QTL Positioning And Quantitative Genetic Analysis Of Tassel Branch Number In Maize

Maize is an important food, feed, economic crops, which has an important position in the national economy.Maize tassel is an important agronomic trait, tassel and ear compete the nutrient, and correlated with the yield of maize n egatively. Therefore, bigger tassel will consume more nutrients, reducing produc tion. Tassel branch number is an important index to measure the tassel size, in genenal, more number of tassel branches, the tassel is larger, consuming more nutrients. Maize breeding, selection of smaller tassel, a fewer number of tasse1 brach number varieties is already a trend. Therefore, study of tassel branch n umber of genetic model and genetic mechanism has important value.In this experiment, maize inbred line 3237, which tassel brach number is 0-2, with maize inbred line 1212 construction of six generation, analysis of tass-el branch number of genetic model and genetic effect. Combined analysis of si x generations of tassel branch number of optimal genetic model for E-3, thus2 major gene+additive-dominance polygene model. The sum of separation of ge neration B1, B2, F2 major genes and polygenes heritability of generations are re spectively 71.7%,82.9%,62.6%, the result is that tassel branch number is mad nly affected by gene control, less environmental effect, early generation selectio n of effective.Using maize inbred lines 3237 and 1212 matched backcross segregation po pulations, constuctin genetic linkage map, analysis of tassel branch number QT L. The linkage map is constition of 114 polymorphic SSR markers, map was 1486.4cM, the average distance of interal markers is 13.04cM. Combined the p henotypic values and molecular markers, detected tassel branch number QTL s ites. BC1 group in Yunnan Xishuangbanna 1 environment, the BC1S1 family gr oups respectively in Yunnan Xishuangbanna, Sichuan Wenjiang 2 environmental detected a total of 10 tassel branch number QTL, located on chromosomes 2, 3,5,7, with explained phenotypic varivation are 10.96%-33.18%. Detected in the same chromosome QTL can be regarded as the same QTL, in bicause of the same locus QTL on chromosome with overlapping area, which Provide imp ortant reference value for the tassel branch number of QTL fine mapping and gene cloning.Mining tassel branch number candidate gene in major QTL. Mining tassel branch number candidate gene in the 2 chromosome QTL, which contibution v alues is bigger, and expressed stably. Analysis of 7 related genes, through com parative analysis, GRMZM2G147241 (G4) gene may be associated with tassel development. In different inbred lines of clone and sequence analysis of the co ding region of the gene, found that the sequence of the coding region of the i nbred line 3237 is shortest.To provide some reference value for tassel branch n umber gene mining.