Selection of oat (Avena sativa L.) drought‐tolerant genotypes based on multiple yield‐associated traits

Abstract

BACKGROUND Most plant breeding and agricultural practices are based on selecting genotypes for yield. However, this is inadequate to screen crop varieties for specific attributes, such as drought tolerance. In this study, we quantified the response of oat (Avena sativa L.) plant physiological and morphological traits to drought stress and selected some key traits to establish a genotype by yield*trait (GYT)‐based method for ranking 30 oat genotypes. The effectiveness of this method was also evaluated under drought conditions. RESULTS Water‐deficit treatment significantly reduced leaf chlorophyll, root morphological traits, groat yield and associated components, such as mean grain weight. We observed that the genotypes ‘JUSTICE’ and ‘BOLINA’ had the smallest and largest yield loss, respectively, after exposure to drought stress, but showed opposite trends in the biomass allocation of roots and grains. This indicated that drought tolerance was highly dependent on the distribution of photoassimilates. Our results also illustrated that the GYT method is a trade‐off approach and more effective in selecting oat ideotypes under drought conditions than the yield‐related index method because it combines yield, yield stability, and related agronomic traits in the calculation process. CONCLUSION Drought‐tolerant genotypes had more biomass allocated to roots and grains with higher chlorophyll content and better root structure, e.g. longer root lengths than drought‐sensitive lines. By integrating yield and yield‐related traits, the GYT approach is more practical than traditional single‐trait selection methods when assessing drought tolerance. © 2023 His Majesty the King in Right of Canada. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri‐Food Canada.

Evaluation of Morpho-Physiological Traits of Oat (Avena sativa L.) under Drought Stress

“…A field study would be valuable to fully determine if a genotype-specific response in root traits under drought exists in oats and if some root characteristics should be targeted for improving tolerance to drought. In oats, Wen et al [52] reported that drought-tolerant oat genotypes could allocate more biomass into root and grain, and had higher chlorophyll content and better root structure than drought-sensitive genotypes. The stimulation of root branching and fine root growth has been reported to mediate the capacity of drought-tolerant oats to cope with water stress [19].…”

Selection based on the phenomenic approach and agronomic ideotic of white oat

“…In white oat, this tool was validated for selecting genotypes with tolerance to water stress (Wen et al, 2023). According to Teixeira et al (2023), phenotyping made it possible to…”