Postharvest water relations in cut rose cultivars with contrasting sensitivity ...

• Author(s): Fanourakis, Dimitrios ; Carvalho, Susana M.P. ; Almeida, Domingos P.F. ; Kooten, Olaf van ; Doorn, Wouter G. van ; Heuvelink, Ep
• Date: 2012
• Persistent ID: http://hdl.handle.net/10400.14/7473
• Origin: Veritati - Repositório Institucional da Universidade Católica Portuguesa
• Subject(s): Air emboli; Flower opening; Stem hydraulic conductivity; Rosa hybrida; Vase life; Vascular occlusion
• Document Type: Article
• Language: English

Description

A constant highrelativeairhumidity (RH) during cultivation can strongly reduce the vase life in some cutrosecultivars. We studied three contrastingcultivars in their tolerance to high RH in order to analyse in detail the waterrelations during postharvest and better understand this genotypic variation. Plants were grown at moderate (60%) and high (95%) RH, and cut flowers were placed in water immediately after cutting. Flowers of cv. Pink Prophyta grown at high RH did not open throughout vase life, while flower opening of cvs. Frisco and Dream was not affected by preharvest RH. Cultivation at high RH resulted in about 80% shorter vase life in Pink Prophyta, whereas in Dream and Frisco the negative effect was considerably smaller (15 and 9% shorter vase life, respectively). The shorter vase life and reduced flower opening of cutroses grown at high RH was due to a higher rate of transpiration both in the light and dark periods. It was found that the leaves of Pink Prophyta grown at high RH could partly close their stomata upon lowering of the water potential or when flower stalks were fed with abscisic acid, but stomata remained far more open than in leaves grown at moderate RH. The RH during cultivation did not affect stem hydraulic conductivity and its recovery after air emboli induction. Preventing vascular occlusion largely alleviated the high-cultivation-RH effect on vase life and flower opening, showing that the effect of high-cultivation-RH becomes only important if water uptake is limited.