摘要
经富集培养,从休闲5个月的土壤中检测到病菌(Erwinia Carotovora subsp. carotovora)。休闲土播种大白菜后,土壤含菌量7天内提高10~3倍.在人工接种的大白菜根际土中,病菌数量随寄主生长持续下降,但可在寄主整个生育期检测到。在幼苗生长50天期间,病菌都可从根系侵入,侵入所需接种菌量低限为3.8×10~2CFU/ml;根系侵入菌量与土壤含菌量呈正相关关系。病菌从种子萌发2天的幼芽侵入后,可进入生长中的根、茎、叶各部位潜伏侵染,以茎组织含菌量最高;组织含菌量随大白菜生长呈逐渐降低趋势,但可在整个生长期检测到。
The population dynamics of soft rot erwinia on Chinese cabbage in soils were studied, for testifying the relationship between the bacterial danymics and root invasion to the host. The bacteria were detectable from the soil of lying—in—fallow fields for 5 mth, with an amount of 60CFU/g. The bacteria numbers of the fallow land were increased by planting chinese cabbge, at 6 times, 10~3 times, and 10~4 times after 2, 7, and 15 days of the plant growth respectively. In inoculated soils, the bacteria were detectable constantly during the plant growth and its numbers decreased gradually. The pathogen showed the capatibility for invading roots of 2—50 day seedlings of the host and positive relation of its invasion ability and population in soil. On invading roots, the bacteria were able to be recovered from tissues of roots, stems, and leaves of the plant during its whole growth period, with a 100% frequency. The amounts of the pathogen in tissues reduced as the plant growth, and the largest number was obtained constantly from stem tissues. The practical significance was disscussed of the effects of the bacterial dynamics on the disease control.
出处
《山东科学》
CAS
1993年第2期87-91,共5页
Shandong Science
关键词
大白菜
软腐菌
根系侵染
软腐病
Chinese cabbage
soft rot erwinia
survival in soils
root invasion
dynamics
