芦笋茎枯病病菌鉴别寄主的构建

正芦笋(Asparagus officinalis Linn)又称石刁柏,百合科天门冬属,是世界十大名菜之一,在国际市场上被称为"蔬菜之王"。由于其营养价值高,并能润肺、镇咳、祛痰,具有抑制肿瘤生长的药理功能,深受人们的喜爱1]。近年来,随着芦笋市场与栽培面积的扩大,病害的发生也逐年加重,尤其茎枯病的严重发生已影响芦笋的产量与质量,轻者生长发育不良,降低产量与品质,重者病株提前枯死,全田毁灭,严重影响芦笋生产与出口创汇2]。目前该

Construction of differential host for the asparagus stem blight pathogen

Asparagus stem blight is a regional devastating disease caused by Phomopsis asparagi (Sacc.) Bubak. In order to construct the differential host for its pathogen, resistance tests of Asparagus officinalis Linn germplasms against P. asparagi were carried out at the seedling stage, followed by phylogenetic analysis based on the resistance level. A differential host set for differentiating the pathogen population was established and the pathogenicity differentiation of isolates from six provinces was distinguished using this differential host set. The results showed that thirty-one A. officinalis germplasms were classified into four groups as similarity coefficient of the disease resistance was 0.7. Group I was composed of eleven cultivars including “JK701”. Group II was composed of fourteen cultivars including “Jingganghong”. Group III was composed of three cultivars including “TC”. Group IV was composed of three cultivars including “TX-4/SD”. “JK701”, “Jingganghong”, “TC” and “TX-4/SD” were selected as the differential host set according to accessibility of germplasm resources. The pathogenicity of forty-eight isolates from six provinces was determined using the differentials and showed obvious divergence. All the isolates were grouped into various pathogenic races. Isolation frequency of race C1 was highest, accounting for 20.83%. Races A1 , A2 followed and isolation frequency of the both races was 18.75%. Isolation frequency of races A4, B3, C2, D1, and E1 was zero. The distribution of race types among these provinces was slightly different. In Jiangxi Province, the dominant race was B2. A1, A2 and B1 were the dominant races in Fujian Province, A1 and C1 in Shandong Province, B1 and C1 in Shanxi Province, and A2, A3, and C1 in Hainan Province. Altogether, differential hosts constructed in this study could distinguish the pathogenicity differentiation among P. asparagi isolates, which revealed that the above four cultivars were quite qualified for the differential host for the asparagus stem blight pathogen.