Browsing by Author "Carvalho, D. R. A"
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- Estudos anatómicos e histológicos em folhas de roseira desenvolvidas em diferentes condições de humidade relativaPublication . Monteiro, A.; Carvalho, D. R. A; Vasconcelos, Marta; Correia, C.; Moutinho-Pereira, J. M.; Gonçalves, B.; Bacelar, E.; Carvalho, S. M. P.High relative air humidity (RH > 85%) during growth has a negative impact on postharvest longevity of cut roses, being described a different susceptibility among cultivars. Poor stomatal functioning has been pointed out as the principal cause of excessive water loss during postharvest in plants grown at high RH. However, to the best of our knowledge up to date no comprehensive studies on the effect of RH on leaf anatomical, histological and biochemical characteristics have been carried out. In this study, we evaluated six genotypes from a cut rose segregating tetraploid population (four sensitive and two with intermediate response to desiccation) grown at moderate (60%) and high (90%) RH. It was found that RH played a very important role on the modification of leaf structure. Leaves developed at high RH showed larger specific leaf area (increasing 12.8% and 26.8% on the sensitive and intermediate genotypes, respectively) and lower succulence (reducing 9.5% on the sensitive and 10.7% on the intermediate genotypes). Moreover, these leaves also showed a reduced thickness of the total lamina, of the cuticle and of the upper and lower epidermis. Stomatal density was also reduced but stomatal dimensions were significantly larger at high RH. At cell level, the sensitive genotypes grown at 90% RH showed higher ion leakage, reflecting the loss of the membrane integrity with negative consequences on the longevity and postharvest quality. Additionally, the lower concentration of photosynthetic pigments and total soluble sugars observed on high RH grown leaves can also contribute to the reduction of the quality and longevity of the flower stalks during postharvest.
- Estudos anatómicos e histológicos em folhas de roseira desenvolvidas em diferentes condições de humidade relativaPublication . Monteiro, A.; Carvalho, D. R. A; Vasconcelos, Marta; Correia, C.; Moutinho-Pereira, J. M.; Gonçalves, B.; Bacelar, E.; Carvalho, S. M. P.High relative air humidity (RH > 85%) during growth has a negative impact on postharvest longevity of cut roses, being described a different susceptibility among cultivars. In this study, we evaluated the effect of RH on leaf anatomical and histological characteristics in six genotypes from a cut rose segregating tetraploid population (four sensitive and two with intermediate response to desiccation) grown at moderate (60%) or high (90%) RH. Leaves developed at high RH showed larger specific leaf area (increasing 12.8% and 26.8% on the sensitive and intermediate genotypes, respectively) and lower succulence (reducing 9.5% on the sensitive and 10.7% on the intermediate genotypes). Moreover, these leaves also showed a reduced thickness of the total lamina, cuticle and the upper and lower epidermis. Stomatal density was also reduced but stomatal dimensions were significantly larger at high RH. It is concluded that RH plays a very important role on the modification of leaf structure.