1.School of City Comstruction,Lu'2.'3.an Vocational College,Lu’an;4.College of Agronomy,Anhui Agricultural University;5.Institute of Crop cultivation and Tillage,Heilongjiang Academy of Agricultural Sciences;6.The Chinese academy of agricultural sciences institute of crop science
The National Natural Science Foundation of China (General Program)
The panicle apical abortion (PAAB) of rice is a typical quantitative trait that is determined by both genotypes and growth environments, and their interactions, particularly, influenced by the ambient temperature. A chromosome segment substitution line Ats1 (aborted top spikelet mutant 1) originated from the cross-combination of Qiuguang ′ Qishanzhan has been used for map-based cloning of PAAB gene ATS1. Previous linkage analysis suggested that the candidate gene of AST1 was located on chromosome 8, sharing a long fragment of positioning interval with that of unidentified gene qPAA8. Due to the failure at the corroboration of candidate genes by transgenic test, we speculated that the results of fine mapping is inaccurate ascribe to the deviation of phenotype with the genotype of the sampled individuals. By comparing the climate differences between 2018 and other years in Beijing and the phenotype of Ats1 under different growth environment conditions, we found that the PAAB severity of Ats1 growth under the high temperature in 2018 was significantly alleviated compared with ordinary years, indicating that high temperature reduced the incidence of PAAB in Ats1. In addition, through the genetic analysis to the F2 population of newly created cross-combination IRAT129′ats1, we further found that the genetic separation of PAAB obviously deviated from ratio of the single gene dominant inheritance, i.e. 3 PAAB to 1 normal, indicating that there is extra PAAB genes involving. Here we provided a convenient strategy on developing a single gene segregating population (SGSP), based on the phenotypic analysis in combination with marker-associated selection to individuals of F2:3 lines. Finally, we finally narrowed the candidate gene of ATS1 into a 57 Kb region including four potential candidate genes, settling a foundation for the final cloning of the target gene. This method could be helpful using in fine mapping on other complex traits easily affected by environmental conditions.