Constructions On The Linkage Genetic Map And QTL Mapping For Forage Yield And Rust Resistance Related Traits In Triticale

Triticale is a cultivated good forage, which is the hybridization progency of genus Triticum and Secale. It is a new kind of forage crop and has achieved significant economic benefits in the forage production.In this experiment, 2 new triticale lines with significant differences in properties were used as parents for hybridization. There were 66 and 184 plants in the F1 and F2 population respectively. Based on the F2 population, ISSR molecular marker was used to construct the genetic linkage map and map Q TLs related to the hay yield and rust resistant genes in triticale. This study would provide theory basis for gene clone and genotype improvement of triticale. The main results were as follows:After the ISSR amplification and field identification of F1 generation, it showed that 46 plants could be used to do the following experiments. The genetic similarity coefficient between the 46 F1 plants and their parents varied from 0.62 to 0.94. According to the genetic similarity coefficient, 48 materials were divided into three major groups, among which the male parent(P2) belonged to the first group, the female parent(P1) belonged to the second group and the third group included 46 F1 population.Fourteen primers screened by the ISSR molecular marker were used to amplify the F2 generation. Based on the genotype data, the genetic linkage analysis was carried out and 1 genetic linkage map was constructed using Joinmap4.0 software. This linage map included 7 linkage groups(named LG1 ~ LG7), there were 92 loci, the averaged distance among markers was 5.90 c M, and the total length of map was 542.9 c M.Phenotype identification showed that characters related to the hay yield and rust resistance in 184 plants of F2 population changed continuously and the distribution frenquency closed to the normaldistribution. Therefor, it was a suitable population to do the linkage map and locate the QTLs related to the hay yield and rust resistance in triticale.QTL results showed that there were 23 QTLs related to the hay yield and rust resistance in triticale. These Q TLs distributed on 7 linkage groups and there were 3.3 QTLs averagely on each linkage group. QTLs did not distribute evenly on 7 linkage groups. There were 5 QTLs controlling the plant height, which distributed on 3 linkage groups(LG2,LG3,LG7) and the contribution rate was 6.7% ~ 13.2%. There were 7 Q TLs controlling the number of tillers, which distributed on 4 linkage groups(LG1,LG2,LG4,LG5) and the contribution rate was 5.4% ~ 15.4%. There were 5 QTLs controlling the biomass of the single plant, which distributed on 4 linkage groups(LG1,LG2,LG4,LG5) and the contribution rate was 7.4% ~ 12.4%. There were 6 QTLs controlling the rust resistance, which distributed on 4 linkage groups( LG1,LG3,LG4,LG5,LG6) and the contribution rate was 5.4% ~ 15.4%. Controlling single biomass QTL has five in four groups, contribution rate was 5.1% ~ 11.2%.