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Abstract(s)
A castanha em fresco é um fruto de elevada qualidade, mas facilmente perecível. A qualidade é influenciada por fatores bióticos e abióticos que ocorrem em pré-colheita, durante a colheita e em pós-colheita. As podridões das castanhas associadas a fungos podem desenvolver-se durante o crescimento dos frutos ainda na árvore, quando da queda dos ouriços na altura da colheita ou por contaminação durante o armazenamento. As podridões associadas a Penicillium spp., Aspergillus spp., Fusarium spp., Phoma. castanea, Acrospeira mirabilis e S. pseudotuberosa são frequentes em condições de conservação e provocam prejuízos muito elevados. Pretende-se, com este trabalho, avaliar os fatores pré-colheita que afetam a produção e a qualidade final da castanha. Para concretizar o estudo selecionaram-se 5 soutos na região de Bragança, tendo-se recolhido castanhas em 3 períodos diferentes, durante o período de colheita. Será avaliado o estado sanitário das castanhas em diferentes tempos de conservação (imediatamente após a colheita, um mês após a colheita e dois meses após a colheita, com as castanhas armazenadas em camara de frio (frigorifico) a 12ºC. As castanhas são avaliadas quanto á presença de pragas (Bichado-da-castanha ou Gorgulho-da-castanha) e verificado a presença de fungos. Nas castanhas com podridões observaram-se as características morfológicas dos sintomas e procede-se ao isolamento do fungo em meio de cultura PDA (Potato Dextrose Agar, 39 gr/L). A identificação das espécies será realizada por observação morfológica dos isolados e por técnicas moleculares por amplificação e sequenciação da região ITS do ADN ribossomal (ADNr) utilizando os iniciadores universais ITS1 e ITS4.
The fresh chestnut is a fruit of high quality, but easily perishable. Quality is influenced by biotic and abiotic factors that occur in pre-harvest, during harvest and post-harvest. Chestnut nut rots associated with fungi may develop during the growth of the fruits still in the tree, during the fall of the burrs at harvest time or through contamination during storage. The rot associated with Penicillium spp., Aspergillus spp., Fusarium spp., P. castanea, Acrospeira mirabilis and S. pseudotuberosa are frequent in that conservation conditions and cause very high losses. This work intends to evaluate the pre-harvest factors that affect the final production and quality of the nuts. In order to complete the study, 5 chestnut trees were selected in the region of Bragança, and chestnuts nuts were collected in 3 different periods during the harvest period. The health status of the nuts will be evaluated at different storage times (immediately after harvest, one month after harvest and two months after harvest), when the chestnuts nuts are stored in an incubator at 12° C. The chestnuts are evaluated for the presence of pests (chestnut beetle or brown weevil) and presence of fungi were observed outside and into the kernel. In the nuts with rotting, the morphological characteristics of the symptoms were observed and the fungus was isolated in PDA culture medium (Potato Dextrose Agar, 39 gr/L). Identification of species will be performed by morphologic microscopic observations and molecular techniques by amplification and sequencing of the ITS region of ribosomal DNA (rDNA) using the universal primers ITS1 and ITS4.
The fresh chestnut is a fruit of high quality, but easily perishable. Quality is influenced by biotic and abiotic factors that occur in pre-harvest, during harvest and post-harvest. Chestnut nut rots associated with fungi may develop during the growth of the fruits still in the tree, during the fall of the burrs at harvest time or through contamination during storage. The rot associated with Penicillium spp., Aspergillus spp., Fusarium spp., P. castanea, Acrospeira mirabilis and S. pseudotuberosa are frequent in that conservation conditions and cause very high losses. This work intends to evaluate the pre-harvest factors that affect the final production and quality of the nuts. In order to complete the study, 5 chestnut trees were selected in the region of Bragança, and chestnuts nuts were collected in 3 different periods during the harvest period. The health status of the nuts will be evaluated at different storage times (immediately after harvest, one month after harvest and two months after harvest), when the chestnuts nuts are stored in an incubator at 12° C. The chestnuts are evaluated for the presence of pests (chestnut beetle or brown weevil) and presence of fungi were observed outside and into the kernel. In the nuts with rotting, the morphological characteristics of the symptoms were observed and the fungus was isolated in PDA culture medium (Potato Dextrose Agar, 39 gr/L). Identification of species will be performed by morphologic microscopic observations and molecular techniques by amplification and sequencing of the ITS region of ribosomal DNA (rDNA) using the universal primers ITS1 and ITS4.
Description
Keywords
Castanhas Contaminação Fungos Pragas Armazenamento Qualidade