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Camelina (Camelina sativa) seeds are known as a rich source of oil and omega-3 fatty acids. In addition to human consumption, this plant can also be used in livestock diets and is able to grow in different climatic conditions. Due to its resistance to environmental stresses such as cold and lower water requirements, it is a suitable candidate for the dryland regions of the country. Stem rot disease caused by the fungus Sclerotinia sclerotiorum is one of the important diseases of this crop and has the ability to cause up to 100% damage. This study was conducted to evaluate 133 advanced Camelina genotypes for resistance to this disease in field and greenhouse conditions. A field test was conducted in Gorgan during the 2020-2021 and 2021-2022 growing seasons, in which plants were planted in one-meter length rows in three replications and 30-centimeter row to row space in a randomized complete block design, and inoculation was performed at the flowering growth stage by making an incision in the stem and placing a piece of fresh fungal colony at the incision site. A greenhouse test was also conducted using two different fungal isolates in the same manner and at the sixth week after planting in Maragheh province. Evaluation in field conditions was performed by measuring the length of necrotic lesion, and in greenhouse conditions, in addition to the necrotic length, the length of chlorosis area, and the number and length of produced sclerotia inside the plant were also assessed. The results showed that in field conditions, 2 (1.5%), 38 (28.57%), 38 (28.57%), 31 (23.31%), 8 (6.02%) and 16 (12.03%) of the genotypes were highly susceptible, susceptible, middle susceptible, middle resistant, resistant and highly resistant, respectively. The results of the greenhouse experiment showed that the genotype × isolate interaction effect was significant in all measured factors, which, considering the small share of this effect in the total variations, was interpreted as the difference between the isolates in terms of aggressiveness. Also, considering the distribution of the genotypes in terms of necrosis length, it was determined that the resistance of the genotypes to the pathogen is horizontal resistance in nature. According to the greenhouse and field results, 7 genotypes, by showing a middle resistant to highly resistant reaction in field conditions and resistance in greenhouse conditions against both isolates, including genotypes no. 24, 54, 59, 60, 132, 133 and 137; were identified as a source of resistance or release as a new commercial variety. This study is the first research conducted to evaluate the resistance of Camelina genotypes to this disease in Iran.
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