بررسی واکنش به شوری سه رقم زودرس گندم دیم با رقم برزگر در استان یزد

کمبود منابع آبی و افزایش شوری از عوامل محدودکننده تولید گندم در مناطق خشک و نیمه خشک است. به منظور بررسی واکنش به شوری سه رقم گندم زودرس دیم با یک رقم آبی منطقه، یک آزمایش مزرعه‌ای به صورت اسپلیت پلات و در سه تکرار در سال زراعی 1400-1399 در استان یزد انجام شد. تیمارها شامل شوری آب آبیاری در دو سطح 2/5  (غیرشور) و 10 (شور) دسی‌زیمنس برمتر در کرت‌های اصلی و سه رقم دیم آسمان، آفتاب و کوهدشت به همراه رقم آبی برزگر در کرت‌های فرعی بودند. گیاهان پس از کاشت با تیمارهای شوری آبیاری شدند و با رسیدن فیزیولوژیک ارقام دیم، آبیاری قطع شد. نتایج نشان داد که تاثیر شوری بر عملکرد دانه و شاخص گلوتن معنی‌دار بود. درصد پروتئین دانه تحت تاثیر تیمار شوری قرار نگرفت. میزان عملکرد دانه ارقام آفتاب، آسمان، برزگر و کوهدشت در شرایط شور به ترتیب 527، 362 ، 447، و 207 گرم در مترمربع بود که در مقایسه با شرایط غیر شور به ترتیب 25، 33، 12 و 55 درصد کمتر بود. رقم دیم آفتاب بیشترین عملکرد دانه به میزان 617/1 گرم در مترمربع را تولید نمود. عملکرد دانه برزگر، آسمان و کوهدشت به ترتیب به میزان 23، 27 و 46 درصد کمتر از آفتاب بود. به دلیل قطع آبیاری و عدم تکمیل دوره رشد، برزگر کمترین میزان وزن هزاردانه را در هر دو شرایط داشت. بیشترین وزن هکتولیتر و شاخص گلوتن در هر دو شرایط مربوط به آفتاب بود. متوسط پروتئین دانه ارقام در هر دو شرایط بدون تفاوت معنی‌دار در حدود 11/4 درصد بود. با توجه به این نتایج و در شرایط مشابه با این آزمایش، رقم آفتاب می‌تواند کاندید مناسبی برای توصیه در مناطقی باشد که منابع آبی محدود و شور هستند. ضمن اینکه صفت زودرسی می‌تواند به عنوان یک فاکتور موثر در انتخاب ارقام مناسب مناطق خشک و نیمه‌خشک بدون توجه به شوری قرار بگیرد.

response to salinity of three early ripening rainfed wheat cultivars and barzegar local check in yazd province of central iran

scarce water resources and raising salinity are limiting factors affecting wheat production in arid and semi-arid regions. many studies have been conducted to release appropriate wheat cultivars for saline and non-saline conditions. but due to the co-existence of drought and salinity stress in arid and semi-arid regions, it is necessary to introduce cultivars that could tolerate salt under water shortage conditions. results of the studies conducted at the iranian dryland agricultural research institute have led to introduction of wheat cultivars with low water requirements due to early maturity. so, if the yield of these cultivars be optimum in saline media, they could be a suitable option for planting in these conditions. the objective of the study was to evaluate the salinity response of three dryland wheat cultivars in water limitation conditions compared to the local check.materials and methods to investigate the response to salinity of three early ripening dryland wheat cultivars along with a commercial irrigated wheat variety cultivated in the region, a field experiment was carried out as split plot during the 2020-2021 cropping season in yazd province, central iran. treatments were irrigation water salinity with two levels of 2.5 and 10 ds m-1 as main plots, and three dryland cultivars of asman, aftab, and kohdasht along with the irrigated cultivar of barzegar as sub plots. all examined cultivars were planted on november 15. row spacing was 20 cm with a planting density of 500 kernels/m2. the plots were subjected to saline irrigation water for 7 times from seeding to physiological maturity, and the irrigation was cut-off when physiological maturity occurred in dryland cultivars. total water consumed throughout the growing period was 7794.8 m3 ha-1. leaf area index was measured by sampling at plant establishment, tillering, mid-stem elongation, spike emergence, and kernel milky and dough stages. at harvesting, total above-ground dry mass and grain yield, harvest index, plant height and thousand kernel weight were measured. the grain quality attributes including hectoliter weight, protein content, zeleny sedimentation volume, bread volume, hardness index, flour water absorption, wet gluten percent, gluten index and sedimentation height were also measured. data were analyzed using sas 9.4 software, and the means were compared using the lsd test at the 5% probability level.results and discussion results showed that the effect of salinity on grain yield and gluten index was significant. grain protein content was not affected by salinity. the grain yields of aftab, aseman, barzegar and kohdasht cultivars in saline conditions were 527, 363, 447, and 207 g m-2, respectively; indicating 25, 33, 12 and 55% decreases compared to non-saline conditions. literature generally confirms 15-30% decreases in wheat grain yield under irrigation with saline water of 8-10 ds m-1. aftab as a dryland variety produced the highest grain yield, i.e. 617 g m-2. the grain yields of barzegar, aseman and kohdasht were 23, 27 and 46% lower compared to aftab, respectively. due to irrigation cut-off and failure to complete the growth period, barzegar had the lowest thousand kernel weight under both saline and non-saline conditions. the highest hectoliter weight and gluten index were observed in aftab under both conditions. grain protein was not affected by the irrigation water salinities. the value for grain protein content of the cultivars was around 11.45% without significant difference in both non-saline and saline conditions. the amount of leaf area index for all cultivars was lower in saline conditions than the non-saline conditions. irrigation with saline water decreased the leaf area index of aftab, aseman, and kohdasht cultivars by 41, 30, and 52% compared to non-saline condition, respectively. as the leaf area index has a major role in current photosynthesis for assimilate partitioning, its decrease leads to a decrease in plant above-ground dry mass, harvest index, and finally grain yield.conclusions based on the results, barzegar as local check suffered more damage from drought stress in both saline and non-saline conditions due to its late maturity. therefore, under similar situation, aftab cultivar could be a suitable candidate for areas where water resources are both scarce and saline. in addition, early wheat varieties may be considered as an effective factor in selecting suitable cultivars for arid and semi-arid regions, regardless of salinity.