Data/hora: 03/06/2024 08:19:15

Biblioteca(s): | Embrapa Mandioca e Fruticultura.
Data corrente: | 21/09/1993
Data da última atualização: | 21/09/1993
Autoria: | BUISSON, D.; LEE, D. W.
Afiliação: | Department of Biological Sciences, Florida International University, Miami, Florida 33199; and Fairchild Tropical Garcen, Maiami, Florida 33155.
Título: | The developmental responses of papaya leaves to simulated canopy shade
Ano de publicação: | 1993
Fonte/Imprenta: | American Journal Botany, v.80, n.8, p.947-952, 1993.
ISSN: | 0002-9122
Idioma: | Inglês
Conteúdo: | The developmental responses of plants to shade underneath foliage are influenced by reductions in irradiance and shifts in spectral quality (characterized by reductions in the quantum ratio of red to far-red wavelenghts, R:FR). Previous research on the influence of shadelight on leaf development has neglacted the reductions in R:FR characteristic of foliage shard, and these studies have almost certainly understimated the extent and array of developmental responses to foliage shade. We have studied the effects of reduced irradiance and R:FR on the leaf development of papaya (Carica papaya L., Caricaceae). Using experimental shadehouses, replicates of plants grown in high light conditions (0.20 of sunlight and R:FR = 0.90) were comparad to low light conditions(0.02 of sunlight) with either the spectral quality of sunlight (R:FR = 0.99) or of foliage shade (F:FR = 0.26). Although many characteristics, such as leaf thickness, specific leaf weight, stomatal density, palisad parenchyma cell shape, and the ratio of mesophyll air surface/leaf sufarce were affected by reductions in irradiance, reduced R:FR contributed to further chages. Some characters, such as reduced chlorophyll a/b ratios, reduced lombring, and greater internode length, were affected primarily by low R:FR. The reduced R:FR of foliage shade, presumably affecting phytochrome equilibrium, strongly, influences the morphology of papaya leaves.
Palavras-Chave: | Composicao; Mofologie.
Thesagro: | Anatomia; Carica Papaya.
Categoria do assunto: | --
Registro original: | Embrapa Mandioca e Fruticultura (CNPMF)
Exemplares: | CNPMF - (2237-1) - ADC - AP - -- - 580.5 -  - 580.5 - DIS