Articles
Differences between the physiological disorders of intumescences and edemata
Article number
1104_59
Pages
401 – 406
Language
English
Abstract
The physiological disorders of intumescences and edemata are characterized by blister-like protrusions of leaf cells that form lesions and become necrotic as they senesce.
The two disorders are frequently confused or viewed as the same disorder in the literature, but light and scanning electron microscopy of lesions on five plant species, as well as environmental factors involved in their occurrence, suggest that the disorders are different.
Lesions on tomato (Solanum lycopersicum ‘Maxifort’), ornamental sweet potato (Ipomoea batatas ‘Blackie’), and bat-faced cuphea (Cuphea llavea ‘Tiny Mice’) all began with one to a few epidermal cells undergoing hypertrophy, and the affected area expanded as lesions developed.
Lesions in interspecific geranium (Pelargonium ‘Caliente Coral’) and ivy geranium (P. peltatum ‘Amethyst 96’) did not involve epidermal cell hypertrophy, but instead, a large group of mesophyll cells hypertrophied to form a blister-like lesion until the swelling tore the epidermal layer and a wound response that included cell suberization occurred.
In different experiments with these crops, we studied whether the environmental factors of root medium water status or presence of ultraviolet B (UVB) light were related to the occurrence of the disorders.
Development of intumescences in sweet potato and tomato ‘Maxifort’ were abated, but not completely prevented, when plants were exposed to UVB light; however, light quality did not affect occurrence of lesions in geranium.
Others’ research has linked plant water relations to the occurrence of lesions in geranium.
Therefore, we propose that edema is the appropriate term to describe the lesions in Pelargonium sp., and intumescence should be used for the disorders of ornamental tomato, sweet potato, and cuphea.
The two disorders are frequently confused or viewed as the same disorder in the literature, but light and scanning electron microscopy of lesions on five plant species, as well as environmental factors involved in their occurrence, suggest that the disorders are different.
Lesions on tomato (Solanum lycopersicum ‘Maxifort’), ornamental sweet potato (Ipomoea batatas ‘Blackie’), and bat-faced cuphea (Cuphea llavea ‘Tiny Mice’) all began with one to a few epidermal cells undergoing hypertrophy, and the affected area expanded as lesions developed.
Lesions in interspecific geranium (Pelargonium ‘Caliente Coral’) and ivy geranium (P. peltatum ‘Amethyst 96’) did not involve epidermal cell hypertrophy, but instead, a large group of mesophyll cells hypertrophied to form a blister-like lesion until the swelling tore the epidermal layer and a wound response that included cell suberization occurred.
In different experiments with these crops, we studied whether the environmental factors of root medium water status or presence of ultraviolet B (UVB) light were related to the occurrence of the disorders.
Development of intumescences in sweet potato and tomato ‘Maxifort’ were abated, but not completely prevented, when plants were exposed to UVB light; however, light quality did not affect occurrence of lesions in geranium.
Others’ research has linked plant water relations to the occurrence of lesions in geranium.
Therefore, we propose that edema is the appropriate term to describe the lesions in Pelargonium sp., and intumescence should be used for the disorders of ornamental tomato, sweet potato, and cuphea.
Authors
K.A. Williams, J.K. Craver, C.T. Miller, N. Rud, M.B. Kirkham
Keywords
Cuphea sp., geranium, Ipomoea sp., oedema, scanning electron microscopy, Solanum sp., tomato
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