从叶片侵入的大白菜软腐病菌在植株内的系统侵染

对近200株3—6叶期的大白菜分别进行注射接种和破伤接种,结果从植株未接种的其它部位均回收到病原细菌,含菌量为10~3——10~7CFU/克鲜组织,且以接种叶叶柄的含菌量为最高,均在10~6CFU/克以上。当4株幼苗同时生长在一个盆钵中,对其中一株的叶片进行接种,从其余3株各部位也分离到病原细菌,第3天组织含菌量为10~2—10~4CFU/克,并以根部为最高,在10~5CFU/克以上。病原细菌从叶片侵入后,可在整个生育期的大白菜组织内回收到。幼苗期伤口接种通常并不引起显著病变。

SYSTEMATIC INFECTION OF ERWINIA CAROTOVORA PV.CAROTOVORA DYE AFTER INVADING CHINESE CABBAGE LEAVES

About 200 seedlings of Chinese cabbage were inoculated with Erwinia carotovora pv. carotovora Dye either by injection or by wound inoculation. The pathogenic bacteria could be recovered in all parts of the plants inoculated. Eventhough a plant of four grown in the Same pot was inoculated, the bacteria could be recovered from other three plants during the whole growth period. The bacterial number in the tissues ranged from 10~3 to 10~6 CFU/g, with the maximal number of 10~6 CFU/g in the inoculated petioles, No evident symptoms occured when the seedlings of the plants were inoculated. The significance of the leaf-invasion of the pathogen was discussed.