Evaluation of physiological traits for improving drought tolerance in faba bean (Vicia faba L.)

Abstract

Among grain legumes, faba bean is becoming increasingly popular in European agriculture due to recent economic and environmental interests. Faba bean can be a highly productive crop, but it is sensitive to drought stress and yields can vary considerably from season to season. Understanding the physiological basis of drought tolerance would indicate traits that can be used as indirect selection criteria for the development of cultivars adapted to drought conditions. To assess genotypic variation in physiological traits associated with drought tolerance in faba bean and to determine relationships among these attributes, two pot experiments were established in a growth chamber using genetic materials that had previously been screened for drought response in the field. Nine inbred lines of diverse genetic backgrounds were tested under adequate water supply and limited water conditions. The genotypes showed substantial variation in shoot dry matter, water use, stomatal conductance, leaf temperature, transpiration efficiency, carbon isotope discrimination (D 13 C), relative water content (RWC) and osmotic potential, determined at pre-flowering vegetative stage. Moisture deficits decreased water usage and consequently shoot dry matter production. RWC, osmotic potential, stomatal conductance and D 13 C were lower, whereas leaf temperature and transpiration efficiency were higher in stressed plants, probably due to restricted transpirational cooling induced by stomatal closure. Furthermore, differences in stomatal conductance, leaf temperature, D 13 C and transpiration efficiency characterized genotypes that were physiologically more adapted to water deficit conditions. Correlation analysis also showed relatively strong relationships among these variables under well watered conditions. The drought tolerant genotypes, ILB-938/2 and Melodie showed lower stomatal conductance associated with warmer leaves, whereas higher stomatal conductance and cooler leaves were observed in sensitive lines (332/2/91/015/1 and Aurora/1). The lower value of D 13 C coupled with higher transpiration efficiency in ILB-938/2, relative to sensitive lines (Aurora/1 and Condor/3), is indeed a desirable characteristic for waterlimited environments. Finally, the results showed that stomatal conductance, leaf temperature and D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables could be measured in pot-grown plants at adequate water supply and may serve as indirect selection criteria to pre-screen genotypes.

Management of crop water under drought: a review

“…Morphological change allows medium-(weeks) to longterm (ontological) adaptation comprehensive understanding of drought resistance in agricultural crops. The classical scheme of Levitt reveals the main drought resistance strategies in natural vegetation communities (Levitt 1980). Figure 6 resumes Levitt's scheme with a contextualisation for agricultural crop production.…”

“…Crops with longer vegetation time such as sugar beet, maize, sunflower and potato growing until autumn will be discussed shortly afterwards. Levitt (1980). Different resistance strategies, examples for corresponding adaptive traits and their potential use/ limitation for agricultural crops.…”

“…Water saving due to higher intrinsic water-use efficiency has been popularised in breeding research with the introduction of carbon isotope discrimination (CID) as an easily measurable parameter in the mid-1980s (Farquhar and Richards 1984). CID has been assessed for various crops such as C 3 cereals (Araus et al 2002), maize (Gresset et al 2014), soybean (Gitz et al 2005), sorghum (Henderson et al 1998), faba bean (Link et al 2007) and others. CID is an indicator of conservative water use and related to earliness.…”

Legume Crops Phylogeny and Genetic Diversity for Science and Breeding

“…Many efforts have been made recently to improve abiotic tolerance and climate adaptation, though progress has been slow, since the partially allogamous nature of faba bean slows the process of developing pure lines. Nevertheless, useful genetic resources with good drought tolerance have been identified (Khan et al, 2007). Enhancing winter-hardiness of faba bean will mitigate the cold damage and ensure crop productivity (Arbaoui et al, 2008;Link et al, 2010;Hu et al, 2011;Flores et al, 2012).…”

Multivariate analysis and drought stress tolerance indices in chickpea (Cicer arietinum L.) under different irrigation regimes

“…Expanding the improved chickpea cultivars and evolution of these genotypes with narrow genetic bases, making them vulnerable to biotic and biotic stresses and it caused low and unsuitable yield productivity in most chickpea cultivation area (Talebi & Fayyaz, 2012). Drought is a major abiotic stress which responsible for production losses (Khan et al, 2007). According to Mafakheri et al (2011), this stress is considered as one of the most important limiting factors for chickpea growth and production.…”