مطالعه مقاومت به خشکی در اکوتیپ‌های مختلف سیر بر اساس شاخص‌های تحمل در شرایط آب‌و‌هوایی همدان

خشکی و محدودیت آب از جمله مهمترین مسائل مرتبط با بخش کشاورزی برای افزایش راندمان و تولید مطلوب محصولات زراعی و باغی در دنیا و از جمله ایران می‌باشد. عبور موفق از خشکی مستلزم تحقیقات و پژوهش‌های کاربردی در این بخش می‌باشد. در این پژوهش برای بررسی تنوع‌ژنتیکی اکوتیپ‌های سیر، غربال و شناسایی اکوتیپ‌های متحمل به تنش خشکی، تعداد شش اکوتیپ سیر در قالب طرح بلوک‌های کامل تصادفی با سه تکرار در سال زراعی 402-1401 در دو شرایط محیطی تحت تنش خشکی و بدون تنش خشکی طراحی و اجرا گردید. شاخص‌های تحمل به خشکی مورد بررسی عبارت بودند از: شاخص عملکرد (yi)، شاخص تحمل تنش (sti)، شاخص میانگین هارمونیک (ham)، شاخص بهره‌وری متوسط (mp)، شاخص پایداری عملکرد (ysi)، شاخص حساسیت به تنش (ssi) و شاخص تحمل (tol) که بر اساس عملکرد اقتصادی سیر در دو شرایط محیطی فوق‌الذکر اندازه‌گیری شدند. بر اساس نتایج حاصله از تجزیه واریانس، شاخص عملکرد در شرایط بدون تنش خشکی و شاخص عملکرد در شرایط تنش خشکی در سطح احتمال یک درصد معنی‌دار گردید. در این مطالعه، شاخص‌های sti، ssi،mp ، gmp، ham، yi، ysi، di و sts در سطح احتمال یک درصد معنی‌دار شدند که نشان‌دهنده تنوع موجود در بین اکوتیپ‌های سیر از نظر شاخص‌های مورد مطالعه می‌باشد. بر اساس نتایج تجزیه به مولفه‌های اصلی برای شاخص‌های تحمل به خشکی، مجموع دو مولفه اول و دوم 94 درصد از تغییرات ایجاد شده را توجیه نمودند. همبستگی بین عملکرد در شرایط بدون تنش خشکی (yp) با صفات عملکرد در شرایط تنش خشکی (ys) و شاخص‌های mp، gmp،ham ، yi، ati، ysi و sts همبستگی مثبت و معنی‌داری را نشان داد. در نمودار بای‌پلات اکوتیپ‌های ̓بهار 2 و ̓سولان در جوار شاخص‌های sti، ati،  gmpو mp که شاخص‌های تحمل به خشکی می‌باشند قرار گرفتند و این دو اکوتیپ (̓بهار 2 و سولان) بر اساس نمودار سه بعدی نیز در گروه اول قرار گرفتند. لذا بر اساس نمودار بای‌پلات نیز این اکوتیپ‌ها، اکوتیپ‌های مطلوب و شاخصی بوده‌اند. بر اساس تجزیه خوشه‌ای اکوتیپ‌ها به دو گروه دسته‌بندی شدند، گروه اول شامل اکوتیپ‌های ̓مریانج، ̓بهار 1 و امام‌زاده‌کوه (̓توئیجین) و گروه دوم شامل اکوتیپ‌های ̓بهار 2، ̓سولان و اسدآباد بودند. در گروه اول اکوتیپ‌هایی با عملکرد کمتر و در گروه دوم اکوتیپ‌هایی با عملکرد بالاتر و مناسب‌تر قرار گرفتند. به‌طور کلی و بر اساس کلیه تجزیه‌های آماری مورد استفاده در پژوهش حاضر به‌ترتیب اکوتیپ‌های بهار 2 و سولان بیشترین عملکرد زیست‌توده را به خود اختصاص دادند.

the study of drought resistance in different ecotypes of garlic based on the tolerance indices in the climatic conditions of hamedan

introduction and objective the garlic (allium sativum) is a plant that is known all over the world as a food additive or flavoring and also because of its medicinal properties. garlic is chemically diverse, and many compounds have been extracted and tested from it, including allicin, diallyl sulfides, and ajoene, which are probably the most studied compounds in garlic. garlic has antibacterial activity, cardiovascular effect, stimulation of the immune system and also has an effect on cancer. therefore, given the statistics on rainfall and the excessive extraction pressure on underground water sources, large-scale research on drought in agriculture is essential. drought is a significant limiting factor in agricultural production, preventing maximum plant yield. thus, comparing performance in various environmental conditions (stressed and non-stressed) and selecting cultivars under such conditions can help evaluate their resistance to stress. drought and water limitation are among the most important problems affecting the agricultural sector to increase the efficiency and optimal production of crops in the world, including iran. successful crossing of land requires research and applied research in this sector. but few studies have been performed in connection with garlic medicinal plant. therefore, the present study was designed and implemented with the aim of investigating yeild indicators in two environmental conditions (environment with supplemental irrigation and dry environment) in garlic plant with the help of drought tolerance indicators. materials and methodsin this research, in order to investigate the genetic diversity of garlic ecotypes, sieve and to identify resistant ecotypes in dry land, 6 garlic ecotypes with the arrangement of randomized complete blocks design with three replications in the crop year 2023 in two stress environmental conditions drought and without drought stress was designed and implemented in the educational-research farm of payame noor university in asadabad. the studied drought tolerance indices are: yield index (yi), stress tolerance index (sti), harmonic mean index (ham), average productivity index (mp), yield stability index (ysi), sensitivity index to stress (ssi) and tolerance index (tol) were based on the economic yield of garlic in two environmental conditions of drought stress and without drought stress. correlation was calculated between tolerance indices and yield under drought stress conditions and supplementary irrigation conditions, and based on the analysis of these correlations, tolerance indices were selected and the most appropriate indices were selected in both environmental conditions, including drought stress conditions and supplementary irrigation that had a good correlation with yield were selected. finally, after identifying the most favorable indicators, a three-dimensional statistical graph was used to determine drought-tolerant cultivars with high yield in both environmental conditions, in which the yield in supplementary irrigation conditions on the x-axis, the yield in stress conditions (rain) was shown on the z-axis and one of the above-mentioned selected indicators on the y-axis. to show the relationship between three variables and distinguish group a from other groups (b, c and d) as well as the usefulness of the mentioned index as a criterion for selecting cultivars with high yield and tolerance to drought, x-z level by drawing cross lines to four groups a, b, c and d were divided and because in a three-dimensional diagram only the relationship between three variables can be evaluated, to study more than three variables at the same time, bi-plot diagrammatic display based on analyzes multi-variables were drawn with the help of the digit-index data matrix to determine the relationships between digits and drought tolerance indices in a single image. before performing data analysis, the presence of outliers was checked. statistical analysis of the data was done using minitab version 15 and spss version 26. results and discussionbased on the results of analysis of variance, the yield index in normal humidity conditions and the yield index in drought stress conditions were significant at the probability level of one percent (p≤1%). in this study, sti, ssi, mp, gmp, ham, yi, ysi, di and sts indicators were significant at the probability level of one percent (p≤1%), which indicates the diversity among ecotypes. garlic in terms of the studied indicators. based on the decomposition into main components for drought tolerance indices, both the first and second components justify 94% of the changes. according to the correlation table, the correlation between yield in normal humidity conditions (yp) with yield traits in drought stress conditions (ys) and mp, gmp, ham, yi, ati, ysi and sts indicators has a positive and significant correlation. be in the bi-plot diagram, ecotypes bahar2 and soolan are located near sti, ati, gmp and mp indicators, which are indicators of drought tolerance. these two ecotypes (bahar2 and soolan) are also located in they were placed in the first group, so it can be concluded that according to the biplot diagram, these ecotypes were desirable and indicative ecotypes. based on cluster analysis, ecotypes are classified into two statistical groups, the first group includes ecotypes maryanaj, bahar1 and emam zadeh koh (toeejin), and the second group includes ecotypes bahar2 and soolan and asadabad. ecotypes with lower yield are placed in the first group and ecotypes with higher and more suitable yield are placed in the second group. conclusionbased on all the statistical analyses used in the research, the bahar2 and soolan ecotypes had the highest biomass yield. the overall results of this research indicated the very important and useful role of drought tolerance indices in differentiating the studied ecotypes.