A Study of Micro-morphology of Grape Berry Surface during Their Development with Speciai Reference to Stoma

Abstract

Using seven grape cultivars, ‘Concord’, ‘Campbell Early’, ‘Delaware’, ‘Takao’, ‘Kyoho’, ‘Muscat of Alexandria’ and ‘Koshu’, changes in the stomatal morphology of berry epidermis accompanied by the growth were observed under scanning electron microscope (SEM).
Average number of stomata on the berry surface of ‘Muscat of Alexandria’ at anthesis was 16, that of ‘Campbell Early’, ‘Delaware’, ‘Kyoho’ and ‘Koshu’ was around 12, and those of ‘Concord’ and ‘Takao’ were 7.0 and 2.4, respectively.
The size of stomata in grape berry epidermis at anthesis was not differed among the cultivars, and was 20-25μ in width and around 25μ in length.
Twenty days before anthesis the guard cells were not yet differentiated, but distinguishable just prior to anthesis. Furrowed feature was seen on the inner wall of opening stomata in this period.
After fertilization cracks occurred in the epidermis circulating around some stomata with berry growth, and cork layers developed beneath such stomata, which sometimes protruded from the epidermal layer forming lenticel-like structure.
From these observations what were visibly seen as brown specks on grape berry surface at near maturity were confirmed as stomata and the suberized cells adjacent to them.