Study the relation of regular bearing fruit schedule with Catecholase and Cresolase enzyme activity in mango (Mangifera indica L.)

Mango is one of the important fruits in tropical regions of the world. A basic problem of its production is alternate bearing. Observation of phenotypic behaviors at maturity phase is used to screen alternation bearing in mango seedlings obtained from controlled hybridization. To evaluate the relationship among polyphenol oxidase enzymes and bearing patterns of tree at the juvenile stage, an experiment was done at Minab during 2008-2010. In this study, 8 mango genotypes with known bearing patterns (alternate or non-alternate bearing) were chosen. Scion of every genotype was grafted on its own rootstock, and then the activity of Catecholase and Cresolase was measured (60 days after grafting). The results showed correlations between low enzyme activity and regular bearing genotypes, with regular bearing trees having lower Catecholase and Cresolase activity than alternate ones. Also, correlation was observed between catecholase and cresolase activities with fruit number production per tree (r= -0.86 and -0.74 respectively) which could be used as an early screening index of mango seedlings.