| چکیده انگلیسی مقاله |
Extended abstract:
Introduction and Objectives: As one of the most important cereals, bread wheat is an essential part of food security in the world, which supplies one fifth of the total calories of the world population. Nowadays, due to climate change, drought has affected the yield of wheat as one of the most important abiotic stresses and has become an important threat to food security in the world. Root and stomatal traits are especially important in breeding plants to withstand drought stress. Stomata play a key role in controlling carbon dioxide uptake and water loss through transpiration. Therefore, stomatal characteristics are used as indicators of water status and plant growth, especially in drought stress conditions. Having a wide range of physiological and morphological characteristics, roots play an essential role in absorbing water and nutrients. They are also the first organ that sends signals to control the stomata in response to dryness. Therefore, the difference in the structure of the root system can cause the difference between the performance in different cultivars. This study was conducted in order to investigate stomatal characteristics and its relationship with root system and plant performance in 24 bread wheat lines and cultivars.
Material and Methods: In order to investigate the relationship between stomatal dimensions and density with root system, an experiment was conducted on 24 bread wheat genotypes in the form of a randomized complete block design with three replications in the rainfed conditions of the research farm of Zanjan University Faculty of Agriculture in the crop year 2018-2019. In this experiment, PVC pipes were used to study the root system. 12 seeds were planted in each tube, which were thinned to 7 after germination. In each experimental unit, there were two tubes for each genotype, one of which was used to evaluate traits and final yield, and the second tube was used for root studies. Stomatal traits including length and width of stomata and number of stomata per unit area, root traits including root length, root diameter, root volume, root surface and root biomass and seed yield were measured. After the traits were measured, the resulting data were analyzed in the form of a randomized complete block design, and the averages were compared using the LSD method. multivariate statistical analyzes including regression analysis, path analysis and factor analysis were performed and cluster analysis was used to group genotypes. Statistical calculations were done using SAS 9.0 and SPSS 21 software.
Results: The results of analysis of variance and mean comparison showed high variability among genotypes for all measured traits. The results of the average comparison of genotypes showed that genotypes 2, 5, 8 and 16 had the highest yield and genotype 23 had the lowest yield among the examined genotypes. The highest number of stomata on the upper and lower surface of the leaf was related to genotypes 5 and 2. In terms of root traits, the highest diameter, volume, length, root surface and root dry weight at the depth of 0-25 cm were related to genotypes 2, 3, 18 and 5, respectively. There was a high and significant correlation between the yield and the number of stomata on the upper and lower surface of the leaf, the length and width of the stomata on the upper surface of the leaf, diameter, volume, dry weight and root surface at a depth of 0-25 cm in the soil. Based on the results of stepwise regression analysis, two variables, the number of stomata on the lower surface of the leaf and the dry weight of the root at a depth of more than 25 cm explained 91.4% of the changes in grain yield, which according to the results of the causality analysis of the number of stomata on the lower surface of the leaf, the most direct effect had a positive effect on seed yield. The results of factor analysis grouped the studied traits into three factors with 82.48% variability justification. The share of the first factor in explaining data changes was 48.86%, the share of the second factor was 24.62%, and the share of the third factor was 8.99%. Based on the plot obtained from factor analysis, genotypes 2, 5, 8, and 16 had high values for the first and second factors, which according to the coefficients of the factors, it can be said that the genotypes located in this area have high performance, the number of stomata high and strong root traits were found at the soil depth of 0-25 cm, for this reason these genotypes are the genotypes that have been able to produce high yields by absorbing water from the surface layers of the soil by having a large number of stomata and carrying out more photosynthesis. Also, the genotypes investigated using They were divided into three groups from cluster analysis by ward method and Euclidean distance. Genotypes 2, 5, 8 and 16 were placed in the first group and had the highest mean values for grain yield traits, number and width of stomata on the upper and lower surface of the leaf and root traits including diameter, volume and dry weight of the root at a depth of 0-25 Soil cm and root diameter at a depth greater than 25 cm and the lowest values for stomatal length were in both leaf surfaces. that these genotypes were the best genotypes for cultivation in dry conditions.
Conclusion: A strong superficial root system can provide the plant with water from scattered rains that occur with low frequency at the end of the growth period. On the other hand, the increase in the number of stomata along with their smaller size reduces leaf pores and enables a faster response of the stomata, and the rapid response of the stomata maximizes the efficiency of water consumption. Therefore, in dry conditions, having a strong superficial root system along with high stomatal density can increase seed yield. |
| نویسندگان مقاله |
رامین صادق قول مقدم | ramin sadegh ghol moghadam
Department of Plant Genetics and Production Engineering, Faculty of Agriculture, Zanjan University, Zanjan, Iran
گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران
جلال صبا | jalal saba
Department of Plant Genetics and Production Engineering, Faculty of Agriculture, Zanjan University, Zanjan, Iran
گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران
فرید شکاری | farid shekari
Dryland Agricultural Research Institute (DARI), Agricultural Research Education and Extension Organization (AREEO), Maragheh, Iran
موسسه تحقیقات کشاورزی دیم کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، مراغه، ایران
مظفر روستایی | mozafar rousraii
Department of Plant Genetics and Production Engineering, Faculty of Agriculture, Zanjan University, Zanjan, Iran
گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران
سهیلا مرادی | soheila moradi
Department of Plant Genetics and Production Engineering, Faculty of Agriculture, Zanjan University, Zanjan, Iran
گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران
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