Ultra-estrutura dos ovaríolos de Tropidacris collaris (Stoll) (Orthoptera: Romaleidae) submetido a três fotoperíodos

Abstract

Ultrastructure of the Ovarioles of Tropidacris collaris (Stoll) (Orthoptera: Romaleidae) Submitted to Three Photoperiods ABSTRACT -The research evaluated the ultrastructure of the ovarioles of Tropidacris collaris (Stoll), submitted to photoperiods 10L:14D, 12L:12D and 14L:10D. Sixty nymphs (30 males and 30 females) in the last stage of development were paired in ten couples in each treatment. Thirty days after adult emergence, the females were immobilized with ethylic ether and dissected under stereomicroscope. The ovarioles were transferred to Karnovsky fixative (2.5% glutaraldehyde, 4% paraformaldehyde and 0.1 M sodium cacodylate buffer) and analyzed in transmission and scanning electron microscopes. The different photoperiods had no effect on the ovarioles' ultrastructure. Each ovariole is covered by a thick sheath constituted by a homogeneous and filamentous material. In the terminal filament, there are cells with large nuclei, some with scarce cytoplasm and projections cytoplasmatic, besides filamentous structures assuming characteristic of conjunctive tissue. In the germarium, the germ cells are big with large nuclei, scarce cytoplasm and plasma membrane containing interdigitations. The follicular cells are small with a small nucleus, yet presenting cytoplasmatic projections. In the vitellarium the follicular cells suffer modifications in their morphology varying from cubic to flat.KEY WORDS: Grasshopper, female reproductive system, ovary, morphology RESUMO -A pesquisa teve o objetivo de avaliar a ultra-estrutura dos ovaríolos de Tropidacris collaris (Stoll), submetido aos fotoperíodos de 10L:14E, 12L:12E e 14L:10E. Foram utilizadas 60 ninfas (30 machos e 30 fêmeas) no último estágio de desenvolvimento, sendo colocados 10 casais em cada tratamento. Trinta dias após atingirem o estágio adulto, as fêmeas foram sedadas com éter etílico e dissecadas sob estereomicroscópio. Os ovaríolos foram fixados em Karnovsky (glutaraldeido 2,5%, paraformaldeído 4% e tampão cacodilato de sódio 0,1 M) e analisados em microscopia eletrônica de transmissão e varredura. Os resultados mostraram não haver influência dos fotoperíodos sobre a ultraestrutura dos ovaríolos, onde estes apresentaram-se revestidos por uma bainha espessa constituída por um material homogêneo e filamentoso. Na região do filamento terminal observaram-se células com núcleos volumosos, algumas com citoplasma escasso, além de estruturas filamentosas assumindo característica de tecido conjuntivo. No germário, as células germinativas são maiores, com núcleos volumosos, escassos citoplasma e membrana celular com interdigitações. As células foliculares são menores com núcleo pequeno, apresentando ainda projeções citoplasmáticas. No vitelário as células foliculares sofrem modificações na sua morfologia, variando de cúbica a achatada. PALAVRAS-CHAVE: Gafanhoto, aparelho reprodutor feminino, ovário, morfologiaNo Brasil, a presença e o aumento da população dos gafanhotos estão ligadas certamente ao desmatamento e aos novos tipos de manejos de culturas agroflorestais...

Biotic and abiotic stress-induced phenylpropanoids in leaves of the mango (Mangifera indica L., Anacardiaceae)

“…Retention indices (RI) for all compounds were determined according to Vandendool and Kratz for each constituent as previously described. [10][11][12][13]…”

“…Mature insects are solitary and they disperse usually to diverse vegetation types, including mango, coconut, avocado, banana, cotton, lemon and rubber crops causing serious damage. 10 We have observed that M. indica leaves infested with the grasshopper T. collaris emit phenylpropanoids as a response to biotic stress as well as abiotic stress caused by mechanical damage. So far, no previous studies have been published regarding the production of mango leaf volatiles induced by abiotic and biotic stresses.…”