苜蓿种质资源对锈病的抗性研究

为获得优良苜蓿(Medicago)抗锈病种质,在实验室条件下,用喷洒夏孢子悬浮液的方法对国内外85份(国内54份、国外31份)苜蓿种质材料进行人工接种,并根据病情指数对其苗期抗锈性进行筛选和评价。结果表明:不同苜蓿种质材料间对苜蓿锈病的抗病性存在较大差异,病情指数变化范围在29.25%~70.65%;没有对苜蓿锈病免疫的种质;丹麦的‘庞迪苜蓿’抗锈性最强;中抗材料10份,其中国内4份,国外6份;中感材料55份;高感材料19份,其中感锈性最强的是‘陇东’天蓝苜蓿。从46份苜蓿种质材料中筛选出了过敏反应型抗锈单株,不同种质中抗锈单株的过敏反应等级不同。

Study of Alfalfa Germplasm Resistance to Alfalfa Rust

In order to screen out excellent germplasm with rust-resistance, 85 germplasm resources were inoculated by spraying urediniospore suspension at seedling stage and evaluated by disease indexes. All tested alfalfa germplasm showed different resistance to alfalfa rust. Disease index changed from 29.25% to 70.65%. None of tested varieties/lines were immune to infection. Medicago sativa ‘Bondi’ was resistant in response. 10 germplasm were moderately resistant while 55 were moderately susceptible. And 19 germplasm was highly susceptible. Medicago lupulina from Longdong China was the most susceptible to alfalfa rust. The germplasm resources were commonly susceptive to alfalfa rust disease, thus excellent rust-resistant germplasm resources were not sufficient. Rust-resistant plants with hypersensitive necrosis reaction were screened out from 46 germplasm resources in this experiment, and different levels of hypersensitive necrosis reaction presented in different germplasm resources.