abortion Mutant (tsr) In Rice

The phenomenon of rice bald tip occurs frequently, rice bald tip phenomenon is caused by panicle apical abortion, panicle apical abortion can cause grain number per spike significantly deduced, lower seed setting rate and seriously reduce rice yield. Therefore, it has attracted a great at many breeders’ attention, but its genetic basis is not clear.This experiment is to combine the SSR and Indel markers techniques with BSA analysis methods to map the panicle apical abortion tsr mutant gene and clone candidate gene. The main resultsa are as follows:(1) The panicle apical florets of tsr mutant was abnormal growth and development, gradually degraded and shed during the matureing stage. The abortion of the panicle apical florets resulted the barren tip. Compared with the wild type 168, the plant height of trs was decreased, the grain number was reduced with the lower seed setting,and the panicle exsertion of tsr was poor.(2) The genetic analysis indicated that the tsr mutant was controlled by a pair of recessive nuclear genes.(3) F2 populations for mapping the tsr gene was constructed from a cross between the mutant tsr and 5364s. Based on the SSR markers and BSA analysis, the tsr gene was roughly mapped on the short arm of chromosome 3 of rice,marked by RM157A.(4)Through the Indel primer design, tsr eventually be fine-mapped on a 67 kb, delimited by Indel markers hc42and hc58,which contains 9 candidate genes.(5) sequencing the candidate genes Os03g0319300 and Os03g0320000, the results found that Os03g0320000 have one Câ†'G nucleic acid sequence mutation on the 129th amino acid,which alanine is replaced by glycine.