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Investigating Genetic Progress and Variation for Nitrogen Use Efficiency in Spring Wheat
Author(s) -
Kubota Hiroshi,
Iqbal Muhammad,
Dyck Miles,
Quideau Sylvie,
Yang Rong-Cai,
Spaner Dean
Publication year - 2018
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2017.10.0598
Subject(s) - dwarfing , biology , cultivar , dry matter , nitrogen , agronomy , grain yield , yield (engineering) , allele , genetic variation , gene–environment interaction , genotype , zoology , horticulture , genetics , gene , chemistry , materials science , rootstock , organic chemistry , metallurgy
Improved N use efficiency (NUE) increases wheat ( Triticum aestivum L.) yields and reduces N losses in the environment. We investigated genetic variation and correlations among agronomic and NUE traits in Canada Western Red Spring wheat cultivars to further improve NUE. Trials were conducted for 3 yr at two locations in Alberta, Canada, under two levels of N (200 and ~50 kg ha −1 ). Genotype × environment interaction was significant for traits associated with vegetative growth, and genotype × N fertilizer treatment interaction was significant for important yield and NUE traits. There were significant positive correlations between total dry matter and N uptake efficiency (NUpE) in the high ( r = 0.74, P < 0.05) and low ( r = 0.83, P < 0.05) N treatments. The effect of dwarfing Rht‐1b allele was more prominent under high N treatment in increasing NUE. However, cultivars with Rht‐1b allele showed inconsistent results for NUpE, indicating that Rht alleles might have pleiotropic effects on N uptake. Grain yield, NUE, and N utilization efficiency (NUtE) exhibited genetic improvement over time only under high N treatment. Our results indicated that grain yield increased mainly due to improved harvest index (HI), suggesting improvement in C assimilation rather than N partitioning efficiency. Nitrogen use efficiency may further be improved by intercrossing cultivars with high HI, N harvest index, and NUtE and those with good NUpE, while using total dry matter production as a selection criterion.