Identification of QTLs Associated with Nitrogen Use Efficiency and Related Traits in a Diploid Potato Population

Baye Berihun Getahun,C Gerard Van Der Linden,Richard G F Visser

doi:10.1007/s12230-020-09766-4

Baye Berihun Getahun, C Gerard Van Der Linden + Show 1 more

Open Access

https://doi.org/10.1007/s12230-020-09766-4

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Abstract

Developing N use efficient potato varieties requires exploring the genetic basis of nitrogen use efficiency (NUE) and associated agronomic and physiological traits. In order to identify QTLs for NUE and NUE-related traits, and to determine the relationships between the traits and QTLs in potato, a diploid potato mapping population (CxE) was evaluated in the field in Ethiopia under low and high N fertilizer levels. QTL detection was performed using interval mapping and multiple QTL mapping (MQM). A total of 52 putative QTLs were identified for ten traits, of which 28 QTLs were detected under low N availability while the remaining 24 QTLs were detected under high N conditions. Several QTLs were location and N level specific, suggesting the presence of QTL x environment interaction. A region on linkage group V (21-38 cM) accumulated the largest number of QTLs. This region coincides with the earliness locus encoded by the CDF1 gene, suggesting that earliness has a profound influence on NUE. A putative second QTL region on linkage group V located 20 cM from the earliness locus (38-56 cM) and a region on linkage group IV (60-72 cM) might be useful other regions to focus on, for NUE improvement in potato. To verify the stability of the identified QTLs and to use these for the detection of possible candidate genes, further multi-environment trials with larger population size may be required.

Highlights

Crop productivity is greatly affected by nutrient availability and nutrient use efficiency
The C x E diploid potato backcross population was grown at three different locations in two different production seasons under low and high N fertilizer regimes to evaluate potato genotypes for Nitrogen use efficiency (NUE)
Breeding for higher yields in crops can be successful via the monitoring and selection for the component physiological traits that determine biomass partitioning and production, and the identification of quantitative trait loci (QTL) that control the heritable variation of these traits (Tuberosa et al 2008)

Summary

Introduction

Crop productivity is greatly affected by nutrient availability and nutrient use efficiency. Nitrogen Use Efficiency (NUE) has become the second priority production constraint after drought in crop abiotic stress improvement programs (Hirel et al 2011). Improving agronomic NUE is relevant for the majority of crops currently cultivated. Less than 50% of the applied nitrogen is typically used by most crops and a large amount of N fertilizer is required to reach maximum yield.

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