Data/hora: 21/06/2024 01:09:26

Biblioteca(s): | Embrapa Meio Norte / UEP-Parnaíba.
Data corrente: | 05/12/1995
Data da última atualização: | 05/12/1995
Autoria: | FERNANDEZ-BAYON, J.M.; BARNES, J. D.; OLLERENSHAW, J. H.; DAVISON, A. W.
Título: | Physiological effects of ozone on cultivars of watermelon (Citrullus lanatus) and muskmelon (Cucumis melo) widely grown in spain.
Ano de publicação: | 1993
Fonte/Imprenta: | Environmental Pollution, v.81, p.199-206, 1993.
Idioma: | Inglês
Conteúdo: | Two cultivars of watermelon (Citrullus lanatus) and muskmelon (Cucumis melo), which are widely grown in Spain, were exposed to ozone (70 nl litre-1, 6 h d-1) for 21 days. Ozone sensitivity was assessed by recording the extent of visible injury, changes in fast-fluorescence kinetics, the relative-growth rate (R) of root (RR) and shoot (RS), and effects on the number of flowers produced per plant. Leaf gas exchange was measured in order to provide some indication of the factors underlying differential response to ozone. After 9-10 days of fumigation, all the cultivars developed typical visible symptoms of ozone injury on the older leaves. However, significant (P menor que 0.05) changes in fast-fluorescence kinetics were detected prior to the development ofvisible foliar injury, indicating that detectable effects of ozone on primary photochemical processes supersede the appearance of visible syptoms. In both muskmelon and watermelon, there was a marked reduction in the rate of CO2 assimilation as a result of exposure to ozone, and this was accompained by a parallel decrease in stomatal conductance. Mean plant-relative-growth rate (R) was markedly (P menor que 0.01) suppressed by ozone in the two cultivars of watermelon, but there were no significant effects on R in muskmelon. Ozone reduced root growth relative to the shoot in three out of four cultivars an effect that may be of considerable ecological significance. Moreover, exposure to ozone reduced flower production in both muskmelon and watermelon, which...
Palavras-Chave: | Muskmelon; Watermelon.
Thesagro: | Citrullus Lanatus; Cucumis Melo; Melancia; Melão; Ozônio.
Thesaurus Nal: | ozone.
Categoria do assunto: | --
Registro original: | Embrapa Meio Norte / UEP-Parnaíba (CPAMN-UEPP)
Exemplares: | CPAMN-UEPP - (4485-1) - ADC - SP - -- -  -  - 1995.00225 - DIS