Multi-environment assessment of the impact of genetic improvement on agronomic performance and on grain quality traits in Moroccan durum wheat varieties of 1949 to 2017

Mona Taghouti, Nasserlehaq Nsa

Abstract

Twenty-nine genotypes released in Morocco during the 20th and early 21st centuries, were evaluated in contrasting environments to assess genotype and genotypes by environment interaction effect and to quantify breeding achievement in productivity and quality related traits. Results indicated that the main effects due to genotypes, environments and genotype by environment interaction were significant. The GGE biplot model revealed two mega-environments with elite line “PM32” producing the highest yield and varieties “Louiza”, “PM9” generates the highest yellow color index. A significant improvement was achieved in durum wheat Moroccan productivity. Modern cultivars exceed their predecessors in terms of yield and related traits. The genetic gain was clearly associated with a reduction in plant cycle and mainly in plant height (-0.42% year-1 ). Lowering the straw yield has resulted in an increase of grain yield estimated to +13Kg ha-1 year-1 corresponding to a relative genetic gain of 0.43% per year. The results detected two main episodes of quality traits improvement. Since the first decade of the 21st century, breeding efforts for durum wheat grain quality in Morocco has allowed an annual improvement of yellow index color (0.27 year-1 ) and gluten strength (0.80 ml year1 ) indicating relative genetic gains of 1.46% and 1.93% per year respectively. Further improvement of the durum wheat cultivars is expected from the deployment of marker –assisted selection to improve breeding efficiency.

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