重庆地区辣椒疫霉菌的分离培养及生理小种鉴定

本试验分离鉴定了来源于重庆不同辣椒产区的14个病原菌分离物,经形态特征鉴定及回接发病特征观察,确定这些菌株均为辣椒疫霉(Phytophthora capsici)。14个菌株在OMA培养基上诱导产生的孢子囊形态类似,形状多为卵圆形或长椭圆形,乳突明显。对PDA、OMA、CA及V8汁4种培养基上的培养性状观察表明,辣椒疫霉菌株在OMA培养基上生长速度最快,但在V8汁培养基上产孢最多。采用灌根法对14个菌株进行生理小种鉴别,其中10个为race 3,2个为race 2,2个为race 1,初步推定race 3为重庆地区辣椒疫病病原菌的优势小种。

Isolation and cultivation of Phytophthora capsici and identification of physiological race in Chongqing

Fourteen isolates collected from different pepper-cultivating regions in Chongqing were determined. Based on their morphological characteristics and symptoms after re-inoculated to pepper, these Isolates were identified as Phytophthora capsici Leonian. The sporangia of the fourteen isolates induced on OMA medium were morphologically similar, and most of them were ovate or elliptic, with obvious papillate. There were evident differences in mycelial growth rate, productivity of sporangia on different medium. On the OMA medium, the mycelia grew fastest, while the largest number sporangium are produced on the V8 medium. Physiological race identification test showed that ten isolate belonged to race 3, two isolates belonged to race 1, and two isolate belonged to race 2. Race 3 is probably the dominant race in Chongqing.