نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه تولیدات گیاهی، دانشکده کشاورزی و منابع طبیعی، دانشگاه گنبد کاووس، گنبد کاووس، ایران.
2 گروه فیزیک، دانشکده علوم پایه، دانشگاه گنبد کاووس، گنبد کاووس، ایران.
3 پژوهشکده آبزی پروری آبهای داخلی، موسسه تحقیقات علوم شیلاتی کشور، سازمان تحقیقات و ترویج کشاورزی، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction: Barley (Hordeum vulgare L.) ranks as the fifth most important crop globally in terms of cultivated area, following wheat, maize, rice, and soybean. This diploid plant with seven chromosomes serves as a vital resource for animal feed, human consumption, and the malting industry. Despite previous studies, limited information exists regarding the genetic diversity of Iranian barley cultivars. The main objective of this research was to map genes affecting key agronomic traits in 99 homozygous recombinant inbred lines (RILs) of the F₉ generation derived from a cross between two local cultivars, Badia and Comino, to provide a foundation for marker-assisted breeding in barley improvement programs.
Materials and methods: This research was conducted during the 2022-2023 cropping season at the research farm of Gonbad Kavous University (Golestan Province, Iran). The plant materials consisted of 99 recombinant inbred lines (RILs) from the F₉ generation derived from a cross between two local cultivars, Badia and Comino. The experiment was carried out using an alpha-lattice design with three replications. Thirteen agronomic traits were measured, including plant height (PH), total number of spikes per plant (TNS), total weight of spikes per plant (TWS), single spike weight (SPW), spike length (SL), awn length (AL), awn weight (AW), total weight of awns (TWA), grain number per spike (GNS), grain length (GL), grain width (GW), grain weight per spike (GSW), and grain yield (YLD). For linkage map construction, 155 SSR markers, 20 ISSR markers, 7 IRAP markers, 30 CAAT markers, 26 SCoT markers, 90 RAPD markers, 73 IJS markers, and 90 iPBS markers were utilized. The linkage map was constructed using Map Manager QTX17 software with the Kosambi mapping function and a LOD threshold of 2.5. QTL mapping was performed using QTL.gCIMapping.GUI v2.0 software with the Composite Interval Mapping (CIM) method and a LOD threshold of 2.5.
Results: Analysis of variance for the measured traits revealed significant differences among the lines for all traits. Strong positive correlations were observed between plant height and total weight of spikes per plant (0.714), single spike weight (0.712), spike length (0.793), grain weight per spike (0.711), grain number per spike (0.806), and grain yield (0.697). The linkage map spanned a total length of 999.2 cM, distributed across seven barley chromosomes ranging from 163.2 to 191.3 cM. The inter-marker distance ranged from 1.84 to 2.85 cM. A total of 10 significant QTLs were identified on chromosomes 3, 4, 6, and 7. Among these regions, qTNS-4 with a LOD of 2.66 and R² = 8.86% exhibited a negative additive effect originating from the Badia parent. Additionally, qGNS-6 showed positive additive effects with a LOD of 3.63 and R² = 21.58%. The qGL-3 region was identified with a LOD of 4.40 and R² = 25.04%, displaying a negative effect derived from the Comino parent. The QTLs qTWS-3 with a LOD of 3.74 and R² = 28.28%, and qYIELD-3 with a LOD of 3.68 and R² = 28.05%, both exhibited positive additive effects from the Comino parent and explained more than 28% of the phenotypic variation. Furthermore, qPH-4 with a LOD of 3.47 and R² = 21.76%, and qAL-6 with a LOD of 2.74 and R² = 21.55% demonstrated positive additive effects.
Conclusion: The present study identified significant genomic loci for important agronomic traits in barley. The markers EBmacc0009, D10-A, IJS25-A, HVM27, ET15-32-B, CAAT7-A, and MGB371, which are associated with these important QTLs, possess high potential for application in future barley breeding programs. Additionally, the superior Lines 80, 95, and 96 were introduced as promising germplasm resources for developing high-yielding barley cultivars. These findings provide a preliminary and efficient genetic framework for improving yield components in barley through targeted breeding approaches.
کلیدواژهها [English]