Effect of amino acids and ascorbic acid onMeloidogyne javanica Chitw. (Tylenchidae,Nematoda)

The effect of aqueous solutions of L-arginine, L-glutamic acid and ascorbic acid onMeloidogyne javanica egg hatch, juvenile survival, and maturity and fecundity of nematode females in susceptible tomato roots was investigated. All tested compounds significantly suppressed egg hatchability at all concentrations (1000, 2000 and 4000 ppm). L-arginine proved to be the best one in inhibition egg hatch and achieved the highest inhibition percentages at all tested concentration. Inhibition rate of egg hatch increased by increasing the concentration of amino acids and vitamin. L-arginine and L-glutamic acid and ascorbic acid at 2000 ppm resulted in 100% mortality ofM. javanica juveniles after 7 days exposure. Application of aqueous solutions of L-arginine, L-glutamic acid, and ascorbic acid at 1000 ppm significantly reduced numbers ofM. javanica populations, mature females and eggmasses in tomato roots. The maximum inhibitory effect was obtained by L-arginine acid which surpassed both ascorbic acid and L-glutamic acid, in reducing nematode population (R% were 84.95, 80.11 and 70.4, respectively) and in affecting maturity and fecundity of females (maturity % were 53.7, 54.2 and 67.7 and fecundity % were 39.2, 46.2 and 61.2 for L-arginine acid, ascorbic acid, and L-glutamic acid respectively, in comparison with that of control group).     

Bio-efficacy of two bacterial insecticide strains ofBacillus thuringiensis as a biological control agent in comparison with a nematicide,nemacur, on certain parasitic nematoda

A greenhouse experiment was conducted to determine the possibility use of commercial bacterial pathogen insecticide,Bacillus thuringiensis, as biocontrol agent againstMeloidogyne javanica andTylenchulus semipenetrans nematodes.The obtained results indicate that the two strains ofB. thuringiensis suppressed the total nematode populations and eggmasses of the two nematode genera. Also, the two strains ofBacillus remarkably reduced the percentages of hatchability of eggs of the two nematode genera. SAN 415Bacillus strain was highly effective than Dipel strain and surpassed it in this respect, but it was approximately similar to the standard nematicide Nemacur.

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Zusammenfassung Es wurde ein Gewächshaus-Versuch durchgeführt zur Untersuchung der Möglichkeit,Meloidogyne javanica undTylenchus semipenetrans (Nematoda) mittelsBac. thuringiensis biologisch zu bekämpfen. Die Ergebnisse zeigen, daßB. thuringiensis die Eigelege und die Populationsdichte beider Nematoden stark reduzierte. Auch wurde die Schlüpflähigkeit der Eier beider Nematodenarten durch Anwendung der zweiBacillus-Präparate deutlich verringert. Der SANBacillus-Stamm zeigte höhere, Wirkung als Dipel und entsprach etwa dem Standard-Nematizid Nemacur.

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With 2 tables     

Biological control study onTylenchulus semipenetrans (Cobb) (Nematodes) by certain soil mesofauna

Pot experiments were carried out to explore the role of macrochilid mites,Macrocheles muscaedomesticae (Scop.), and staphylinid beetles,Philonthus longicornis Steph. and collembola,Onychiurus sp. singly and in combination onTylenchulus semipenetrans (Cobb) on sour orange at 29±5°C 74±5% R. H. in green house. All tested soil mesofauna significantly reduced the population of the nematode. The highest predation rate was achieved by the predator mite,M. muscaedomesticae (Scop.) singly, followed by the combination of soil mite plus collembola. The numbers of soil mesofauna recovered from soil at the end of the experiment were significantly higher in treatments of nematode plus one of each of soil mesofauna than monoinoculation of each.     

Studies on the predation efficiency ofAgistemus exsertus Gonzalez (Acarina,Stigmaeidae) on the eriophyid miteAculops lycopersici (Massee)

The predacious miteAgistemus exsertus Gonzalez was reared in the laboratory on the eriophyid miteAculops lycopersici (Massee) for studying the development, fecundity and predation efficiency. At 30°C and R.H. 75% the duration of the predator egg incubation, immature stages, life cycle, oviposition and longevity of the adult female was 0.92, 2.10, 3.02, 4.89 and 7.20 days respectively in average. The consumption by one adult female ofA. exsertus per day on the different stages of the eriophyid miteA. lycopersici was 60.3 eggs and 45.3 immature and mature stages.     

Response of tylenchulus semipenetrans to plant hormone,Giberellic acid and nematicide,Aldicarb singly and in combination

Field experiment was conducted to evaluate the efficiency of Aldicarb and Giberellic acid singly and in combination for controllingTylenchulus semipenetrans nematode, infectingCitrus sinensis var.Balady, in relation to its growth and yield Plant hormone, Giberellic acid and nematicide, Aldicarb and their combination significantly suppressedT. semipenetrans population in both soil and roots of Balady orange one and two months post application, and increased its growth and yield than that of control. The combination of Aldicarb and Giberellic acid proved good control of citrus nematode and caused subsequent increase in the growth and yield of orange tress more than the application of these chemicals alone. Yield of citrus per tree increased by up to 18.4, 17.8 and 43.6% over untreated control for treated trees with Aldicarb, Giberellic acid and their combination, respectively. The hatchability ofT. semipenetrans eggs was highly suppressed by Aldicarb and its combination with Giberellic acid. On the contrary, Giberellic acid alone did not affect the egg hatching.     

Effects of low concentrations of dietary cobalt on liveweight gains, haematology, serum vitamin B(12) and biochemistry of Omani goats

Seventy-three, 10-week-old, newly weaned Omani goats of three different breeds, namely Dhofari (D), Batinah (B) and Jebel Akhdar (JA) were randomly divided into a control (n=38) and a treated group (n=35) for an experimental period of 10 months. Goats in both groups were fed 150 g/day per head of a pelleted concentrate, based on body weight and their requirements and Rhodes grass hay ad libitum, containing 0.12 and 0.10 mg/kg DM cobalt, respectively. Goats in the treated group also received bi-monthly subcutaneous injections of 2000 microg hydroxycobalamin. In contrast to the treated goats, the control animals of all breeds experienced a severe decrease in their serum vitamin B(12) levels, developed pale mucous membranes, appeared scruffy and two breeds (D and B) had significantly lower weight gains from month 5. Untreated kids of all breeds had significant decreases in their red blood cell counts and erythrocyte indices after approximately four months. Controls developed low total serum protein levels whilst activities of alkaline phosphatase and aspartate aminotransferase significantly increased. Although it is widely assumed that goats are more resistant to cobalt deficiency than sheep this is apparently not true for Omani goats. Based on experimental data from previously reported studies and those from the present study it can be concluded that the reduction in weight gains in D and B goats is related to their lower digestibility coefficients for dry matter, crude protein and energy while the increase in alkaline phosphatase and aspartate aminotransferase are associated with developing hepatic lipidosis.     

Clinical, haematological and therapeutic studies on tropical theileriosis in water buffaloes (Bubalus bubalis) in Egypt

Thirty buffaloes naturally infected with Theileria annulata and 10 parasitologically free controls were used to determine the potential clinical, haematological and therapeutic impact of tropical theileriosis in Egypt. The clinical signs in the infected buffaloes were pyrexia (40.5-41.5 degrees C), enlargement of superficial lymph nodes, slight nasal and ocular discharges, salivation, anaemia and respiratory distress. Eye lesions also were recorded. There was a significant decrease in erythrocyte counts and haemoglobin content and a significant decrease in total leucocyte counts in infected buffaloes compared to controls. Early treatment with buparvaquone was 100% effective in eliminating the protozoan parasites from the blood and lymph nodes and led to an improvement in the clinical state whereas treatment in the later stages of the disease whilst eliminating the parasites failed to improve the clinical condition of the animal.     

Oil Absorption Characteristics of a Multigrain Extrudate During Frying: Effect of Extrusion Temperature and Screw Speed

The oil absorption characteristics of a multigrain extruded and fried snack product were studied as a function of extruder screw speed and cooking temperature using a central composite response surface methodology (RSM). The extruded product was produced using a corotating twin screw extruder, dehydrated to a uniform moisture content, and subsequently deep‐fat‐fried at 192 ± 1°C for 10–40 sec to complete expansion. Significant RSM models were developed for oil absorption and extrudate water absorption index (WAI). According to the lowest oil model, absorption (19.9%) was obtained with an extruder screw speed of 218.6 rpm and a cooking temperature of 117.8°C. WAI reached a maximum at a screw speed of 221.9 rpm and a cooking temperature of 109°C. Oil absorption characteristics and extrudate WAI were significantly correlated (r= ‐0.84, P = 0.0002). The data suggest that extrusion conditions can be optimized to influence the physicochemical structures in the extrudate matrix so that oil absorption can be minimized.     

Domiati奶酪中抗黄曲霉毒素活性物质产生菌的分离鉴定及其抑菌作用

通过抑菌活性试验、蛋白酶敏感性试验、菌株的动力学生长曲线测定,菌株的生理生化试验以及1 6S rRNA序列鉴定试验,对埃及传统Domiati奶酪中的产抗黄曲霉毒素的活性物质的菌株进行分离与鉴定.结果显示:分离得到的菌株的发酵上清液对多株受试真菌均有明显抑制作用,尤其对产生黄曲霉毒素的黄曲霉(Asper-gillus flauus)有很强的抑制效果;该菌株产生的抑菌活性物质不是蛋白类物质,也不同于一般细菌素;该菌鉴定为扩展短杆菌(Brevibacterium linens),命名为lpl-8菌.     

Effect of light and dark on the growth and development of downy mildew pathogen Hyaloperonospora arabidopsidis

Disease development in plants requires a susceptible host, a virulent pathogen, and a favourable environment. Oomycete pathogens cause many important diseases and have evolved sophisticated molecular mechanisms to manipulate their hosts. Day length has been shown to impact plant–oomycete interactions but a need exists for a tractable reference system to understand the mechanistic interplay between light regulation, oomycete pathogen virulence, and plant host immunity. Here we present data demonstrating that light is a critical factor in the interaction between Arabidopsis thaliana and its naturally occurring downy mildew pathogen Hyaloperonospora arabidopsidis (Hpa). We investigated the role of light on spore germination, mycelium development, sporulation, and oospore formation of Hpa, along with defence responses in the host. We observed abundant Hpa sporulation on compatible Arabidopsis under day lengths ranging from 10 to 14 hr. In contrast, exposure to constant light or constant dark suppressed sporulation. Exposure to constant dark suppressed spore germination, mycelial development, and oospore formation, whereas exposure to constant light stimulated these three stages of development. A biomarker of plant immune system activation was induced under both constant light and constant dark. Altogether, these findings demonstrate that Hpa has the molecular mechanisms to perceive and respond to light and that both the host and pathogen responses are influenced by the light regime. Therefore, this pathosystem can be used for investigations to understand the molecular mechanisms through which oomycete pathogens like Hpa perceive and integrate light signals, and how light influences pathogen virulence and host immunity during their interactions.