QTL Mapping For Pericarp Thickness And For Hundred Kernel Weight With F_2:3 Family Of Sweet Corn

Pericarp tenderness is not only the measure of pericarp resistant to the chew,but also one of the most significant factor for quality and is significantly correlated with pericarp thickness.In recent years,because of more and more attention to sweet corn,the industry rises gradually.The research on structure and function about pericarp thickness of sweet corn has been increasing,but the studies of gene location and of genetic effect are still rarely reported.The increasing demand of sweet corn makes farmers grow high-yielding sweet corn varieties.Kernel weight is one of the most important factors for production and the key of high-yield breeding of sweet corn.Therefore,it is of great significance to study the yield trait of sweet corn in depth for exploiting the potential of sweet corn and improving the efficiency of breeding.In this study,a F_2:3 families segregation population from South China Agricultural University has been developed from one inbred lines?M06?and one inbred line?M01?for the research of the pericarp thickness and kernel weight in sweet corn.The main results are as follows:1.Comparing these two methods to measure pericarp thickness,we found that it is simple to use spiral micrometer to measure the pericarp thickness.Although it is complicated to use improved frozen section to measure pericarp thickness.it is simpler than the paraffin section method and truly represent the growth of and the thickness of pericarp.2.A genetic linkage map was constructed by 51 markers,covering 10 linkage groups,with total length of 1813.7c M and average distance of 26.8⁵1.5 cM.3.Mapping for pericarp thickness,we detected two QTLs located on chromosome 7by using spiral micrometer.These two QTLs explained respectively 14.21%and 7.33%of the total phenotypic variance.In addition,three QTLs respectively located on chromosome5,6 and 7 were detected by frozen section.These three Q TLs explained respectively40.75%,33.78%and 8.60%of the total phenotypic variance.4.Mapping for kernel weight,we detected five QTLs respectively located on chromosome 6,7 and 9 by kernel fresh weight.These five QTLs explained respectively6.39%,18.31%,17.16%,12.84%and 5.40%of the total phenotypic variance.In addition,three QTLs respectively located on chromosome 6 and 7 were detected by kernel dry weight.These three Q TLs explained respectively 7.06%,6.10%and 14.47%of the total phenotypic variance.