ارزیابی عملکرد و کیفیت علوفه لاین‌های شبدر ایرانی (trifolium resupinatum) یک‌چین در شرایط اقلیمی کرج

به‌منظور بررسی عملکرد و کیفیت علوفه لاین‌های شبدر ایرانی یک‌چین، آزمایشی مزرعه ای با 18 ژنوتیپ (ده لاین با منشاء بروجرد و هشت لاین با منشاء کرج) در قالب طرح بلوک‌های کامل تصادفی و سه تکرار در مزرعه پژوهشی موسسه تحقیقات اصلاح و تهیه نهال و بذر کرج در دو سال زراعی (1403-1401) اجرا شد. تجزیه واریانس مرکب داده ها نشان داد برهمکنش سال × ژنوتیپ بر عملکرد علوفه خشک، عملکرد پروتئین علوفه، محتوی کربوهیدرات‌های محلول در آب و خاکستر علوفه در سطح احتمال یک درصد و بر محتوای الیاف نامحلول در شوینده اسیدی، قابلیت هضم ماده خشک، کل مواد مغذی قابل‌هضم، ارزش نسبی تغذیه‌ای و انرژی خالص شیردهی در سطح احتمال پنج درصد معنی‌دار بود. بیشترین عملکرد علوفه خشک (5/9 تن در هکتار) در لاین‌های lb2 با منشاء بروجرد و lk12 با منشاء کرج در سال دوم کشت به‌دست آمد، در حالی که کمترین عملکرد علوفه خشک (3/3 تن در هکتار) در لاین lb3 با منشاء بروجرد در سال دوم برداشت شد. بیشترین عملکرد پروتئین علوفه (1/07 تن در هکتار) و حداقل مقادیر الیاف نامحلول در شوینده‌های اسیدی و خنثی (به ترتیب 30/67و 41/71درصد) در لاین lb2 در سال اول ثبت شد، در حالی که لاین lk16 با منشاء کرج در سال دوم بالاترین محتوی الیاف نامحلول در شوینده اسیدی (38/80درصد) را داشت. لاین‌های lb2 و lk12 در هر دو سال، بالاترین مقادیر خاکستر علوفه، محتوای ماده خشک مصرفی، کربوهیدرات‌های محلول در آب، ارزش نسبی تغذیه‌ای، انرژی خالص شیردهی و جذب عناصر غذایی (نیتروژن، فسفر و پتاسیم) را داشت. به‌طور کلی، لاین‌های lb2 و lk12 به‌عنوان لاین های برتر با عملکرد و کیفیت مطلوب علوفه شناسایی شدند که می‌توانند برای تولید علوفه با ارزش غذایی بالا در تغذیه دام مورد استفاده قرار گیرند.

evaluation of forage yield and quality of single-cut persian clover (trifolium resupinatum) lines under climatic conditions of karaj in iran

this study aimed to evaluate forage yield and nutritional quality of 18 single-cut persian clover (trifolium resupinatum) lines over two growing seasons (2022-23 and 2023-24) in karaj, iran, using randomized complete block design with three replications. the main objective of the study was to identify superior lines for sustainable forage production. line 3 had the highest dry forage yield (5.9 t ha-1) and protein yield (1.07 t ha-1), with low fiber content and high nutrient uptake. the lowest levels of acid detergent fiber (30.67%) and neutral detergent fiber (41.71%) were recorded in line 3. lines 3 and 16 showed the highest values for ash content, dry matter intake, water-soluble carbohydrates, relative feed value, net energy for lactation, and nutrient uptake (nitrogen, phosphorus, and potassium) in both growing seasons. overall, lines 3 and 16 were identified as superior lines with desirable quantity and qualitatit of forage. these two lines are identified for being used in persian clover breeding programs and production of high-quality forage for feeding livestock. keywords: clover, relative feed value, net energy for lactation, ash, protein yield.   introductionpersian clover (trifolium resupinatum) is an important forage legume in semi-arid regions, and is valued for its high protein content and nitrogen-fixing ability (balazadeh et al., 2021). recent studies have explored the genetic diversity of clovers, focusing on yield and quality traits under varying conditions (zamanian et al., 2024). different genotypes exhibit variable responses due to interactions between their genetic and environmental conditions (nazari et al., 2017). despite its important, information on single-cut persian clover lines remains limited, particularly under iran’s diverse climatic conditions. finding of previous researches emphasize on multi-cut clover or other forgae crop species, however, this study focuseed on single-cut persian clover lines under environmental conditions of kraj in iran. although variability in forage traits of clover, due to genotype × environment interactions, has been published (balazadeh et al., 2021; zamanian et al., 2024), specific publications for single-cut persian clover are still limited. this research aims to evaluate 18 persian clover lines to identify genotypes with optimal yield and forage quality for sustainable forage production for livestock in karaj in iran. materials and methodsthe experiment was carried out at the research filed sation of the seed and plant improvement institute, karaj, iran (35.798°n, 50.937°e, 1323 m above sea level), in 2022-23 and 2023-24 growing seasons. eighteen single-cult persian clover lines were evaluated using randomized complete block design with three replications. soil (loam-clay, ph 7.9) was fertilized with 150 kg ha-1 triple superphosphate and 50 kg ha-1 urea, before planting, based on soil analysis.seeds were sown manually at depth of 3 cm on september 06 in 2022, and september 08 in 2023, with irrigation interval of 7–10 days. each experimental plot consisted of four rows, each 5 meters long, with a row spacing of 50 cm. forage was harvested at 25% flowering stage, and dry matter yield, protein, acid detergent fiber (adf), neutral detergent fiber (ndf), and nutrient content were measured using nirs (zamanian et al., 2024). data were analyzed using sas software, and means were compared using tukey’s test (p ≤ 0.05). principal component analysis (pca) based on the correlation matrix of traits was performed using minitab software. results and discussionthe results of this study revealed significant differences among single-cult persian clover lines for forage yield and quality. these variations for quantitative and quality traits indicated that the high genetic potential of this clover species can be utilized for improving its forage yield and quality (salimpour et al., 2022; zamanian et al., 2024). line 3 outperformed other lines with the highest dry forage yield (5.9 t ha-1), and protein yield (1.07 t ha-1), low adf content (30.67%) and ndf content (41.71%), indicating its high digestibility. lines 3 and 16 showed high ash content, water-soluble carbohydrates, and nutrient uptake (n, p, k). these characteristics were aligned with its superior relative feed value and net energy for lactation.significant genotype × year interaction effects on different quantative and quality traits revealed that different single-cut persian clover lines performed differently in two growing seasond (balazadeh et al., 2021). line 5 recorded the lowest dry forage yield (3.3 t ha-1), which can be due to poor nutrient uptake (pourali et al., 2021). the findings of this research underscore genotype selection’s role in optimizing forage yield and quality in semi-arid regions. lines 3 and 16 were identified as superior lies due to their high dry matter and protein yields as well as desirable nutritional value. in addition to these two lines, lines 18, 2, and 13 also had reasonable dry forage yield and quality. principal component analysis confirmed that forage quality and yield are positively correlated in these lines, suggesting their potential use in breeding programs for development of improved cultivars (zamanian et al., 2024). given their superior dry forage yield and quality, lines 3 and 16 are recommended for autumn cultivation to enhance forage yield and production efficiency. referencesbalazadeh, m., zamanian, m., golzardi, f. and torkashvand, a. m. 2021. effects of limited irrigation on forage yield, nutritive value and water use efficiency of persian clover (trifolium resupinatum) compared to berseem clover (trifolium alexandrinum). communications in soil science and plant analysis, 52(16), pp.1927-1942. doi: 10.1080/00103624.2021.1900228pourali, s., aghayari, f., ardakani, m. r., paknejad, f. and golzardi, f. 2023. benefits from intercropped forage sorghum–red clover under drought stress conditions. gesunde pflanzen, 75, pp.1769–1780. doi: 10.1007/s10343-023-00833-4salimpour, m. e., omoomi, f. d. and salimpour, f. 2022. investigation of agro-morphological characters between 34 accessions of trifolium resupinatum l. asian journal of advances in agricultural research, 20(4), pp.10-16. doi: 10.9734/ajaar/2022/v20i4403zamanian, m., golzardi, f., gitari, h., nungula, e., salehi, f. and heydarzadeh, s. 2024. enhancing forage nutritional value in persian clover (trifolium resupinatum) and crimson clover (trifolium incarnatum) through intercropping and optimized seeding rate. cogent food and agriculture, 10(1), p.2410459. doi: 10.1080/23311932.2024.2410459