Characterization of some mushroom and earthy off-odors microbially induced by the development of rot on grapes

Grape rot is one of the major causes of degradation of many grape components and, thus, of deterioration in wine quality. In particular, the association of Botrytis cinerea with other, less visible, fungi frequently leads to the development of organoleptic defects in grapes and sometimes in wines. This study examines the nature of the volatile compounds responsible for mushroom, mossy, or earthy odors detected by gas chromatography-olfactometry in organic extracts of rotten grapes and musts. 2-Methylisoborneol, (-)-geosmin, 1-octen-3-one, 1-octen-3-ol, 2-octen-1-ol, and 2-heptanol were identified or tentatively identified. Their concentrations in musts were determined, and the impact of alcoholic fermentation by the yeast Saccharomyces cerevisiae was studied. The ability of fungi isolated from rotten grapes (Botrytis cinerea; Penicillium species including P. brevicompactum, P. expansum, P. miczynskii, P. pinophilum, P. purpurogenum, and P. thomii; Aspergillus section nigri; Rhizopus nigricans; and Coniothyrium sp.) to produce some of the identified compounds was evidenced.     

Changes in the diversity and geographic distribution of cultivated millet (Pennisetum glaucum (L.) R. Br.) and sorghum (Sorghum bicolor (L.) Moench) varieties in Niger between 1976 and 2003

Changes in the diversity of landraces in centres of diversity of cultivated plants need to be assessed in order to monitor and conserve agrobioversity—a key-element of sustainable agriculture. This notably applies in tropical areas where factors such as increased populations, climate change and shifts in cropping systems are hypothesized to cause varietal erosion. To assess varietal erosion of staple crops in a country subjected to various anthropogenic and natural environmental changes, we carried out a study based on a comparison of the diversity of pearl millet and sorghum varieties collected in 79 villages spanning the entire cereal-growing zone of Niger over a 26 year period (1976–2003). For these two crops, the number, name and type of varieties according to important traits for farmers were considered at different spatial scales (country, region, village) at the two collection dates. The results confirmed the high diversity of millet and sorghum varieties in Niger. No erosion of varietal diversity was noted on a national scale during the period covered. Some changes were observed but were limited to the geographical distribution of certain varieties. This highlights that farmers’ management can preserve the diversity of millet and sorghum varieties in Niger despite recurrent and severe drought periods and major social changes. It also indicates that rainfed cereal cropping systems in Niger should remain to be based on millet and sorghum, while reinforcing farmers’ seed systems.     

Extremely potent antifeedant neo-clerodane derivatives of scutecyprol A

Two known neo-clerodane diterpenoids, scutecyprol A (1) and scutalbin C (2), have been isolated from the acetone extract of the aerial parts of Scutellaria sieberi. The antifeedant activity of scutecyprol A (1), of its 15-oxo derivative (3), and of several halohydrins (4-9), synthesized starting from compounds 1 and 3, against Spodoptera littoralis have been determined and structure-antifeedant relationships are discussed.     

Identification and antioxidant potential of flavonoids and low molecular weight phenols in olive cultivar chemlali growing in Tunisia

Increasing interest in phenolic compounds in olives is due to their antioxidant and health-enhancing properties. In this study the phenolics in fruits of the Tunisian olive cultivar Chemlali were extracted by methanol-water and fractionated using Sephadex LH-20 column chromatography. The identification of phenolic monomers and flavonoids was based on separation by high-performance liquid chromatography equipped with a diode array detector followed by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analysis. Oleuropein, a secoiridoid glycoside esterified with a phenolic acid, was the major compound. Eight phenolic monomers and 12 flavonoids were also identified in Chemlali olives. Five flavonoids were isolated and purified using Sephadex LH-20 column chromatography and preparative paper chromatography. The antioxidant activity of the extract and the purified compounds was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and by using the beta-carotene-linoleate model assay. Acid hydrolysis of the extract enhanced its antioxidant activity. Hydroxytyrosol and quercetin showed antioxidant activities similar to that of 2,6-di-tert-butyl-4-methylphenol. A hydroxyl group at the ortho position at 3' on the B ring of the flavonoid nucleus could contribute to the antioxidant activity of the flavonoids.     

Cost-effective control of a quarantine disease: a quantitative exploration using "design of experiments" methodology and bio-economic modeling

ABSTRACT An integrated approach to control of quarantine diseases at the level of the plant production chain is complicated. The involved actors have different interests and the system is complex. Consequently, control policies may not be cost effective. By means of a bio-economic model for brown rot in the Dutch potato production chain, the efficacy of different control options was quantitatively analyzed. An impact analysis was performed using the methodology of "design of experiments" to quantify the effect of factors in interaction on incidence and costs of brown rot. Factors can be grouped as policy, sector, economic, and exogenous factors. Results show that brown rot incidence and economic consequences are determined predominantly by policy and sector factors and, to a lesser extent, by economic and exogenous factors. Scenario studies were performed to elucidate how the government and sector can optimize the cost-effectiveness of brown rot control. Optimal cost-effectiveness of control requires cooperation of the sector and government, in which case brown rot incidence can be reduced by 75% and the costs of control can be reduced by at least 2 million euros per year. This study demonstrates quantitatively the potential contribution of an integrated approach to cost-effective disease control at chain level.     

Andromonoecy in <Emphasis Type="Italic">Gynandropsis gynandra</Emphasis> (L.) Briq. (Cleomaceae) and effects on fruit and seed production

Spider plant (Gynandropsis gynandra) is a traditional leafy vegetable widespread in sub-Saharan Africa and tropical Asia that is also valued for its medicinal properties. Developing a breeding program for the species requires detailed knowledge of its phenology, floral morphology and pollination system. This study investigates the effects of floral morphology and pollination mechanisms on the reproductive success in G. gynandra. The experiments were conducted in two locations in Benin. A split-plot design was used with four randomized complete blocks. Three accessions were randomly assigned to the whole plots and five treatments including natural self-pollination, hand self-pollination, geitonogamy, open pollination and hand cross-pollination were randomized over the sub-plots. We observed that individual plant exhibited 70% of staminate (male) flowers and 30% of hermaphrodite flowers. G. gynandra was andromonoecious. Open pollination and hand cross-pollination led to higher fruit and seed set. Natural self-pollination and hand self-pollination resulted in lower fruit and seed production. G. gynandra is a self-compatible and predominantly out-crossing species. Cross-pollination resulted in a significant increase in fruit set. This study set the ground for the development of improved cultivars in G. gynandra.     

Dris calculation methods for evaluating the nutritional status of oil palm in the Eastern Amazon

This study aimed to evaluate six Diagnosis and Recommendation Integrated System (DRIS) calculation methods, including two ways to choose the nutrient ratio [F (Letzsch) or R (Nick) values] combined with three functions (Beaufils, Jones, or Elwali and Gascho), and to generate nutritional diagnoses for oil palm. A total of 144 foliar samples in 33 plots in the Eastern Amazon, Brazil, were used. Except for potassium (K) in all calculation methods, the DRIS indices showed no correlation with soil nutrients. Regardless of the formula, the nutritional balance index correlated with the productivity (significant r values) and similar diagnostics were obtained. These diagnoses were reliable according to the chi-square test (χ2), and most observed frequencies presented χ2 calculated less than χ2 tabulated. The average frequencies of samples with nutrient deficiency were 51%, 42%, 37%, 35%, 32%, 30%, 30%, 25%, 20%, 12%, and 12% for samples with nitrogen (N), boron (B), manganese (Mn), sulfur (S), K, copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), phosphorus (P), and magnesium (Mg), respectively. All tested DRIS methods may be used, and their diagnoses indicate the most common nutritional deficiencies in oil palm.     

Genetic and molecular organization of the short arm and pericentromeric region of tomato chromsome 6

We have previously presented an integrated linkage map of tomato chromosome 6, that showed the position of restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) markers relative to a variety of classical markers. As for the short arm, map resolution has now been improved by crossing the chromosome 6 substitution line WSL6 to additional tester lines, carrying markers on the short arm. Molecular linkage analysis of the F₂ populations enabled us to produce an integrated linkage map showing the position of molecular markers relative to the classical markers Aps-1, yv, Mi, Cf-2/Cf-5, tl and pds. In order to incorporate the centromere into the integrated map, a radiation-induced deletion mapping strategy was applied, using irradiated pollen from L. pennellii LA716 in crosses to a L. esculentum line recessive for the markers yv and tl, that flank the centromere. Molecular analysis of the hemizygous yv-deletion and tl-deletion plants identified among the F₁ progeny, provided an estimate of the size of the respective deletions and, thus, of the position of the centromere relative to the molecular markers linked to yv and tl. This radiation mapping approach also provided evidence showing that, unlike published data, the root knot nematode resistance gene Mi as well as the Cladosporium fulvum resistance genes Cf-2/Cf-5 are located on the short arm.     

Radiographic Calibration for Analysis of Bone Mineral Density of the Equine Third Metacarpal Bone

Digital radiography represents the primary diagnostic tool the veterinarian uses to diagnose skeletal injuries in the horse. Advances in digital radiography have provided the veterinarian with opportunities to make simple radiographic assessments from calibrated digital radiographs such as dimensional analyses; however, more complex variables such as radiographic opacity have yet to be standardized. Therefore, we investigated the quantification of bone mineral density (BMD) via computed radiographic absorptiometry at various radiographic exposure intensities (kV), times (sec), and milliamps (mA) in the third metacarpal in the horse. By developing a brightness/darkness index (BDI), the grayscale of radiographs, calibrated with an aluminum (Al) marker of various known thicknesses and uniform densities, can be compared to the average BMD of a region of interest at various radiographic exposures. Al BDI was a significant predictor of bone BDI (r² = 0.960, P < .001) and BMD (r² = 0.971, P < .001). This method of calibration can be used for quantitative noninvasive bone mineral analysis and allows direct comparison of radiographs taken under different exposure settings.     

Effects of seasonal variations and pond age on trace elements and their correlations with plankton productivity in commercial freshwater crayfish (cherax cainii austin, 2002) earthen ponds

Seasonal variations can affect the concentration of trace elements, and the change in their concentrations can affect the natural productivity of freshwater aquaculture ponds. Hence, we studied the seasonal variations of the 12 pre‐selected trace elements (Co, Cu, Fe, Mn, Zn, Se, Ca, Mg, P, S, Al, Si) and their relationships with primary and secondary productivity in two aged ponds, stocked with three different life stages of marron (Cherax cainii), for a period of 1 year. Trace element analysis was performed by using (Agilent, ICP‐OES). Except Co and Se, all trace elements, and primary and secondary productivity were influenced by seasonal variation. The pond age significantly influenced the concentrations of some trace elements. On a seasonal basis, trace elements were positively correlated with the plankton abundance, species diversity, and wet and dry plankton weights. Seasonal variations and pond age affected the dissolved concentrations of trace elements and plankton productivity.