芝麻菜品种对尖镰孢菌枯萎病的抗性评价

摘要

尖镰孢菌枯萎病是意大利西北部芝麻菜栽培品种(Eruca vesicaria)和野生品种(Diplotaxis spp.)上的重要病害之一,常引起严重的损失.为评价芝麻菜品种对尖镰孢菌枯萎病的抗性,2004年6 ～11月,选用了44个栽培及野生品种资源在玻璃温室进行抗性试验,使用浓度为1×106 cfu/mL的孢子悬浮液蘸根法人工接种30天苗龄的芝麻菜幼苗,以分离自芝麻菜两个不同野生品种的菌株Fus.Ruc.9A/02和Fus.Ruc.13/03,以及分离自栽培和野生品种的32个菌株混合(MIX),分别作为抗病试验接种体,每次接种试验设A、B、C三个重复.整个试验重复进行2次.调查病害引起的死苗率(%)和病情指数(DI), 作为评价芝麻菜品种抗性差异的两项指标. 研究结果显示,这两项指标间的相关性极显著(P＜0.01),即表明可采用其中一项指标评价芝麻菜品种对尖镰孢菌枯萎病的抗性.供试的44个栽培及野生芝麻菜品种中,多数品种抗尖镰孢菌菌株Fus.Ruc.13/03,而对菌株Fus.Ruc.9A/02及菌株混合MIX表现为易感性,而且这些易感品种在菌株Fus.Ruc.9A/02及菌株混合MIX两试验中的抗性表现较为一致,Fus.Ruc.9A/02和MIX的毒性也更强于Fus.Ruc.13/03菌株.芝麻菜品种12/03 和品种 20/03高抗菌株混合MIX,品种 6/03和品种 7/04高抗菌株Fus.Ruc.9A/02,而品种9/02、2/03、5/03、6/03、7/03、9/03、11/03、12/03、20/03、21/03、24/03、3/04、6/04、7/04 和11/04高抗菌株Fus.Ruc.13/03.%In north-western Italy serious losses were observed in cultivated (Eruca vesicaria) and wild (Diplotaxis spp.) rocket varieties infected by Fusarium oxysporum, as one of important diseases in horticultural production. For the evaluation of varietal resistance of rocket to Fusarium wilt, forty-four varieties of rocket, belonging to cultivated and wild rockets, respectively, were chosen for resistance test carried out in glasshouse from June to November, 2004. Roots of 30 day old plants were artificially inoculated by dipping in a spore suspension (1×106 cfu/mL) of the pathogen. The trials were independently conducted, with three replicates, using, as inoculum, a mixture of thirty-two strains (MIX) isolated from different varieties of cultivated and wild rockets, and other two strains, Fus.Ruc.9A/02 and Fus.Ruc.13/03, respectively, gotten from two different varieties of wild rocket. The trials were repeated twice. Two indicators were used to evaluate the different resistance, one of which was percentage of dead plants, the other disease index (DI). Significant correlation (P<0.01) was found between these two indicators, which showed that both methods were feasible for the evaluation of rocket' s resistance to Fusarium wilt. The majority of rocket varieties showed a resistance to strain Fus.Ruc.13/03, while the majority of them showed a susceptibility to mixtured strains MIX and strain Fus.Ruc.9A/02. MIX and strain Fus.Ruc.9A/02 behaved similarly on the tested varieties and were more virulent than strain Fus.Ruc.13/03. The varieties 12/03 and 20/03 showed a high resistance to MIX, the varieties 6/03 and 7/04 showed a high resistance to strain Fus.Ruc.9A/02, and the varieties 9/02, 2/03, 5/03, 6/03, 7/03, 9/03, 11/03, 12/03, 20/03, 21/03, 24/03, 3/04, 6/04, 7/04 and 11/04 showed a high resistance to strain Fus.Ruc.13/03.