Understanding drought response mechanisms in wheat and multi-trait selection

Abstract

Wheat crop is very sensitive to osmotic stress conditions. As an abiotic stress, drought may exert a considerable effect on the levels of specialized metabolites in plants. These metabolites may exert beneficial biological activities in the prevention or treatment of disorders linked to oxidative stress in plants and humans. Furthermore, osmoprotector accumulation helps wheat to increase the maintenance of osmotic balance. Therefore, identifying wheat genotypes with better drought tolerance is extremely important. In this sense, this research aimed to understand agronomic, physiological and biochemical responses of spring wheat strains and cultivars to drought stress, under field conditions, and jointly select strains via multi-trait index. We evaluated agronomic, physiological and biochemical variables in 18 genotypes under field condition. The results demonstrated that all variables were affected by the drought. Most genotypes were significantly reduced in grain yield, except VI_14774, VI_14668, VI_9007 and TBIO_ATON. The variables related to photosynthesis were also affected. An increase above 800% was observed in proline contents in genotypes under drought. Sodium and potassium also increased, mainly for VI_131313 (Na), while VI_130758 and VI_14774 presented increased K. We evaluated the antioxidant potential of the different strains and the total content of phenolic compounds. The most drought-responsive genotypes were BRS_264, VI_14050 and VI_14426. Reduced grain yield and photosynthetic variables, and increased specialized metabolism compounds are due to plant defense mechanisms against drought conditions. Furthermore, variation in genotypes can be explained by the fact that each plant presents a different defense and tolerance mechanism, which may also occur between genotypes of the same species. Four strains were selected by the multivariate index: VI_14055, VI_14001, VI_14426 and VI_1466. Such results allow us to predict which genotype(s) performed best in semi-arid environments and under climatic fluctuations.

Genetic gains in tropical maize hybrids across moisture regimes with multi-trait-based index selection

“…The method emerged as a powerful tool to identify the genotypes with better mean performance and desired SGs and also to estimate the strengths and weaknesses of hybrids (selected/ unselected). The multi-trait selection index (MTSI) and MGIDI evaluation systems are novel and unique techniques that have many practical applications in plant breeding practices (Nelimor et al, 2020;Benakanahalli et al, 2021;Koundinya et al, 2021;Pour-Aboughadareh et al, 2021;Hadou el hadj et al, 2022;Yue et al, 2022a;Yue et al,2022b;Nardino et al, 2022;Dhand and Garg, 2023;Memon et al, 2023). The multi-trait frameworks and MGIDI and MTSI indices follow a similar rescaling process to retain the unchanged correlation structure of original data and to identify the superior genotypes with respect to multiple traits simultaneously (Olivoto et al, 2019b).…”

Multi-trait selection for mean performance and stability of maize hybrids in mega-environments delineated using envirotyping techniques

“…Grain yield and its components are very complex agronomic traits influenced by genotype (G), environment (E), and their interactions (GEI). The GEI makes the genotype-to-phenotype relationship environment-dependent, which makes the selection of widely adapted hybrids more difficult ( Ebdon and Gauch, 2002 ) and occurs due to the differential response of a given genotype to a given environment stimulated by both biotic, abiotic, or an interaction between them ( Nardino et al., 2022 ). In maize, for example, high temperatures (> 35°C) during flowering generate a cascade effect that starts with the reduction of RuBPCase activity by downregulating genes Zm0001d052595 and Zm0001d004894 which limited photosynthesis and consequently affects maize growth and development ( Niu et al., 2021 ).…”

Improving the effects of drought priming against post-anthesis drought stress in wheat (Triticum aestivum L.) using nitrogen

“…The recent global climate events are continuously impacting agriculture, threatening global food security. Drought stress is the primary factor affecting plant metabolism and disturbing the photosynthesis machinery ( Ahmad S. et al, 2021 ; Nardino et al, 2022 ). In the process, drought stress reduces the stomata conductance to restrict water losses during evapo-transpiration and reduces the CO 2 in the grass ( Gaikwad et al, 2020 ), subsequently disturbing photosystem II (Fv/Fm) ( Grassi and Magnani, 2005 ).…”