Utilização do teste de raios - x na avaliação dos efeitos da dessecação e infestação em diásporos de Canela-Batalha - Cryptocarya aschersoniana Mez (Lauraceae)
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Data
2012-12-01
Autores
Muxfeldt, Rejane Elize
Faria, José Mareio Rocha
Tonetti, Olívia Alvina Oliveira
Silva, Edvaldo Aparecido Amaral da [UNESP][
Título da Revista
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Editor
Universidade Federal de Lavras (UFLA)
Resumo
No presente trabalho, objetivou-se avaliar os efeitos da dessecação e identificar lesões por predação por insetos, em diásporos de canela-batalha (Cryptocarya aschersoniana Mez.), utilizando-se testes de raios X. Os danos provocados pela dessecação foram dimensionados nas imagens e associados à formação de plântulas. Diásporos recém-beneficiados (45 % de umidade e 37 % de germinação) foram colocados para secar em sala climatizada (20 ºC e 60 % UR), dentro de bandejas plásticas em camada única. Posteriormente, com o intuito de acelerar o processo de secagem, foram colocados em caixas de secagem com solução saturada de hidróxido de sódio (28 % UR) e amostrados com 45, 37, 35, 31 e 26 % de umidade. Para as radiografias, utilizou-se a intensidade de radiação de 40 kVp e tempo de exposição de 1,5 minutos. Posteriormente, as radiografias foram fotografadas e as imagens analisadas em computador, sendo medido o afastamento entre o endocarpo e a semente. As sementes foram classificadas em sementes intactas, sementes com afastamento parcial, sementes com afastamento total e sementes predadas. Os testes de germinação foram realizados sobre areia, em germinadores tipo Mangelsdorf a 25 ºC e luz branca constante. Pelos resultados, observa-se que a germinação é comprometida quando o teor de água das sementes fica abaixo de 26 %. Nesse ponto, o afastamento entre o endocarpo e a semente é de 0,65 mm. Houve uma correlação positiva entre a viabilidade das sementes, avaliada pelo teste de germinação, e o afastamento entre o endocarpo e a semente observado nas radiografias. A análise radiográfica possibilita identificar danos provocados por predação após infestação por insetos.
This study evaluated the effect of desiccation, and identified injuries and predation by insects in diaspores of canelabatalha (Cryptocarya aschersoniana Mez.) by using X-rays. The damages caused by desiccation were measured in the images and related to the formation of seedlings. Right after fruit depulping, the diaspores (endocarp plus seed) (45 % moisture content-MC and 37 % germination) were dried in acclimatized room (20 ºC and 60 %% RH), inside of plastic trays in a single layer. Later, in order to speed up the drying process, they were placed in drying boxes with saturated solution of sodium hydroxide (28 %% RH) and sampled with 45, 37, 35, 31 and 26 % MC. For the X-rays, an intensity of radiation of 40 KVp was used and the time of exposition of 1.5 min. The radiographies were then photographed and the images analyzed in computer, being measured the separation between endocarp and the seed. The diaspores were classified as intact; with partial separation; with total separation and predated. The germination tests were carried out on sand, in incubators Mangelsdorf at 25 ºC and constant white light. The results showed that the germination is affected when the diaspore MC reaches values below 26 %. In this point, the separation between endocarp and the seed is 0.65 mm. There was a positive correlation between the viability of the seeds, evaluated through germination tests and the separation between endocarp and the seed, observed through X-rays. The radiographic analysis helps identify damage caused by predation after insect infestation.
This study evaluated the effect of desiccation, and identified injuries and predation by insects in diaspores of canelabatalha (Cryptocarya aschersoniana Mez.) by using X-rays. The damages caused by desiccation were measured in the images and related to the formation of seedlings. Right after fruit depulping, the diaspores (endocarp plus seed) (45 % moisture content-MC and 37 % germination) were dried in acclimatized room (20 ºC and 60 %% RH), inside of plastic trays in a single layer. Later, in order to speed up the drying process, they were placed in drying boxes with saturated solution of sodium hydroxide (28 %% RH) and sampled with 45, 37, 35, 31 and 26 % MC. For the X-rays, an intensity of radiation of 40 KVp was used and the time of exposition of 1.5 min. The radiographies were then photographed and the images analyzed in computer, being measured the separation between endocarp and the seed. The diaspores were classified as intact; with partial separation; with total separation and predated. The germination tests were carried out on sand, in incubators Mangelsdorf at 25 ºC and constant white light. The results showed that the germination is affected when the diaspore MC reaches values below 26 %. In this point, the separation between endocarp and the seed is 0.65 mm. There was a positive correlation between the viability of the seeds, evaluated through germination tests and the separation between endocarp and the seed, observed through X-rays. The radiographic analysis helps identify damage caused by predation after insect infestation.
Descrição
Palavras-chave
Análise radiográfica, sementes recalcitrantes, espécie florestal, predação de sementes, Radiographic analysis, forest species, seed predation
Como citar
CERNE. UFLA - Universidade Federal de Lavras (UFLA), v. 18, n. 4, p. 657-666, 2012.