Rind structure, epicuticular wax morphology and water permeability of 'Fortune' mandarin fruits affected by peel pitting.
Vercher, R.; Tadeo, F. R.; Almela, V.; Zaragoza, S.; Primo-Millo, E.; Agusti, M.;
Annals of Botany Year: 1994 Vol: 74 Issue: 6 Pages: 619-625 Ref: 26 ref.
1994
บทคัดย่อ
ABSTRACT :
The effects of preharvest peel pitting [rind pitting] on rind structure and surface wax morphology of mandarins (cv. Fortune) were examined in relation to the severity of this disorder. In fruits with slight symptoms of pitting (<10% surface area pitted) a discrete number of epidermal cells were injured with signs of cellular breakdown. In fruits with moderate symptoms of pitting (10-50% surface area pitted) the injured zones also involved hypodermal cells. The rind surface had an undulating appearance in fruits with severe symptoms of pitting (>50% surface area pitted). The depressed areas in these fruits were devoid of crystalline wax structures and had a rough morphology. Broad regions of rind had crushed epidermal and hypodermal cells with infolded walls. These cells were either empty or filled with reduced cytoplasm amounts located in central positions in the cell. No signs of disruption in the cuticle were observed. Under field conditions, pitting occurrence coincided with periods of high
permeability of isolated cuticles. Furthermore, length of cold treatments (4 deg C) required to cause postharvest pitting symptoms was shorter in fruits sampled at this stage than in those collected earlier or later. The results indicate that low temperatures induce breakdown of the more external cellular strata of the rind. Thus, the physiological function of cuticle is highly impaired and water permeability is considerably increased.