Search results for "drought stress"
showing 10 items of 20 documents
Carbohydrate and Nutritional Responses to Stem Girdling and Drought Stress with Respect to Understanding Symptoms of Huanglongbing in Citrus
2013
The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by a phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as “blotchy mottle,” thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-year-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 days, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought-stressed trees…
Some morphological, anatomical, physiological responses of different olive cultivars to high temperatures and drought stress
2004
The aim of this work is to find relationships between morphology and physiology in three different olive cultivars: Biancolilla, Cerasuola and Nocellara del Belice, when plants were subjected to high temperature and drought. These cultivars are estensively used in Sicily for productive purposes. The results about ultrastructural and physiological studies on shoot growth, leaf anatomy, chloroplast ultrastructure and oxygen production, indicate that Biancolilla is the cultivar in which the studied traits showed fewer changes and can be considered to have the best tolerance to both high temperatures and water deficit. In the other hand, the morphological and physiological characteristics studi…
Carbohydrate and nutritional responses to stem girdling and drought stress with respect to understanding symptoms of Huanglongbing (HLB) in Citrus
2013
The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as “blotchy mottle”, thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-yr-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 d, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought stressed trees. Starc…
STUDIES ON SOME ECOPHYSIOLOGICAL, METABOLIC AND AGRONOMIC ASPECTS OF TREE NUTS
Potassium deficiency and drought stress in grapevine cultivars
2014
Potassium availability affects drought responses in plants through several metabolic roles, among which stomatal regulation, cell growth and xylem hydraulics. Vitis vinifera L. is a highly valuable crop and several genotypes have been selected during its millennial cultivation. Varieties show differences in their adaptability to stress conditions, making them more or less suitable to certain climatic and edaphic conditions. The varieties cultivated in Sicily are characterized by high variability. We investigated the response of two Sicilian cultivars (Nero d'Avola and Catarratto) to potassium deficiency and drought stress. Two-year-old grafted plants were grown in agriperlite, with or witho…
Effects of drought and re-watering on water transport in Sedum sediforme (Jacq.) Pau
2011
Recovery from water stress in laurel plants: influence of short term potassium fertilization
2013
Plant xylem hydraulic conductance varies with changes in sap solute concentrations, particularly potassium, a phenomenon known as 'ionic effect'. In well-watered Laurus nobilis plants, short term potassium fertilization increased xylem sap potassium concentration, resulting in an increase in plant hydraulic conductance (Kplant), leaf-specific conductivity of the shoot (kshoot) and transpiration rate (Eplant). The ionic effect is enhanced in embolized stems, where it can compensate the cavitation-induced loss of hydraulic conductance. The aim of this work was to test if water-stressed potassium-starved laurel plants could recover earlier from stress when irrigated with a potassium solution i…
Response of transgenic mannitol-producing tobacco plants to water deficit
2008
Transgenic mannitol-producing (+mtlD) and wild type (-mtlD) tobacco plants were exposed to water deficit to test whether mannitol is involved in drought stress protection. Rooted cuttings of -mtlD and +mtlD plants were fully irrigated (100% ET) or received 25% ET for 40 days, followed by 20 days of re-watering. Water deficit reduced RWC of both plant types starting on the 22nd day, total stem length of -mtlD 25% ET already after 11 days, whereas that of +mtlD 25% ET only after 34 days. After 30 days of deficit, a greater percentage of mature foliage was retained by +mtlD 25% ET compared to -mtlD 25% ET. Mannitol-1-phosphate dehydrogenase activity of +mtlD plants was not affected by water de…
Morpho-physiologic traits in two sage taxa grown under different irrigation regime
2017
Sage is an important aromatic crop, extensively cultivated worldwide. Drought stress affects yield and composition of secondary metabolites such as fatty acids, essential oils, antioxidants, changing the essential oil composition profile with respect to the ISO 9909 standard. Drought tolerance may differ among genotypes, so we compared the response of Salvia officinalis L. and S. officinalis cv. ‘Maxima’ grown under two different irrigation regimes to highlight differences in leaf growth, water potential, gas exchange and essential oil composition. Potted plants were grown in the greenhouse at 100% or 50% of field water capacity for three months. Monthly measurements of 3rd node leaf length…