نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
 Fire blight is the most important disease of pome fruits in Iran, as well as in more than 40 other countries. Using the resistant cultivars is the most effective and economic method to decrease damages of the disease. To find resistant cultivars for subsequent use at the breeding programs, correlation between fire blight resistance and different vegetative and reproductive traits were evaluated in the local, foreign and spur type apple cultivars. Evaluation of resistance was carried out by natural infection through using the severity ( IS), percentage of infected shoots ( IINF) and USDA (IUSDA) indices during two epidemic years (1998-1999). The highest frequency of resistant cultivars was observed in spur type (66.7%), local (59.5%) and foreign (43.6%) cultivars, respectively. In addition, the frequency of resistance, in the local cultivars originated from North East region of Iran was approximately twice of those originated from North West regions. The results did not show any correlation between time of vegetative bud burst and resistance to the disease, but more susceptible cultivars intended to flower earlier than the resistant ones. In the local apple cultivars, percentage of shoot lignification had a high correlation with fire blight resistance, while in the foreign and spur type cultivars, the internode length and tree vigor, respectively had the highest correlation with the fire blight resistance.Â
کلیدواژهها [English]
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