مقاومت برخی از ارقام تجاری و لاین‌های امیدبخش گندم ایران به بیماری زنگ قهوه‌ای (.puccinia triticina eriks) در مراحل گیاهچه و گیاه کامل

بیماری زنگ قهوه‌ای گندم، که توسط قارچ puccinia triticina ایجاد می‌شود، یکی از بیماری‌های مهم گندم در ایران است. کشت ارقام مقاوم به بیماری موثرترین، اقتصادی‌ترین و از نظر زیست محیطی سالم‌ترین روش کنترل بیماری به‌شمار می‌رود. در تحقیق حاضر، مجموعه‌ای جدید از 52 ژنوتیپ‌ گندم نان و دوروم متشکل از ارقام تجاری و لاین‌های امیدبخش در دست نامگذاری برنامه‌های به‌نژادی گندم آبی موسسه تحقیقات اصلاح و تهیه نهال و بذر به همراه شاهد حساس به بیماری (رقم بولانی) در مراحل گیاهچه و گیاه کامل نسبت به بیماری زنگ قهوه‌ای مورد ارزیابی قرار گرفتند. بررسی در مرحله گیاهچه با استفاده از شش پاتوتیپ از قارچ عامل بیماری در شرایط گلخانه درکرج و بررسی در مرحله گیاه کامل طی دو سال زراعی 02-1401 و 03-1402 در دو ایستگاه تحقیقات کشاورزی صفی‌آباد (دزفول) و شاوور (اهواز) در شرایط آلودگی مصنوعی مزرعه و در دو ایستگاه تحقیقاتی کلاردشت و پارس‌آباد مغان در شرایط آلودگی طبیعی انجام شد. بر اساس نتایج آزمایشات انجام شده در مرحله گیاهچه،‌ 35% ژنوتیپ‌های مورد آزمایش در این مرحله نسبت به تمام جدایه‌های قارچ عامل بیماری مقاوم بودند. نتایج بررسی‌های مزرعه‌ای نیز نشان داد که تمامی ژنوتیپ‌های اقلیم گرم و مرطوب شمال، اقلیم گرم و خشک جنوب و برنامه دوروم، 75% از ژنوتیپ‌های اقلیم معتدل، 60% از ژنوتیپ‌های برنامه شوری و 42% از ژنوتیپ‌های اقلیم سرد از مقاومت قابل قبول (شدت آلودگی 50ms، 50mr، 40s و کمتر) در برابر بیماری برخوردارند. در این پژوهش پنج ژنوتیپ گندم آراز، n-98-20، c-98-7، c-98-8 و cd-99-15 با وجود حساسیت در مرحله گیاهچه نسبت به تمام جدایه‌های زنگ قهوه‌ای، در مرحله گیاه کامل در برابر بیماری مقاوم بودند. احتمال دارد که این ارقام دارای ژن یا ژن‌های مقاومت مرحله گیاه کامل باشند.

resistance of some wheat commercial cultivars and promising lines to leaf rust (puccinia triticina eriks.) disease at seedling and adult-plant stages

wheat leaf rust (brown rust) caused by puccinia triticina eriks. is an important disease of wheat crop in iran. this research project was carried out to evaluate the reaction of 52 commercial cultivars and promising lines of different national wheat breeding programs of iran to wheat leaf rust disease at seedling and adult plant stages. the results showed that at the seedling stage, 35% of the tested cultivars and promising lines were resistant to used leaf rust isolates. the results of field showed that all wheat genotypes of the south warm and dry zone, wheat genotypes of north warm and humid zone, and all durum wheat genotypes, 75% of wheat genotypes of the temperate zone, 60% of wheat genotypes of the salinity breeding program and 42% of wheat genotypes of cold zone, had reasonable level of resistance (50ms, 50mr, 40s and less) to used leaf rust isolates. in this research, five wheat genotypes; cv. araz, n-98-20, c-98-7, c-98-8 and cd-99-15 were resistant in all regions under field conditions. but they were susceptible to all used leaf rust isolates in the seedling stage, therefore, these wheat genotypes may carry adult plant resistance gene(genes). keywords: bread wheat, durum wheat, adult plant resistance, seedling resistance, susceptibility.introductionwheat leaf rust, caused by puccinia triticina (pt), is one of the most important foliar diseases in wheat worldwide. recent studies have showed that the average damage caused by leaf rusts (brown), stripe rust (yellow) and stem rust (black) in wheat crop is about 15 million tons per year, which is equivalent to an annual average of about us $2.9 billion per year (huerta-espino et al., 2020). dadrezaei et al., (2018) reported that the average wheat yield loss caused by leaf rust in iran was estimated to be about 25%, and the yield loss varied from 7 to 46 percent in different regions and cultivars (dadrezaei et al., 2018). although fungicides are widely used to control the disease, the use of resistant cultivars is considered the most effective, most efficient, economical, and the safest approach for controlling and managing this disease, and is compatible with the environment. the main focus in global wheat breeding programs is the development of rust-resistant cultivars. the development of resistant cultivars is a continuous process because the resistance of resistant cultivars may break by mutation in the genome of the pathogen. for this reason, there is a constant need to investigate the virulence/avirulence of the disease agent, and identify and develop new sources of resistance. materials and methodsthis research was carried out to evaluate reaction of 52 wheat commercial cultivars and promising lines from different national wheat breeding programs, and susceptible control (bolani), to wheat leaf rust at seedling and adult plant stages with artificial inoculation.  resistance of wheat commercial cultivars and promising lines at seedling stage was evaluated using six wheat leaf rust isolates from the areas where the field experiments for adult plant stages resistance were carried out. the wheat commercial cultivars and promising lines were evaluated at adult plant stages in kalardasht and parsabad moghan under natural infection and in dezful and shavour under artificial infection conditions in 2023 and 2024 cropping seasons. to evaluate the reaction of the wheat genotypes in field conditions and in leaf rust epidemic conditions, cultivars and promising lines were cultivated in early december 2023 and 2024 at safiabad dezful, shavour, kalardasht and parsabad moghan, agricultural and natural resources research field stations. the inoculation of the wheat genotypes was done using the leaf rust isolate of each region in the form of a mixture of rust spores and talcum powder in ahvaz and dezful during three stages under favorable environmental conditions in the evening in 2023-2024 cropping seasons, however, at kalardasht and parsabad moghan research filed stations, the incidence and spread of leaf rust occurred naturally without artificial inoculation. results and discussionreferencesdadrezaei, s. t., tabatabaei, n., lakzadeh, i., jafarnejad, a., afshari, f. and hassanbayat, z. 2018. evaluation of tolerance to leaf rust disease in some selected bread wheat genotypes. applied entomology and phytopathology, 86, pp. 29-40 (in persian). doi: 10.22092/jaep.2018.109374.1153huerta-espino, j., singh, r., crespo-herrera, l. a., villaseñor-mir, h. e., rodriguez-garcia, m. f., dreisigacker, s., barcenas-santana, d. and lagudah, e. 2020. adult plant slow rusting genes confer high levels of resistance to rusts in bread wheat cultivars from mexico. frontiers in plant science, 11, 824. doi: 10.3389/fpls.2020.00824singh, r. p. 1993. resistance to leaf rust in 26 mexican wheat cultivars. crop science, 33, pp.633-637. doi:10.2135/cropsci1993.0011183x003300030041x