Genetic Analysis And Location Of Three Main Agronomic Traits In Xinjiang Melon

In this experiment,the genetic segregation population F₂ was obtained from the cross between inbred lines ‘PHHL’ and inbred lines ‘XM2’.Inbred lines ‘PHHL’ and ‘XM2’ which have high purity genotype were obtained through continuous selfing.Inbred lines ‘PHHL’ has crack resistance,resistance to powdery mildew,low sugar,while inbred lines ‘XM2’ show susceptible to cracking,powdery mildew,with high sugar character.Through the field planting,the architecture of traits incudling crack melons,resistance to powdery mildew,sugar content in segregation population were calculated and measured.Using the BSA（Bulked Segregation Analysis）method and the SSR（Simple Sequence Repeat）molecular marker technology,the resistance to fruit cracking,sugar content and resistance genes to powdery mildew were studied by means of genetic Analysis and mapping.The experimental results are as follows:（1）In F₂ populations of PHHL x XM2,the ratio between the susceptible and resistance to powdery mildew is 77:33,conforms to the separation ratio of 3:1（chi-square=1.47,P =0.23）,shows t resistance to powdery mildew（Podosphaera xanthii）are controlled by a dominant gene in melon PHHL strains.The powdery mildew resistance gene was located in chromosome 12 between marker SSR12510 and ECM123;（2）In F₂ populations of PHHL x XM2,according to the statistical analysis of the trait data on the field,through the judgment of skewness and kurtosis,the inheritance of resistance to dehiscent melon conforms to the quantitative traits.Through Mapmaker3.0 and winQTL Cart2.0 software analysis,the gene which controls cracking fruit was located in LGVI between marker ECM81 and MU10920,the genetic distance between the two markers is 11.1 cM.And marker ECM81 which linked with the gene was Selected;（3）To the same,the inheritance of sugar content was in line with quantitative traits in F₂ segregation population of PHHL x XM2 through statistical analysis.The gene which controls sugar content was located in LGVI between marker ECM135 and CMBR108 in XM2 varieties by Mapmaker3.0 and winQTL Cart2.0 software analysis.Marker CMBR108 which linked with the gene was Selected;（4）When constructing genetic linkage map,Segregation distortion phenomenon was happened in five markers and the difference was significant,and there were three markers distorting to disease-resistant varieties PHHL,and 2 markers were partial to to another parent XM2.