Chlorophyll Values Research Articles

Genomic predictions and genome-wide association studies based on RAD-seq of quality-related metabolites for the genomics-assisted breeding of tea plants

Effectively using genomic information greatly accelerates conventional breeding and applying it to long-lived crops promotes the conversion to genomic breeding. Because tea plants are bred using conventional methods, we evaluated the potential of genomic predictions (GPs) and genome-wide association studies (GWASs) for the genetic breeding of tea quality-related metabolites using genome-wide single nucleotide polymorphisms (SNPs) detected from restriction site-associated DNA sequencing of 150 tea accessions. The present GP, based on genome-wide SNPs, and six models produced moderate prediction accuracy values (r) for the levels of most catechins, represented by ( −)-epigallocatechin gallate (r = 0.32–0.41) and caffeine (r = 0.44–0.51), but low r values for free amino acids and chlorophylls. Integrated analysis of GWAS and GP detected potential candidate genes for each metabolite using 80–160 top-ranked SNPs that resulted in the maximum cumulative prediction value. Applying GPs and GWASs to tea accession traits will contribute to genomics-assisted tea breeding.

Assessing Mungbean Productivity under Organic Management

Background: Now a day’s demand for organic food has increased. Being leguminous, requirement of nitrogen for mung is low. Soil organic matter could affect the soil microbial community and increase the crop growth and yield. In mungbean, roots have symbiotic rhizobia bacteria, which help in fixing atmospheric nitrogen into the soil. Nitrogen plays a major role in synthesis of protein, chlorophyll and plant enzymes of legume. The chemical fertilizers is used in huge quantity which hazards the soil and environment. Synthetic fertilizers have mainly macronutrients in large quantities and cemented the soil for worsening the soil and also the negative impact on crops, livestock and human being. The application of organic sources of nutrients improves the soil physical-chemical condition by adding macro and micronutrients bothMethods: A field experiment in Kharif season was conducted at Agronomy field of CCSHAU, Hisar, Haryana, to study the yield, quality and physiological parameters of mungbean under different organic sources. The experiment was conducted with nine treatments viz., T1- RDF, T2-FYM @ 5 t/ha, T3-Vermicompost@ 2.5 t/ha, T4-FYM @ 5t/ha + Rhizobium, T5-Vermicompost @ 2.5 t/ha + Rhizobium, T6-Green manuring +FYM @ 5 t/ha, T7- Green manuring + Vermicompost @ 2.5 t/ha, T8-Green manuring + FYM @ 5t/ha + Rhizobium and T9-Green manuring + Vermi-compost @ 2.5 t/ha + Rhizobium in RBD replicated thrice.Result: Application of recommended dose of fertilizer produced 6.93 and 4.04 percent higher yield as compared to green manuring + FYM @ 5t/ha + Rhizobium and green manuring + vermicompost @ 2.5 t/ha, respectively. The data revealed that the SPAD value of chlorophyll, RWC and LWP was higher with the application of various organic sources over to recommended dose of fertilizer.

An assessment of chlorophyll preservation in lake sediments using multiple analytical techniques applied to the annually laminated lake sediments of Nylandssj\xf6n

Chlorophyll is frequently used as a proxy for autochthonous production in lakes. This use of chlorophyll concentrations in sediments to infer historical changes in lake primary production relies heavily on the assumption that preservation is sufficient to reflect the productivity in a meaningful way. In this study, we use a series of freeze cores from a lake with annually laminated sediments to assess how reliable down-core trends in chlorophyll are, and to what extent chlorophyll is degraded in the sediment. A striking consistency in the down-core chlorophyll trends in four sediment cores collected in different years (1983, 1992, 2002 and 2010) shows that the sediment preserves a consistent chlorophyll signal over longer timescales. However, there are also clear signs that diagenetic processes within the sediment affect the chlorophyll concentration in sediment layers younger than 10–15 years. This implies that care is needed when interpreting chlorophyll trends in recent sediments. Further, our data show that high-performance liquid chromatography (HPLC) and visible reflectance spectroscopy (VRS) detect similar chlorophyll concentrations for recently dried samples. A third analytical technique, pyrolysis–gas chromatography/mass spectrometry, which provides semi-quantitative values for chlorophyll, also produce a temporal trend that is highly correlated with data from the two quantitative techniques. For samples that have been stored dried at room temperature for several years there is, however, a large discrepancy between the two quantitative techniques. The VRS method is more robust with regards to degradation during storage, while HPLC results demonstrate clear storage effects.

Multidimensional Evaluation for Detecting Salt Tolerance of Bread Wheat Genotypes Under Actual Saline Field Growing Conditions.

Field-based trials and genotype evaluation until yielding stage are two important steps in improving the salt tolerance of crop genotypes and identifying what parameters can be strong candidates for the better understanding of salt tolerance mechanisms in different genotypes. In this study, the salt tolerance of 18 bread wheat genotypes was evaluated under natural saline field conditions and at three saline irrigation levels (5.25, 8.35, and 11.12 dS m−1) extracted from wells. Multidimensional evaluation for salt tolerance of these genotypes was done using a set of agronomic and physio-biochemical attributes. Based on yield index under three salinity levels, the genotypes were classified into four groups ranging from salt-tolerant to salt-sensitive genotypes. The salt-tolerant genotypes exhibited values of total chlorophyll, gas exchange (net photosynthetic rate, transpiration rate, and stomatal conductance), water relation (relative water content and membrane stability index), nonenzymatic osmolytes (soluble sugar, free proline, and ascorbic acid), antioxidant enzyme activities (superoxide dismutase, catalase, and peroxidase), K+ content, and K+/Na+ ratio that were greater than those of salt-sensitive genotypes. Additionally, the salt-tolerant genotypes consistently exhibited good control of Na+ and Cl− levels and maintained lower contents of malondialdehyde and electrolyte leakage under high salinity level, compared with the salt-sensitive genotypes. Several physio-biochemical parameters showed highly positive associations with grain yield and its components, whereas negative association was observed in other parameters. Accordingly, these physio-biochemical parameters can be used as individual or complementary screening criteria for evaluating salt tolerance and improvement of bread wheat genotypes under natural saline field conditions.

Influência do tempo de infusão nas características físico-químicas e no conteúdo de compostos bioativos nutracêuticos de folha de mangaba (Hancornia speciosa Gomes)

A folhas da mangabeira são popularmente utilizadas no preparo de chás e infusões com fins medicinais. Infusões de ervas apresentam propriedades benéficas devido as substâncias bioativas que atuam como antioxidantes. Assim, o objetivo desse estudo foi avaliar as características físico-químicas e o conteúdo de compostos bioativos nutracêuticos e, verificar a influência do tempo em infusões de folhas de mangaba. As infusões foram preparadas em triplicada a 5 e 10 (I5 e I10) minutos, adicionando 1 g de material vegetal in natura em 50 mL de água fervente. Foram efetuadas análises para caracterização físico-química das folhas in natura, infusões e resíduos: cor e índice de escurecimento (I.E.); sólidos solúveis totais em ºBrix e; pH. As análises dos compostos bioativos foram: clorofilas, carotenóides e fenóis totais. Nas análises físico-químicas, o teor de sólidos solúveis totais não variou significativamente, indicando que os tempos analisados extraíram conteúdos similares. O I.E. permaneceu constante, indicando que o tratamento térmico não foi associado com a ativação enzimática e escurecimento. Entretanto, o tempo de infusão afetou significativamente os fitoquímicos. Os valores de clorofila total e suas frações variaram com diminuição progressiva em comparação da folha in natura em diferentes tempos de infusão, bem como os carotenóides totais, β-caroteno e fenóis, o que sugere influência do tempo na quantidade desses compostos presentes nas infusões, sendo que, a I5 proporcionou menor perda dos compostos comparado à I10, podendo correlacionar-se positivamente com a concentração de flavonóides e com a atividade antioxidante.

Physiological responses of the xerohalophyte Suaeda vermiculata to salinity in its hyper-arid environment

Few plants can survive and grow equally well in salty and salt-free substrates (i.e., habitat-indifferent halophytes). Such plants provide a good opportunity to understand physiological and biochemical mechanisms underlying salinity tolerance. In this study, we investigated the environmental salinity impacts on several physiological and biochemical features of Suaeda vermiculata, a habitat-indifferent halophyte. Samples of different organs were collected from S. vermiculata from both a highly saline marsh habitat (HSMH) and non-salty gravel plain (NSGP) for the determination of the following physiological and bio-chemical features: chlorophyll and carotenoids, proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2), antioxidant enzymes (Catalase, CAT; guaiacol peroxidase, GPX; Ascorbate peroxidase, APX) activities. Elemental compositions in soil and plant samples from both habitats were also assessed. Results showed that plants from HSMH had significantly lower values of chlorophyll a, b, carotenoids and leaf biomass, compared to those from NSGP. Roots from HSMH attained higher levels of antioxidant enzymes (CAT, GPX, APX) and lower values of reactive oxygen species (MDA and H2O2), indicating that the enzymes are more likely scavenging the reactive oxygen species (ROS). The enzyme activities and ROS levels were much lower in the shoots of both HSMH and NSGP than in roots. Accumulation of sodium was higher in leaves and shoots than roots of S. vermiculata. This study indicates that Suaeda vermiculata is a salt tolerant plant with adaptations to different environments through down-regulation of different biochemical and physiological features to avoid oxidative stress.

Effects of straw biochar application on soil temperature, available nitrogen and growth of corn

Straw biochar could improve the water holding capacity effectivity of salinized soil, increase soil fertili, enhance crop yield, reduce greenhouse gas emission, and mitigate climate change. The mechanism of using straw biochar for soil improvement is different under various climate and soil texture conditions. To explore the mechanism of using straw biochar to improve soil and its influence on crop yield in the typical arid and semi-arid, a large temperature difference between day and night, soil temperature at different depths, and physiological changes and crop yield of maize at different growth stages were studied. It is assumed that straw biochar can improve the properties of salinized soil including physicochemical indexes, and crop physiological index, stimulates the positive circulation between soil, vegetation, and microorganisms, and plays a role in improving soil quality. The results showed that biochar application increased the average soil temperature (T) by 2 °C and reduced day-night T differences. Application of 30 t/ha biochar increased the average maize leaf T by 2.2 °C and photosynthetic rate by 16.5%. Furthermore, the average transpiration rate doubled compared to control, and the chlorophyll value increased by 21%. The application of biochar improved the utilization rate of nitrogen fertilizer by enhancing ammonification. Biochar application caused a maximum overall yield increase of 11.9% compared to control treatment (CK). Therefore, these results provide a practical basis for improving weakly alkaline farmland soils in arid and semi-arid areas, and provide an effective method to potentially mitigate the environmental crisis and promote sustainable development in agriculture.

Ultrasound-Assisted Extraction of Chlorophylls and Phycocyanin from Spirulina platensis

Spirulina platensis found enormous applications in agriculture, food industry, pharmacy, cosmetics, medicine, mainly because of its high nutritional content and health-promoting properties. Therefore, the extraction of bioactive compounds from it still remains a challenge. The aim of the current study was to extract photosynthetic pigments from different Spirulina platensis samples and to evaluate the yield and purity of phycocyanin using ultrasonic irradiation at two different frequencies. The content of chlorophylls and phycocyanin was determined in three samples of Spirulina platensis (dry, lyophilized and frozen). The highest values of total chlorophyll were found in SP 1 (Spirulina platensis dry biosample) – 9080 µg/g dw. For the extraction of phycocyanin the classical and the ultrasound-assisted extractions were performed with distilled water under two frequencies. The highest yield of phycocyanin (2.5 mg/g dw) and purity 0.8 were obtained for 3 hours at 35 kHz sonification. This study remained the main advantage of using ultrasonic power as green extraction for the highest phycocyanin yield and purity, reducing both processing times and costs.

Prediction of monthly Hilsa (Tenualosa ilisha) catch in the Northern Bay of Bengal using Bayesian structural time series model

Monthly catch of Hilsa in the Northern Bay of Bengal was modeled and predicted using the Bayesian structural time series (BSTS) with chlorophyll and rainfall as explanatory covariates. Chlorophyll and rainfall were used in the model with a lag time of eleven months and one month, respectively. These lag time values were determined from the exploratory data analysis. In this study, four separate models were developed to predict the Hilsa catch and compare the results. In the first model, the catch was predicted based on trend and seasonality of the previous years’ catch data. The second and third models predicted monthly catch with chlorophyll (having a lag time of 11 months) and rainfall (having a lag time of 1 month), respectively, as the only covariate in the model. The fourth model had both chlorophyll and rainfall as covariates with a lag time of 11 months and 1 month, respectively. The training mean absolute percentage error (MAPE) of the fourth model (measuring model fit) was observed as 0.2827, while the test MAPE (measuring model accuracy) was 0.2786. The coefficient values for both chlorophyll and rainfall were very close (0.999 and 1.064) which indicated the almost equal effect of both the parameters on the Hilsa catch. This study indicated that more abundance of the food material (phytoplankton) during the post-monsoon season would promote the growth and maturity of more Hilsa that would successively migrate towards river or estuary during the subsequent monsoon season and the catch would likely increase with the intensification of the southwest monsoon.

Standardization of grafting method and time in kiwifruit under temperate conditions of Kashmir

The present studies entitled “Standardization of grafting method and time in kiwifruit under temperate conditions of Kashmir” was carried out in the experimental farm, Division of Fruit Science during 2017 and 2018. The experiment was laid out in a Completely Randomized block Design with three replications. In this experiment, three methods of grafting (cleft, tongue and whip) were performed on three different dates (3rdweek of February, 1st week of March and 3rd week of March) with Hayward/Tomuri grafted on 2 years old seedling rootstock under field conditions. The results indicated that leaf width(8.57cm) were significantly better with cleft grafting. Leaf area (94.45 cm2) was recorded highest in tongue grafting and specific leaf area(127.63cm2) was recorded highest with whip grafting. Leaf area (91.90 cm2) and Leaf width(8.54cm) was found highest during 3rd week of March and specific leaf area(143.82cm2/g) with 3rd week of February. Cleft grafting performed during 3rd week of March with Hayward resulted in the highest value of leaf chlorophyll(2.23mg/g). The interaction between method and type of scion was found significant for different parameters under study. From this experiment it can be concluded that among different methods, time and scion type used, cleft grafting performed during 3rd week of February with Hayward cultivar significantly influenced specific leaf area.

Dynamics of Bioluminescence Potential and Physical, Bio‐Optical Properties on the Shelf and Shelf‐Slope of Delaware Bay

AbstractThe dynamics of physical and bio‐optical properties on the shelf and the shelf‐slope break areas offshore of the Delaware Bay were investigated. Compared to monthly means, there were elevated daily freshwater outflows. Glider observations demonstrated significant changes in bio‐optical properties before and after sampling fresher water masses. Prior to sampling fresher water masses, the glider observations exhibited a coincidence of high values in bioluminescence (BL) potential, chlorophyll, and optical backscattering. However, as the glider started to sample fresher water masses, there was a gradual decoupling of high values in BL potential with the high values in chlorophyll and optical backscattering. This indicates a shift from an autotrophic and mixotrophic toward a more heterotrophic bioluminescent community between water masses. During the glider survey, a high chlorophyll filament was observed by satellite ocean color imagery along the shelf‐slope break of the Delaware Bay. The high chlorophyll filament had weakened and disappeared in satellite imagery over the next 2 days when upwelling was progressing, and the glider started to sample fresher water masses. The filament was on the dense side of the shelf‐slope front, and the glider observations indicated a subduction of high chlorophyll values into subsurface (below the fresher surface water masses) with high values of BL potential deeper than high values of chlorophyll. The studies presented here are the first BL potential studies on the shelf and the shelf slope areas of the Delaware Bay, as well as the first studies of BL potential resulted from deployments of the glider with BL potential sensor on board.

Effects of cobalt oxide nanoparticles (Co3O4 NPs) on ion leakage, total phenol, antioxidant enzymes activities and cobalt accumulation in Brassica napus L.

Interaction of nanoparticles (NPs) as a significant threat to ecosystems with biological processes of plants is very important. Here, the effects of cobalt oxide (Co3O4) NPs on some physio-biochemical characteristics of Brassica napus L. were investigated. The two-weeks seedlings were sprayed with different concentrations of Co3O4 NPs (0, 50, 100, 250, 500, 1000, 2000, and 4000 mg L-1). The results showed that this treatment significantly affected the fresh and dry weights, area, relative water content (RWC) and relative chlorophyll value (SPAD) of leaves. The highest reduction of growth and biomass indexes occurred at 4000 mg L-1 NPs. The content of H2O2 and electrolyte leakage (EL) increased respectively, after 100 and 250 mg L-1 of Co3O4 NPs and showed a maximum level at 4000 mg L-1. The activities of phenylalanine ammonia lyase (PAL), ascorbate peroxidase (APX) and superoxide dismutase (SOD) increased after 100 mg L-1 of Co3O4 NPs. However, tyrosine ammonia lyase (TAL) activity enhanced after 500 mg L-1. The catalase (CAT) activity and protein content decreased after 1000 mg L-1 of Co3O4 NPs. Application of concentrations higher than 500 mg L-1 of Co3O4 NPs induced polyphenol oxidase (PPO) activity but reduced glutathione reductase (GR). The activities of guaiacol peroxidase (GPX) and glutathione S-transferase (GST) increased at 250-1000 mg L-1 of Co3O4 NPs and then decreased. These results suggested that low concentrations of Co3O4 NPs induced a positive effect on growth parameters but high levels caused extensive oxidative damage and mediated defense responses by organization of phenolic compounds and antioxidative system.

A natural post-emergence herbicide based on essential oil encapsulation by cross-linked biopolymers: characterization and herbicidal activity.

This work describes efforts to encapsulate savory (Satureja hortensis L.) essential oil (EO) with different natural polymers (i.e., Arabic gum/gelatin (AGG), apple pectin (AP), gelatin (G)) and, as a separate set of experiments, with bio cross-linkers (i.e., citric acid and transglutaminase enzyme). The phytotoxic activity of encapsulated savory EO on tomato (Lycopersicon esculentum Mill.) and amaranth weed (Amaranthus retroflexus L.) was investigated. The micro-capsules were evaluated in terms of size, polydispersity, stability, encapsulation efficiency, morphology, and release properties. The Korsmeyer-Peppas model operated when EO was being released from the micro-capsules. Carvacrol (52.5%) and γ-terpinene (30.2%) comprised the main constituents of the savory EO. Based on the results, encapsulating the EO with cross-linked biopolymers increased the stability and herbicidal activity of EO, as compared to simple EO emulsions. Maximum toxicity injuries (MTI) were caused by encapsulations of apple pectin, cross-linked with APe enzyme (15ml/L) on both plant species. MTI were observed 2days after using the micro-encapsulated herbicides (MCHs). However, the injury caused by MCHs on tomato was not significant. The lowest values of fresh weight (2.80g), chlorophyll a (0.194mg/g Fw), and total chlorophyll content (0.219mg/g Fw) of amaranth occurred in response to APe (15ml/L). Moreover, using AP(e) (10ml/L) caused the lowest values of starch (0.444mg/g Fw) and flavonoid contents (4.18mg Cat/g Fw) in amaranth which measured as 59% and 90% reductions, respectively, in comparison with the control. The highest values of MDA (0.0109nmol/g Fw) and H2O2 (0.0432μmol/g Fw) were observed in amaranth plants treated with AP(e) (10ml/L). In summary, cross-linked apple pectin can perform well in slow release delivery systems of agrochemicals. It can be recommended for use in the production of commercial, EO-based natural herbicides.

Chemical and biological activities of faveleira (Cnidoscolus quercifolius Pohl) seed oil for potential health applications

Faveleira (Cnidoscolus quercifolius) is an emerging Brazilian plant, with seeds rich in edible oil. This study investigates physicochemical properties, chemical composition, thermal and oxidative stability, in vitro and in vivo toxicity, antioxidant, antinociceptive and anti-inflammatory activities of faveleira seed oil. It was observed that the oil has low acidity, value of peroxide, chlorophyll, carotenoids, β-carotene and high concentrations of unsaturated fatty acids. In addition to presenting thermal and oxidative stability and high total phenolic content, with vanillin, eugenol and quercetin were predominating. The oil showed no toxicity in vitro and in vivo, and presented antioxidant, anti-inflammatory and antinociceptive activities. These findings provide relevant and appropriate conditions for processing of faveleira seed oil as functional food.

Oceanic Environmental Effects on American Eel Recruitment to the East River, Chester, Nova Scotia

AbstractThe effect of oceanic environmental conditions on the recruitment of American Eel Anguilla rostrata to coastal waters is poorly understood. This study examined correlations between the annual elver count index of the East River, Chester, Nova Scotia, seasonal oceanic environmental conditions associated with the larval and glass eel stages, and larval and glass eel migration times between the spawning area and continental recruitment. In recent years, the elver fishery of the East River has started earlier in conjunction with increasing inshore, continental shelf, and Gulf Stream water temperatures, with the strength of the correlation decreasing with distance from shore. A northward shift of the Gulf Stream may also have contributed to earlier arrival dates. Annual elver index values increased over the study period but were not significantly correlated with any atmospheric or oceanic environmental conditions, perhaps due to a relatively short time series, although effect sizes (correlation coefficient r) were often medium, a level potentially considered of biological importance. Elver mean lengths varied annually with no trend and were not significantly correlated with the elver index. Significant correlations occurred between the North Atlantic Oscillation and Sargasso Sea primary productivity (lag of 0) and Emerald Basin (Scotian Shelf) water temperatures (lag of –5), while Scotian Shelf chlorophyll values decreased with increasing water temperatures (lag of –3). The mean migration period from spawning to stream entrance at the East River was estimated at 1.2 years, mostly spent growing in and ultimately leaving the Sargasso Sea, then crossing oceanic and continental shelf waters between the Gulf Stream and coastal streams, with a short period of transport along the Gulf Stream. The estimate of total migration period based on observed recruitment times at various sites and the mean of the estimated spawning period averaged 45.5% greater than those estimated from otolith methods, perhaps due to the effect on otolith daily ring deposition during glass eel migration in oceanic water temperatures <10ºC between the Gulf Stream and coast.

Foliar application of magnesium oxide nanoparticles on nutrient element concentrations, growth, physiological, and yield parameters of cotton

In order to investigate the effects of different magnesium (Mg) sources of fertilizers like magnesium sulfate (MgSO4), magnesium oxide (MgO), and magnesium oxide nanoparticles (nMgO) on cotton growth and development, a pot culture experiment was carried out at different concentrations viz., 20, 40, 60, 80, and 100 ppm in factorial completely randomized design (FCRD). From the pot culture studies, 60 ppm of nMgO was found as the optimal dose for improvement in SPAD chlorophyll value, boll weight, and seed cotton yield. Consequently, field experiment was carried out in randomized block design (RBD) with optimized dose of 60 ppm (from pot culture study) of Mg fertilizers like MgSO4, MgO, and nMgO to elucidate their effect on growth, physiological, yield, fiber quality parameters, and nutrient element concentrations in cotton. The treatments were foliar sprayed at vegetative and boll formation stages of cotton similar to pot culture studies. It is confirmed that foliar application of 60 ppm of 50 nm of MgO nanoparticles significantly increased the number of opened bolls per plant (20.6), single plant yield (58 g/plant) and seed cotton yield (1729 kg/ha). The increased seed cotton yield of 42.2, 39.9, and 24.8% was recorded by nMgO, MgO, and MgSO4 over control. Besides, fiber quality parameters like fiber length and fiber strength of cotton were improved by MgO nanoparticles than sulfate form of Mg fertilizers. Moreover, significant and positive influence was achieved by foliar nutrition of MgO nanoparticles on macronutrients like nitrogen (N), phosphorus (P), potassium (K), and Mg concentration in cotton plants.

Microgreen Quality of Broccoli Plants (Brassica oleracea L.) and Correlation between Parameters

Micro greens are vegetables harvested at a very early age, harvesting is done when cotyledon leaves and a pair of new leaves appear. Plant growth phases include germination, micro greens, baby greens, and mature in greens. This research aimed to determine the quality of microgreens broccoli (Brassica oleracea L.) that are water content, total chlorophyll, and dietary fiber due to the influence of planting media and coconut water nutrition. Broccoli microgreens are planted at the Green House of the Faculty of Agriculture, UPN “Veteran” East Java in November-December 2018. Analysis of water content using drying method(thermogravimetri), chlorophyll analysis using spectrophotometry method, and analysis of fiber content with Enzymatic-Gravimetric method. The data were analyzed using Completely Randomized Design (CRD) with the post hoc test LSD 5% and HSD 5% and correlation regression between parameters. The results of the study showed an increase in the quality of parameters and there was a close correlation between parameters. Correlation value of water content and total chlorophyll (r = 0.81) with a regression equation y = 1.907 × - 143.2, water content and fiber content (r = 0.84) with regression equation y = 2.628 × - 235.3 and total chlorophyll and fiber content (r = 0.88) with the regression equation y = 1.178 × - 32.05.

Cadmium Toxicity Alleviates by Seed Priming with Proline or Glycine Betaine in Cowpea ( Vigna unguiculata (L.) Walp.)

CADMIUM (Cd) as a non-essential metal is a soil pollutant that inhibits plant growth and development. Proline (Pro) and Glycine betaine (GB) are two important compatible solutes that accumulate in response to abiotic stresses in different plant species. Here, a pot experiment was carried out to assess the role of exogenously applied Pro and GB in improving Cd toxicity tolerance in cowpea plants. Seeds were soaked in 0, 25 and 50mM Pro or GB, and then were sown in plastic pots that were irrigated with 0 or 100μM cadmium chloride. Results showed that Cd stress markedly decreased shoot length, shoot biomass, leaf area, chlorophyll value, stomatal conductance and relative water content (RWC) but increased root and shoot Cd levels, malondialdehyde (MDA) content and antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). Nevertheless, seed treatment with Pro or GB reduced Cd toxicity and improved growth attributes via reducing Cd uptake and translocation, increasing the chlorophyll value, stomatal conductance, and RWC as well as more enhancing the activities of antioxidant enzymes and lowering the MDA level. Although both Pro and GB were effective, pre-treatment of seeds with Pro improved Cd stress tolerance better than GB. Thus, seed treatment with Pro (especially 50mM) could be used as an effective method for protecting cowpea plants against Cd toxicity.

Quantification of chlorophyll a, chlorophyll b and pheopigments a in lake sediments through deconvolution of bulk UV–VIS absorption spectra

Assessments of aquatic paleoproduction and pigment preservation require accurate identification and quantification of sedimentary chlorophylls. Using chromatographic techniques to analyze long records at high resolution is impractical because they are expensive and labor intensive. We have developed a new rapid and low-cost approach to infer the concentrations of chlorophyll a, chlorophyll b and related chlorophyll derivatives (pheopigments a) from the mathematical decomposition of UV–VIS measured bulk spectrophotometer absorption spectra of standard solutions and sediment extracts. We validated our method against high-performance liquid chromatography (HPLC) measurements on standard solutions and on varved, anoxic sediment from eutrophic Lake Lugano (Ponte Tresa sub-basin, southern Switzerland), where the history of productivity is relatively well known for the twentieth century. Our mathematical approach quantifies the concentration of chlorophyll b ( $$ {\text{R}}_{{{\text{ad}}_{\text{J}}}}^{2} $$ = 0.99, RMSEP ~ 5.9%), chlorophyll a ( $$ {\text{R}}_{{{\text{ad}}_{\text{J}}}}^{2} $$ = 0.98, RMSEP ~ 5.0%), and pyropheophorbide a ( $$ {\text{R}}_{{{\text{ad}}_{\text{J}}}}^{2} $$ = 0.99, RMSEP ~ 7.8%) in standard solutions. We obtain comparable results for total chloropigment a (chlorophyll a + pheopigments a), chlorophyll a and diagenetic products (pheopigments a) in the sediment samples of our case study (Ponte Tresa). Here, HPLC concentrations of chlorophyll b are very low. The method has, however, the potential to achieve values for chlorophyll b concentrations in sediments with chlorophylls a/chlorophylls b ratios lower than 3.4. The pigment stratigraphy of the Ponte Tresa sediments correspond very well with the paleoproduction and eutrophication history of the twentieth century. The ratio between chlorophyll a and pheopigments a used as a qualitative indicator of sedimentary chlorophyll preservation (chlorophyll a/{chlorophyll a + pheopigments a}) is only weakly correlated with aquatic paleoproduction (radj = 0.35, p-value = 0.045) and remained remarkably constant in the recent century despite strong anthropogenic eutrophication. The new method is useful for obtaining, in a cost- and time-efficient way, information about major sedimentary pigment groups that are relevant to inferring paleoproduction, potentially green algae biomass, pigment preservation and early diagenetic effects.

AGRONOMIC AND PHYSIOLOGICAL STUDIES ON SOME EXOTIC AND LOCAL BREAD WHEAT GENOTYPES UNDER SALINE SOIL CONDITIONS IN NORTH DELTA REGION

Soil salinity is the major global limitation to wheat production. Thus, ten bread wheat exotic lines and local cultivars were studied under normal and moderate saline soil conditions during 2017/18 and 2018/19 growing seasons. the objective was to understand the effects of salinity stress on some agronomic and physiological characters and to estimate some selection indices for salt tolerance in wheat. The studied characters were plant height and grain yield and its components in addition to relative water content, contents of chlorophyll a and b, proline and malondialdehyde and catalase activity in the flag leaves. The two seasons and saline conditions behaved differently. Besides, sufficient genetic variability among the studied genotypes was detected. Moreover, the variance due to saline conditions was the most important comparing to the other sources. Most of studied characters were higher in their mean values in the second season than the first one. All mean values of the studied characters decreased under the saline conditions, except for proline and malondialdehyde contents and catalase activity. Genotypic main effect plus genotype by environment interaction (GGE) Biplot analysis revealed that Line 2, Sakha 95, Misr 3 and Sids 14 had high yielding ability and relative tolerance under salinity conditions. Based on correlation coefficients, the high values of relative water content, chlorophyll, proline contents and catalase activity in addition to the low value of malondialdehyde content may be used as physiological selection criteria for salt tolerance screening of wheat genotypes