Physiological and biochemical responses to water deficit in Lotus uliginosus × L. corniculatus hybrids

Abstract

Lotus uliginosus (greater lotus, GL) and L. corniculatus (birdsfoot trefoil, BT) are species markedly different in their genetics, morphology and environmental adaptation. We evaluated the hybrids and parental species under differential conditions: in vitro culture, growth chamber and open field environments. The experimental evaluation included biochemical, physiological, developmental and productive parameters. Parental species exhibited significant differences in root growth under different osmotic potentials generated by polyethylene glycol, and hybrids exhibited variability in their response compared with their parents. Plants grown in pots and subjected to drought exhibited differences in biochemical parameters. Proline accumulation and oxidative damage measured by lipid peroxidation were higher in birdsfoot trefoil than any other genotype, and the lowest values were observed in greater lotus. The total phenolic content in shoot ranged from 147 to 279 mg gallic acid equivalents 100 g–1 dry mater. With regard to antioxidant capacity estimated by 2,2-diphenyl-1-picrylhydrazyl, greater lotus had the highest value and birdsfoot trefoil the lowest, at almost one-third, whereas hybrids had intermediate values. Under stress conditions, water-use efficiency showed significant differences between both parental species. In the field, under either irrigation or drought, the dry matter accumulated by the hybrids was higher than that of the parents. Hybrids express recombination of features, making them an interesting material to continue evaluation.