Physiological and Molecular Insights to Drought Responsiveness in Erianthus spp.

Erianthus is a wild relative of the genus Saccharum. It is well known for its high fibre, high biomass, tolerance to drought and water logging, pest and disease resistance with multi-ratooning ability. This study was conducted to investigate physiological and molecular responses of Erianthus spp. to drought stress. Out of seven Erianthus accessions screened, the drought responsiveness of the broad-leaved accession of Erianthus arundinaceus IK 76-81 was found the best and characterised by high cell membrane thermostability, stomatal conductance, transpiration rate and relative water content and low photosynthetic rate under increased soil moisture stress. In addition, IK 76-81 also showed many fold increase in DREB2 and expansin gene expression with increase in soil moisture stress in comparison with the most popular moderately drought tolerant variety Co 86032. We have also evaluated few selected sugarcane x Erianthus hybrids and assessed the introgression of one of the key drought responsive characters i.e., cell membrane stability from Erianthus to sugarcane. This is perhaps the first report on the drought responsiveness of Erianthus.