Morfoanatomia de órgãos reprodutivos de cinco espécies de malpighiaceae
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2011-02-17
Autores
Souto, Letícia Silva [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A família Malpighiaceae possui 1.200 espécies e 66 gêneros, com importância para as formações florestais e savânicas do Velho e do Novo Mundo. A origem monofilética da família é incontestável, entretanto seus táxons intrafamiliares ainda são bastante controversos e considerados artificiais por diversos autores. A morfologia floral de Malpighiaceae é bastante homogênea, mas os frutos possuem extrema diversidade, ocorrendo pericarpos deiscentes ou indeiscentes, carnosos ou secos. Embora caracteres morfológicos dos frutos sejam usados na delimitação de táxons dentro de Malpighiaceae, recentes estudos moleculares indicam a ocorrência de caracteres carpológicos homoplásticos. Assim, estudos minuciosos sobre os frutos da família têm grande potencial taxonômico. Além disso, a vascularização floral pode revelar passos evolutivos, anteriores à morfologia floral atual das espécies. Desta forma, a presente proposta tem como objetivos: 1) descrever, ontogeneticamente, a estrutura dos frutos e sementes de quatro espécies de Malpighiaceae, abrangendo os gêneros Janusia, Mascagnia e Tetrapterys; 2) caracterizar a anatomia floral das espécies do item anterior e de Camarea linearifolia, com ênfase em sua vascularização, buscando correlacionar esses aspectos com o significado evolutivo e ecológico das flores de Malpighiaceae; 3) relatar a esporogênese e gametogênese feminina de Janusia occhionii, investigando a provável ocorrência de apomixia. A vascularização floral encontrada nas espécies segue o padrão geral de número de traços vasculares, com exceção de M. cordifolia, onde a sépala aglandular recebe um traço vascular, mas compartilha os traços laterais das sépalas adjacentes, os quais se bifurcam. No ovário, não é emitido traço dorsal de carpelo, ocorrendo um complexo de procâmbio e meristema fundamental; M. cordifolia, possui conação entre...
The family Malpighiaceae includes 1,200 species and 66 genera and has been important for forests and savannas from the Old and the New World. Its monophyletic origin is unquestionable; however, its intrafamilial taxa have still been controversial and considered artificial by several authors. The flower morphology of Malpighiaceae is quite homogeneous, but fruits present extreme diversity, with dehiscent or indehiscent, fleshy or dry pericarps. Although morphological traits of fruits have been used to delimit taxa within Malpighiaceae, recent molecular studies have indicated the occurrence of carpological homoplastic traits. Thus, detailed studies on Malpighiaceae fruits have great taxonomic potential. Furthermore, flower vascularization can reveal evolution steps prior to the current flower morphology of the species. Thus, the present work aimed to: 1) describe, ontogenetically, the structure of fruits and seeds from four Malpighiaceae species, including the genera Janusia, Mascagnia and Tetrapterys; 2) characterize the flower anatomy of such species and Camarea linearifolia, highlighting their vasculature, in order to correlate these aspects with the evolutive and ecological meaning of Malpighiaceae flowers; 3) report female sporogenesis and gametogenesis in Janusia occhionii, investigating the probable occurrence of apomixis. The flower vasculature observed in the species follows the general pattern as to number of vascular traces, except for M. cordifolia, in which the non-glandular sepal receives one vascular trace but shares the lateral traces from adjacent sepals that bifurcate. In the ovary, the dorsal carpel trace is not emitted, occurring a complex of procambium and ground meristem; M. cordifolia presented conated glands from the anterior and adjacent sepals. In T. chamaecerasifolia and Janusia species, the anterior sepal lost their glands probably by reduction... (Complete abstract click electronic access below)
The family Malpighiaceae includes 1,200 species and 66 genera and has been important for forests and savannas from the Old and the New World. Its monophyletic origin is unquestionable; however, its intrafamilial taxa have still been controversial and considered artificial by several authors. The flower morphology of Malpighiaceae is quite homogeneous, but fruits present extreme diversity, with dehiscent or indehiscent, fleshy or dry pericarps. Although morphological traits of fruits have been used to delimit taxa within Malpighiaceae, recent molecular studies have indicated the occurrence of carpological homoplastic traits. Thus, detailed studies on Malpighiaceae fruits have great taxonomic potential. Furthermore, flower vascularization can reveal evolution steps prior to the current flower morphology of the species. Thus, the present work aimed to: 1) describe, ontogenetically, the structure of fruits and seeds from four Malpighiaceae species, including the genera Janusia, Mascagnia and Tetrapterys; 2) characterize the flower anatomy of such species and Camarea linearifolia, highlighting their vasculature, in order to correlate these aspects with the evolutive and ecological meaning of Malpighiaceae flowers; 3) report female sporogenesis and gametogenesis in Janusia occhionii, investigating the probable occurrence of apomixis. The flower vasculature observed in the species follows the general pattern as to number of vascular traces, except for M. cordifolia, in which the non-glandular sepal receives one vascular trace but shares the lateral traces from adjacent sepals that bifurcate. In the ovary, the dorsal carpel trace is not emitted, occurring a complex of procambium and ground meristem; M. cordifolia presented conated glands from the anterior and adjacent sepals. In T. chamaecerasifolia and Janusia species, the anterior sepal lost their glands probably by reduction... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Anatomia vegetal, Malpiguiasea, Flower vasculature
Como citar
SOUTO, Letícia Silva. Morfoanatomia de órgãos reprodutivos de cinco espécies de malpighiaceae. 2011. 133 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2011.