Ecophysiological and genetic variation in seedling traits and in first-year field performance of eight <Emphasis Type="Italic">Acacia senegal</Emphasis> provenances in the Blue Nile,Sudan

The genetic variation in seed weight, seed number per kg and seedling traits was compared among eight Acacia senegal provenances originating from the clay plain (east) and sand plains (west) of the gum belt in Sudan. The main objective of this study was to identify germplasm sources of A. senegal that have a good seed germination capacity and seedling traits suitable for reforestation in the clay-soil part of the dryland gum belt in the Blue Nile region in Sudan. A specific objective was to tentatively explore the adaptive strategy of A. senegal populations. Seventeen-week-old seedlings were planted in the field at spacing of 3 m × 3 m, giving 100 trees per plot and replication; within a randomized complete block design with four replications. The experimental site was in the clay plain region. Seed variables showed significant differences. Clay plain provenances showed considerable variation in seed weight and seed number. They had the smallest seed weight but the highest seed number, while the sand (western) provenances had the largest seed weight but lowest seed number. Seedling branch number, root length, root to shoot ratio and shoot dry weight differed significantly among the provenances 12 weeks after germination. Clay provenances had the highest branch number and shoot dry weight but the shortest roots and lowest root to shoot ratio. This was interpreted as showing better adaptation to the site in these local provenances in comparison to those originating from the western sandy soil regions. High positive correlations were observed between seedling variables, such as root nodule and branch numbers; this could be used for early selection. The variation was greater between provenance groups than within them, suggesting that especially selection among groups would yield genetic gain.     

Sources of resistance to Watermelon Chlorotic Stunt Virus in melon

Watermelon Chlorotic Stunt Virus (WmCSV) is a bipartite geminivirus residing in the genus Begomovirus (family Geminiviridae) and is whitefly transmitted ( Bemisia tabaci ). WmCSV infects members of the Cucurbitaceae , and represents a considerable threat to melon and watermelon crops in Sudan, Yemen, and Iran. One hundred twenty-eight melon accessions, mostly collected from Sudan, were screened in the open-field in Sudan under severe whitefly inoculation pressure in order to identify sources of resistance to WmCSV. One WmCSV resistant line HSD 2445-005 selected from this first screening along with 22 new melon accessions were agro-inoculated with an infectious Sudanese clone of WmCSV. Ten accessions exhibited resistance to WmCSV infection upon agro-inoculation. Six of them were confirmed to have complete resistance to WmCSV through graft-inoculation as well as multiple field trials in Sudan. These lines include the Sudanese accession HSD 2445-005, the South African accession PI 282448, and three Indian accessions: 90625, PI 124112, and PI 414723. Resistant plants exhibited no disease symptoms, and virus DNA could not be detected by hybridization with a WmCSV-specific probe.     

The immune response to bovine viral diarrhea virus: a constantly changing picture.

Bovine viral diarrhea virus (BVDV) is one of the major immuno-suppressive viruses of cattle. The effect on the innate and acquired immune system is unique and results in dramatic immune dysfunction. BVDV infection also has the ability to cause persistent infection (PI) in the developing fetus. This Pl syndrome creates a requirement for high levels of BVDV immunity from vaccines to prevent these infections. BVDV vaccines and their future development continue to be an enigma in the control of BVDV.     

Influence of boron concentrations on some meta‐bolites of date palm and sorghum seedlings

Date palm (Phoenix dactylifera L. cv Khedhri) and sorghum (sorghum Sudan grass hybrid cv sugar Graze 11) plants were grown in vermiculite in a controlled environment and watered with a nutrient solution containing eight different concentrations of boron (B) (0 to 500 ppm), six months for date palm and four weeks for sorghum. The chlorophyll (Chl) content of the seedlings increased significantly with low concentrations of B for both date palm and sorghum, but no further significant increases were observed at higher concentrations. Generally, there was a positive correlation between B and calcium (Ca) content in the tissues of both seedlings when B concentrations were increased in the media. A negative correlation was found between B concentration in the media and the tissue content of phenolic compounds and the activity of some enzymes, such as polyphenol oxidase, IAA‐oxidase and phenylalanine ammonia‐lyase in the tissue, while there was a positive correlation in the case of peroxidase. Ribonucleic acid (RNA) increased significantly in date palm with the increase of B in the medium, but for sorghum, the increase occurred at 10–100 ppm and decreased at 300 and 500 ppm B in the media.     

Effect of fermentation on sorghum protein fractions and in vitro protein digestibility

Changes in pH, titratable acidity, total soluble solids and proteins ofDabar sorghum (Sorghum bicolor (Linn) Moench.) during naturalfermentation at 37 ^°C for up to 36 h were monitored. The pH ofthe fermenting material decreased sharply with a concomitant increase in the titratable acidity. Total soluble solids increased with progressivefermentation time. The crude protein and non-protein nitrogen slightlyincreased during the last stages of fermentation. The in vitroprotein digestibility markedly increased as a result of fermentation.The globulin plus albumin fractions increased significantly (p 0.05)during the first 8 h of fermentation. Kaffirin fraction decreasedduring the first 8 h of fermentation but increased sharply as fermentationprogressed. Cross-linked kaffirins fluctuated during the fermentationprocess. Glutelin like protein, which was the minor fraction, trueglutelins, the second most abundant fraction, together with non-extractableproteins fluctuated during the fermentation process.     

Light and electron microscopic studies on the effect of a contraceptive drug on the stomach of mouse

The present study was an investigation of the effect of the contraceptive drug, Nordette, on the stomach of the mouse when administered daily at a recommended therapeutic dose rate of 0.0026 mg kg(-1) for 30 days. Extensive light and electron microscopic changes were noticed. The drug caused enlargement in the all types of cells. The oxyntic cells appeared hypertrophied with irregular cell boundaries, enlarged nuclei and faintly stained cytoplasm. Their cytoplasm contained irregularly distributed mitochondria with dense matrix, decreased rER, obviously increased sER, disorganized intracellular canaliculi and some lysosomes. The peptic cells appeared enlarged and contained hypertrophied rough endoplasmic reticulum and an increase amount of ribosomes and secretory granules. There was an increase in the amount of the secretory granules in the lumen of the gastric gland. The mucus cells at the upper region of the gastric gland were greatly decreased. Smooth muscle fibers showed enlargement and degeneration. The submucosa and lamina propria showed vacuolation. The most pathological effects were restricted to the obvious decrease of the lymphoid cells in the submucosa and lamina propria. Dilatation and congestion of the blood vessels and blood capillaries were noticed. Blood capillaries lined by enlarged endothelial cells containing enlarged heterochromatic nuclei.     

Semiochemical modulation of oviposition behaviour in the gregarious desert locust Schistocerca gregaria

Bioassays have shown that sand freshly contaminated by ovipositing females of the gregarious desert locust Schistocerca gregaria (Forskal) is more effective in inducing further oviposition from conspecifics than contaminated sand stored for three or six months, which contrasts with results obtained previously with Locusta migratoria (Reiche & Farmaire). The activity of contaminated sand correlated with the levels of three unsaturated aliphatic ketones, (Z)-6-octen-2-one, (E,E)-3,5-octadien-2-one and its geometric isomer (E,Z)-3,5-octadien-2-one present in the volatile emissions from the sand.