Catecholase and cresolase activity as a biochemical index for screening mango (Mangifera indica L.) seedlings at nursery stage for bearing behaviour in their future reproductive life.
Sharma R. R.
Author Affiliation: Division of Fruits and Horticultural Technology, Indian Agricultural Research Institute, New Delhi 110 012, India.
Plant Genetic Resources Newsletter : 31-34
Abstract : Mango has a very long juvenile period and suffers from the problem of alternate bearing. There is no effective tool to screen mango germplasm or seedlings for their future bearing behaviour i.e. regularity or bienniality. Polyphenol oxidase [catechol oxidase] (PPO) enzyme plays some vital roles in plants and it may also have some relationship with the bearing behaviour of mango. To establish a relationship between bearing behaviour and PPO activity, catecholase and cresolase enzyme (two forms of PPO) activity was measured during the vegetatove growth of the actively growing one-year-old grafted plants of eight regular (Sensation, Eldon, Tommy Atkins, Amrapali, Totapuri Red Small, Neelum, Rumani and Bangalora) and eight alternate bearing cultivars (Dashehari, Extrema, Bombay Green, Langra, Rataul, Chausa, Fazli and Edward). Polyphenol oxidase activity was observed to be low in regular bearers compared with alternate bearers. On the basis of these studies, it can be concluded that catecholase and cresolase activities can be used as a biochemical index for screening mango germplasm for its future bearing behaviour, which is also evident from the inverse correlation (r=-0.893) between enzyme activity and fruited panicles, indicating that low PPO activity favoured regularity in mango.