31 research outputs found
Pearl millet populations characterized by Fusarium prevalence, morphological traits, phenolic content, and antioxidant potential
Background: Pearl millet (Pennisetum glaucum L.) has become increasingly attractive due to its health benefits. It is grown as
food for human consumption and fodder for livestock in Africa and Asia. This study focused on five pearl millet populations
from different agro-ecological zones from Tunisia, and on characterization by morphological traits, total phenolic and flavonoid
content, antioxidant activity, and occurrence of Fusarium.
Results: Analysis of variance revealed highly significant differences between populations for the quantitative traits. The highest
grain weights occurred in the pearlmillet cultivated in Zaafrana and Gergis of Tunisia. Early flowering and earlymaturing populations
cultivated in the center (Zaafrana, Rejiche) and south (Gergis) of Tunisia tended to have a higher grain yield. The Zaafrana
population showed the highest value of green fodder potentiel (number andweight of leaves/cultivar and theweight of tillers and
total plant/cultivar) followed by Gergis and Rejiche. The Kelibia population showed the highest total phenolic and flavonoid content.
Rejiche exhibited the greatest antioxidant activity. Trans-cinnamic, protocatechuic, and hydroxybenzoic acids were the
major phenolic compounds in all the extracts. Three Fusarium species were identified in Tunisian pearl millet populations based
on morphologic and molecular characterization. Fusarium graminearum and Fusarium culmorum occurred most frequently. The
average incidence of the three Fusarium species was relatively low (<5%) in all populations. The lowest infection rate (0.1%)
was recorded in the samples from Zaafrana.
Conclusion: Chemometric analysis confirmed the usefulness of the above traits for discrimination of pearl millet populations,
where a considerable variation according to geographical origin and bioclimatic conditions was observed.
© 2020 Society of Chemical Industr
Characterization of crop residues from false banana/Ensete ventricosum/in Ethiopia in view of a full-resource valorization
Research ArticleFalse banana /Ensete ventricosum [Welw.] Cheesman/ is exploited as a food crop in
Ethiopia where it represents an important staple food. The plant is harvested and large
amounts of biomass residues are originated, mainly from the pseudo stem (i.e., fiber bundles
obtained from the leaf sheaths after being scrapped to produce starchy food) and the
inflorescence stalk. These materials were studied in relation to their summative chemical
composition, composition of lignin, lipophilic and polar extracts. Moreover, their structural
characteristics, in view of their valorization, were scrutinized. The analytical studies were
performed with the aid of FTIR, GC/MS, Py-GC/MS and SEM. The fiber bundles are aggregates
of mainly long and slender fibers with low ash, extractives and lignin contents (3.8%.
4.4% and 10.5% respectively) and high holocellulose and α-cellulose contents (87.5% and
59.6% respectively). The hemicelluloses in the fibers are mostly highly acetylated xylans
and the lignin is of the H-type (H:G:S, 1:0.7:0.8). This lignin composition is in line with the
FTIR peaks at 1670 cm-1 and 1250 cm-1.The inflorescence stalk has high ash content
(12.3% in the main stalk and 24.6% in fines) with a major proportion of potassium, high
extractives (25.9%), and low lignin and α-cellulose contents (5.8% and 17.9% respectively).
The stalk includes numerous starch granules in the cellular structure with the predominant
presence of parenchyma. The potential valorization routes for these materials are clearly different.
The fiber bundles could be used as a fiber source for paper pulp production with the
possibility of a prior hemicelluloses removal while the inflorescence stalk has nutritional
value for food and fodder. Furthermore, it can also be used for sugar fermentation productsinfo:eu-repo/semantics/publishedVersio
Nutritional and Antinutritional Potentials of Sorghum: A Comparative Study among Different Sorghum Landraces of Tigray, Northern Ethiopia
Sorghum is one of the staple food crops in Tigray, northern Ethiopia. Despite this, limited research attention was given to the nutritional and antinutritional profiling of sorghum. Thus, this research was initiated to profile and evaluate the variabilities in protein, starch, minerals, flavonoid, tannin, and antioxidant activities among sorghum landraces of Tigray, northern Ethiopia. Protein and starch were analyzed using an infrared spectrophotometer, whereas mineral elements were estimated using an atomic absorption spectrophotometer. Antioxidant activity was analyzed using DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging, ferric-reducing antioxidant power, and phosphomolybdenum assays. The result revealed significant variation among the landraces for all the evaluated parameters. Protein and starch contents ranged from 6.21 to 18% and 33.42 to 78.30%, respectively. Wider variations were observed for Fe (32–101), Zn (16.9–42.98), Cu (1.48–5.25), Mn (9.21–20.23), and Cr (0–1.5) as measured in mg/100 g. The variabilities were high for total flavonoid (0–665 mg CE/g) and tannin (0.18–7.5 mgCE/100 g). DPPH (EC50 = 29.09–818.37 µg/mL), ferric reducing antioxidant power (17.85–334.81 mgAAE/g), and total antioxidant activity (1.71–63.88 mgBHTE/g) were also highly variable among the samples. The relationship between seed color and phenolics, as well as antioxidant activities, are discussed. Multivariate analysis revealed that the landraces were clustered into four distinct groups. The rich genetic diversity in the nutritional and antinutritional attributes may be an opportunity for breeding for grain quality improvements of sorghum that, in turn, helps in addressing malnutrition
Contributions of Lake Erie and Lake St. Clair Walleye Populations to the Saginaw Bay, Lake Huron, Recreational Fishery: Evidence from Genetic Stock Identification
<div><p></p><p>Genetic stock identification analyses were conducted to determine spawning population contributions to the recreational fishery for Walleyes <i>Sander vitreus</i> in Saginaw Bay, Lake Huron. Two spawning population groups were considered: (1) the Tittabawassee River, which has been identified as the largest source of spawning Walleyes for Saginaw Bay; and (2) an aggregate of six spawning populations from Lake Erie and Lake St. Clair that were found to be genetically similar. Overall, the Lake Erie and Lake St. Clair spawning populations were estimated to comprise approximately 26% of the Walleye recreational harvest in Saginaw Bay during 2008–2009. Contribution levels were similar for the 2 years in which genetic samples were collected. Contributions from the Lake Erie and Lake St. Clair spawning populations to the harvest of age-5 and older Walleyes were greater during summer (31.8%; SE = 6.2%) than during late winter and spring (6.0%; SE = 3.7%). Conversely, contributions from the Lake Erie and Lake St. Clair spawning populations to the harvest of age-3 and age-4 fish were fairly similar between seasons (late winter and spring: 31.2%, SE = 6.7%; summer: 41.7%, SE = 5.6%), suggesting that younger Walleyes migrate earlier or reside in Saginaw Bay for extended periods. Our finding that one-quarter of the Saginaw Bay recreational harvest of Walleyes comprises fish from Lake Erie and Lake St. Clair has important management implications, as policies for one lake may have bearing on the other lake—one of the challenges associated with managing migratory fish species. Fisheries management in the Laurentian Great Lakes has a history of being highly coordinated and cooperative among the states and province bordering the individual lakes. Results from this study suggest that cooperation may need to be expanded to account for fish movement between lakes.</p><p>Received October 28, 2014; accepted February 11, 2015</p></div
Mixed stock analysis of genetic compositions of lake sturgeon (Acipenser fulvescens) mixtures in Lake Michigan: hierarchical spatial heterogeneity and evidence of improving recruitment in Wisconsin spawning populations
Information regarding site occupancy of fish that migrate long distances during nonspawning periods together with estimates of recruitment trends for individual populations can be informative for management, especially when individuals from different spawning populations intermix and are sampled or harvested together. Tendencies for individuals from different populations to preferentially occupy specific regions increases vulnerability to anthropogenic and natural disturbances. Using mixed stock analysis (MSA), we estimated population-specific occupancy of lake sturgeon (Acipenser fulvescens) in open-water and nearshore regions of Lake Michigan across a hierarchy of spatial scales. Open-water mixture composition differed between Lake Michigan’s eastern and western basins. Significant heterogeneity in habitat occupancy was also observed at microgeographic scales throughout open-water regions of Green Bay, indicating nonrandom occupancy to regions proximal to natal streams. Estimates of relative recruitment levels determined from MSA extensions indicated increasing recruitment trends for spawning populations associated with Wisconsin tributaries (Oconto–Peshtigo, Fox, and Menominee rivers). Our lake sturgeon results demonstrate the utility of genetic data for informing management efforts for spatially structured, highly migratory species. Similar analyses could prove beneficial for species with similar characteristics
Limnological and ecological characteristics of tropical highland reservoirs in Tigray, Northern Ethiopia
The semi-arid highlands of Northern Ethiopia (Tigray) have numerous small reservoirs that have been created by microdams in an attempt to provide water supply for irrigation and livestock drinking. Although the reservoirs have substantial added value to residents, their use as water resource is jeopardized by eutrophication and a high occurrence of blooms of toxic cyanobacteria. So far, there is no systematic information available on the limnological and aquatic ecological characteristics of these dams. We carried out a standardized survey of 32 reservoirs and assessed a wide set of morphometric, abiotic and biotic variables. The sampling was performed during two seasons, September-October 2004 (end of the wet season/start of the dry season) and April-May 2005 (towards the end of the dry season). Using multivariate analysis, we revealed dominating patterns of variable associations and compared the variability in these patterns among seasons. According to standardized PCA and RDA analyses, the most important axis of variation was mainly represented by a gradient in nutrients and altitude that was also positively associated with phytoplankton biomass, suspended matter and oxygen concentration, and negatively with water transparency. For most variables, correlations between the wet and dry season were weak, which suggests that individual reservoirs behaved rather differently in their response to seasonal changes. Nevertheless, a Mantel correlation (r = 0.32; P = 0.035) showed a weak but significant overall concordance in the variable association patterns among seasons. A number of reservoirs became very shallow or fell dry in the dry season, a process that was associated with an increase in suspended matter and conductivity and a decrease in transparency. These reservoirs contained lower amounts of fish and tended to be less eutrophic than the deeper, permanent systems, as they had lower levels of phosphorus and chlorophyll-a. With multiple regression analysis, we constructed most parsimonious models in an attempt to explain the variation in key biotic variables: phytoplankton and cyanobacteria biomass, cladoceran biomass, fish biomass and the abundance of submerged vegetation. Phytoplankton and fish biomass tended to be positively related with the concentration of total phosphorus, whereas cladoceran biomass was not associated with nutrient concentrations. The positive association of fish and phytoplankton with nutrient concentrations suggests a bottom-up control, whereas the absence of an association between zooplankton and nutrient concentrations may be indicative for top-down control. The biomass of cyanobacteria was negatively related to the biomass of cladocerans (Daphnia), which likely reflects a top-down effect. Most reservoirs were turbid. The occurrence and abundance of macrophytes tended to be positively related to water transparency and was negatively associated to TP and the amount of livestock frequenting the reservoirs. However, macrophytes were not limited to clear-water reservoirs