Vol. 10, Issue 11 (2021)

Author(s):
Hari Narayan, Tapas Chaudhary, K Chattopadhyay, AK Nayak and Upendra Kumar

Abstract:
Salinity-tolerant Azolla is generally screened under hydroponics condition but its applicability under ex situ and in vivo is very challenging mainly because of stress heterogeneity, presence of other soil-related stresses and the significant influence of environmental factors such as temperature, relative humidity and solar radiation. Therefore, the present study aimed to standardise a suitable, rapid and efficient protocol to screen salt-tolerant Azolla for the first time by using already developed salinity-screening protocol for rice cultivars. Two species of Azolla (Azolla microphylla and Azolla rubra) and two rice varieties (Luna sankhi and IR- 64) were used as experimental material in this modified protocol where dimension of pots and quantity of soil and gravels have been reduced without altering its composition ratio. Two saline treatments were imposed by adding sodium chloride (80 mM and 120 mM NaCl) in pots and results were analyzed with respect to control (0 mM NaCl). By using the modified protocol, the observed parameters like soil electrical conductivity, soil pH, growth rate and antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase) showed the similar trend of results in Azolla with respect to rice. Finally, our study revealed that the modified salinity-screening protocol worked well for Azolla and it could be employed further for the identification of salt-tolerant Azolla strains in very efficient manner.