Browsing by Author "Teresa Lao, Maria"
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- Irrigation with drainage solutions improves the growth and nutrients uptake in Juncus acutusPublication . Garcia-Caparros, Pedro; Llanderal, Alfonso; El-Tarawy, Ahmed; Correia, Pedro José; Pestana, Maribela; Teresa Lao, MariaThe potential contamination of surface and ground water by the nurseries in the Mediterranean area obligates the use of novel systems such as the cascade cropping system. The aim of this work was to evaluate the effects of drainage water derived from an ornamental (Ruscus aculeatus L. and Maytenus senegalensis (Lam.) Exell.) cascade crop system on the growth and polluting elements uptake (N and P) against a standard nutrient solution in Juncus acutus L. plants. The experiment consisted of three treatments: a standard nutrient solution (T-0J; EC = 150 mS m(-1)), 1:2 diluted drainage water (T-1J; EC = 245 mS m(-1)) and the raw drainage water (T-2J; EC = 310 mS m(-1)). Biomass, plant and substrate parameters and total N and P uptake by plants were determined at the beginning and at the end of the experiment. This experiment showed that the irrigation with diluted and raw drainage water (T-1J and T-2J) with lower concentrations of N and P compared to the control treatment (T-0J) supposed an increase of biomass and consequently the increase of N and P uptake, where the plants irrigated with higher EC (raw drainage water) showed the highest biomass and total N and P uptake. (C) 2016 Elsevier B.V. All rights reserved.
- Lavandula multifida response to salinity: Growth, nutrient uptake, and physiological changesPublication . Garcia-Caparros, Pedro; Llanderal, Alfonso; Pestana, Maribela; Correia, Pedro José; Teresa Lao, MariaFern leaf lavender (Lavandula multifida L.) is a perennial shrub native to Almeria with known medicinal properties, which grows in saline soils that are increasingly present in the Mediterranean region. However, the effects of salinity on the mineral nutrition and physiology of L. multifida are unknown. In the present study, we evaluated the salt resistance of this species and compared it with other members of the Lamiaceae. Plants of L. multifida were grown in pots in a mixture of sphagnum peat-moss and Perlite, and treated with five different NaCl concentrations [10 (control), 30, 60, 100, and 200 mM NaCl] over a period of 60 d. The effects of different levels of salinity on mineral nutrient and osmolyte concentrations and on biomass were evaluated. Our results show that L. multifida plants were able to grow with 60 mM NaCl without significant biomass reduction. Na+ and Cl- were the main contributors to the osmotic potential in both roots and leaves, whereas total soluble sugars (TSS) and proline made only a small contribution. The concentrations of TSS and proline showed different trends in the different organs: in roots, both showed the highest concentrations at 60 mM NaCl, whereas in leaves TSS increased and proline decreased with increasing salt stress. To survive salinity, L. multifida plants increased salt excretion (Na+ and Cl-) by leaves at 100 and 200 mM NaCl and leaf succulence at 60, 100, and 200 mM NaCl. Excessive accumulation of Na+ and Cl- was avoided by shedding leaves. Our results indicate that L. multifida is better adapted to salinity compared to other members of the Lamiaceael, a consideration that is particularly relevant for their growth in and saline areas.
- Nutritional and physiological responses of the dicotyledonous halophyte Sarcocornia fruticosa to salinityPublication . Garcia-Caparros, Pedro; Llanderal, Alfonso; Pestana, Maribela; Correia, Pedro José; Teresa Lao, MariaSarcocornia fruticosa (L.) A.J. Scott is a dicotyledonous halophyte that grows in areas with an arid climate such as the marshes of southern Spain. The species has potential uses for saline agriculture and biofuel production, but the effects of salt stress on its nutrition and physiology remain unclear. Plants of S. fruticosa were grown in pots with a mixture of sphagnum peat-moss and Perlite. In order to evaluate the effects of different levels of salinity, five treatments using different NaCl concentrations (10 (control), 60, 100, 200 and 300 mM NaCl) were applied over a period of 60 days. At the end of the experiment, the dry weight, the biomass allocation and the tissue water content were measured for each salinity treatment. The net uptake of various nutrients and their translocation rates were calculated for each salt treatment. Salt loss, shedding of plant parts and succulence in shoots were evaluated together with the K+/Na+ ratio, K-Na selectivity, concentrations of osmolytes and their estimated contributions to the osmotic potential. Our results showed that S. fruticosa can maintain its major physiological processes at 60 mM NaCl without significant dry weight reduction. Higher salinity resulted in negative values for net uptake and translocation rates from roots to shoots of N and P. As might be predicted from other dicotyledonous halophytes, S. fruticosa plants increased Cl- and Na+ uptake using both as osmotica instead of organic osmolytes. However, to survive salinity, this species has also evolved others mechanisms such as shedding old shoots, increased succulence in shoots at higher salt concentrations and the ability to maintain a lower K+/Na+ ratio and higher K-Na selectivity in all organs.
- Tolerance mechanisms of three potted ornamental plants grown under moderate salinityPublication . Garcia-Caparros, Pedro; Llanderal, Alfonso; Pestana, Maribela; Correia, Pedro José; Teresa Lao, MariaThe scarcity of water in the Mediterranean area has frequently led to the use of saline water in order to irrigate ornamental plants in many nurseries. However, before the large-scale use of such waters, the ways in which the plants deal with the salinity need to be evaluated. Plants of Aloe vera L. Burm, Kalanchoe blossfeldiana Poelln and Gazania splendens Lem sp. were grown in pots with a mixture of sphagnum peat moss and Perlite. In order to evaluate the effects of different levels of salinity, three treatments using different NaCl concentrations (Electrical conductivity = 2.0 (control), 4.5 and 7.5 dS m(-1)) were applied over a period of 60 days. At the end of the experiment, the growth, physiological parameters and mineral content of the roots and leaves were assessed for each salinity treatment. After 60 days of exposure to salinity, the total biomass of all species decreased similarly. The mineral composition of roots and leaves was clearly affected. Osmolytes, such as praline, played an important role in the osmotic adjustment in all species increasing in the roots and leaves at the higher ECi. Different mechanisms of the salt tolerance were triggered in each species. A vera plants showed Na+ accumulation at the root level and a decrease in succulence index of leaves. K. blossfeldiana plants shed leaves to release Na+ and G. splendens plants accumulated Cl- and Na+ at the root level, secreted salt from leaves, lost salt by shedding of old leaves and increased the succulence index of remaining leaves. We concluded that the use of saline waters is feasible for growing these ornamental plants, and G. splendens seems to be particularly well adapted to salinity, a consideration that is particularly relevant in arid saline areas. (C) 2016 Elsevier B.V. All rights reserved.