Trade-off between grain weight and grain number in wheat depends on GxE interaction: A case study of an elite CIMMYT panel (CIMCOG)

• Published in: European journal of agronomy 2018-01, Vol.92, p.17-29
• Main Authors: Quintero, Alejandro, Molero, Gemma, Reynolds, Matthew P., Calderini, Daniel F.
• Format: Article
• Language: English
• Subjects: Genotypic correlations; Grain yield; GxE interaction; Source-sink ratio
• ISSN: 1161-0301; 1873-7331
• DOI: 10.1016/j.eja.2017.09.007

•TGW and GN across 27 elite CIMMYT genotypes showed contrasting associations between locations.•The trade-off between TGW and GN was affected by the environmental conditions during grain growth.•A low trade-off between TGW and GN was due to heavier IGW of both proximal and distal grain position of the spike.•Different breeding strategies aimed at increasing grain yield are suggested depending on the TGW-GN interaction. Identifying the functionally linked mechanisms of grain yield (GY) and its components —i.e. grain number (GN) and grain weight (GW) is necessary for boosting GY potential of wheat. The objectives of the current study were to: (i) analyze the trade-off between GW and GN in 27 elite wheat genotypes grown in two contrasting locations with different yield potential, (ii) assess its causes, and (iii) gain a better understanding of the physiology behind the trade-off between GW and GN. A set of 27 elite wheat genotypes was evaluated during three years in Ciudad Obregón, Mexico (CO), and two years in Valdivia, Chile (Val). GY was higher in Val than CO (783gm−2 and 665gm−2, respectively) and positively associated with above-ground biomass (BM) in both locations. In CO, 15,850 grains m−2 were recorded and 15,197 grains m−2 in Val, while thousand-grain weight (TGW) was higher (P