نوع مقاله : مقاله پژوهشی
نویسندگان
1 ژنتیک و به نژادی - دانشکده علوم زراعی - دانشگاه علوم کشاورزی و منابع طبیعی -تهران - ایران
2 .ژنتیک و به نژادی - دانشکده علوم زراعی - دانشگاه علوم کشاورزی و منابع طبیعی ساری
3 ژنتیک و به نژادی - دانشکده علوم زراعی - دانشگاه علوم کشاورزی و منابع طبیعی ساری
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
ntroduction:
The escalating population growth in Iran, coupled with diminishing arable land and severe water scarcity, necessitates a significant increase in rice yield per unit area. The adoption of innovative breeding strategies is imperative to meet this challenge, as traditional low-yielding cultivars are inadequate to satisfy the growing demand. Hybrid rice technology has demonstrated remarkable success in enhancing rice yield, offering a 15-25% yield advantage over conventional varieties. This research aimed to evaluate 34 rice genotypes and identify fertility restoration genes Rf3 and Rf4 using SSR molecular markers.
Materials and Methods:
This study involved 34 diverse rice genotypes, including F1 hybrids derived from crosses between two cytoplasmic male-sterile lines (CMS), Jelodar A and Neda A, with 13 tenth-generation mutant lines (Dast, Nemat, Pazhuhesh, Sepidrood, and Damsiah) and four exotic fertility restorer lines. The experiment was conducted at the research farm of the Tabarestan Agricultural Genetics and Biotechnology Research Institute during 2018-2019. A randomized complete block design with three replications was employed. Superior hybrids, characterized by high yield performance, were selected and subjected to detailed analysis of physicochemical grain quality traits. These traits included amylose content, gelatinization temperature, grain elongation after cooking, gel consistency, grain size and shape, and aroma. Two SSR molecular markers, RM 3148 (linked to Rf3) and RM 171 (linked to Rf4), were utilized to detect the presence of fertility restoration genes in the genotypes.
Results:
The results of mean comparisons of agronomic traits revealed significant variations among the evaluated genotypes. Hybrids H27, H28, H29, H30, and H33 exhibited the highest fertility and yield. These superior hybrids were derived from crosses between the CMS lines and the restorer lines IR 68078-15-2-1-2-2-R, IR 65622-151-1-2-2-2-R, and NSIC RC 434. Statistical analysis demonstrated significant differences in all measured traits. Notably, hybrid H29 (3.423.33) displayed the highest aroma among the check varieties. Cluster analysis, based on grain quality traits, grouped hybrid H33 with the high-quality check variety Fajar, confirming its superior grain quality with respect to grain elongation after cooking (12.15), low breakage rate (4.64), and intense aroma (5.922.00). Molecular marker analysis using RM 3148 showed a banding pattern in hybrids derived from IR 68078-15-2-1-2-2-R, IR 65622-151-1-2-2-2-R, and IR 86403-5-5-2-1-1-1-1-1R with Jelodar A, similar to the restorer check. Hybrids H27, H29, and H33 exhibited heterozygous banding patterns, suggesting the presence of the Rf3rf3 genotype. RM 171 confirmed the presence of the Rf4 gene in IR 68078-15-2-1-2-2-R and IR 65622-151-1-2-2-2-R and their corresponding hybrids in a heterozygous state. The identified restorer lines hold great potential for utilization in hybrid rice breeding programs aimed at developing high-yielding cultivars.
Discussion:
The findings of this study underscore the importance of hybrid rice technology in addressing the challenges of increasing rice production in Iran. The identified superior hybrids, particularly H33, demonstrate a combination of high yield and excellent grain quality, making them promising candidates for commercial cultivation. The detection of fertility restoration genes Rf3 and Rf4 in the restorer lines and hybrids provides valuable genetic resources for future breeding efforts. The use of SSR markers proved to be an effective approach for identifying these genes, enabling breeders to select and utilize them efficiently. Further research should focus on evaluating these hybrids under diverse environmental conditions and conducting multi-location trials to assess their adaptability and stability. Additionally, efforts should be directed towards developing new CMS lines and restorer lines with improved agronomic traits and enhanced resistance to biotic and abiotic stresses. The integration of molecular breeding techniques with conventional breeding approaches will accelerate the development of high-yielding and climate-resilient rice varieties, contributing to food security and sustainable agriculture in Iran.
on evaluating these hybrids under diverse environmental conditions and conducting multi-location trials to assess their adaptability and stability. Additionally, efforts should be directed towards developing new CMS lines and restorer lines with improved agronomic traits and enhanced resistance to biotic and abiotic stresses. The integration of molecular breeding techniques with conventional breeding approaches will accelerate the development of high-yielding and climate-resilient rice varieties, contributing to food security and sustainable agriculture in Iran.
on evaluating these hybrids under diverse environmental conditions and conducting multi-location trials to assess their adaptability and stability. Additionally, efforts should be directed towards developing new CMS lines and restorer lines with improved agronomic traits and enhanced resistance to biotic and abiotic stresses. The integration of molecular breeding techniques with conventional breeding approaches will accelerate the development of high-yielding and climate-resilient rice varieties, contributing to food security and sustainable agriculture in Iran.
Marker RM 171 indicated the possible presence of the Rf4 gene in the varieties IR 68078-15-2-1-2-2-R and IR 65622-151-1-2-2-2-R, and their hybrids also showed this gene in a heterozygous state. The identified restorer lines, including IR 68078-15-2-1-2-2-R, IR 65622-151-1-2-2-2-R, and IR 86403-5-5-2-1-1-1-1-1R, can be used in hybrid rice breeding programs to develop high-yielding progenies
کلیدواژهها [English]
)