Physiological response of chickpea (Cicer arietinum L.) in symbiosis with arbuscular mycorrhizal fungi under salinity conditions

Objective: The effect of salinity by NaCl based on physiological variables of chickpea plants was evaluated with the use of native strains of arbuscular mycorrhizal fungi Glomus cubensis and Rizoglomus irregulare during the pre-flowering phenophase. Design/methodology/approach: The research was carried out under controlled environmental conditions, using as an experimental model the chickpea variety N-29, obtained at INIFAT, Cuba. The treatments consist of the combination of three salinity levels: 25, 50 and 75 mM of NaCl and the respective control (Source of variation A) and two strains of AMFs (source of variation B) for a total of 12 treatments with six repetitions. Treatments were distributed under a completely randomized experimental design. The variables evaluated were: number of green and dry leaves, biomass by organs (leaves, stem, root), net assimilation rate (TAN), relative growth rate (TCR) and leaf area ratio (RAF). Results: Green leaves, TAN and leaf and root biomass were the variables with the highest response in the 50 mM NaCl + R. irregulare treatment, with an average increase of 15% compared to the rest of the treatments. Limitations on study/implications: There is a decrease in the variables evaluated due to the salinity effect, however, chickpea plants subjected to 50 mM NaCl inoculated with R. irregulare were less affected by saline stress. Findings/conclusions: It was also found that the R. irregulare strain contributed more than G. cubense to mitigating the adverse effects of the salinity factor.Objective. Evaluate the effect of salinity due to NaCl on physiological variables of chickpea plants using native strains of arbuscular mycorrhizal fungi (AMF) Glomus cubensis and Rhizoglomus irregulare during the pre-flowering stage. Design/methodology/approach. The research was carried out under controlled weather conditions using the chickpea variety N-29 as an experimental model. The treatments consisted on the combination of four salinity levels: 0, 25, 50 and 75 mM NaCl (variation source A) and AMF (variation source B) in three levels. In total there were 12 treatments with six repetitions, which were distributed in a completely randomized experimental design. The evaluated variables were number of green and dry leaves, dry biomass per organ (leaves, root and stem), net assimilation rate (NAR), relative growth rate (RGR) and leaf area ratio (LAR). Results. The green leaves, the NAR and the dry biomass from roots and leaves, were the variables with the greatest response in the 50 mM NaCl + R. irregulare treatment, with an average increase of 15% with respect to the rest of the treatments. Limitations/implications. A decrease on the evaluated variables was observed due to the salinity effect; however, chickpea plants subjected to NaCl 50 mM inoculated with R. irregulare were less affected by salt stress. Findings/conclusions. The R. irregulare strain was found to contribute more than the G. cubensis to the mitigation of the adverse effects from the salinity factor

Probing solution behaviour of metallosupramolecular complexes using pyrene fluorescence

A new method for assessing the topology of metallosupramolecular assemblies using pyrene-appended ligands is reported. Two potentially tetradentate ligands containing one (L1) and two (L2) terminal pyrene moieties were synthesised and their complexes with Cu+ and Cd2+ were characterised. Photophysical measurements demonstrate that in [Cu2(L1)2]2+, [CdL1]2+ and [Cu2(L2)2]2+ the emission spectra are dominated by monomeric emission but in the cadmium complex of L2 (where the pyrene units are in close proximity) a quenching of the luminescence coupled with weak emission at 540 nm is indicative of excimer formation

Categorization of the water status of rice inoculated with arbuscular mycorrhizae and with water deficit Categorización del estado hídrico del arroz inoculado con micorrizas arbusculares y con déficit hídrico

Introduction. The water deficit negatively affects rice plants and limits their productivity. Arbuscular mycorrhizal symbiosis has been shown to improve rice productivity in drought conditions. Objective. To propose a new categorization for the state of water stress of rice plants inoculated (AM) or not with arbuscular mycorrhizal fungi (nonAM) and exposed to water deficit (D) during the vegetative phase. Materials and methods. The experiment was carried out under controlled greenhouse conditions during the years 2009 and 2010 at the Zaidín Experimental Station, Granada, Spain. The rice transplantation was carried out fourteen days after germination to pots with a 5 cm water sheet and at 30, 40, or 50 days after transplantation (DAT) they were subjected to water deficit during a period of 15 days, at which time the water sheet was restored. The control treatment was maintained throughout the cycle under flood conditions (ww). Evaluations were performed at 45, 55, 65 DAT and after recovery at 122 DAT. The harvest was carried out at 147 DAT. Results. The reduction in water supply demonstrated water stress in the plants, manifested by the decrease in the water potential of the leaves. Arbuscular mycorrhizal symbiosis always favored the water status of the plant. Four categories of water status of plants were proposed taking into account water potentials and agricultural yield: no stress (≥-0.67 MPa); light stress (<-0.67 to -1.20 MPa); moderate stress (<-1.20 to -1.60 MPa), and severe stress (<-1.60 MPa). Conclusion. The categorization of stress due to the water deficit is a tool of high scientific value for the specific case of rice, since this plant has the capacity to adapt to tolerate the presence of a sheet of water throughout its biological cycle and is highly susceptible to water deficit.The research was funded by AECID (Grant MAE-AECID 2008/09 260940)

Categorization of the water status of rice inoculated with arbuscular mycorrhizae and with water deficit

Introduction. The water deficit negatively affects rice plants and limits their productivity. Arbuscular mycorrhizal symbiosis has been shown to improve rice productivity in drought conditions. Objective. To propose a new categorization for the state of water stress of rice plants inoculated (AM) or not with arbuscular mycorrhizal fungi (nonAM) and exposed to water deficit (D) during the vegetative phase. Materials and methods. The experiment was carried out under controlled greenhouse conditions during the years 2009 and 2010 at the Zaidín Experimental Station, Granada, Spain. The rice transplantation was carried out fourteen days after germination to pots with a 5 cm water sheet and at 30, 40, or 50 days after transplantation (DAT) they were subjected to water deficit during a period of 15 days, at which time the water sheet was restored. The control treatment was maintained throughout the cycle under flood conditions (ww). Evaluations were performed at 45, 55, 65 DAT and after recovery at 122 DAT. The harvest was carried out at 147 DAT. Results. The reduction in water supply demonstrated water stress in the plants, manifested by the decrease in the water potential of the leaves. Arbuscular mycorrhizal symbiosis always favored the water status of the plant. Four categories of water status of plants were proposed taking into account water potentials and agricultural yield: no stress (≥-0.67 MPa); light stress (<-0.67 to -1.20 MPa); moderate stress (<-1.20 to -1.60 MPa), and severe stress (<-1.60 MPa). Conclusion. The categorization of stress due to the water deficit is a tool of high scientific value for the specific case of rice, since this plant has the capacity to adapt to tolerate the presence of a sheet of water throughout its biological cycle and is highly susceptible to water deficit.Introducción. El déficit hídrico afecta negativamente a las plantas de arroz y limita su productividad. Se ha demostrado que la simbiosis micorrízica arbuscular mejora la productividad del arroz en condiciones de sequía. Objetivo. Proponer una nueva categorización para el estado de estrés hídrico de las plantas de arroz inoculadas (MA) o no con hongos micorrízicos arbusculares (noMA) y expuestos al déficit hídrico (D) durante la fase vegetativa. Materiales y métodos. El experimento se llevó a cabo bajo condiciones controladas de invernadero durante los años 2009 y 2010 en la Estación Experimental del Zaidín, Granada, España. El trasplante del arroz se realizó catorce días después de la germinación a macetas con una lámina de agua de 5 cm y a los 30, 40 o 50 días después del trasplante (DAT) se sometieron a déficit hídrico durante un período de quince días, momento en que se restableció la lámina de agua. El tratamiento de control se mantuvo durante todo el ciclo en condiciones de inundación (ww). Las evaluaciones se realizaron a los 45, 55, 65 DAT y después de la recuperación a 122 DAT. La cosecha se efectuó a los 147 DAT. Resultados. La reducción del suministro de agua evidenció estrés hídrico en las plantas, manifestado por la disminución del potencial hídrico de las hojas. La simbiosis micorrízica arbuscular siempre favoreció el estado hídrico de la planta. Se propusieron cuatro categorías de estado hídrico de plantas teniendo en cuenta los potenciales hídricos y el rendimiento agrícola: sin estrés (≥-0,67 MPa); estrés ligero (<-0,67 a -1,20 MPa); estrés moderado (<- 1,20 a -1,60 MPa) y estrés severo (<-1,60 MPa). Conclusión. La categorización del estrés debido al déficit hídrico es una herramienta de alto valor científico para el caso específico del arroz, ya que esta planta tiene la capacidad de adaptación para tolerar la presencia de una lámina de agua durante todo su ciclo biológico y es altamente susceptible al déficit hídrico