6-BA对大白菜根肿病发病率的影响

目的]研究细胞分裂素与大白菜根肿病的关系,探讨大白菜根肿病的发病机理。方法]从发病植株的肿瘤提取孢子,再提取孢子DNA进行PCR检测。将鉴定出的根肿菌孢子于播种期、发芽期以及发芽后21 d接种到三角瓶内的培养土中,于发芽期在培养土中添加0.08μmol/L 6-BA。从接菌植株长出的肿瘤提取孢子,对孢子进行电镜检验,并统计6-BA处理及对照的根肿病发病率。结果]在三角瓶内,根肿菌可引起大白菜植株发病;添加0.08μmol/L 6-BA处理的根肿病发病率为100%,未加细胞分裂素处理的发病率为57%,前者肿瘤体积也明显大于后者。扫描电镜显示大白菜根肿菌休眠孢子的大小为1.5～4.3μm。结论]6-BA能明显促进大白菜根肿病肿瘤的形成。

Influence of 6-BA on Incidence Rate of Chinese Cabbage Clubroot ( Plasmodiophora brassicae)

Objective] The paper was to study the relationship between cytokinin and Chinese cabbage clubroot,and to explore the incidence mechanism of clubroot.Method] The spores were extracted from tumors of incidence plant,and their DNA was extracted for PCR test.The diagnosed spores were inoculated to the culture soils in erlenmeyer flask at seeding time,germination period and 21 d after germination,and 0.08 μmol/L 6-BA was added to soil during germination period.Spores were extracted from the root tumors developed in inoculated plants and examined by scanning electronic microscope(SEM),and the incidence rate of clubroot in 6-BA treatment and control was recorded.Result] Plasmodiophora brassicae could cause the incidence of Chinese cabbage,the incidence rate of clubroot in the treatment adding with 0.08 μmol/L 6-BA was 100%,while that in the treatment without 6-BA was 57%,and the volume of former tumo was much larger than the latter.Conclusion] SEM showed that the size of resting spore of P.brassicae was 1.5-4.3 μm.