International Center For Biosaline Agriculture Research Articles

Silver Nanoparticles (Ag NPs) Boost Mitigation Powers of Chenopodium Quinoa (Q6 Line) Grown under In Vitro Salt-Stressing Conditions

Quinoa (Chenopodium quinoa) is of great economic importance and constitutes one of the model plants for salinity and drought tolerance in the Mediterranean climate. This study aimed to study the physiological responses of Q6 (a quinoa line developed by International Center for Bio-saline Agriculture (ICBA) in cooperation with the National Center for Agricultural Research (NARC), Jordan) grown under in vitro salt-stressing conditions (MS Media plus either 0, 25, 50, 75, 100, 150, or 200 mM of NaCl) and to determine the highest salt level that Q6 plantlets can tolerate. After this, different levels of chemically synthesized silver nanoparticles (Ag NPs) (25, 50, and 75 mg/L) were added to the growth MS media to examine if they can boost the mitigation powers of Q6 plantlets against the highest salt level that the Q6 plantlets could tolerate. Data showed that all tested growth parameters were negatively affected by adding NaCl to the media at all levels. Shoot length, proliferation, and fresh and dry weights declined to reach minimum values at 200 mM NaCl when compared to the other NaCl levels. Similarly, chlorophyll, protein, and ion content were negatively affected when exposed to NaCl at all levels, while proline increased significantly with increasing NaCl in the growth media. The addition of Ag NPs resulted in improving the mitigation powers of Q6 plantlets, especially when 75 mg/L Ag NPs were added, as this resulted in a significant improvement in microshoot growth under 200 mM NaCl when compared to the control. Adding 75 mg/L of Ag NPs to 200 mM NaCl improved shoot growth (3.56 cm) when compared to (1.04 cm) obtained plantlets that were grown in 200 mM NaCl alone. Further, other growth parameters were almost doubled by adding 75 mg/L of Ag NPs to 200 mM NaCl when compared to 200 mM NaCl alone. Additionally, adding Ag NPs (especially at the 75 mg/L level) to the media improved total chlorophyll, protein, and ion content while also reducing proline when compared to the control, which indicated an improvement in microshoot tolerance to salt-stressing conditions. These results indicate that adding specific concentrations of Ag NPs improves the growth performance and stress tolerance of Q6 grown under salt-stressing conditions.

Genomic Regions Associated With Salinity Stress Tolerance in Tropical Maize (Zea Mays L.).

Being a widely cultivated crop globally under diverse climatic conditions and soil types, maize is often exposed to an array of biotic and abiotic stresses. Soil salinity is one of the challenges for maize cultivation in many parts of lowland tropics that significantly affects crop growth and reduces economic yields. Breeding strategies integrated with molecular approach might accelerate the process of identifying and developing salinity-tolerant maize cultivars. In this study, an association mapping panel consisting of 305 diverse maize inbred lines was phenotyped in a managed salinity stress phenotyping facility at International Center for Biosaline Agriculture (ICBA), Dubai, United Arab Emirates (UAE). Wide genotypic variability was observed in the panel under salinity stress for key phenotypic traits viz., grain yield, days to anthesis, anthesis-silking interval, plant height, cob length, cob girth, and kernel number. The panel was genotyped following the genome-based sequencing approach to generate 955,690 SNPs. Total SNPs were filtered to 213,043 at a call rate of 0.85 and minor allele frequency of 0.05 for association analysis. A total of 259 highly significant (P ≤ 1 × 10–5) marker-trait associations (MTAs) were identified for seven phenotypic traits. The phenotypic variance for MTAs ranged between 5.2 and 9%. A total of 64 associations were found in 19 unique putative gene expression regions. Among them, 12 associations were found in gene models with stress-related biological functions.

Agronomic performance of irrigated quinoa in desert areas: Comparing different approaches for early assessment of salinity stress

Quinoa is a very versatile crop, amenable to the hot agronomical conditions of the Middle East, where it is cultivated under irrigation, frequently using saline water. This study aims to compare different approaches for early detection of the effect of salinity on the agronomic performance of this crop. A set of 20 genotypes was grown under drip irrigation in sandy soil at the International Center for Biosaline Agriculture (UAE). The crop was established using fresh water (0.3 dS m−1) for two weeks, after which half of the trial was submitted to irrigation with saline water, (15 dS m−1) and this was continued until crop maturity. After eight weeks of applying each specific irrigation, pigment contents were evaluated in fully expanded leaves. The same leaves were then harvested, dried and the stable carbon and nitrogen isotope compositions (δ13C and δ15N) and the total nitrogen and carbon content of the dry matter analyzed, together with the total content of K+, Na+, Mg2+, and Ca2+ ions. Genotypic and treatment effects existed for yield and biomass, as well as for the analytical traits above. The best traits in terms of correlation with biomass and yield within each irrigation regime were the Mg2+ and K+ contents and the δ15N. A stepwise model using different traits (mainly Mg2+, K+, and δ15N) explained 33.1 % of the variability in biomass and 56.0 % in seed yield, under saline irrigation, 52.4 % and 34.9 % under fresh water, and 42.4 % and 38.6 % under the combination of both irrigation regimes, respectively. Regardless of irrigation conditions, the results also showed that manure application causes salinity that is associated with high magnesium content. The combined analysis of ion concentrations and δ15N allows early evaluation of the effect of irrigation salinity and identification of the best performing genotypes under each irrigation condition.

Agronomical and analytical trait data assessed in a set of quinoa genotypes growing in the UAE under different irrigation salinity conditions.

The importance of quinoa has been emphasized considerably in the recent decades, as a highly nutritional crop seed that is tolerant to salinity and amenable to arid agronomical conditions. The focus of this paper is to provide raw and a supplemental data of the research article entitled "Agronomic performance of irrigated quinoa in desert areas: comparing different approaches for early assessment of salinity stress" [1], aiming to compare different approaches for early detection, at the genotypic and crop levels, of the effect of salinity caused by irrigation on the agronomic performance of this crop. A set of 20 genotypes was grown under drip irrigation in sandy soil, amended with manure, at the International Center for Biosaline Agriculture (UAE) for two weeks, after which half of the trial was submitted to irrigation with saline water and this was continued until crop maturity. After eight weeks of applying the two irrigation regimes, pigment contents were evaluated in fully expanded leaves. The same leaves were then harvested, dried and the stable carbon and nitrogen isotope compositions (δ13C and δ15N) and the total nitrogen and carbon contents of the dry matter analyzed, together with ion concentrations. At maturity yield components were assessed and yield harvested. Data analysis demonstrated significant differences in genotypes response under each treatment, within all assessed parameters. The significant level was provided using the Tukey-b test on independent samples. The present dataset highlights the potential use of different approaches to crop phenotyping and monitoring decision making.

Vegetation indices derived from digital images and stable carbon and nitrogen isotope signatures as indicators of date palm performance under salinity

Date palm is frequently irrigated with brackish water. Developing tools to monitor salinity effects at the single-tree level may assist agronomy and phenotyping. Sixteen elite varieties were grown for 15 years under irrigation with three levels of saline water (5, 10 and 15 dS m−1) at the International Center for Biosaline Agriculture (UAE). Trunk length and diameter, number of branches, and fruit yield per tree were recorded. Different vegetation indices were calculated from single tree-top images taken from the ground with an RGB (Red/Green/Blue) camera. These included indices derived from CIE (Commission Internationale de l’Eclairage) color space models; lightness, together with a* and b* dimensions (CIELab) and u* and v* coordinates (CIELuv); and the HSI color space, referring to the components Hue, Saturation and Intensity. Moreover, Green Area (GA) and the Greener Area (GGA) were also formulated. Also canopy temperature (CT) was measured as an indicator of canopy water status with an infrared thermometer. The carbon isotope composition (δ13C), as a time-integrated indicator of water status, and the nitrogen isotope composition (δ15N) and total nitrogen concentration (N), as nitrogen metabolism indicators, were analyzed in leaflet dry matter. Irrigation conditions and genotypes exhibited significant effects for biomass, fruit yield and all the remote sensing and stable isotope traits evaluated. Hue correlated positively, whereas most of the other RGB vegetation indices along with δ13C and CT correlated negatively with biomass and fruit yield across salinities. Leaf N concentration and δ15N did not correlate with biomass and fruit yield across salinities, but were the only traits correlated with genotypic variability in fruit yield within a given salinity level. Traits that describe canopy color characteristics represent affordable tools for monitoring palm growth and productivity under saline irrigation. However, the results do not support the direct use of RGB indices to phenotype genotypic variability.

Linear spectral unmixing to monitor crop growth in typical organic and inorganic amended arid soil

The soils of the GCC countries are dominantly sandy which is typical of arid regions such as the Arabian Peninsula. Such soils are low in nutrients and have a poor water holding capacity associated with a high infiltration rate. Soil amendments may rehabilitate these soils by restoring essential soil properties and hence enable site revegetation and revitalization for crop production, especially in a region where food security is a priority. In this study, two inorganic amendments; AustraHort and Zeoplant pellet, and one organic locally produced compost were tested as soil amendments at the experimental field of the International Center for Biosaline Agriculture in Dubai, UAE. The main objective is to assess the remote sensing ability to monitor crop growth, for instance Okra (Abelmoschus esculentus), having these amendments, as background with the soil. Three biomass spectral vegetation indices were used namely; NDVI, TDVI and SAVI. Pure spectral signatures of the soil and the three amendments were collected, using a field spectroradiometer, in addition to the spectral signatures of Okra in two growing stages (vegetative and flowering) in the field with a mixed F.O.V of the plant and amended soil during March and May 2015. The spectral signatures were all collected using the FieldSpec® HandHeld 2 (HH2) in the spectral range 325 nm - 1075 nm over 12 plots. A set of 4 plots were assigned for each of the three amendments as follow: three replicates of a 1.5 by 1.5 meter plot with 3kg/m2 of each amendment and 54 plants, one plot as control and all plots were given irrigation treatments at 100% based on ETc. Spectra collected over the plots were inversed in the range of 400-900 nm via a Linear Mixture Model using pure soil and amendments spectral signatures as reference. Field pictures were used to determine the vegetation fraction (in term of area of the F.O.V). Hence, the Okra spectral signatures were isolated for all plots with the three types of amendments. The three vegetation indices were then calculated and compared in the vegetation fraction of the entire F.O.V. The key outcome of this analysis was that a considerable bias was induced when using a mixed F.O.V. In fact, the compost as an organic soil amendment containing dead vegetation affects similarly the sensitivity of the three vegetation indices in the vegetative stage of Okra compared to AustraHort and Zeoplant pellet amended plots. However, the TDVI is very sensitive to vegetation presence even with unmixed crop spectra. AustraHort amendment led to better status of Okra both in March and May with values of 0.19 and 0.28 respectively. Bias induced by some soil amendments can be misleading when upscaling spectral information to satellite imagery with low spectral and spatial resolutions. The results obtained are encouraging for further use of spectral information for crop monitoring in soil containing amendments.

Priming of prosopis cineraria (L.) druce and acacia tortilis (forssk) seeds with fulvic acid extracted from compost to improve germination and seedling vigor

ABS TRACT: Composting of waste plant materials and its use in agriculture and landscape sites is an environmental friendly way of reducing waste material and conserving the environment. In this perspective, we have taken the initiative at the Dubai based International Center for Biosaline Agriculture to compost the plant based waste material (lawn cuttingsgrass) to compost. The material was inoculated with a consortium of microbes leading to the formation stable and mature compost with high organic matter (38%). In order to conduct seed germination tests, fulvic acid was extracted from the compost. A pot experiment was conducted over a period of 30 days in the green house to study the effect of fulvic acid on the seed germination, and plant growth of Prosopis cineraria (L.) druce (Ghaff) and Acacia tortilis(Forssk.) Hayne. Seeds of both trees were treated with fulvic acid at 0.5% and 1% concentrations water treatment was used as control. Generally seed germination and biomass were increased at both rates of fulvic acid application, However, a pronounced increase was found in seed germination when fulvic acid was used at 1.0% (Prosopis cineraria 27%; Acacia tortilis 20% increase over control). Similarly biomass (shoot and root) of A. tortilis and P. cineraria showed an increase of increase 34% and 94% respectively.