پديد آورندگان :
فرزادي، حسين سازمان تحقيقات آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي صفي آباد - بخش تحقيقات اصلاح و تهيه نهال و بذر، دزفول , ظريفي نيا، ناصر سازمان تحقيقات آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي صفي آباد - بخش تحقيقات اصلاح و تهيه نهال و بذر، دزفول , عصاره، علي دانشگاه آزاد اسلامي واحد اهواز - گروه علوم و مهندسي آب , شوشي دزفولي، احمدعلي سازمان تحقيقات آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي صفي آباد - بخش تحقيقات فني مهندسي و كشاورزي، دزفول
كليدواژه :
تحمل خشكي , تجزيه به مؤلفه‌هاي اصلي , گندم دوروم , عملكرد دانه
چكيده فارسي :
به منظور بررسي شاخص‌هاي تحمل به تنش و شناسايي ژنوتيپ‌هاي متحمل به شرايط تنش كم آبي در گندم دوروم، تعداد 8 ژنوتيپ اميد بخش گندم دوروم در قالب طرح بلوك‌هاي كامل تصادفي با سه تكرار در دو شرايط نرمال و تنش كم آبي در مركز تحقيقات كشاورزي صفي آباد در دو سال زراعي 1395-1393 مورد آزمايش قرار گرفتند. اين تحقيق در قالب 2 آزمايش مجزا شامل: آبياري كامل تا زمان رسيدگي و اعمال تنش كم آبي انتهائي از طريق قطع آب از مرحله ظهور سنبله تا رسيدگي فيزيولوژيكي، هر يك در قالب طرح بلوك‌هاي كامل تصادفي در 3 تكرار اجرا شد. نتايج حاصل از تجزيه واريانس مركب نشان دهنده اختلافات معني‌دار بين سال‌ها در شرايط تنش كم آبي و همچنين اثر متقابل ژنوتيپ در سال تحت شرايط نرمال براي عملكرد دانه بود. ميانگين كل عملكرد دانه در شرايط نرمال و تنش كم آبي به ترتيب برابر 4844 و 3099 كيلوگرم در هكتار بود. بالاترين عملكرد دانه در شرايط نرمال و تنش كم آبي به ترتيب برابر 5101 و 4232 كيلوگرم در هكتار مربوط به رقم بهرنگ و ژنوتيپ شماره 4 بود. تحليل همبستگي بين عملكرد دانه در شرايط بدون تنش و تنش كم آبي آخر فصل با شاخص‌هاي تحمل به خشكي نشان داد كه شاخص‌هاي STI، MP، GMP از كارايي بالايي براي گزينش ژنوتيپ‌هاي متحمل به تنش كم آبي بر خوردارند. نتايج حاصل از تجزيه به مؤلفه‌هاي اصلي با استفاده از شاخص‌هاي تنش كم آبي نشان داد كه رقم بهرنگ و ژنوتيپ شماره 3 بترتيب با عملكرد 5101 و 5039 كيلوگرم در هكتار در شرايط نرمال و 4184 و 4215 كيلوگرم در هكتار در شرايط تنش آبي داراي تحمل نسبي به تنش كم آبي بودند.
چكيده لاتين :
Water stress is the most important cause of reduced wheat yield in semi-arid areas. In most regions under wheat cultivation, especially in regions with Mediterranean climates, wheat plants are exposed to various stresses during the seed filling. Seed filling often occurs when temperature rises and less water is available. Irrigated wheat in Khuzestan Province mainly faces end-season drought caused by limited water supply on the one hand and the reduced precipitation and competition by other crops for water on the other hand. Therefore, introducing wheat genotypes tolerant to end-season drought is of great importance for this Province. Materials and methods This research was conducted at the Agricultural and Natural Resources Research Center of Safiabad- Dezful in the crop years 2014-2015 and 2015-2016. Eight promising durum wheat lines in warm regions in Iran together with the Behrang cultivar were studied. The following two separate experiments were conducted using the randomized complete block design with two replications: (1) full irrigation until maturity and (2) application of end-season water deficit stress through irrigation cessation from the spike emergence stage to physiological maturity.Results and discussion Results indicated that the effect of year was significant under drought conditions but not significant in the absence of drought conditions. Moreover, the mutual effect of genotype and year were significant in the absence of drought but not significant under drought conditions. The mean two-year yield under conditions without water deficit stress was 4844 kg/ha, with the highest average seed yield (5101 kg/ha) belonging to line 1 and the lowest (4669 kg/la) to line 2. Although yield of line 3 under conditions without water deficit stress (5039 kg/ha) was a little lower than that of line 1, it enjoyed higher yield stability compared to the other lines because it had the average ranking of 2.5 and the standard deviation of 0.5. Furthermore, the mean two-year seed yield under end-season drought conditions was 3991 kg/ha, with the highest mean seed yield of 4332.5 kg/ha belonging to line 4 and the lowest (3710 kg/ha) to line 9. Under end-season drought conditions, line 4 had the largest seed yield and the highest yield stability in the two years of experiments with the average ranking of 2.5 and the standard deviation of 0.5. Principal component analysis (PCA) and the shape of the by plot were employed for the simultaneous study of the relationships between the genotypes and the quantitative drought tolerance indices. Results of the PCA showed that most of the variance in the data could be explained by the two components of PCA1 (the first component) and PCA2 (the second component) with 63% and 30%, respectively. In addition, among all of the calculated components, only PCA1 and PCA2 had eigenvalues higher than 1 (5.67 and 2.66, respectively). ConclusionThe strong positive correlation between seed yield in the two environments with and without water stress and the STI, MP, and GMP indices indicated that these indices had a high efficiency in selecting drought tolerant genotypes. Based on the results of PCA, genotypes 1 and 3 were selected as water deficit stress tolerant genotypes because of their high PCA1 and suitable PCA2 values and also due to their closeness to the important drought tolerance indices MP, GMP, K1STI, K2STI, and STI; whereas lines 6, 9, and 10 were introduced as water deficit stress sensitive genotypes because of their low PCA1 and PCA2 values and also due to their closeness to the SSI vector. Line 7 was between important drought tolerance indices and drought sensitivity indices and enjoyed relatively desirable drought tolerance, but the high estimated values of SSI and TOL for this cultivar indicated that it lacks suitable yield stability. Moreover, this cultivar is close to the Yp vector, which shows that drought tolerance in this genotype is due to its high yield in stress free environments
