نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Fire blight caused by Erwinia amylovora, is one of the most catastrophic diseases of plants in the Rosaceae subfamily Pomoideae. The objective of this study was to determine the resistance of thirty pear cultivars to a mixture of four E. amylovora strains. Disease development was assessed according to severity index (I.V.S.) based on the progression of necrosis rate through shoots, from the inoculation point at 3, 6, 9, 12 and 18 days after inoculation. Analysis of variance showed significant differences among cultivars, indicating a wide range of relative resistance to the fire blight pathogen. Pear cultivars showed considerable variations in resistance to fire blight with the severity of infection ranging from 0.4% to 100%. Cultivars were divided into four groups including very resistant (0-10%), moderately resistant (11%-50%), susceptible (51%- 80%) and very susceptible (81% - 100%) according to the percentage of the length of necrosis to the total shoot length. Three cultivars ‘Dargazi’, ‘Harrow Sweet’ and ‘Natanzi’ were very resistant, 14 cultivars were moderately resistant, 10 cultivars were susceptible and three cultivars ‘Mohamad Ali’, ‘Duchesse’ and ‘KS6’ were very susceptible. Results obtained from specific primers link to fire blight showed that RLG1 and CH02c02b primers produced resistance allele in Dargazi and some of other cultivars.
کلیدواژهها [English]
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