Condicionamento fisiológico em sementes de limão cravo e citrumelo ‘Swingle’

• Ano de defesa: 2009
• Autor(a) principal: Dantas, Ísis Barreto
• Orientador(a): Guimarães, Renato Mendes
• Banca de defesa: Oliveira, João Almir de, Vieira, Antônio Rodrigues
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNIVERSIDADE FEDERAL DE LAVRAS
• Programa de Pós-Graduação: DAG - Programa de Pós-graduação
• País: BRASIL
• Palavras-chave em Português: Limão cravo; Citrumelo ‘Swingle’; Semente; Armazenamento; Condicionamento fisiológico
• Área do conhecimento CNPq: CNPQ_NÃO_INFORMADO
• Link de acesso: https://repositorio.ufla.br/handle/1/4116

Many mechanisms have been used for that citrus seeds germinate faster and with uniformity, such as water embibition, osmotic conditioning and seed standardization. In this work the objective was evaluate osmotic conditioning methodologies in physiological performance for rangpur lime and ´Swingle´ citrumelo seeds. The experiment was lead in the Laboratory of Seeds Analysis of the Department of Agriculture of the Federal University of Lavras, Minas Gerais. Rangpur lemon (limonia Citrus Osbeck) and ´Swingle´ citrumelo (Citrus paradisi Macfad. cv. Duncan x Poncirus trifoliata (L.)) Raf. seeds, received from the interprise CUTRALE®, were used. Seeds were treated with Captan+Tecto 600 (30g+10g/20l of seed) and stored in cold chamber (10 ºC e 50% UR), without drying, for 3, 6 and 9 months. After each period of storage, seeds were submitted to osmotic conditioning for immersion in airy solution of Poliethylenoglicol (PEG 6000), potassium nitrate (KNO3) and combination of 70% of PEG and 30% of KNO3, with osmotic potential of -1,1MPa, in the periods of 3, 6, 9 and 12 days, with a controlled treatment (dry seeds). The osmoconditioning was carried through in chambers BOD, at 25ºC, in the light presence. After each period of established embibition, samples were removed, washed in current water and evaluated by germination tests, index of germination speed (IVG), emergency in tray, index of emergency speed (IVE), electrical condutivity and enzyme and proteic activity (ADH, MDH, SOD, PO, EST, CAT and LEA protein). Physiological conditioning in airy PEG 6000 solution, independent of the embibition period, or in KNO3 or PEG 6000 + KNO3 solution, for up to 9 days, is efficient to improve physiological seeds performance, stored for until 3 months, of rangpur lemon. For citrumelo ´Swingle´ seeds that were not stored, conditioning in solution containing PEG 6000 or KNO3, for 6 days, increased germination percentage. After 3 months stores, the most efficient treatments were conditioning in PEG 6000, for 6 days, or in KNO3, in a embibition period from 6 to 12 days. The most eficcient enzymes used to evaluate changes due to conditioning were superoxide dismutase, malate desidrogenase and alcohol desidrogenase, for rangpur lemon such as for ´Swingle´ citrumelo. Seeds physiological conditioning is a promising technique to improve physiological quality of rangpur lemon and citrumelo ´Swingle´ seeds.