| چکیده انگلیسی مقاله |
Extended Abstract
Introduction and Objective: Black rust is one of the important fungal diseases that widely affects the quantity and quality of wheat in many regions of the world. The damages caused by black rust disease can be more than other pathogens in wheat and its importance is such that millions of hectares of healthy fields with high production potential can be destroyed in less time. Destroy it completely in one month. Resistance is one of the genetic characteristics of the host that plant breeders use to produce cultivars. Lines that are recognized as resistant in a survey can be used as a source of resistance in another breeding program. Genetic resistance reduces or eliminates the consumption of chemical poisons, and as a result, it is considered as the most economical and healthiest method of combating plant diseases. Accordingly, in order to statistically investigate some physiological markers related to resistance to black rust disease, 24 bread wheat genotypes including 8 cultivars and 16 promising lines were studied. In this study, two varieties MV-17 (disease-resistant variety) and Morocco (disease-susceptible variety) were selected as controls in this study due to their different behavior in resistance to wheat black rust.
Material and Methods: This experiment was carried out in 2019 in the greenhouse of the Research Institute of Plant Breeding and Seed Preparation under the conditions of infection and non- infection with the native race TKTTF of wheat black rust disease and in the form of a randomized complete block design with four replications. Physiological traits including relative leaf water content (RWC), cell membrane stability (MP), electrical conductivity (EC), chlorophyll content (SPAD) and chlorophyll fluorescence were measured and recorded.
Results: At the probability level of 1%, a significant difference between genotypes was observed and the interaction effect of disease x genotype was significant for all traits, which indicates the non-homogeneous difference of genotypes for the studied traits in two conditions of infection and non- infection. Also, for all measured traits, there was a significant difference between two different levels of disease infection, which shows the effect of the black rust pathogen on the relative content of leaves, membrane permeability, electrical conductivity, chlorophyll concentration, primary fluorescence, fluorescence It has maximum, variable fluorescence and photochemical efficiency of photosystem II. The results showed that pathogen contamination increases the relative water content, chlorophyll concentration, membrane permeability, initial fluorescence, maximum fluorescence, variable fluorescence, photochemical efficiency of photosystem II and decrease in electrical conductivity. Based on all studied physiological traits of genotypes MV-17, C-98-17, C-98-11, C-98-5, C-98-12, C-98-18, C-98- 16, C-98-3 and CD-94-9 were identified as the genotypes that showed more resistance to the disease agent. There was a high correlation between initial fluorescence, maximum fluorescence, variable fluorescence, photochemical efficiency of photosystem II, membrane permeability and electrical conductivity in response to stem rust. Based on Ward's cluster analysis and detection function analysis, the genotypes were divided into four separate groups in the conditions of infection and non-infection with black rust. They were placed in a group. While, in the condition of no disease contamination, 6, 9, 4 and 5 genotypes were clustered in four separate groups, respectively.
Conclusion: This study showed the effect of East Azerbaijan stem rust TKTTF race on the physiological traits of winter cultivars and lines of wheat. This race caused changes in the studied physiological traits in both experimental conditions, from this output it can be concluded that the resistant lines are more resistant to the disease than the commercial variety and are recommended as selected lines in breeding programs should be used. It is worth mentioning that according to the results of the grouping of genotypes and also the placement of valuable genotypes in terms of relative water content traits, membrane permeability index, chlorophyll content, initial fluorescence, maximum fluorescence, variable fluorescence, and photochemical efficiency. Photosystem II and electrical conductivity in the first and second groups in the conditions of disease infection and non- infection, it was concluded that the results of cluster analysis had a good relationship with the results of variance analysis and comparing the average of the studied traits. The results showed that the physiological traits measured in response to black rust disease have diversity. Therefore, possible genotypes with resistance to this pathogen can be identified by using the changes of these traits. Also, considering the relationship between the results obtained from the evaluation of physiological and pathological traits, the possibility of using physiological traits as indicators related to resistance to wheat black rust disease was benefited. In other words, the physiological indicators used were able to detect the existence of diversity and response to resistance to black rust disease and they can be used as physiological indicators related to resistance to black rust disease of wheat. Examining different traits in different environmental conditions has shown that the way the genotypes act and respond to the pathogen changes with the change of environmental conditions. For this purpose, these studies should be carried out in several years and in different environments. It is also recommended to carry out the above test using agricultural traits at the stage of the sorghum plant as well as biochemical traits related to the disease.
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