Contrasting Root and Photosynthesis Traits in a Large-Acreage Canadian Durum Variety and Its Distant Parent of Algerian Origin for Assembling Drought/Heat Tolerance Attributes

Abstract

In Canada, the world's top exporter of high-protein durum, varietal development over its nearly six-decade history has been driven by a quest for yield improvement without compromise on grain protein content and other quality aspects. Pelissier, a landrace selection from Algeria that was introduced into North America more than a century ago and the variety Strongfield that was released in 2004 are notable. Pelissier, known to elaborate more roots and considered as drought tolerant, has been cultivated commercially and thus deemed adapted. Strongfield has Pelissier in its pedigree, and it remains a high-acreage variety. Strongfield was found to elaborate only about half of the root biomass of Pelissier at maturity in greenhouse trials under well-watered conditions. Extended drought stress caused a significant reduction in the root biomass of both lines. However, Pelissier under drought maintained at least as much root biomass as that of Strongfield under well-watered conditions. In comparison to Pelissier, it had a superior photosynthesis rate (27.16 μmol CO2 m−2 s−1), capacity for carboxylation (Vcmax: 132.83 μmol CO2 m−2 s−1) and electron transport/ribulose-1,5–bisphosphate (RuBP) regeneration (Jmax: 265.40 μmol CO2 m−2 s−1); the corresponding values for Pelissier were 19.62 μmol CO2 m−2 s−1, 91.87 μmol CO2 m−2 s−1, and 163.83 μmol CO2 m−2 s−1, respectively, under well-watered conditions. Under short-term/mild drought conditions, the carbon assimilation rate remained stable in Pelissier while it declined in Strongfield to the Pelissier level. However, Strongfield succumbed to extended drought sooner than Pelissier. Photosynthesis in Strongfield but not Pelissier was found to be sensitive to high temperature stress. These results provide encouraging prospects for further exploitation of beneficial physiological traits from Pelissier in constructing climate-resilient, agronomically favorable wheat ideotypes.

Arbuscular Mycorrhizal Fungi and Higher Plants

“…In Canada, technologies employed have been limited to shovelomics, soil columns, rhizotrons, and WinRHIZO™ except in a few cases-LCR meter ) and CI-600 In Situ Root Imager (Bourgault et al 2022). A few studies have looked at harnessing root traits to mitigate drought stress (Ashe et al 2017;Gorim and Vandenberg 2017); root traits, root lodging parameters, and canola yield Ma 2016, Wu et al 2020); water and nutrient uptake (Liu et al , 2011Gan et al 2011;Cutforth et al 2013); and effects of low and high N levels versus rhizobia inoculation on root traits in wild and cultivated lentil (Vargas Palacio 2021) and relate root mass to photosynthetic efficiency in durum wheat varieties with different pedigrees (Ashe et al 2017). In the United States and Australia, identifying and incorporating root ideotypes rather than individual root traits into breeding programs is a recommended approach that can also be pursued in prairie breeding programs (Lynch 2013;Rao et al 2021).…”

Multi‐omics atlas of combinatorial abiotic stress responses in wheat

“…The resulting effects of either stress are an intensity‐dependent reduction in yield. Drought tolerance involves minimization of water loss, osmotic adjustment, increased rooting depth and effective mobilization of carbon stores (Ashe et al., 2017; Ashraf, 2010; Yang & Zhang, 2006). Known key regulators during drought stress include TaER genes for determining plant transpiration efficiency (Zheng et al., 2015) and TaMOR genes for enhanced root architecture (Li, Liu, et al., 2016).…”

Algerian durum wheat assessment for early drought tolerance shows landraces superiority

“…In several cases, winter cereal landraces have shown better performances than modern varieties, usually under challenging environmental conditions (Yahiaoui et al, 2014;Erice et al, 2019). When root systems were compared, an Algerian wheat landrace (Pelissier) had more root growth than a widely grown modern variety (Ashe et al, 2017).…”