Original scientific paper

Ultrastructural Changes of Plastids in Ripe Fruit of Cucurbita pepo cv. ovifera

Zvonimir Devidé ; Hrvatska

Abstract

The ripe fruit of Cucurbita pepo cv. ovifera has characteristic dark and light alternate meridional zones on its surface. The dark zones are at first dark green and turn later intense orange, while the light ones are white yellow and finally yellow.
In the dark zones the chromoplasts develop from large chloroplasts (diameter about 5 micro m). During this process the thylakoid system is successively degraded and light as well as dark plastoglobules appear. From several dark plastoglobules crystals (probably carotenoids) are protruding. The thylakoid membranes are eighter single or packed together to dense long layers, some of which show a characteristic striation with a period of 12 — 13 nm.
In light zones of the ripe fruit the chromoplasts are already fully developed. They are small (diameter 2 micro m) and contain few single thylakoids, numerous tubules and many ligth plastoglobules.
During the senescence of the fruit the differences in the plastid ultrastructure of both zones gradually disappear and after the disintegration of the thylakoid system only numerous light plastoglobules remain in the stroma. There is a difference however in the presence of needle-shaped crystal-like formations (showing a fine parallel striation and a distinct bounding membrane), which could be found so far in the chromoplasts of the dark zones only.

Keywords

Hrčak ID:

156338

URI

https://hrcak.srce.hr/156338

Publication date:

31.12.1970.

Article data in other languages: croatian german

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