Leaf Water Potential, Relative Water Content, and Diffusive Resistance as Screening Techniques for Drought Resistance in Barley

Abstract

Rapid drought resistance screening techniques could accelerate selection of improved cultivars for semiarid areas. This study was conducted to determine if total leaf water potential, leaf relative water content, and leaf diffusive resistance could be used to differentiate between barley (Hordeum vulgare L.) cultivars differing in apparent drought resistance. Resistant and susceptible cultivars were selected by regressing individual cultivar yields against site mean yield for numerous yield trials. Individual plants were grown in cone-tainers (plastic tubes 25 mm in diameter and 123 mm long). The lower 30 mm of the cone-tainers were imbedded in sand so that roots emerging from the bottom of the cone-tainers were in the capillary fringe above a water table in the sand. Fifty plants were grown at a time in a sand bed, five replications each of five resistant and five susceptible barley cultivars of either two-or six-row head types. At the three-leaf growth stage total leaf water potential (.J;,) was measured on the third leaf of each plant under low stress conditions (predawn). Water was then drained from the sand bed to stress the plants. Leaf diffusive resistance (LDR) was measured at 1000 and 1300 h each day as stress developed. When the PM diffusive resistance reached about 1000 s m-•, relative water content (RWC) of the second leaf was determined. All measurements were repeated in three different trials for each head type. Relative water content and .J;, differentiated between drought-resistant and drought-susceptible groups of twoand six-rowed barley at the 0.01 probability level in every trial. Leaf diffusive resistance differentiated between resistant and susceptible groups at the 0.01 or 0.05 level under low and high stress conditions. Neither RWC nor LDR allowed separation of cultivars within resistant or susceptible groups, but .J;, did show differences between cultivars within groups. These techniques provide an easy method to screen for drought-resistant barley.

Use of physiological parameters as fast tools to screen for drought tolerance in sugarcane

“…Following the LT measurements, leaf disks (1.3 cm diameter each) were collected with a cork borer from the same leaves used for F v /F m , SPAD index and LT measurements and used to determine leaf relative water content (RWC) following the method of Matin et al (1989). Five disks per plant were collected, immediately sealed in glass vials and quickly transported to the laboratory in an ice-cooled chest.…”

Photosynthesis and antioxidant activity in Jatropha curcas L. under salt stress

“…Key antioxidant enzymes, including APX (EC 1.11.1.11) and CAT (EC 1.11.1.6), were assayed exactly as described by Pompelli et al (2010a). Chl and total carotenoids were extracted using 80% (v/v) aqueous acetone and quantified spectrophotometrically, according to Lichtenthaler, in 1987. Leaf disks (each 1.3 cm in diameter) were collected with a cork borer from the same leaves used for P N measurements and were used to determine the leaf relative water content (RWC), based on the method of Matin et al (1989), with some modifications. Five disks per plant were collected immediately sealed in glass vials and quickly transported to the laboratory in an ice-cooled chest.…”

“…Then, the disks were quickly and carefully blotted dry with lint-free tissue paper before determining the turgid weights. Dry weights were recorded after drying the leaf samples in an oven for 48 hours at 80ºC (Matin et al, 1989).…”

Genetic Variability Study Among Wheat Genotypes Under Normal and Drought Conditions

“…Among testers, the line 9451 have highest positive GCA effects of 0.49 closely followed by the tester line 9437 (0.34) which is desirable under normal and drought conditions. Seropian andPlanchon, andMatin et al 1989 who also worked on combiningabilitz and reported similar findings. .…”

“…Assessment of genotypes for drought resistance on the basis of combining ability estimates for leaf and other physiological attributes, play a vital role in water relations of wheat under different sowing regimes (Seropian, C. and C. Planchon. 1984;Matin et al 1989). The knowledge of general combining ability (GCA) provided an estimation of degree of additive gene action and specific combining ability (SCA) exhibited the performance of two particular varieties/lines in a specific cross, which would reflect non-additive type of gene action (Phoelman, J.M.…”