MIDATHALA RAGHAVENDRA, DOMMALAPATI SUDHAKARA RAO, NARESH KUMAR, SHASHI MADAN, RENU MUNJAL2 AND GADELLI RAMESH
Abstract
Soil salinity is a major problem in many countries that adversely affects crop growth. Salinity affected areas are not fit for crop cultivation and they only support a few halophytes. Several million ha of land were turned into saline soils due to human interference. Salinity stress is considered as one of the major environmental stresses and mitigation of it is necessary for sustainable crop production. In the present investigation four wheat cultivars differ in their tolerance to salinity viz. DBW 88, HD 3086, Kharchia 65 and KRL 210 were chosen with an aim to study the effect of salinity stress and subsequent spermine treatment on catalase and peroxidase enzymes which are responsible for the detoxification of reactive oxygen species (ROS). It is well documented that plant polyamine (PA), spermine is induced under stress conditions and imparts tolerance against salinity stress. Effect of exogenous spermine treatment on catalase and peroxide activities were also studied. Catalase activity increased in all four varieties and more increase was observed in Kharchia 65 and lesser increase was observed in DBW88 at 21 days after sowing (DAS). Highest catalase activity with spermine 0.5 mM concentration was observed and it was higher at 15 days after treatment (DAT). Mean catalase activity was found higher at 0 DAT in Kharchia 65 and KRL 210 and the activity was highest at 5 DAT in DBW88 and HD 3086 at 90 DAS. Peroxidase activity increased with increasing levels of salinity, but the activity was decreased with spermine treatment at 21 DAS. Highest peroxidase activity recorded in Kharchia 65 at 15 DAT and lowest was in DBW 88 at 5 DAT. Peroxidase activity decreased with spermine treatment in control and 8 dsm-1 and increased at 12 dsm-1 in all four varieties at 90 DAS.