ارزیابی پاسخ ژنوتیپ‎های گندم نان (triticum aestivum l.) به کمبود روی با استفاده از برخی پارامترهای فیزیولوژیک در خاک آهکی تحت شرایط کنترل شده در مرحله پنجه‎زنی

کمبود روی قابل دسترس در خاک‎های زراعی ایران شایع بوده و گندم از سایر غلات به کمبود روی حساس‎تر است. وجود تنوع بالا در ژنوتیپ‎های متحمل به کمبود روی، راهکاری جهت دستیابی به ارقام متحمل‎تر است. به‎منظور بررسی پاسخ ژنوتیپ‎های گندم نان به کمبود عنصر روی و با هدف شناسایی ژنوتیپ‌های متحمل و حساس، آزمایشی به‎صورت فاکتوریل، بر پایه طرح بلوک‎های کامل تصادفی در سه تکرار و با 28 ژنوتیپ پائیزه گندم نان در خاک آهکی با بافت لومی اجرا شد. فاکتورهای مورد مطالعه شامل ژنوتیپ گندم و کاربرد خاکی روی (شاهد) و افزودن 5 میلی‎گرم روی بر کیلوگرم خاک از منبع cuso4. 7h2o بود. بوته‎های گندم 45 روز در شرایط کنترل شده نگهداری و سپس، نمونه‎ها کف‎بر و میزان ماده خشک بخش هوایی، کارایی روی، غلظت، محتوا و کارایی مصرف روی، مورد مطالعه قرار گرفتند. نتایج نشان داد بین ژنوتیپ‎های مورد بررسی از نظر میزان ماده خشک بخش هوایی، کارایی روی، محتوا و غلظت روی تنوع بالایی وجود دارد. همچنین، به دلیل مقادیر یکسان و یا بیشتر بودن محتوا و غلظت روی در ژنوتیپ‎های حساس نسبت به ژنوتیپ‎های مقاوم، پارامترهای غلظت و محتوای روی گیاهچه‎ها معیار مناسبی برای گزینش، نیستند. در مجموع، ماده خشک بخش هوایی و کارایی روی برای گزینش ژنوتیپ‎های حساس و مقاوم قابل اعتمادتر بوده و ژنوتیپ‎های 28l، 22l و 10l از ماده خشک بخش هوایی و کارایی روی بالاتری برخوردار بوده و متحمل به کمبود روی بودند. در مقابل ژنوتیپ‎های 2l، 32l و 13l کارایی روی و ماده خشک پائینی در شرایط کمبود روی داشتند و حساس به کمبود روی می‎باشند.

genetic diversity of beard wheat genotypes in response to zinc efficiency in a calcareous soil

introduction: zinc is an essential micronutrient in plant nutrition and, plays a critical role in enzymatic reactions in plants. zinc deficiency in the soils limits crops’ growth and development, reduces the yield-related quantitative and qualitative traits. wheat is the main source of food in iranian diets. wheat production is negatively affected by insufficient zinc in soils. because of the high amount of lime in iranian soils, zinc deficiency is a common phenomenon in these soils. to overcome this challenge, the selection of zinc deficiency tolerant wheat cultivars could be one of the best strategies. to reach this goal; in this research, 28 genotypes and bread wheat cultivars were evaluated for their response to zinc deficiency in a calcareous soil containing 39% caco3. we expected that zinc-deficient tolerant wheat cultivars should perform well under zinc deficiency compared to other wheat cultivars.materials and methods: to test this hypothesis, 24 genotypes and 4 bread wheat cultivars were collected from the institute of seedlings and seeds and, their growth characteristics were evaluated under control and zinc sulfate (5 mg. kg-1) application. this experiment was performed as a factorial based on a randomized complete block design with three replications. wheat genotypes and cultivars seedlings were kept under controlled conditions for 45 days and, irrigation was done with deionized water during the experiment. at the end of the experiment, wheat seedlings were cut from the land surface and the dry mass of areal part, zinc efficiency, zinc concentration, zinc content, and zinc use efficiency were assayed in the laboratory of agronomy at the university of maragheh.results and discussion: results showed high variation among the cultivars and genotypes of wheat for the dry weight mass of aerial parts at zinc deficiency and with zinc treatment. the dry weight of aerial parts was varied between 99.5±3.08 to 172.833± 2.69 mg.plant-1 in l34 and l28 genotypes and 139.889±3.37 to 155.55±1.39 mg.plant-1 in sardari and azar 2 cultivars, respectively under zinc deficiency conditions. but, the dry weight mass of aerial parts in the conditions of sufficient zinc absorption was between 101.5±0.92 to 196.611±13.55 mg.plant-1 in l34 and l2 genotypes and in wheat cultivars, respectively. zinc concentration of seedlings in conditions of zinc deficiency in l27 genotype was 10.3 mg.kg-1 zinc and, baran cultivar with 11.7 mg.kg-1 zinc had the lowest and l15 genotype with 14.7 mg.kg-1 zinc and azar 2 cultivar with 13 mg.kg-1 contained the highest amount. while with zinc application, l5 genotype with 13.7 mg.kg-1 and ouhadi cultivar with 14 mg.kg-1had the lowest and l11 genotype with 18 mg.kg-1 and azar 2 and baran cultivar both with 16 mg.kg-1 had the highest amount of zinc. genotypes l15 with 63.8 and l2 with 66.3 mg dry weight mass per µgr zinc had the lowest and, l5 and l1 genotypes respectively with 83.2 and 81.5 mg dry weight mass per µgr zinc, had the highest efficiency of zinc use. zinc application from zinc sulfate sources decreased the zinc efficiency of wheat genotypes and cultivars. also, the efficiency of zinc application due to the application of zinc sulfate in seedlings of wheat cultivars and genotypes decreased from 83.4 to 63.2 mg dry weight mass per µgr zinc. among genotypes, a desirable diversity of zinc efficiency was observed. the value of this index was varied between 65.15 to 110.94 %.conclusion: the results showed that despite the sensitivity of wheat to zinc deficiency, there was a high diversity between genotypes and cultivars in terms of shoot dry matter, zinc efficiency, and the content and concentration of zinc. also, due to the same or more amounts of zinc content and concentration in sensitive genotypes compared to the resistant ones, the seedlings’ zinc concentration and content are not suitable parameters for genotype selection programs. overall, among the studied parameters, shoot dry matter and zinc efficacy are more reliable criteria for selecting sensitive and resistant zinc-deficient genotypes.