Identification of agronomical and morphological traits contributing to drought stress tolerance in soybean

Abstract

Abiotic stresses, especially drought, may seriously affect soybean yield. Due to the complexity of drought tolerance, one of the difficulties in selecting genotypes is the identification of traits contributing to improve stress tolerance. This study carried out soybean phenotyping under water deficit in vegetative and reproductive stages in field conditions at two consecutive crop seasons (2012/13 and 2013/14). The experiment was performed in Londrina, PR, Brazil, with two soybean cultivars with distinct levels of drought tolerance, BR 16 (sensitive) and Embrapa 48 (less sensitive). Water deficit was applied through rainout shelters, moving on rails to cover plots when the rainfall begins and uncover them when it ends. Then, some agronomic and morphological traits were measured. Multivariate statistics through the principal component analysis (PCA) associated with the biplot graph identified traits contributing to greater yield stability under drought. Result showed that water deficit affected soybean yield, mainly in the reproductive stage, in which Embrapa 48 had greater yield stability when compared to BR 16. However, opposite results were obtained for stress induced in the vegetative stage, when Embrapa 48 was more negatively affected than BR16 cultivar. Seed weight influenced yield differences between cultivars. Lighter seeds, but in larger number, constituted an advantage under water deficit. Due to the difficulty in introducing all drought tolerance mechanisms in one genotype, breeding programs need to define selection parameters according to regional drought conditions.

Soil Water Deficit and Fertilizer Placement Effects on Root Biomass Distribution, Soil Water Extraction, Water Use, Yield, and Yield Components of Soybean [Glycine max (L.) Merr.] Grown in 1-m Rooting Columns

“…An unexpected result of the present work was the increased HI under drought stress. Contrary to this, reduced HI under drought stress has been reported in maize ( Earl and Davis, 2003 ) and soybean ( Oya et al, 2004 ; Giordani et al, 2019 ).…”

“…Even in unusually wet years, soybean yields in Ontario are reduced by transient soil water deficits, and in drier years, yield losses may exceed 25% (H. J. Earl, unpublished data). Numerous controlled environment and field studies have also reported yield reductions ranging from 24 to 80% in soybean subjected to different levels of drought stress (e.g., Frederick et al, 2001 ; Sadeghipour and Abbasi, 2012 ; He et al, 2016 , 2017 ; Wei et al, 2018 ; Giordani et al, 2019 ; Gebre, 2020 ).…”

Multi‐trait stability index: A tool for simultaneous selection of soya bean genotypes in drought and saline stress

“…Selection methods for several environments are always of interest to soya bean breeders (Füzy et al, 2019;Giordani et al, 2019;Vianna et al, 2019) and other crops of economic interest (Mazengo, Tryphone, & Tarimo, 2019;Ramzan, Aslam, Ahsan, & Awan, 2019), attributed mainly by the strong G × E interaction that occurs in most crops and the changing conditions found in the field (abiotic and biotic stresses), which contribute to the decreased performance of several genotypes across environments.…”

“…To manage and understand these variations when evaluating a relatively large set of genotypes, as well as several stresses at the same time, it is necessary to employ appropriate techniques for this purpose. Techniques such as PCA (principal component analysis) (Füzy et al, 2019;Giordani et al, 2019;Ramzan et al, 2019), ranking (Mazengo et al, 2019), BLUP (best linear unbiased prediction) (Nardino et al, 2016;Olivoto et al, 2017), AMMI (additive main effects and multiplicative interaction) (Bocianowski, Niemann, & Nowosad, 2019;Veenstra, Santantonio, Jannink, & Sorrells, 2019), and the combination of BLUP and AMMI (Olivoto, Lúcio, Silva, Marchioro, et al, 2019) and MTSI (multi-trait stability index) (Olivoto, Lúcio, Silva, Sari, et al, 2019) have been employed.…”

An integrative analysis of yield stability for a GWAS in a small soybean breeding population

“…Due to the drought tolerance complexity, most breeders are still using total yield, yield stability (Giordani et al., 2019), or traits that have been associated with yield stability, such as canopy wilting (Ye et al., 2020) and root structure (Pantalone et al., 1996; Prince et al., 2015), as an indirect selection for drought tolerance. To evaluate yield stability, several authors have developed drought susceptibility indices (DSIs), based on a regression coefficient between contrasting environments (i.e., irrigated vs. nonirrigated conditions) (Clarke et al., 1992; Fischer & Maurer, 1978 ).…”