EFFECT OF EXOGENOUS SUGAR CLASSES AND CONCENTRATIONS ON SALT-TOLERANT ABILITY OF INDICA RICE (ORYZA SATIVA L.)
The aim of this investigation is to find out which exogenous sugar types out of glucose, lactose, maltose, mannose, xylose and sucrose, and in what concentrations: 0, 2, 4 and 6%, can be used to enhance the salt-tolerant ability of jasmine rice seedlings and the effects when applied to the media of salt-tolerant and salt-sensitive cultivars, on their defense mechanisms under salt-stress conditions (342 mM NaCl). Jasmine rice seedlings showed a 100% survival rate in media containing glucose or sucrose after exposure to salt-stress conditions for 7 days. The number of roots in rice seedlings grown in media supplemented with 4% glucose and 6% sucrose was significantly higher than those grown under control conditions by 2.04 and 2.05 times, respectively. Moreover, the growth characteristics, in terms of fresh weight and dry weight, were expressed in patterns similar to the root characters. Homjan salt-tolerant plantlets had a survival rate of 100% in media containing glucose or sucrose and media without sugar. Similarly, IR29 salt-sensitive plantlets survived on media containing glucose, maltose or sucrose, while they all died in media without all sugars. In addition, the number of cortex cells of root systems in salt-tolerant and salt-sensitive cultivars treated with 4% sucrose or 6% glucose, was greater than those cultivated without sugar under salt-stress conditions. Exogenous sucrose and glucose in the culture media of rice plantlets play a direct role as the main carbon source to stimulate growth and development as well as alternatively functioning as defense mechanisms to salt-stress.
Boriboonkaset, T., Bunyakijjinda, V., Cha-um, S. and Kirdmanee, C. (2007). EFFECT OF EXOGENOUS SUGAR CLASSES AND CONCENTRATIONS ON SALT-TOLERANT ABILITY OF INDICA RICE (ORYZA SATIVA L.). Acta Hortic. 764, 155-164
cortex, in vitro, jasmine rice, root system, survival percentage, salt-stress