The occurrence of petiole spot in detached leaves of Chinese cabbage was investigated by nutrient solution cutting identification at seedling stage.Combined with the previous results of field investigation,the occurring status and degree of petiole spot in advanced inbred lines with high resistance or susceptibility and their F1 hybrids were also analyzed.The results showed that the petiole spot occurrence degree of F1 hybrids was between that of their parents and was influenced significantly by environment...