Differential response of tossa jute (Corchorus olitorius) submitted to water deficit stress

Abstract

We aimed towards investigating the effects of water deficit stress (WDS) on phenotypic traits, leaf gas exchange, water relations, secondary metabolite profile and fibre properties of six tossa jute (Corchorus olitorius) genotypes grown under control or water withholding conditions. Root length, root weight, stem weight and whole biomass were reduced significantly (p<0.05) in susceptible genotypes but remain unaltered in tolerant genotypes following WDS. The tolerant genotypes showed significantly higher (p<0.05) photosynthetic carbon assimilation (PCA) and water use efficiency (WUE) along with significant reduction (p<0.05) in stomatal conductance (SC), transpiration rate (TR) and vapour pressure deficit (VPD) as compared to susceptible genotypes after WDS. Tolerant genotypes exhibited significantly higher (p<0.05) % RWC as compared to susceptible plants following WDS. Polyphenol and flavonoid content were significantly increased (p<0.05) in tolerant and susceptible genotypes respectively following WDS. Susceptible plants exhibited significantly reduced (p<0.05) proline content as compared to tolerant genotypes. Number of phytochemotypes identified by GC–MS showed 46% and 81% increase in tolerant and susceptible groups respectively, after prolonged WDS. Major phytochemical groups in tolerant genotypes under WDS were ketone, acyclic diterpene alcohol, steroid/sterol, heterocyclic compound, alicyclic hydrocarbon, thiophenol and fatty acid ester. Whereas, the susceptible genotypes exhibited steroid/sterol, acyclic diterpene alcohol, alcohol and heterocyclic compound as the major phytochemical groups under WDS. Tolerant genotypes showed significantly higher (p<0.05) fibre strength as compared to susceptible plants under stress. Our results show identifiable traits manifested by the tolerant and susceptible tossa jute genotypes under WDS which could therefore be utilized successfully for future selection and breeding programs, crop improvement initiatives and production of new varieties having optimum potential toward water deficit stress adaptation.