Post Graduate Botany Department, Gangadhar Meher College, Sambalpur-768004
*Present address: Post Graduate Botany Department, Rajendra College, Bolangir, Orissa.
** Director of Education, Govt. of Orissa, Bhubaneswar.
Catalase activity and chlorophyll content in papaya leaves of different physiological ages are positively correlated. Both catalase activity and chlorophyll content increased with physiological age upto maturity and declined thereafter due to senescence. Distribution of peroxidase activity was irregular but leaves with visual sign of senescence showed high activity. Young leaves comparatively were more susceptible to papaya mosaic virus (PMV) infection which accelerated the process of leaf ageing and senescence. This effect progressively decreased with an increase in the physiological age of leaves. From the findings it is suggested that changes in the activities of catalase and peroxidase immediately following PMV infection has a functional significance in acceleration of leaf ageing.
