Sivanantham Amrutha (1), Abdul Bari Muneera Parveen (1), Muthusamy Muthupandi (1), Veerasamy Sivakumar (1), Raman Nautiyal (2), Modhumita Ghosh Dasgupta (1*)
(1) Institute of Forest Genetics and Tree Breeding, R. S. Puram, Coimbatore 641002, India
(2) Indian Council of Forestry Research and Education, P. O. New Forest, Dehradun 248006, Uttarakhand, India
The genus Eucalyptus occurs in a wide range of environmental conditions, including rainforests, subalpine, arid/semi-arid, and moist temperate zones.
It includes species with the capacity to cope with extremely low water potential. This study aims to screen water stress tolerance in two Eucalyptus species under nursery conditions.
Inter-specific variation in morphological, physiological, biochemical, and molecular parameters in two Eucalyptus species (E. tereticornis and E. camaldulensis) with contrasting levels of tolerance to progressive short-term water-deprived conditions was evaluated.
Water stress reduced growth measured in terms of root:shoot ratio and specific leaf area (SLA), photosynthetic parameters, leaf water potential, and relative water content (RWC) in both genotypes.
Biochemical parameters including total sugars, phenol, phytohormones (indole acetic acid and abscisic acid), and proline were found to significantly increase during stress in both genotypes.
Water responsive transcripts like osmotin and DREB/CBF registered significant expression variation in the two genotypes, suggesting their key role in regulating water stress tolerance in Eucalyptus.
Keywords: drought stress, leaf temperature, osmotin, sugars, transcription factors