M. D. Lazar

Genotypic Variation of Osmotic Adjustment, Water-use and Transpiration Efficiency among Closely Related Wheat Lines

Osmotic adjustment (OA) is an important adaptive response to water stress (WS) in wheat (Triticum aestivum L.). The objectives of this study were to determine the relationships between (1) OA and drought susceptibility, (2) OA and biomass, and (3) biomass, water-use efficiency (WUE), and transpiration efficiency (TE) in two cultivars and three closely related lines. Water stress treatments were imposed by polyethylene glycol (PEG)-8000 in nutrient solutions. Under WS, drought-resistant genotypes had higher OA than drought-susceptible ones. Comparing the two cultivars, higher OA may contribute to higher biomass. Among the three closely related lines, there was no correlation between OA and biomass and the genotype with higher OA having lower biomass. Under WS, biomass had a strong correlation with evapotranspiration (ET) and transpiration (T), but a weak correlation with WUE and TE. The results indicated that selecting traits related to effective use of water might be more important than traits related to WUE or TE.