Characteristics of micro-propagated banana (Musa spp.) cultures stressed with NaCl and polyethylene glycol

Abstract

The effect of NaCl and PEG was assessed on plant micro-propagation rate in banana (Musa spp.) cv., Basrai. Well micro-propagated plantlets were cultured on four different stresses of NaCl and PEG-4000 including control level: MS_2b (MS₀ + 3.0 mg l^-1 BAP), MS_2c (MS₀ + 100 mol m^-3 NaCl), MS_2d (MS₀ + 5% PEG) and MS_2e (MS₀ + 100 mol m^-3 NaCl + 5 % PEG) for 6-weeks. Efficiency of plant micro-propagation was reduced significantly among the stressed cultures. Similarly, photosynthetic pigments like chl a was decreased non-significantly but chl b, chl ab were decreased significantly. Total carotenoids were increased in the saline as well as PEG stressed cultures. Cell size of epidermis and aerenchyma was increased (p < 0.05), while parenchyma decreased. Proline and glycinebetain contents were increased (p < 0.05) in each stressed culture but were high in MS₂ than in MS₃ and MS₄ cultures. Meanwhile, proteins, sugars, phenolics and nitrates were observed to be in the reversed (p < 0.05) phenomena. In conclusion, NaCl treatment was observed to be most toxic than the PEG or PEG with NaCl on the banana micro-propagation.

Key words: Musa spp., micro-propagation, NaCl (sodium chloride), PEG (polyethylene glycol), chlorophyll contents, proline, reducing sugars.