Genetic variation in stomatal characteristics and behaviour, water use and growth of five Vicia faba L. genotypes under contrasting soil moisture regimes

Abstract

Five genotypes of Viciafuba L. with contrasting stomata1 frequencies were grown in a controlled environment in soil moisture regimes of 100x, 78% and 61% of field capacity. Growth, water use and leaf conductance characteristics were measured. Stomata were more frequent on abaxial than adaxial surfaces, the abaxial/adaxial ratio ranging from 1.12 to 1.34. There were significant (P < 0.001) correlations between calculated stomata1 conductance, based on measurements of stomata1 frequency and length, and leaf conductance measured with a diffusion porometer, in the two higher soil moisture treatments. In the 100 % regime only, abaxial stomata opened wider than adaxial. Ranking of the genotypes for leaf conductance and plant transpiration was similar in all three regimes with large leaved types having the lowest conductance and greatest water use efficiency. Growing plants with reduced soil moisture availability improved water use efficiency, the ranking for which was also similar in all treatments. Relative growth rate and net assimilation rate were greatest with full watering, less in the 78% and least in the 61% regime. Leaf area ratio was less affected by available soil moisture and only in some genotypes.

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

“…Nerkar et al (1981) found considerable differences in water loss and transpiration in faba bean genotypes having contrasting stomatal features, and suggested that lower transpiration rate would contribute to drought tolerance. Furthermore, excessive water use in the droughtsensitive faba bean cultivar Adriewaalse from Netherlands was associated with its higher transpiration, while L-7, a breeding line of Mediterranean background was modest in water use and hence drought tolerant (Amede et al 1999).…”

Abiotic Stress Responses in Legumes: Strategies Used to Cope with Environmental Challenges

“…Selection of drought escaping germplasm (White & Singh, 1991) Selection of drought avoidant germplasm (Asfaw & Balir, 2012, Beebe et al, 2013bDevi et al, 2013) Selection of drought tolerant germplasm (Beebe, 2012;Beebe et al, 2008Beebe et al, , 2013aRao et al, 2009Rao et al, , 2013Rao 2014) • (Ismail et al, 2000;Hall et al, 2004;Muchero et al, 2009Muchero et al, , 2010 • (Nerkar et al, 1981;Amede et al, 1999;Link et al, 1999;Khan et al, 2007;Patrick & Stoddard, 2010;Khazaei et al, 2011Khazaei et al, , 2013a • (Stoddard et al, 2006) • Early maturing,…”

“…To uncover, understand and exploit genetic variation for stress tolerance, the stress needs to be specified. As an example, level and pattern of applied drought stress varies widely among researchers (e.g., Grzesiak et al, 1997;Nerkar et al, 1981). Under water stress, the plant may find virtually unlimited amount of water yet hard to take up or a limited offer of water as in terminal drought.…”

Stomatal numbers of soybean and response to water stress

“…EISharkawy and Hesketh (1965) showed that in species where stomata were rare or absent on the upper leaf surface, resistance to gas flow was increased, and both photosynthesis and transpiration were reduced. Nerkar et al (1981) found a correlation between stomatal frequency and leaf conductance, but Jones (1977) found that two barley lines which differed in stomatal frequency were similar in leaf conductance, probably because the stomatal pores were larger in the line with lesser numbers.…”