Polyphenol oxidase activity in relation to flowering and malformation incidence in mango (Mangifera indica L.).
Sharma R. R.
Author Affiliation: Division of Fruits and Horticultural Technology, Indian Agricultural Research Institute, New Delhi - 110 012, India.
Annals of Agricultural Research 23 : 334-337
Abstract : The relationship between polyphenol oxidase [catechol oxidase] (PPO) activity and bearing behaviour and malformation incidence was studied in fourteen- to fifteen-year-old trees of regular-bearing (Sensation, Eldons, Tommy Atkins, Amrapali, Totapuri Red Small, Neelum, Rumani, and Bangalora) and biennial-bearing (Dashehari, Extremas, Bombay Green, Langra, Rataul, Chausa, Fazli, and Edward) mango cultivars. Shoot tips from fully swollen buds at the panicle initiation stage were excised and used for the measurement of PPO (catecholase and cresolase [monophenol monooxygenase]) activity. In general, the regular bearers exhibited lower PPO activity than the biennial bearers. Catecholase and cresolase activities were highest in Sensation and Rataul, and lowest in Tommy Atkins and Chausa. In regular and biennial bearers, catecholase activity was higher than cresolase activity. The incidence of malformation was higher in regular bearers than in the biennial bearers. Among the regular bearers, Sensation had the lowest incidence of malformation (37.88%) and Tommy Atkins had the highest (57.35%). Among the biennial bearers, Chausa was most affected by malformation incidence (36.24%), whereas Rataul was least affected (26.30%). The correlation between PPO activity and malformation incidence was significant and negative.