Genotype by environment interactions for spring durum wheat in Kazakhstan and Russia

Durum wheat (Triticum durum) is grown over an estimated 1.4 Mha in Kazakhstan and Russia with its production increasing to satisfy growing demand. Kazakhstan-Siberian Network on Spring Wheat Improvement (KASIB) was established in 2000 to exchange the germplasm and conduct cooperative multilocation testing for characterization of the germplasm. This study used the multilocation data from 80 sites x years, nine KASIB spring durum wheat trials conducted in 2003–2020 across five sites in Kazakhstan and Russia to evaluate genotype × environment interactions and identify superior germplasm. Aktobe and Samara were the driest and hottest locations with short growing seasons. Barnaul was the most favorable environment with high and stable rainfall. Omsk and Karabalyk sites were intermediate in production environment and grain yield. Analysis of weather variation between years demonstrated that all sites were subject to the same climatic events. Air temperature in May–August was negatively associated with grain yield and had a relatively higher effect compared to rainfall. Performance of germplasm was generally similar between all five sites. Breeding of cultivars widely adapted to the three subregions is not particularly realistic but targeting adaptation for two neighboring subregions would be justified. Grain yield and 1000 kernel weight were closely associated at all sites suggesting the importance of breeding for grain size. Superior germplasm was identified combining high grain yield across the five sites, variable response to environments, variable maturity range and large grain. Breeding programs at Samara and Omsk contributed the most germplasm to high-yielding performers.