Mapping QTLs For Cold-resistance Physiological Traits Of Theratio Of Free Water To Bound Water In Winter Wheat

Wheat is one of the most important food crops in the world. Chilling and freezing areamong the most natural disasters to endanger wheat production heavily, and which havebeen found in almost all wheat-growing states.It is very important to start the heredity and gene mapping analysison indices offreezing damage of wheat, and which will provide the basis for wheat hardiness breedingand genetic resources researches. In study, from the cross Huapei3×Yumai57, we couldconsist of double haploid lines to construct a genetic linkage map.In six environments, we collected the regularly growing leaves of wheat inover-wintering stage, and then measured the content of free water and bound water anddetermined the ratio of free water to bound water. QTL analyses on the ratio of free waterto bound water of leaf in wheat were further performed by using software Icimapping3.3,which will provide reference information for gene cloning and molecular marker assistedselection associated with cold-resistance in wheat. The results are as follows:1The correlation coefficient between the ratio of free water to bound water of leafand the survey data of field freeze was remarkably positive correlation.According to sixenvironment value of the ratio of free water to bound water of leaf，it can judge theseratio accords with normal distribution, and it indicated that those characters werequantitative in nature, and controlled by many genes with small effects.2. A total of357markers were mapped on24linkage groups. The total coverage ofthe map is2485.7cM，the average genetic distance between marks is7.67cM. Everylinkage groups consists14.9locus.3. In the6environments,A total of9additive QTLs were distributed on7chromosomes:1A，1B，1D，2A，2D，3A，5D.And there were3major QTLs whosegenetic contribution higher than10%. The locus in the Xcfd53-Xwmc18interval onchromosome2D was detected in the three environments.