The opportunity of using durum wheat landraces to tolerate drought stress: screening morpho-physiological components

Abstract

Local genetic resources could constitute a promising solution to overcome drought stress. Thus, eight (8) durum wheat landraces and one improved variety were assessed for drought tolerance in pots under controlled conditions. Three water treatments were tested: control (100% of the field capacity (FC)), medium (50% FC), and severe (25% FC) stress. The assessment was carried out at the seedling stage to mimic stress during crop set-up. Results showed that increased water stress led to a decrease in biomass and morpho-physiological parameters and an increase in antioxidant enzyme activities. Severe water stress decreased the chlorophyll fluorescence parameters, relative water content, and water potential of the investigated genotypes by 56.45%, 20.58%, 50.18%, and 139.4%, respectively. Besides, the phenolic compounds content increased by 169.2% compared to the control. Catalase (CAT) and Guaiacol Peroxidase (GPX) activities increased at 17 days after treatment for most genotypes except Karim and Hmira. A principal component analysis showed that the most contributed drought tolerance traits were Chlorophyll fluorescence parameters, relative water content, and electrolyte conductivity. UPGMA clustering showed that the landraces Aouija, Biskri, and Hedhba exhibited a higher adaptive response to drought stress treatments indicating that water stress-adaptive traits are included in Tunisian landraces germplasm.

Study of the genetic variability of durum wheat (Triticum durum Desf.) in the face of combined stress: water and heat

“…A reduction in F v/m by water deficit and high temperature suggests a possible inhibition of PSII photochemistry, which may be due to an inadequate relocation of the energy of the light-harvesting chlorophyll complex towards the reaction centre ( Ahmed et al 2013 ). A minimal decrease in F v/m was observed for Aouija indicating that higher defensive capacity for PSII is a key resistance mechanism for durum wheat landraces, which is in agreement with previous studies for durum wheat accessions under water and heat stress conditions ( Marček et al 2019 ; Doneva et al 2021 ; Chaouachi et al 2023 ; Raza et al 2023 ). For the parameters reported in this work, Aouija is more tolerant to abiotic stress and could be an opportunity for breeding programs.…”

“…durum ) genotypes, including four Tunisian landrace genotypes (Hmira, Biskri, Hedhba, and Aouija) from the Tunisian National Gene Bank (BNG) and an improved variety (Karim) from the Central Seed Mutual Fund company (COSEM) in Manouba, Tunisia. These genotypes have been previously reported for screening for drought stress conditions ( Chaouachi et al 2023 ).…”

“…Several physiological, morphological, and biochemical criteria have thus been identified ( Benkadja et al 2022 ). Proline and soluble sugar accumulation, vegetative growth, and photosynthetic efficiency have been considered as tolerance criteria ( Boussakouran et al 2019 ; Jallouli et al 2019 ; Othmani et al 2019 ; Gholamin and Khayatnezhad 2020 ; Pour-Aboughadareh et al 2020 ; Ayed et al 2021 ; Tefera et al 2021 ; Chaouachi et al . 2023 ; Quagliata et al 2023 ).…”

Genetic diversity of durum wheat (Triticum turgidum ssp. durum) to mitigate abiotic stress: Drought, heat, and their combination

“…It is interesting to note, from PCA results, that, under both individual and combined stress, the landrace Aouija was the only genotype that kept the same tolerance to both abiotic stresses, which indicates that Aouija is the most stable genotype and could be considered as tolerant to drought or/and heat stresses. Furthermore, the landrace Aouija showed the same behavior under drought stress and combined drought and heat stresses in previous studies at the seedling stage [ 101 , 104 ]…”

“…These results are in complete accordance with several other studies for the variety Karim [ 98 – 100 ]. Indeed, a reduction in the hydration of durum wheat induces a reduction in biomass [ 101 – 103 ]. Plant water status is highly dependent on thermal stability, and an excessive increase in heat causes dehydration of plant tissues, which limits the growth and development of plants [ 75 ].…”