Influência climática sobre a plasticidade fenotípica floral de Catasetum fimbriatum lindley

Abstract

RESUMOComo tentativa de elucidar os fatores ambientais que controlam a plasticidade fenotípica floral de Catasetum fimbriatum Lindley, iniciaram-se estudos climáticos da espécie, com o acompanhamento de 45 indivíduos divididos em três tratamentos, com quinze indivíduos cada um. O primeiro tratamento foi instalado em casa-de-vegetação, onde predominou intensa luminosidade (1300 a 1900 mol/m 2 s), altas temperaturas (38 O C) e baixa umidade relativa do ar (35%). O segundo tratamento foi instalado em ripado e submetido à baixa intensidade luminosa (400 a 650 mol/m 2 s), menor temperatura (17 O C) e a uma umidade relativa do ar mais elevada em relação ao primeiro (85%). O terceiro tratamento foi mantido nas condições ambientais naturais (intensidade luminosa entre 500 a 800 mol/m 2 s, temperaturas de 23 o C e umidade relativa do ar de 65%). Ao final do experimento, pôde-se constatar a grande adaptabilidade da espécie aos diferenciados ambientes, mediante formação de ecótipos. Termos para indexação:Orquídeas, Catasetum, ecótipos, clima.ABSTRACT As attempt of elucidating the environmental factors that they control the plasticity floral fenotipic of Catasetum fimbriatum Lindley, climatics studies of the species began, through of the accompaniment of 45 individuals divided in three installed treatments. The first fifteen individuals, they were conditioned at green house where intense brightness prevailed (1300 at 1900 mol/m 2 s), high temperatures (38 O C) and it lowers relative humidity of the air (35%). Such treatment was entitled treatment 1. The other collected individuals that were put in the pot, and that they constituted the treatment 2, they were submitted the low luminous intensity (400 at 650 mol/m 2 s), to a smaller temperature (17 O C) and a relative humidity of the highest air (85%). The last fifteen individuals, presented the natural conditions of survival of the species, and they constituted in that way, the treatment 3 (luminous intensity between 500 at 800 mol/m 2 s, temperature of 23 o C and a relative humidity of the highest air of 65%). At the end of the experiment, the great adaptability could be verified of the species to the differentiated environments, through the ecotipes formation. O gênero Catasetum foi descrito em 1822 por L.C. Richard ex Kunth. Esse gênero já há várias décadas desperta interesses em botânicos e zoólogos, em razão de sua incrível adaptação à entomofilia (HOEHNE, 1938) e ao extraordinário trimorfismo em suas flores, presente na sé-rie Orthocatasetum. Essas plantas vegetam em segmentos de troncos de árvores velhas, onde existe acúmulo de material orgânico em decomposição, expostos geralmente à grande radiação solar (HOEHNE, 1938; MACHADO, 1998). Os autores citam ainda a existência de pseudobulbos grossos e bem desenvolvidos, relacionados com o armazenamento de água, que permitem a sobrevivência da planta nos períodos de estiagem.Infelizmente a destruição contínua dos habitats naturais desse gênero põe em risco sua existência, justificando-se, dessa forma, estudos mais detalhad...

Radicular anatomy of twelve representatives of the Catasetinae subtribe (Orchidaceae: Cymbidieae)

“…The Catasetinae subtribe presents a sympodial growth, with well-developed pseudobulbs that promote the storage of water during dry periods, and decidual leaves after matured (Dodson 1975, Moraes andAlmeida 2004). They appear mainly in the top of trees, from where their roots, usually pulpous, absorb nutrients (Hoehne 1938).…”

Techniques Used by Bearded Capuchin Monkeys (Sapajus libidinosus) to Access Water in a Semi-Arid Environment of North-Eastern Brazil

“…Young ( n = 4) and adult ( n = 6) monkeys of both sexes used their hands to inspect the pseudobulbs of Catasetum sp. orchids (thickened stems that serve as water storage organs [Moraes and Almeida, 2004]) growing on palm (Syagrus sp.) tree trunks.…”

Floral sexual differentiation in Catasetum fimbriatum (Catasetinae, Orchidaceae) exposed to different light intensities

“…Richard., with about 100 species (Barros et al 2012), constitutes one of the main Brazilian orchid genera presenting high commercial value in markets due to the difficulty of sexual propagation and obtainment of hybrids (Pedroso-de- Moraes et al 2007). Its great ornamental potential resulted in an extensive extraction in past decades, which culminated in population reduction and in the danger of extinction of countless species (Joly 1998, Moraes & Almeida 2004. Representatives of the genus present sophisticated specializations for the acquirement of allogamy (Zimermam 1991), which, for several decades, raised academic interest in many orchidologists and zoologists, mainly due to their adaptations to entomophily and to its flower trimorphism (Hoehne 1938, Moraes & Almeida 2004.…”

“…Its great ornamental potential resulted in an extensive extraction in past decades, which culminated in population reduction and in the danger of extinction of countless species (Joly 1998, Moraes & Almeida 2004. Representatives of the genus present sophisticated specializations for the acquirement of allogamy (Zimermam 1991), which, for several decades, raised academic interest in many orchidologists and zoologists, mainly due to their adaptations to entomophily and to its flower trimorphism (Hoehne 1938, Moraes & Almeida 2004. The difference between male and female diclinous flowers is so visual that they have already been described in distinct genera; the male ones as belonging to Myanthus, and the female ones as representatives of the Monochantus (Decker 1946).…”