جستجوی مقالات مرتبط با کلیدواژه "پوسیدگی خشک" در نشریات گروه "کشاورزی"

Members of Fusarium species are common pathogens of potato¡ causing dry rot in Iran and entire the world. Therefore¡ the objectives in this study were to isolate and identify disease-causing Fusarium spp. from infected potato tubers in Kurdistan province wet markets based on the morphological and molecular characteristics. Fifty-five isolates of Fusarium were obtained from potato tubers collected from the wet market in different cities of Kurdistan province in Iran. All isolates belonged to F. incarnatum¡ F. oxysporum¡ F. acuminatum¡ F. graminearum¡ and F. solani through morphological characters. All of the isolates were evaluated for their pathogenicity on healthy potato tubers in the planthouse. The tubers rot symptoms were observed on the 21th day after inoculation of Fusarium isolates on the tubers tested. In the tubers inoculation tests¡ lesion sizes were quite variable. Based on the sequence data from translation elongation factor (EF-lα) gene analysis¡ 10 pathogenic Fusarium isolates were divided into five major groups. Although the data obtained from morphological and molecular studies sufficiently supported each other¡ the resulting phylogenetic trees based on TEF-1α dataset clearly distinguished closely related species and distinctly separated all morphological taxa. This is the first report on molecular identification of Fusarium spp. strains isolated from potato tubers in Iran and F. incarnatum was reported for the first time in Iran and F. graminearum was isolated for the first time from potato tubers inIran.

In the present study, resistance of 29 potato clones to fusarium dry rot disease was compared with some commercial cultivars and a susceptible check cultivar Lady Roseta. Tubers of the potato clones and cultivars were artificially inocutate with aggressive isolates of Fusarium sambucinum and F. solani and maintained in a growth chamber at 16°C and 95% relative humidity for four weeks. The experiment was in factorial with two factors of Fusarium species and potato clones, using three replications. Disease index, infected area of tubers and sprouting rate were recorded for each treatment after four weeks. Based on the results of experiment, potato clones 397009, 39709713, 39708-10, 397097-2, 397007-16, 397074-3 and cultivar Aria having the lowest disease index (ranging from 168.52 to 228.25) and lowest tuber infected area, were considered as resistant, while clones 396124-97 × 396151-15 and 396151-29 with highest disease index and tuber infected area were susceptible. Fusarium species had an invert effect on tuber sprouting so that susceptible potato clones and cultivars had the least tuber sprouting rate.