Large genetic yield potential and genetic yield gap estimated for wheat in Europe

Nimai Senapati,Mikhail A Semenov

doi:10.1016/j.gfs.2019.100340

Abstract

Improving yield potential and closing the yield gap are important to achieve global food security. Europe is the largest wheat producer, delivering about 35% of wheat globally, but European wheat's yield potential from genetic improvements is as yet unknown. We estimated wheat ‘genetic yield potential’, i.e. the yield of optimal or ideal genotypes in a target environment, across major wheat growing regions in Europe by designing in silico ideotypes. These ideotypes were optimised for current climatic conditions and based on optimal physiology, constrained by available genetic variation in target traits. A ‘genetic yield gap’ in a location was estimated as the difference between the yield potential of the optimal ideotype compared with a current, well-adapted cultivar. A large mean genetic yield potential (11–13 t ha−1) and genetic yield gap (3.5–5.2 t ha−1) were estimated under rainfed conditions in Europe. In other words, despite intensive wheat breeding efforts, current local cultivars were found to be far from their optimum, meaning that a large genetic yield gap still exists in European wheat. Heat and drought tolerance around flowering, optimal canopy structure and phenology, improved root water uptake and reduced leaf senescence under drought were identified as key traits for improvement. Closing this unexploited genetic yield gap in Europe through crop improvements and genetic adaptations could contribute towards global food security.

Highlights

Ensuring global food security, while protecting the environment, non-agricultural lands and biodiversity, is the single greatest scientific challenge facing humankind (Cassman, 2012)
A ‘genetic yield gap’ in a location was estimated as the difference between the yield potential of the optimal ideotype compared with a current, well-adapted cultivar
The highest yield benefit (3–4 t ha-1; ~39–55%) of heat and drought tolerance around flowering compared with heat and drought sensitivity was obtained in SW Europe, followed by NE and CE Europe (0.9–3 t ha1; ~ 8–27%), whereas a minimum or almost no benefit was found in NW and CW Europe (0.3–0.8 t ha-1; ~ 3–6%) (Fig. 1)

Summary

Introduction

While protecting the environment, non-agricultural lands and biodiversity, is the single greatest scientific challenge facing humankind (Cassman, 2012). Crop yield gaps could exist due to many factors, viz: (a) bio-physical and edaphic constraints (biotic/abiotic stress, poor soil fertility and health, high slope and local soil problems); (b) climatic variability and extreme climatic events (drought, flood, hail, heat stress, frost etc.); (c) sub-optimal land and crop management practices (nutrient deficiency or imbalance, poor disease, pest and weed control, non-optimal planting/sowing, inefficient water management etc.); and (d) socioeconomical limitations (limited access to financial services, as well as institutional or political constraints, including market access and price) (van Ittersum et al, 2013; Kassie et al, 2014; Beza et al, 2017; van Oort et al, 2017). It should be noted that a full yield gap closure is not always feasible, economically viable or environmentally desirable due to climatic risk, diminishing returns and negative environmental impacts (Lobell et al, 2009; van Ittersum et al, 2013)

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Methods

Results