Characteristic variation in pigment composition, photosynthetic carbon assimilation and phytonutrients content of Dendrophthoe falcata, a hemiparasite growing on host trees of saline and non-saline environments

Abstract

The Indian Mistletoe Dendrophthoe falcata (L.f) Ettingsh is highly specialized perennial flowering plant adapted to parasitic life on aerial parts of their hosts. Photosynthetic characteristics in leaves of D. falcata growing on a halophilic (Rhizophora mucronata) and a glycophilic (Albizia lebbeck) host trees were determined. The chlorophyll a/b ratio was lower (1.0–1.5) and showed no significant difference between the leaf samples collected from both the host species. The CO2 assimilation rate (PN) was significantly lower (5.2 µmol/(m2 s)) in the parasite growing on R. mucronata, compared to the other host A. lebbeck (6.7 µmol/(m2s)). There was no host-specific variation in the activity of ribulose-1,5-bisphosphate carboxylse (Rubisco) and phosphoenolpyruvate carboxylase (PEPC); however, D. falcata infecting R. mucronata showed significantly higher activity of Rubisco (6.63 mmol CO2/(s kg protein)). The Fourier transform infrared (FTIR) spectral studies revealed the presence of quercitrin in the leaf samples of D. falcata, which is reported as a taxonomic marker of the Loranthaceae family. The non host-specific hemiparasite, D. falcate, exhibited significant variation among the halophilic and glycophilic host trees, particularly in photosynthetic activity and nutrients accumulation.