Water productivity and crop yield in five chickpea varieties – how important is supplemental irrigation?

Chickpea (Cicer arietinum L.) is one of the most important pulse crops in the world as a source of protein for human consumption. In Mediterranean regions, chickpea is traditionally grown as a rainfed crop, thus highly dependent on rainfall. In this situation, supplemental irrigation may be applied. The objective of our study was to evaluate the improvement in crop yield and water productivity with supplemental irrigation in five chickpea varieties (three kabuli type and two desi type) from the Portuguese breeding selection program. Field tests were carried out over two cropping seasons (2009, dry year and 2010, wet year), in Southern Portugal, using four irrigation treatments, full (100%) crop irrigation requirements(IR), 50 % of IR, 25 % of IR and rainfed. A significant increase in grain and shoot biomass yields was observed especially in dry years. Elixir (kabuli type) variety showed the highest grain and biomass yield, harvest index and water productivity. In the dry year, the highest water productivity for grain and biomass production was attained at the 50% and in the wet year in the rainfed treatment

Evaluating chickpea genotypes for abiotic stress tolerance

Being a leguminous crop chickpea (Cicer arietinum L.) is important for the establishment of sustainable and economically viable farming systems. Chickpea is grown and consumed across five continents, making this crop more important in international markets than other food legumes. Adaptation trials of 15 accessions of chickpea, 13 from the ICARDA collection and 2 from the Portuguese national catalogue, took place during two years in two different countries (Portugal, Syria). The trials were conducted under rainfed conditions using a late sowing date to naturally expose the plants to drought and heat stress. The accumulated results indicate a high variability in the yield response among genotypes and regions. In Portugal differences between the most productive accession and the least productive one was higher than 1000 kg/ha in 2009 (drought year) and than 1500Kg/ha in 2010 (rainy year). In general, genotypes that fasten their development cycle showed higher grain yield, especially in drought years. Comparing the two years, we observed three groups of genotypes: i) Stable genotypes, well adapted to distinct environments (like ILC588). ii) Genotypes adapted to adverse conditions, but not responding to favourable conditions (ICL 216); this genotype was also among the best performers under drought conditions in Syria. iii) Genotypes adapted to good conditions, but with bad performance under adverse conditions (ICL 3279). Across the two locations, Portugal and Syria, FLIP03-145C, FLIP87-8C and ILC 588 were on the top 5 during 2009. In 2010, only FLIP87-8C standout to be among the best performers under drought conditions in both countries

Lipid profile with eslicarbazepine acetate and carbamazepine monotherapy in adult patients with newly diagnosed focal seizures: post hoc analysis of a phase III trial and open-label extension study

BACKGROUND: Antiseizure medications can have negative effects on plasma lipid levels. OBJECTIVES: To evaluate plasma lipid changes in patients with newly diagnosed focal epilepsy treated with eslicarbazepine acetate (ESL) or controlled-release carbamazepine (CBZ-CR) monotherapy during a phase III, randomized, double-blind (DB) trial and 2 years of ESL treatment in an open-label extension (OLE). DESIGN: Post hoc analysis of a phase III trial and OLE study. METHODS": Proportions of patients with elevated levels of total cholesterol and low-density lipoprotein (LDL) cholesterol were assessed at DB baseline, OLE baseline (last visit of DB trial), and end of OLE. RESULTS: A total of 184 patients received ESL monotherapy during the OLE: 96 received ESL monotherapy in the DB trial and 88 patients received CBZ-CR monotherapy. The proportions of patients with elevated total cholesterol and LDL cholesterol increased significantly during the DB trial in those treated with CBZ-CR monotherapy [total cholesterol, +14.9% (p < 0.001); LDL cholesterol, +11.5% (p = 0.012)] but decreased significantly after switching to ESL monotherapy in the OLE [total cholesterol, −15.3% (p = 0.008); LDL cholesterol, −11.1% (p = 0.021)]. No significant changes were observed in those treated with ESL monotherapy during the DB trial and OLE. At the end of the DB trial, between-group differences (ESL–CBZ-CR) in the proportions of patients with elevated total and LDL cholesterol were −13.6% (p = 0.037) and −12.3% (p = 0.061), respectively; at the end of the OLE, these between-group differences were −6.0% (p = 0.360) and −0.6% (p = 1.000), respectively. CONCLUSION:A lower proportion of patients with newly diagnosed focal epilepsy had increased levels of total and LDL cholesterol, compared to baseline, following monotherapy with ESL versus CBZ-CR; after switching from CBZ-CR to ESL, the proportions of patients with increased levels decreased significantly. REGISTRATION: ClinicalTrials.gov NCT01162460/NCT02484001; EudraCT 2009-011135-13/2015-001243-36

Midday measurements of leaf water potential and stomatal conductance are highly correlated with daily water use of Thompson Seedless grapevines

A study was conducted to determine the relationship between midday measurements of vine water status and daily water use of grapevines measured with a weighing lysimeter. Water applications to the vines were terminated on August 24th for 9 days and again on September 14th for 22 days. Daily water use of the vines in the lysimeter (ETLYS) was approximately 40 L vine−1 (5.3 mm) prior to turning the pump off, and it decreased to 22.3 L vine−1 by September 2nd. Pre-dawn leaf water potential (ΨPD) and midday Ψl on August 24th were −0.075 and −0.76 MPa, respectively, with midday Ψl decreasing to −1.28 MPa on September 2nd. Leaf g s decreased from ~500 to ~200 mmol m−2 s−1 during the two dry-down periods. Midday measurements of g s and Ψl were significantly correlated with one another (r = 0.96) and both with ETLYS/ETo (r = ~0.9). The decreases in Ψl, g s, and ETLYS/ETo in this study were also a linear function of the decrease in volumetric soil water content. The results indicate that even modest water stress can greatly reduce grapevine water use and that short-term measures of vine water status taken at midday are a reflection of daily grapevine water us

Metabolomics demonstrates divergent responses of two Eucalyptus species to water stress

Past studies of water stress in Eucalyptus spp. generally highlighted the role of fewer than five “important” metabolites, whereas recent metabolomic studies on other genera have shown tens of compounds are affected. There are currently no metabolite profiling data for responses of stress-tolerant species to water stress. We used GC–MS metabolite profiling to examine the response of leaf metabolites to a long (2 month) and severe (Ψpredawn < −2 MPa) water stress in two species of the perennial tree genus Eucalyptus (the mesic Eucalyptus pauciflora and the semi-arid Eucalyptus dumosa). Polar metabolites in leaves were analysed by GC–MS and inorganic ions by capillary electrophoresis. Pressure–volume curves and metabolite measurements showed that water stress led to more negative osmotic potential and increased total osmotically active solutes in leaves of both species. Water stress affected around 30–40% of measured metabolites in E. dumosa and 10–15% in E. pauciflora. There were many metabolites that were affected in E. dumosa but not E. pauciflora, and some that had opposite responses in the two species. For example, in E. dumosa there were increases in five acyclic sugar alcohols and four low-abundance carbohydrates that were unaffected by water stress in E. pauciflora. Re-watering increased osmotic potential and decreased total osmotically active solutes in E. pauciflora, whereas in E. dumosa re-watering led to further decreases in osmotic potential and increases in total osmotically active solutes. This experiment has added several extra dimensions to previous targeted analyses of water stress responses in Eucalyptus, and highlights that even species that are closely related (e.g. congeners) may respond differently to water stress and re-waterin

Heat and water stress induce unique transcriptional signatures of heat-shock proteins and transcription factors in grapevine

Grapevine is an extremely important crop worldwide. In southern Europe, post-flowering phases of the growth cycle can occur under high temperatures, excessive light, and drought conditions at soil and/or atmospheric level. In this study, we subjected greenhouse grown grapevine, variety Aragonez, to two individual abiotic stresses, water deficit stress (WDS), and heat stress (HS). The adaptation of plants to stress is a complex response triggered by cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Approaches such as array-based transcript profiling allow assessing the expression of thousands of genes in control and stress tissues. Using microarrays, we analyzed the leaf transcriptomic profile of the grapevine plants. Photosynthesis measurements verified that the plants were significantly affected by the stresses applied. Leaf gene expression was obtained using a high-throughput transcriptomic grapevine array, the 23K custom-made Affymetrix Vitis GeneChip. We identified 1,594 genes as differentially expressed between control and treatments and grouped them into ten major functional categories using MapMan software. The transcriptome of Aragonez was more significantly affected by HS when compared with WDS. The number of genes coding for heat-shock proteins and transcription factors expressed solely in response to HS suggesting their expression as unique signatures of HS. However, a cross-talk between the response pathways to both stresses was observed at the level of AP2/ERF transcription factors