Vol. 5 Issue 1
M.O. Basalah
The effect of Parlatoria blanchardi on some metabolites of healthy and injured leaf discs of date palm (Phoenix dactylifera L.) was studied. No significant changes were observed in the reducing and non-reducing sugars of leaf discs before and after injury by the insect. The analysis of soluble sugars by GLC revealed the presence of fructose, glucose, inositol, sucrose, and glycerol. However, the kind of soluble sugars changed in the injured lead discs; glycerol content increased and sorbitol appeared after the injury. Organic acids did not change significantly in healthy and injured lead discs. Soluble protein content, however, increased significantly in injured lead discs as compared to healthy ones.
Youssry E. Saleh and Mary S. Khalil
The effect of different concentrations of sodium fluoride on growth and the enzymatic activities, in vivo, of Erwinia carotovora var. carotovora; Erwinia carotovora var. citrullus; Erwinia toxica and Pseudomonas lachrymans was studied. The results show that E. toxica seemed to be highly tolerant to sodium fluoride (LD50 at 10^-2 M), followed by P. lachrymans and E. carotovora var. carotovora whereas E. carotovora car. citrullus was most sensitive.
Neither glutamic acid decarboxylase nor lysine decarboxylase was detected in the four pathogens, but arginine decarboxylase was present in E. carotovora var. citrullus. Its activity decreased with increased sodium fluoride concentration and ceased at 10^-1 M.
Sodium fluoride inhibited alkaline and acid phosphatase of E. toxica and P. lachrymans. Such effect was only apparent at 10^-3 M or above for E. carotovora var. carotovora or at 10^-2 M or above for E. carotovora var. citrullus. Lower concentrations seemed without effect for the former but were stimulatory for the latter organism. Sodium fluoride did not induce the production of the proteolytic or asparaginase enzymes.
M.I. Naguib, Y.E. Saleh, and A.A. Amin
An attempt to differentiate 40 members of bacteria, belonging mostly to the family Enterobacteriaceae, on the basis of their capacity to decarboxylate 24 different amino acids has been carried out.
The results showed that the majority of the bacteria were able to decarboxylate threonine (29 members), ornithine (25 members), lysine (24 members), histidine (22 members) and arginine (21 members). Very few members were able to decarboxylate alanine, aspartic acid, or methionine (4 members for each), cystine, glycine or leucine (3 members for each), hydroxyproline, iso-leucine, nor-leucine, proline, tryptophan or valine (2 members for each). Only one bacterium decarboxylated tyrosine while non could carboxylate dihydroxyphenyl alanine.
Within the limits of these results, a preliminary key is proposed for the identification of each or a small group or closely related species and/or strains of one genus.
Z.N. Mahmoud and I.B. Wilson
The effects on exposure to light of shielding parietal eye and of parietal ectomy on testicular activity were investigated in Chalcides ocellatus. Differences between the means of the numbers of lizards exposed to light after shielding their parietal eyes and of control animals was not significant (P> 0.1). There was a significant variation (P< 0.7) however, in the numbers of animals exposing themselves to light at different hours of the day, but no significant difference was obtained between the sums of the daily counts (P> 0.05). Histological assessment of testicular activity showed that neither the parietal ectomized nor the control lizards performed better than one another
A.M. Ibrahim
The present study shows that the population growth of Caenorhabditis elegans was significantly reduced after treatment with 5-40 µg/ml of the wettable formulations of diflubenzuron, a phenyl benzoyl urea compound (P< 0.01), whereas treatment with similar concentrations of the analytical grade diflubenzuron in acetone or dimethyl sulphoxide were less effective. The percentage reduction in population growth of C. elegans was shown to be greatest (62-99%) in treatments with wettable formulations of diflubenzuron (5-40 µg/ml). Formulation B of diflubenzuron has the lowest EC50 value: 0.2 µg/ml. The study also shows that diflubenzuron significantly affects egg production of C. elegans (P < 0.05) at low concentrations (20 µg/ml) while other biological activities such as development, survival, feeding and movement are not significantly affected (P < 0.05). About 56, 85 and 91% reduction in egg production was observed in treatments with 5, 10, 20 µg/ml diflubenzuron for 96 hr. respectively.
Gregory Smith, Mostafa Saleh, and Khatoon Sangoor
Seventy-one species of fishes are recorded from shallow-water (4-15 m) reefs northeast of Bahrain in the Arabian Gulf. Most (39 spp.) of these range widely throughout the Indo-West Pacific Region; others exhibit more restricted distributions and help clarify zoogeographic relationships of the Arabian Gulf ichthyofauna.
Distributions of reef fishes support the notion of a major zoogeographic discontinuity within the Arabian Gulf. Moreover, levels of endemism for Arabian Gulf reef fishes are higher than hitherto recognized and may approach those of the Red Sea. A strong faunal relationship exists between the Red Sea and Arabian Gulf; seven species reported herein are Arabian endemics, i.e. restricted to the Red Sea, Arabian Peninsula, and Arabian Gulf. One species (Ptereleotris sp.) constitutes a new addition to the Arabian Gulf ichthyofauna. Additional species confirm dubious or frequently overlooked Arabian Gulf records. Previous checklists of Arabian Gulf reef fishes are amended in light of the most recent systematic literature.
Maissa M. Abdel-Kader, R.M. Abdu and M.A. Hussien
Sex pheromone production by virgin females of T. castaneum (Herbst) was greatly affected by the time of the day. It started at low concentration in the early morning and then increased until it reached its maximum at 1500 hr. It decreased again in the late afternoon and reached its lowest titer at night. Male responsiveness to sex pheromone extracts followed almost a similar trend, with a maximum response between 1300 and 1500 hr.
Sex pheromone production also varied at the different temperature at which the beetles were kept. Temperatures between 30 and 40°C appeared optimum for sex pheromone production. None of the temperatures tested (15-40°C) inhibited pheromone production.