@article { author = {Zareei Siahbidi, Asadolah and Rezaizad, Abbas}, title = {Study on response of some oilseed rape genotypes to drought stress}, journal = {Applied Field Crops Research}, volume = {32}, number = {04}, pages = {59-75}, year = {2020}, publisher = {Agricultural Research and Natural Resources Center of Khorasan Razavi}, issn = {2538-4066}, eissn = {2538-4058}, doi = {10.22092/aj.2019.121181.1266}, abstract = {In order to determine tolerant oilseed rape genotypes to terminal drought stress, 13 oilseed rape genotypes including Karaj1, Karaj2, Karaj3, Talaye, Zarfam, Okapi, Licord, SLM046, Modena, WPN5, Opera, WPN2 and GKH305 were evaluated in agricultural research station of Islamabade Gharb since 2010 for two growing season. Oilseed genotypes were planted using randomized complete block design with three replications under normal and drought stress conditions so that irrigation was cut from flowering stage. Combined variance analysis showed that the effect of terminal drought stress was significant for recorded characters except oil content, the number of branches and 1000 seed weight. Results showed that mean of seed yield decreased by 20% due to drought stress so that seed yield in normal and terminal drought stress conditions was 4586 kg/ha and 3736 kg/ha, respectively. This reduction was because of drought stress effect on yield components i.e. pods per plant and seed per pods. Genotype GKH305 had the highest seed yield with 5230 and 3941 kg/ha in normal and drought stress conditions, respectively. Bi plot derived from principal components showed that GKH305, WPN5 Zarfam and had high seed potential meanwhile were tolerant to drought stress. In current study, well known genotypes namely Licord, Talaye and SLM046 had low seed yield under both conditions. Introduction Environmental stresses are the most important factors reducing the yield of agricultural products worldwide. Drought is one of the most common environmental stresses that have limited agricultural production and decrease the efficiency of using dry and dry areas. In the field of drought stress, many experiments have been carried out in the world, but in most cases, the severe interaction between the environment and the genotype, selection of drought tolerant varieties is difficult. Improvement of drought tolerant cultivars is also one of the research priorities of the country. The effect of drought stress on plant depents on genotype, length of drought period, climatic conditions and plant growth stage (Roa & Mandham, 1991). The occurrence time of drought stress is more important than severity of drought stress (Kazi et al., 2002). Rapeseed plants, which are cultivated like wheat in both dry and wet conditions, generally experience drought stress during their life cycle. In irrigated areas and areas where surface water is used for irrigation, due to the reduction of rainfall and the use of water resources for the lucrative spring crops, the amount of water is severely depleted. As a result, the intervals between irrigation periods will be long and and plants encounter with water stress during filling seeds. According to some studies, the most sensitive time for irrigation is the flowering and early flowering stage (Richard, 1978; Richard & Thrling, 1978; Richard & Thrling, 1979; Richard & Thrling, 1979b; Pouzet, 1995). the country's largest cultivation of rapeseed belongs to the northern provinces of the country due to the presence of humidity and rainfall in these areas. However, cold and temperate cold regions like Kermanshah have a good potential for growing canola. In these areas, one of the main problems of canola cultivation is the lack of proper rainfall during the flowering stage of rapeseed and later. In these areas, rapeseed farmers who, in addition to canola, cultivate corn or wheat, canceled the canola irrigation in April, and irrigate wheat and corn, and the cut off of irrigation of canola at flowering and seeding time caused Stress and reduction of canola production. Therefore, identifying genotypes tolerant to late season drought stress in rapeseed is of great importance. In this study, in addition to investigating the effects of drought stress on yield and yield components of rapeseed, the most resistant genotypes to late drought stress were identified.}, keywords = {Key words:oilseed rape grain yield,oil content,tolerant indices}, title_fa = {بررسی واکنش برخی ژنوتیپ های کلزا به تنش خشکی}, abstract_fa = {به‌منظور شناسایی ارقام متحمل به خشکی آخر فصل تعداد 13 ژنوتیپ کلزا شامل کرج1، کرج2، کرج3، طلایه، زرفام، اوکاپی، لیکورد، اس.ال.ام.046، مودنا، دابل یو. پی.ان.5 ، اپرا، دابل یو. پی.ان.2 و جی.کا.اچ.305 به‌صورت دو آزمایش جداگانه در شرایط نرمال و تنش خشکی آخر فصل (قطع آبیاری از مرحله گلدهی) در قالب طرح بلوک‌های کامل تصادفی با 3 تکرار در ایستگاه تحقیقات کشاورزی اسلام‌آباد غرب از مهر 1391 به مدت دو سال زراعی مورد ارزیابی قرار گرفت. نتایج تجزیه واریانس مرکب داده‌ها نشان داد که اثر تنش خشکی آخر فصل بر همه صفات به‌جز درصد روغن دانه، تعداد شاخه‌های فرعی و وزن هزار دانه معنی‌دار بود. عملکرد دانه در اثر تنش خشکی به میزان 20 درصد کاهش یافت به‌طوری‌که میانگین عملکرد دانه ارقام کلزا در شرایط آبیاری کامل 4586 کیلوگرم در هکتار و در شرایط تنش 3736 کیلوگرم در هکتار بود، این کاهش حاصل تأثیرپذیری اجزای عملکرد دانه یعنی تعداد خورجین در بوته و تعداد دانه در خورجین از تنش خشکی بود. بیشترین عملکرد دانه در شرایط آبیاری کامل و تنش خشکی متعلق به ژنوتیپ‌ جی.کا.اچ.305 به ترتیب با 5230 و 3941 کیلوگرم در هکتار بود. نمودار دوبعدی حاصل از تجزیه به مؤلفه‌های اصلی نشان داد ژنوتیپ‌های جی.کا.اچ.305، زرفام و دابل یو. پی.ان.5 دارای پتانسیل عملکرد بالایی هستند، ضمناً متحمل به تنش خشکی نیز هستند. در این مطالعه ژنوتیپ‌های شناخته‌شده لیکورد، طلایه و اس.ال.ام.046 نسبت به سایر ژنوتیپ‌ها در هر دو شرایط از میانگین عملکرد کمتری برخوردار بودند.}, keywords_fa = {کلمات کلیدی: کلزا,شاخص‌های تحمل,درصد روغن,عملکرد دانه}, url = {https://aj.areeo.ac.ir/article_121380.html}, eprint = {https://aj.areeo.ac.ir/article_121380_01fbfc8236fd204e9947ba1d85ab5e13.pdf} }