Estrutura e desenvolvimento dos tricomas secretores em folhas de Piper regnellii (Miq.) C. DC. var. regnellii (Piperaceae)
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Data
1999-08-01
Autores
SILVA, ELAINE MARIA J.
MACHADO, SILVIA RODRIGUES [UNESP]
Título da Revista
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Editor
Sociedade Botânica de São Paulo
Resumo
Nesta espécie ocorrem dois tipos de tricomas secretores: glândula perolada e tricoma saculiforme. Ambos originam-se na protoderme do primórdio foliar e atingem sua maturidade nas folhas jovens presentes no ápice caulinar. A densidade dos dois tipos de tricomas diminui durante a expansão do limbo, sendo raros na folha adulta. As glândulas peroladas são constituídas por uma célula basal e por uma célula apical grande cuja forma varia de semi-globóide a espatulada. A liberação da secreção ocorre após a ruptura da cutícula distendida. Os tricomas saculiformes são constituídos por uma célula basal, 1-2 células colares e uma célula apical cônica, de posição inclinada à superfície foliar. A secreção acumula-se em espaços subcuticulares diminutos, não tendo sido observada ruptura da cutícula.
Piper regnellii has two types of trichomes: pearl glands and sac-like trichomes. Both secretory trichomes originate from the protoderm of the leaf primordium and reach maturity in the young leaves found in the shoot apex. The pearl glands are more abundant on the abaxial surface, while the sac-like trichomes cover completely both young leaf blade. The density of both trichomes decreases during blade expansion, being scarce in the adult leaf. The pearl glands are composed of a basal cell and an apical cell whose shape ranges from semi-globular to spatula-like. Secretion release occurs after rupture of the distended cuticle. The sac-like trichomes are composed of a basal cell, 1-2 stalked cells and an apical conical cell parallel to the leaf surface. The secretion is accumulated in minute subcuticular spaces. No cuticular ruptures have been observed.
Piper regnellii has two types of trichomes: pearl glands and sac-like trichomes. Both secretory trichomes originate from the protoderm of the leaf primordium and reach maturity in the young leaves found in the shoot apex. The pearl glands are more abundant on the abaxial surface, while the sac-like trichomes cover completely both young leaf blade. The density of both trichomes decreases during blade expansion, being scarce in the adult leaf. The pearl glands are composed of a basal cell and an apical cell whose shape ranges from semi-globular to spatula-like. Secretion release occurs after rupture of the distended cuticle. The sac-like trichomes are composed of a basal cell, 1-2 stalked cells and an apical conical cell parallel to the leaf surface. The secretion is accumulated in minute subcuticular spaces. No cuticular ruptures have been observed.
Descrição
Palavras-chave
Piperaceae, Piper regnellii, ontogeny, glandular trichomes, secretion
Como citar
Brazilian Journal of Botany. Sociedade Botânica de São Paulo, v. 22, n. 2, p. 117-124, 1999.