**Department of Botany, University of Delhi.
Division of Horticulture and Fruit Technology, Indian Agricultural Research Institute, New Delhi.
*A part of thesis submitted by the senior author for M.Sc. degree in Horticulture of the Post-Graduate School, Indian Agricultural Research Institute, New Delhi.
The pericarp of the mango fruit gets distinguished into three regions—exocarp, mesocarp and endocarp—14 days after anthesis. The differentiation of the exocarp region from the mesocarp region is not pronounced but the demarcation of the latter from the endocarp region is well defined. The laticiferous canals, meant for the storage of the fruit called mango ‘chep’, secreted by a well organized layer of secretory cells surrounding the canal, originate schizogenously. Initially the growth of the fruit is mainly due to cell division accompanied by cell enlargement together with increase in the size and number of laticiferous canals in all the three regions of the fruit. Once the cell division has stopped, other factors which contribute to the fruit growth are cell enlargement and increase in size and number of laticiferous canals. Increase in cell size and intercellular spaces are more rapid in the mesocarp region than other regions. This process continues up to maturity, although at a very reduced rate in later stages. Hardening of the endocarp region started 64 days after anthesis in Dashehari and slightly later in Chausa and continue up to maturity. The ultimate size acquired by the different tissues show that the thickness of the exocarp and the endocarp is almost comparable whereas mesocarp region is more than ten times thicker as compared to the exocarp or endocarp, individually. Variations in the size of the fruits at maturity have been shown to result mostly on account of variations in the cell number and to a small extent due to mean cell size. The observations on ergastic substances indicate that reserve materials, particularly starch grains started accumulating in the cells after they had ceased to divide. Among the waste products accumulated in the fruit only druses were located and these were present right from anthesis to maturity in both the cultivars.
