Fluorescence and levels of chlorophyll in pineapple plants cv. perola submitted to different concentration of ammonium sulphate/Fluorescencia e teores de clorofilas em abacaxizeiro cv. perola submetido a diferentes concentracoes de sulfato de amonio

• Published in: Revista Brasileira de fruticultura Vol. 32; no. 2; p. 360
• Main Authors: Vieira, Darlene Ana de Paula, Portes, Tomas De Aquino, Stacciarini-Seraphin, Eliane, Teixeira, Joao Batista
• Format: Journal Article
• Language: Spanish
• Published: Sociedade Brasileira de Fruticultura 01.06.2010
• ISSN: 0100-2945

The present research aimed to analyze chlorophyll a fluorescence emission as well as chlorophyll levels in Ananas comosus (L. Merril) cv Perola grown under greenhouse conditions and submitted to four concentration of nitrogen, through addition or not of ammonium sulphate according to the following treatments: [T.sub.0] = 0.000; [T.sub.1/2] = 0.015; [T.sub.1] = 0.030; and [T.sub.2] = 0.060 g/kg soil. Determinations of minimum ([F.sub.0]), maximum ([F.sub.m]), variable ([F.sub.v]), and terminal ([F.sub.t]) fluorescence and maximum photochemical efficiency ([F.sub.v]/[F.sub.m]) of dark-adapted leaves were realized during the day, five days after the second application of ammonium sulphate, carried out 120 days after the transplant. The results showed that the addition of ammonium sulphate affected variable and maximum fluorescence, but not minimum and terminal fluorescence neither the photochemical efficiency. There were significant alterations in relation to the time of the day in which the fluorescence was read. Differences in leaf chlorophyll concentration were significant among treatments in relation to variations of ammonium sulphate concentration, with increase for chlorophyll a, total and to the ratio chlorophyll a/b, but not for chlorophyll b. Index terms: Ananas comosus, nitrogen, photosynthesis, CAM plants. O presente trabalho teve como objetivo a analise da emissao da fluorescencia da clorofila a e dos teores de clorofilas em plantas de Ananas comosus (L. Merril) cv perola, cultivadas em casa de vegetacao, submetidas a quatro concentracoes de nitrogenio por adicao ou nao de sulfato de amonio, de acordo com os seguintes tratamentos: [T.sub.0] = 0 [T.sub.1/2] = 15; [T.sub.1] = 30; e [T.sub.2] = 60 mg/kg solo. As determinacoes de fluorescencia minima ([F.sub.0]), maxima ([F.sub.m]), variavel ([F.sub.v]) terminal ([F.sub.t]) e da eficiencia fotoquimica maxima ([F.sub.v]/[F.sub.m]) de folhas adaptadas ao escuro foram realizadas ao longo do dia, aos cinco dias apos a segunda aplicacao de sulfato de amonio, efetuada 120 dias apos o transplantio. A adicao de sulfato de amonio afetou a fluorescencia variavel e a maxima, mas nao afetou a fluorescencia minima, a terminal nem a eficiencia fotoquimica. Houve diferencas significativas entre os valores das variaveis da fluorescencia ao longo do dia em que foram feitas as leituras. Houve diferencas nos teores de clorofilas foliares, em funcao das concentracoes de sulfato de amonio aplicadas, com aumento para clorofila a e para a relacao clorofila a/b, mas nao para clorofila b. Termos para indexacao: Ananas comosus, nitrogenio, fotossintese, plantas MAC.