No abstract

Water stress is one of the foremost categories of stress damaging plants’ overall growth and development. The aim of the present study was to explore and demonstrate stress-induced drought to calibrate changes in stress parameters of two banana plant varieties viz. Grand naine (G9)  and Nalla bontha were cultured in Murashige and Skoog medium (MS) media supplemented with stress inducers -Poly ethylene glycol (PEG)  and sorbitol. The different concentrations of inducers were used to induce drought stress in two varieties of banana with contrasting characters for drought condition. The study indicated that PEG contrived mild to moderate osmotic stress and so does the alditol i.e. sorbitol on in vitro banana plants.  The different concentrations of PEG and sorbitol produced significant effects on various parameters. The maximum decrease in shoot length was prominent in G9(52%) as compared to Nalla bontha (11%). When treated with 3% w/v sorbitol, even average root length showed the same level of damage with G9(59%) while in case of Nalla bontha there  was  a 17% decrease. The banana plantlet produced in vitro was estimated at one and two weeks after inoculation, respectively. Proline content tended to increase as the concentration of osmotic inducers increased (-44 % in G9 at 3% w/v sorbitol), whereas RWC (8.9% in G9 at 3% w/v Peg) showed an opposite effect. It was concluded that quantitative and qualitative changes in physiological (shoot and root length) and biochemical (Proline and relative water content, RWC) parameters played an important role in plants under drought stress conditions. This pattern varied from species to species. This work has been attempted for the first time in banana, especially Grand naine varieties with contrasting characters under induced drought stress.

The present study was carried out to investigate the impact of different substrates on the primary and secondary hardening of tissue culture raised banana plantlets. Among eight different treatment combinations of potting mixtures, treatment PHT7 which contained cocopeat with the combination of perlite and vermiculite (2:1:1) emerged as the best potting media with the survival percentage of 98.90% with comparative better growth during primary hardening. Simultaneously maximum growth and development including plant height (15.36 cm), number of leaves (5.71), pseudostem girth (3.88 cm), maximum number of roots (5.90), maximum root length (3.69 cm) has been observed during primary hardening. For secondary hardening, eight combinations of substrates were used in conjunction with soil. Among all the treatments in the secondary hardening, SHT4 (soil+ bonemeal; 3:1) along with the application of Jeevamrit have shown highest field survivability (100%). Moreover a maximum shoot length (33.40 cm) has been observed during secondary hardening with maximum number of leaves were recorded (9.25) with pseudo stem girth 6.98 cm. The outcome of the present study suggested that the treatment PHT7 performed better growth during primary hardening. However the treatment SHT4 has shown comparatively higher growth during secondary hardening.