山桃对根癌病的抗性评价

为探明山桃(Prunus davidiana(Carr.)Franch.)的抗根癌病种质资源价值,采用人工接种的方法评价了实生山桃苗对发根土壤杆菌(Agrobacterium rhizogenes Conn)和根癌土壤杆菌(A.tumefaciens Conn)的抗性。结果表明:接种后70d,接种发根土壤杆菌的山桃株最大瘤茎为0~20.3mm,病情指数为59,根据抗性评价标准判定为低度抗病类型;接种根癌土壤杆菌的山桃株最大瘤茎为0~5.3mm,病情指数为15,根据抗性评价标准判定为高度抗病类型;实生山桃群体对根癌菌的抗性存在广泛的株间分离现象,其对发根土壤杆菌的抗性分离为免疫、高度抗病、中度抗病、低度抗病、感病和易感病6种类型,分别占群体总数的20.8%、5.0%、12.5%、11.7%、20.0%和30.0%;对根癌土壤杆菌的抗性分离为免疫、高度抗病、中度抗病和低度抗病4种类型,分别占群体总数的35.0%、55.8%、8.4%和0.8%。山桃实生群体存在大量对发根土壤杆菌和根癌土壤杆菌免疫型单株,是优异的抗根癌病桃树砧木种质资源树种。

Resistance evaluation of Prunus davidiana (Carr.) Franch to crown gall disease

In order to evaluate the resistance of Prunus davidiana (Carr.) Franch to crown gall disease, annual pot seedlings were used as tested materials which were injected artificially with A.rhizogenes Conn and A.tumefaciens Conn.The experiment results indicated that Prunus davidiana (Carr.) Franch was an excellent germplasm resource in terms of the resistance to crown gall disease.70 days later, the maximum tumor diameter of seedlings vaccinated with A.rhizogenes Conn was 20.3 mm, while it was 5.3 mm with A.tumefaciens Conn.According to the resistance evaluation standard to crown gall disease, it lowly resisted to A.rhizogenes Conn with the disease index of 59 and was separated into 6 types, including being immune, highly resistant, moderately resistant, lowly resistant, susceptible and highly susceptible and their corresponding percentages were 20.8%, 5.0%, 12.5%, 11.7%, 20.0% and 30.0% respectively.But it highly resisted to A.tumefaciens Conn with the disease index of 15 and it included 4 types:being immune, highly resistant, moderately resistant and lowly resistant with percentages of 35.0%, 55.8%, 8.4% and 0.8% respectively.