Inheritance Analysis And Molecular Markers Of Tipburn Resisitance In Heading Chinese Cabbage

InIn order to reseach the performance and disease-resistance inheritance of heading Chinese cabbage. Nutrient solution cultivation method was employed in cultivating6heading Chinese cabbage materials which are susceptible to tipburn and F2generation of which parents are of high resistance and high susceptibility to tipburn, respectively. The observation of the tipburn course, distribution of tipburn levels, the performance of symptoms and molecular markers were taken into reseach. The results are as follow.1. Best observation period for tipburn in heading Chinese cabbage is50-55days after Ca-free treatment. The course of disease and sensitivity of low calcium was showed differently in all these materials.2. Symptoms, differed in different period and different plant, are mainly rot at leaf margin, necrotic lesion, death of growing points, necrotic spots, cessation of growth and chlorotic. The occurring characteristics were initially explicited.3.1/4of the stipe from blade was chosen as the proper position to for insertion and the ripening leaves were better for cutting4. Tipburn resistance of F2generation showed a continuous distribution, tipburn level distribution peresented a single peak curve, accorded with the quantitative inheritance. Therefore, tipburn resistance was supposed to be controlled by several minor genes.5. The specific band was amplified by the combination of the SRAP markers ga3and pm37in the susceptible, but not in the resistent. of which genetic distance is6.5cM. Besides, by the combination of ga3and pml, the specific band was amplified in the shrinkage symptom and the others, of which genetic distance is5.8cM.