茄子黄萎病的发生及病菌生长影响因子

Occurrence of eggplant wilt and factors affecting growth of Verticillium dahliae

江苏扬州等地棚室栽培条件下,茄子黄萎病一般始见于现蕾期,5月上、中旬进入座果期开始大量发生,5月中下旬至6月上旬达发病高峰;病田土壤2年未栽作物仍能造成茄植株较高发病率。病叶混入土壤引起茄植株发病率最高,而病根混入土壤未见发病。分离自茄子、辣椒和棉花的黄萎病菌菌株在供试的玉米粉、燕麦、理查、马铃薯等培养基上均生长良好,茄子、辣椒黄萎病菌在理查培养基上出现明显的紫红色,棉花黄萎病菌则未出现;三种病菌在 pH4～9的培养基上均能生长;棉叶、茄叶、辣椒叶的汁液能刺激茄黄萎病菌分生孢子的萌发,其中以茄叶汁液最明显;病菌经55℃水浴处理20 min,各菌株均未见生长。

Verticilium wilt of eggplants occurred firstly at the bud stage and reached the peakfrom mid-May to early June in the greenhouse in Yangzhou.In the diseased fields,eggplantscan still be infected by the pathogen after two years.The disease incidence of eggplants washighest when the soil was mixed with diseased leaves,however,the plants were not infectedwhen the soil was mixed with diseased root.The hyphae of Verticillium dahliae isolated fromeggplants,pepper and cotton grew well on various media made of corn,oat,Richard and pota-to.The Richard media becomes purplish red when culturing the isolates from eggplants andpepper,but not from cotton.The pathogen grew well on media with pH value from 4 to 9.Theconidia germination of V.dahliae from eggplants was stimulated by leaf extract of cotton,egg-plant and pepper.After keeping in water bath at 55℃ for 20 min,three of strains could not