Variegation, Leaf

Variegation, Leaf

 

the uneven coloring of leaves, forming a unique design. Variegation may depend on such anatomic features as the formation of pneumatic cavities under the epidermis (imparting to the leaf a silvery coloring), the uneven distribution of hairs, and the absence of stomata (giving the leaf a mat appearance). Variegation also results from the formation in some cells of such pigments as anthocyanins, which impart a red coloring, and phytomelanins, which impart a black coloring. The loss of coloring substances in chlorophyll grains causes the appearance of light green, yellow, or white areas on the leaf. Variegation may be characteristic of a plant species or variety. The design, in the form of irregular spots or a ring, may be concentrated along the veins or margin of the leaf or may be distributed over the entire leaf.

If the variegation is the result of somatic mutation, the variegated plants are chimeras, whose different tissues have diverse genetic constitutions. For example, in variegated pelargonium, the white areas give rise to white offspring, and the green areas to green offspring. Variegated plants are widely used as ornamentals and in genetic research. They are useful in studying morphogenesis, especially if the variegation is based on a change in the coloring of chlorophyll grains, which often depends on the interaction of genes of the nucleus with genes of the chlorophyll grains.

V. L. RYZHKOV

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In turn, 21 descriptors were applied to determine the qualitative features: plant habit; leaf variegation, leaf variegation distribution, main color of the sheet on the upper face, leaf anthocyanin pigmentation, spinescence, color of spines, wavy-edged blades, shape of the peduncle, external color of the shell syncarp, syncarp shape, bract apex shape of the fruitlet, overlapping bracts in relation to the fruitlet, bract color of the fruitlet, bracts at the base of the crown, bract color at the base in relation to the crown, bract color of the crown, crown length/syncarp length ratio, crown diameter/syncarp diameter ratio, number of colors of the crown and the shape of the crown apex.
"All three breeding lines contain unique combinations of genes for leaf variegation, leaf pigmentation, and multiple fruiting."