QTL Analysis Of Main Agronomic Traits And Inheritance Of Isozymes Peroxidase,Esterase And Cytochrome Oxidase In Barley

Barley is the fourth largest crop in China, and widely used in genetic research as a model plant. The development of society and barley industry require barley cultivars with high yield, better quality, strong resistance and wide adaptability. QTL mapping of agronomic traits and genetic analysis of main isoenzymes will provide important information to reach the breeding objectives.In this study, the DH mapping population was derived from the cross between a new dwarfism Huaaill and a mid-height cultivar Huadamai6. Several agronomic traits were evaluated. Correlation analyses were performed among the traits examined. The DH population was genotyped with SSR markers, and their linkage maps were constructed with Kosambi function using software MapMaker/EXP3.0. QTLs for main agronomic traits were mapped onto the chromosomes. Peroxidase, esterase and cytochrome were found different between parents, and their inheritance pattern was analyzed in the DH population. The main results are summarized as follow:1. The linkage map for the DH population was constructed based on SSR data. The map covered 328.6cM with an average interval of 5.2cM. The minimum and maximum of distance between markers are 0.3cM and 28.6cM, respectively. Number of markers mapped onto linkage group varied from 6 to 12.2. Spike numbers per plant showed significantly correlation with other 11 agronomic traits. Plant height and rachis internode length showed a highly significant positive correlation with the remaining traits except with spikelet numbers of main spike and tiller number.3. The composite interval mapping was used mapping each trait. Numbers of QTL detected for different traits varied from 2 to 8. QTL accounted for 4.02% to54.88% of the genetic variation. Spike numbers per plant. It was found that a main effect QTL controlled main spike length, rachis internode length, tiller number and grain weight per plant.4. The band of peroxidase Rf4 (0.19), esterase Rf3 (0.34) and cytochrome oxidase Rf4 (0.18) did not show difference in the offspring. Peroxidase Rf2 (0.14), esterase Rf2 (0.25), Rf4 (0.51) and Rf5 (0.54) and cytochrome oxidase Rf6 (0.55) showed 1:1 segregation in DH population, suggesting Mendelian inheritance of one gene.