QTL Mapping On Important Agronomic Traits Of The Wheat Founder Parent Mazhamai

Founder parents have played a crucial role in wheat breeding and production,which have produced many fine varieties or many valuable materials. But there werefew systematic theoretical studies on founder parents about the formation andinherent genetic mechanism. In order to reveal the genetic mechanism of founderparent Mazhamai, selecte parents in wheat breeding and improve breeding efficiencyin wheat, the important agronomic taits of the F2:3populations derived from the crossbetween Mazhamai and Quality were analyzed in this study using agronomic traitsand molecular markers.1. In this study, a total of383the polymorphic primers of SSR and EST-SSRwere used to genotype the F2population derived from the cross between theMazhamai and Quality.249primers of which were used to construct the geneticlinkage map. This genetic map, covering the genetic distance of3492.34cM and anaverage primer interval of14.03cM, covered all the wheat chromosomes except thechromosome4D.2. The F2:3population derived from the cross between the founder parentMazhamai and Quality was developed for the first time, which the population consistsof185families. The phenotype data of F2:3population and their parents wereanalyzed, the results showed that the parent Mazhamai was superior to Quality ingrains number per spike, spikelet number per spike and kernel number per spike,many traits had the significant difference between the parents under the sameenvironment; the majority of traits of population generally have transgressiveperformance. The variance and correlation analysis indicated that plant height, grainsnumber per spike and spike length had high heritability between the population, is82%,82%and85%respectively, the yield traits between the population showed somegenetic variation and which were mainly influenced by genetic factors; there werepositive or significantly positive relationships between grains number per spike andspikelet number per spike, kernel number per spike, spike length, while grain numberper spike was negatively related to fertile tillers number and significantly negative related to thousand grain weight only in Beijing environment. All the agronomic traitsof the F_2:3 population performed well and the structure was reasonable whichsuggested it would suitable for QTL analysis of wheat important agronomic traits andhave the important value in wheat breeding in the further.3. Combined with the constructed genetic map and the investigation of the yieldand related traits from Beijing, Shandong and Shanxi, QTL analysis of the mappingpopulation for the important agronomic traits including GNS, KNS, SL, SNS, PH,FTN, and TGW, were conducted. As a result, a total of113QTLs were detected. Ofwhich,19QTLs were indentified for grains number per spike,18QTLs wereindentified for kernel number per spike,19QTLs were detected for spikelet numberper spike,18QTLs were detected for spike length,11QTLs were indentified forplant height,19QTLs were indentified for fertile tillers number and9QTLs wereindentified for thousand grains weight. These QTLs distributed on all the wheatchromosomes except the chromosomes7D.4. In this study, these QTLs distributed on the different chromosomes,homologous groups and genomes. The QTLs were detected on all the genetic linkagegroups except7D, the number of QTLs on the linkage group2A was most, its numberwere22, and then were the linkages groups6B,4A,2B,5B and5D. For thehomologous groups, the number of QTLs on the homologous groups2were most, itsnumber were40, and then were the homologous groups5and groups6, its numberwere22, respectively. The QTLs difference distribution were also be found ongenomes, The most of QTLs were detected on A genome and B genome, the majorQTLs were also mainly from the two genomes..5. In this study, a total of eight important chromosome regions were found,which including the maker interval barc212-xgdm5on the chromosome2A,barc343-xgwm160on the chromosome4A, cfd73-MAG122and wmc179-barc13onthe chromosome2B, xgwm544-xgwm159on the chromosome5B, Mag972-cfe159and xgwm626-wmc737on the chromosome6B and cfa2185-barc322on thechromosome5D. The number of QTLs which were detected in each chromosomeregion was over three and these QTLs formed some important QTL-clusters and weremain effects of QTLs. These important chromosome regions may be the main genetic characteristics of the founder parent Mazhamai.