Genomic-assisted Pyramiding of Semi-dwarfism and Micronutrient-enrichment Traits for Developing Climate-smart Wheat (Triticum aestivum L.)
Sachin Kumar
Janta Vedic College, Affiliated to Choudhary Charan Singh University, Meerut, Uttar Pradesh, India.
Raju Ratan Yadav
Department of Molecular Biology and Genetic Engineering, College of Basic Sciences and Humanities, Govind Ballabh Pant University of Agriculture and Technology, India.
Jajati Keshari Nayak
Department of Molecular Biology and Genetic Engineering, College of Basic Sciences and Humanities, Govind Ballabh Pant University of Agriculture and Technology, India.
Himanshika L. Bisht
Janta Vedic College, Affiliated to Choudhary Charan Singh University, Meerut, Uttar Pradesh, India.
Avinash Singh
Department of Life Sciences, Axis Institute of Higher Education, Kanpur, Uttar Pradesh, India.
Imamuddin Shah
Department of Vegetable Science, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India.
Ajeet Singh
Janta Vedic College, Affiliated to Choudhary Charan Singh University, Meerut, Uttar Pradesh, India.
Rajesh Gupta *
Janta Vedic College, Affiliated to Choudhary Charan Singh University, Meerut, Uttar Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
The identification of this new dwarfing gene and its linked markers will greatly facilitate its utilization in wheat high-yield breeding for reducing plant height. The tall wheat variety C-306, renowned for its chapatti-making quality, suffers from lodging under high-input conditions, limiting its yield potential. This study aimed to improve C-306 by introgressing the semi-dwarfing gene Rht1 using marker-assisted selection (MAS) and to evaluate the subsequent effects on agronomic performance and grain micronutrient content. C-306 was used as the recurrent parent in backcrosses with three semi-dwarf donor varieties (WH 1105, DBW 14, HD 2932). Foreground selection for the Rht1 gene was performed using gene-specific PCR markers. The resulting near-isogenic lines (NILs) were evaluated for morphological traits, yield components, and grain Fe/Zn concentrations via atomic absorption spectroscopy. The marker-assisted introgression successfully reduced plant height in the C-306 background. Correlation analysis revealed a moderate positive relationship between plant height and biomass (r = 0.55) and yield (r ≈ 0.40), highlighting a critical breeding trade-off. Crucially, grain Fe and Zn concentrations were positively correlated (r = 0.44) and showed a modest positive association with yield, demonstrating that biofortification can be pursued without a significant yield penalty. Furthermore, total biomass was identified as the primary driver of economic yield (r = 0.87). This study establishes an effective framework for combining MAS with phenotypic analysis to improve traditional cultivars, providing valuable genetic resources for developing shorter, lodging-resistant, and nutritionally enhanced wheat varieties.
Keywords: Triticum aestivum, marker-assisted selection (MAS), Rht genes, biofortification