Anatomical and compositional changes during fruit development of ‘Galia’ melons

Abstract

‘Galia’ melons were grown under controlled conditions and pruned to bear two fruits with 19 leaves per plant. Leaves and fruits were sampled and analysed at eight different stages. Pericarp cell division and enlargement occurred during the first week after anthesis but only cell enlargement was responsible for fruit growth thereafter. An increase in fruit-peel surface during the first 3 days after anthesis (DAA) was due mainly to epidermal cell division. During the following 11 days fruit-peel area increased due to increases in epidermal cell size. At 14 DAA no further epidermal cell enlargement occurred, probably due to an increase in cuticle thickness. After this stage fruit peel surface increased due to cracks in the epidermal layer which preceded and probably initiated lenticel development. In leaves adjacent to developing fruit, a reduction in starch occurred during the last week of fruit development, coinciding with sharp increases in glucose, fructose and sucrose levels and an increase in total fruit-flesh sucrose from 50.4 g to 111.6 g per fruit, illustrating the importance not to harvest prematurely.

Keywords:

• lenticel
• mineral elements
• net development
• starch
• sugars