Cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis> Crantz) genetic resources: a case of high iron and zinc

Cassava hybrids from interspecific crosses with Manihot caerulescens Pohl, M. pseudoglaziovii Pax and Hoffmann and M. dichotoma Ule showed a very high iron and zinc content in both roots and leaves, e.g. 98.15 mg kg⁻¹ in roots of the interspecific hybrid cassava-M. caerulescens versus 12.17 mg kg⁻¹ in a cassava cultivar. This promising results show the potential of wild Manihot species for micronutrient enhancement of cassava.     

Genetic diversity and connectivity patterns of harvested and aquacultured molluscs in estuaries from Asturias (northern Spain). Implications for management strategies

Estuaries are among the most important habitats of coastal areas. However, they are significantly affected by human activities worldwide, threatening their resources and the commercial uses depending on them. Fisheries and aquaculture are some of the main factors affecting the estuarine ecosystems today. In this work, we pursue the aims of genetically identifying the cultured and harvested oyster and razor clam species inhabiting Asturian estuaries (Eo, Ribadesella and Villaviciosa) and describing the genetic diversity and patterns of genetic connectivity between those species in these estuaries. The results revealed the almost complete dominance of the introduced Crassostrea gigas as the species that supports the oyster's production in Asturias with a striking diversity of gene pools in wild environments (Ría de Villaviciosa and Ribadesella) which significantly exceeds the diversity found in the hatcheries seeds commonly used for culturing. Moreover, we detected two different species of Ensis sp. inhabiting the Asturian estuaries: Ensis ensis inside Ría del Eo and Ensis directus, an invasive species, in Ría de Villaviciosa. Significant genetic differentiation between estuaries for the exotic oyster C. gigas and also for the native razor clam Solen marginatus were found. These results suggest Asturian estuaries are not a single management unit for some species and thus prevention must be taken for avoiding intentional or human‐mediated translocations among them. Biodiversity monitoring for discovering newcomer invasive species, measures for environmental recovery of these ecosystems and strict controls to avoid increasing of harvesting pressures are also a necessity to improve the management of these relevant ecosystems.     

Growth and carcass characteristics of lambs passively immunized with antibodies developed against ovine adipocyte plasma membranes

Polyclonal antisera were collected from a mare immunized with ovine adipocyte plasma membranes. Ten crossbred wether lambs received three consecutive daily intraperitoneal injections of horse antisheep adipocyte plasma membrane immunoglobulin (ASIg) or nonimmune serum immunoglobulin (NSIg). Each injection delivered 1.5 ml serum Ig protein equivalent to either 53.4 mg ASIg or 51.1 mg NSIg per kilogram of live body weight. Lambs were housed in individual metabolic crates during the 28-d experiment and given ad libitum access to a pelleted, high-concentrate diet. Daily feed consumption was monitored individually over the experimental period and N retention was determined. Blood was collected on d 0, 4, 7, 14 and 28 for determination of nonesterified fatty acid (NEFA), triacylglycerides (TG) and hematocrit. At the conclusion of the experiment, lambs were slaughtered and carcasses were evaluated. Passive immunization against sheep adipocyte plasma membrane reduced (P less than .05) perirenal adipose tissue weight and decreased ether extract content of both subcutaneous and perirenal fat. Treatment tended to reduce average backfat thickness (24%) and estimated kidney pelvic fat (16%). Treatment with ASIg reduced (P less than .05) blood plasma NEFA but did not alter blood TG or hematocrit values. Average daily weight gain was lower (P less than .01) in the ASIg-treated group. However, the efficiency of carcass production, measured as carcass weight, was not affected by ASIg treatment.     

Risk factors associated with camel brucellosis in Jordan

During the period between February, 2004 and December, 2006, a cross-sectional study was performed to investigate some epidemiological aspects related to camel brucellosis in Jordan. Four hundred twelve camel sera from 37 herds were randomly collected and analyzed using Rose Bengal plate test and complement fixation test. A structured pre-tested questionnaire was administered to collect information on camel herd health and management. A multivariable logistic regression model was constructed to investigate risk factors associated with seropositivity to Brucella antigens. Moreover, the incidence of Brucella-specific abortion was investigated in 7 camel herds located in different locations in Southern Jordan. The true prevalence of Brucella-seropositive in camels was 12.1%. Thirteen (35.1%) herds had at least one positive camel. The seroprevalence of brucellosis in camels was significantly higher in the southern part of Jordan than that in central or northern Jordan. The multivariable logistic regression model on both individual and herd levels revealed large herds and contact with small ruminants as risk factors for Brucella seropositivity. On the other hand, using disinfectants was identified as a protective factor (OR = 0.8; 95% CI: 0.1, 0.9) only on the camel herd level. The incidence of Brucella-caused abortion was 1.9%. Brucella melitensis biotype 3 was isolated from 4 aborted camel fetuses.     

The nutritive value of cassava starch extraction residue for growing ducks

The cassava root meal (CRM) has been utilized as a cheap energy alternative to replace maize in poultry diets. Recently, the CRM in turn has an increasing demand for starch extraction industry, which renders large amounts of residues. This study evaluated the nutrient composition, amino acid profile, and feeding value of cassava starch extraction residue meal (CReM) for growing ducks. A total of 960, 11-day-old, ducklings were housed in 24 floor pens and allocated randomly into four dietary treatments: (i) 0CReM (control), (ii) 50 g CReM/kg, (iii) 100 g CReM/kg, and (iv) 150 g CReM/kg. The analyses (/kg) of CReM showed high gross energy (3306.88 kcal), ME (2109.54 kcal), and starch (514.0 g), with poor crude protein (20.9 g) and moderate crude fiber (140.0 g) and ash (60.0 g) contents. The total amino acid (AA) content amounted to 19.9 g/kg of CReM DM, in which the methionine, lysine, cystine, and isoleucine were present in low levels. The dietary inclusion of CReM up to 150 g/kg, between 11 and 42 days of age, had no significant effects (P?>?0.05) on duck growth parameters, mortality, dressed weight, internal organs, or abdominal fat. Besides, the tested CReM levels did not show any significant effect on the blood proteins or liver enzymes. The results, therefore, revealed that the CReM contains a considerable amount of energy and could be incorporated successfully up to 150 g/kg in the diets of growing ducks.     

Assessment of nitrogen maintenance requirement and potential for protein deposition in juvenile Tilapia genotypes by application of an exponential nitrogen utilization model

Assessment of quantitative amino acid requirement data in fish nutrition is predominantly based on dose response studies with supplementation of the dietary limiting amino acid. Studies with modeling amino acid requirements are scarce. Three experiments were conducted with different genotypes of juvenile Tilapia [A: all male O. niloticus; B: red Tilpia (O. mossambicus × O. hornorum); C: hybrid Tilapia (A × B)] using fishmeal-wheat gluten diets with five graded levels of dietary protein supply (17.2-48.5% CP). The dietary amino acid ratio was similar, dietary energy contents were adapted to avoid limiting energy supply. Growth response was studied in a semi-closed in-door water recirculation system with 38 tanks (320 l/tank; water temperature 28 ± 0.5 °C; regulated photoperiod 12 h light/12 h dark). Four replicate groups (25 fish per tank) were utilized in a 70 d growth experiment with three times a day feeding until apparent satiation. Ten fish at the beginning and three fish per tank at the end of the growth study were analyzed for body composition to calculate N-deposition and N-excretion. The nitrogen maintenance requirement (NMR) was established based on nonlinear fitting of N-excretion depending on N-intake. The intersection of the applied exponential function with the y-axis was used as NMR, simulating protein free feeding. The theoretical potential for daily N-deposition of the genotypes under study (ND_maxT) was estimated as threshold value due to exponential fitting of N-deposition depending on N-intake. The observed average NMR (70 mg N/BW_kg^0.67/d) and threshold values for genotype A (ND_maxT = 388 mg/BW_kg^0.67/d), genotype B (ND_maxT = 389 mg/BW_kg^0.67/d) and genotype C (ND_maxT = 319 mg/BW_kg^0.67/d), respectively, are the starting point for the studied exponential N-utilization model and its subsequent application for assessing amino acid requirements depending on growth performance and dietary amino acid efficiency in fish feed.     

Wild and indigenous cassava, <Emphasis Type="Italic">Manihot esculenta</Emphasis> Crantz diversity: An untapped genetic resource

Cassava is the most important food for poor people in the tropics. Its roots are used either fresh or in numerous processed forms. It is a shrub with tuberous adventitious roots arising from stem cutting. Wild relatives of cassava are perennial and vary in growth pattern from nearly acaulescent subshrubs to small trees. They have been used as a source of useful characters such as high protein content, apomixis, resistance to mealy bug and mosaic disease and tolerance to drought. Cultivars stem from interspecific hybrids of cassava with M. glaziovii Muell.-Arg. are cultivated now in about 4 millions hectars in Nigeria. Indigenous clones are potential source of B-carotene and lycopene.     

Promotion of plant growth by an auxin-producing isolate of the yeast Williopsis saturnus endophytic in maize (Zea mays L.) roots

A plant-growth-promoting isolate of the yeast Williopsis saturnus endophytic in maize roots was found to be capable of producing indole-3-acetic acid (IAA) and indole-3-pyruvic acid (IPYA) in vitro in a chemically defined medium. It was selected from among 24 endophytic yeasts isolated from surface-disinfested maize roots and evaluated for their potential to produce IAA and to promote maize growth under gnotobiotic and glasshouse conditions. The addition of l-tryptophan (L-TRP), as a precursor for auxins, to the medium inoculated with W. saturnus enhanced the production of IAA and IPYA severalfold compared to an L-TRP-non-amended medium. The introduction of W. saturnus to maize seedlings by the pruned-root dip method significantly (P<0.05) enhanced the growth of maize plants grown under gnotobiotic and glasshouse conditions in a soil amended with or without L-TRP. This was evident from the increases in the dry weights and lengths of roots and shoots and also in the significant (P<0.05) increases in the levels of in planta IAA and IPYA compared with control plants grown in L-TRP-amended or non-amended soil. The plant growth promotion by W. saturnus was most pronounced in the presence of L-TRP as soil amendment compared to seedlings inoculated with W. saturnus and grown in soil not amended with L-TRP. In the glasshouse test, W. saturnus was recovered from inside the root at all samplings, up to 8 weeks after inoculation, indicating that the roots of healthy maize may be a habitat for the endophytic yeast. An endophytic isolate of Rhodotorula glutinis that was incapable of producing detectable levels of IAA or IPYA in vitro failed to increase the endogenous levels of IAA and IPYA and failed to promote plant growth compared to W. saturnus, although colonization of maize root tissues by R. glutinis was similar to that of W. saturnus. Both endophytic yeasts, W. saturnus and R. glutinis, were incapable of producing in vitro detectable levels of gibberellic acid, isopentenyl adenine, isopentenyl adenoside or zeatin in their culture filtrates. This study is the first published report to demonstrate the potential of an endophytic yeast to promote plant growth. This is also the first report of the production of auxins by yeasts endophytic in plant roots.     

Non-streptomycete actinomycetes as biocontrol agents of soil-borne fungal plant pathogens and as plant growth promoters

Among soil microorganisms, bacteria and fungi and to a lesser extent actinomycetes, have received considerable attention as biocontrol agents of soil-borne fungal plant pathogens and as plant growth promoters. Within actinomycetes, Streptomyces spp. have been investigated predominantly, mainly because of their dominance on, and the ease of isolation from, dilution plates and because of the commercial interest shown on the antibiotics produced by certain Streptomyces spp. Many of non-streptomycete actinomycetes (NSA) taxa are therefore rarely reported in literature dealing with routine isolations of biocontrol agents and/or plant growth promoters from plant and soil. It is clear that special isolation methods need to be employed in routine isolations to selectively isolate NSA. Some interesting information exists, albeit in relatively few reports compared to that on other microorganisms, on the biological activities of NSA, especially in relation to their mechanisms of action in the biological control of soil-borne fungal plant pathogens and plant growth promotion. This review presents an overview of this information and seeks to encourage further investigations into what may be considered a relatively unexplored area of research. Certain soil environmental factors, especially in horticultural systems, could be manipulated to render the soil conducive for the biological activities of NSA. A variety of NSA isolated by selective methods have not only shown to be rhizosphere competent but also adapted for an endophytic life in root cortices. Some of the NSA, including endophytic strains that have shown potential to suppress soil-borne fungal plant pathogens, are able to employ one or more mechanisms of antagonism including antibiosis, hyperparasitism and the production of cell-wall degrading enzymes. Strains of NSA promote plant growth by producing plant growth regulators. Enhancement of plant growth by the antagonists are considered to help the host by producing compensatory roots that mask the impact of root diseases.     

Extraction of carotenoids from <Emphasis Type="Italic">Lycium ferocissimum</Emphasis> fruits for cotton dyeing: Optimization survey based on a central composite design method

Studies were carried out to assess the extraction yield of carotenoids from the African boxthorn (Lycium ferocissimum Miers, Solanaceae) fruits with different solvents and solvent mixtures, to optimize the extraction conditions for maximum recovery and to improve the extraction efficiency. Among other solvents, a mixture of hexane and acetone gave the highest carotenoid extraction. Extraction conditions, such as hexane percentage in hexane/acetone solvent mixture, solvent-solid ratio, and extraction time were optimized using a statistically designed experiment. A regression equation for predicting the carotenoid yield as a function of three extraction variables was derived by statistical analysis. The optimized conditions for maximum carotenoids yield were 45 % hexane in solvent mixture, solvent-solid ratio of 70 (ml/g) and extraction time 70 min. The dyeability of cotton with carotenoids extract has also been studied. Unmordant and postmordanted bleached cotton fabric with alum and ferrous sulphatewas dyed. Color measurements and fastness properties as light, rubbing and wash were tested.