Maturação de sementes e aplicação pré-produção de substâncias antietilênicas em pimenta ornamental

• Autor(a) principal: Lima, Júlien da Silva
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1004
• topic: Pimenta ornamental; Etileno; Semente; Qualidade fisiologica; Ornamental pepper; Ethylene; Seed; Physiological quality; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::FISIOLOGIA VEGETAL

Peppers are important commercial plants, as for ornamental and food industryas source of pigments, flavor and peculiar taste. Since pepper is propagated by seed, it is important to control the physiological quality and processes of seed and fruits formation, allowing to obtain seeds with elevated germination and vigor. This work had the goal to evaluate the physical, physiological and enzymatic changes in seeds of ornamental peppers of variety MG 302, harvested from fruits in different stages of maturation. Fruits were collected at 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 and 80 days after flowering (DAF) and the seeds were extracted and submitted to physiological quality tests and the activity of peroxidase (POD) and alcohol dehydrogenase (ADH) after accelerated ageing. Seeds with 45 DAF did not germinate, beginning at 50 DAF, the germination jumped from 0 to 66%, reaching 90% at 80 DAF. It determined two phases of seeds development, one with probable cell division and another with accumulation of dry matter. The transition of the two phases probably occurred between 55 and 60 DAF, parallel to the color change from dark green to red. The fruits harvest of the ornamental pepper MG 302 can be done by following the changes in the fruit color, which happens when the fruits are completely red. The physiological maturation of the seeds for the MG 302 occurred between 75 and 80 DAF. The seeds became tolerant to drying after 50 DAF. The activities ADH and POD were reduced in the seeds with the time of ageing and increased with the maturation, according to the accelerated ageing test. With the goal to increase thre longevity of ornamental peppers, another study was conducted to determine the viiiefficiency of the ethylene synthesis ans action inhibitors, applied alone and in combination during growth in potted variety Calypso. For that, pots of cultivar Calypso were treated with the inhibitors followed or not by ethylene treatment. It was determined the quality and commercial duration by the leaf color, determined with the SPAD apparatus and total abscission. The values of SPAD and abscission showed elevation of leaf abscission, with average superior to 50% for the plants treated with ethylene. Better response was obtained when the plants were treated with the ethylene inhibitors aminoethoxyvinylglycine (AVG) and 1- methylcyclopropene (1-MCP), without treatment with ethylene accounting with less than 50% abscission after 22 days. The palnts of Calypso sprayed with AVG and 1- MCP, without ethylene treatment, had longed postharvest longevity. Plants fumigated with 1-MCP, followed by ethylene was efficient in minimizing leaf yellowing. The simultaneous use of AVG and 1-MCP had no additive effect in the pepper plants.