Epistatic QTLsPlay a Major Role in Nitrogen Use Efficiency and Its Component Traits in Indian Spring Wheat

Manjeet Kumar,Neelu Jain,Rumesh Ranjan,Nivedita Sinha,Naresh Kumar Bainsla,Kiran B Gaikwad,Rajbir Yadav

doi:10.3390/agriculture11111149

Manjeet Kumar, Neelu Jain + Show 5 more

Open Access

https://doi.org/10.3390/agriculture11111149

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Abstract

Nitrogen use efficiency (NUE) in wheat may significantly reduce the excessive use of N fertilizers. However, being a quantitative trait, understanding its genetic basis is required for efficient wheat breeding. The present study was carried out to dissect the complex trait through the mapping of quantitative trait locus (QTLs) related to NUE component traits in Indian wheat. A linkage map was constructed using F2 population derived from two parents contrasting for nitrogen-responsive traits using simple sequence repeat (SSR) markers. Phenotyping for root dry weight, N uptake and utilization were carried out under a high nitrogen environment. Twenty-seven main effect QTLs for eight traits and 26 interaction QTLs for three traits were detected. The main effect QTLs explained a significant amount of phenotypic variance up to the extent of 11.18%. The QTLs were also found to have significant epistatic interactions governed by both additive and non-additive gene action. In particular, chromosome 2A harbours QTLs for many traits viz. SDW, RDW, TDW, R:S, %N, NUtE, and NUpE, including epistasis and interaction QTLs that were flanked by markers Xwmc728-Xwmc473 and Xwmc779-Xgwm249. Taken together, the genomic regions on 2A, 4A, and 7A were found to contain QTLs for a majority of the studied NUE traits that can be potentially exploited in future wheat breeding programmes.

Highlights

Wheat (Triticum aestivum L.) is an important source of energy, contributing mainly through carbohydrates and nutritional protein for both humans and livestock [1]; and the necessity to raise its production is unquestioned
The detection of quantitative trait locus (QTLs) for Nitrogen use efficiency (NUE) and component traits in the present study provides many valuable clues for understanding the genetic basis of NUE
Chromosome 2A and 4A harbour genomic regions flanked by the markers, Xwmc728Xwmc473 and Xwmc262-Xwmc617, respectively, for a number of traits related to NUE including SDW, TDW, R:S, N utilization efficiency (NUtE), and N uptake efficiency (NUpE), and can be used for molecular breeding in the future

Summary

Introduction

Wheat (Triticum aestivum L.) is an important source of energy, contributing mainly through carbohydrates and nutritional protein for both humans and livestock [1]; and the necessity to raise its production is unquestioned. Around 765 MT of wheat is produced from the acreage of 220 Mha [2]. It is well-known that irrigation, semi-dwarf varieties, and increased nitrogen (N) fertilization were important factors for the increase in wheat yields during the 20th century [3]. Processes like volatilization, runoff, denitrification, and leaching results in loss of a large proportion of the applied N (50–70%) from the plant-soil framework [8], still the adverse effects of fertilizer use can be seen including damage to the environment, a large carbon footprint, and depletion of non-renewable resources [9]

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