Effect of Microsphaeropsis sp. Strain P130A on Germination and Production of Sclerotia of Rhizoctonia solani and Interaction Between the Antagonist and the Pathogen

Microsphaeropsis sp. strain P130A was evaluated for the control of tuber-borne inoculum of Rhizoctonia solani based on the viability of sclerotia produced in vitro and on both the viability and production of tuber-borne sclerotia. The interactions between the antagonist and the pathogen, as well as the effect of the toxins produced by the antagonist on mycelial growth of R. solani were studied using transmission electron microscopy. On sclerotia produced in vitro, for all incubation periods (1 to 42 days), Microsphaeropsis sp. significantly reduced germination. Percent germination of sclerotia treated with Microsphaeropsis sp. decreased with increasing incubation period from an average of 82.0% after 1 day to stabilize at an average of 5.8% after 35 days. Similarly, percent germination of tuber-borne sclerotia was significantly lower when tubers were treated with Microsphaeropsis sp. Both 2% formaldehyde and Microsphaeropsis sp. treatments significantly reduced sclerotia germination to approximately 10% after 42 days of incubation at 4 degrees C. Furthermore, on tubers treated with the antagonist, the number of sclerotia per square centimeter decreased from 1.6 to 0.5 during the 8 months of storage at 4 degrees C, whereas an increase from 1.2 to 7.8 sclerotia per square centimeter was observed on untreated tubers. Microsphaeropsis sp. (strain P130A) colonized hyphae of R. solani within 4 days after contact on culture media. Transmission electron microscopic observations showed that the antagonist induced a rupture of the pathogen plasma membrane and that a chitin-enriched matrix was deposited at sites of potential antagonist penetration. Host penetration was not associated with pathogen cell wall alterations, which occurred at the time of progress of the antagonist in the pathogen cytoplasm. In the presence of a crude extract of Microsphaeropsis sp., cells of R. solani showed cytoplasm disorganization and breakdown of plasma membranes. Antibiosis and mycoparasitism were involved in the antagonism of R. solani by Microsphaeropsis sp., but the sequence by which these events occur, as well as the significance of wall appositions produced by R. solani, is yet to be established.     

Local plants as potential sources of tannins in Egypt,part. IV (Aceraceae to Flacourtiaceae)

Continuing a previous study, the leaves and barks of thirty one plants collected from the botanical gardens in Cairo, were subjected to detailed studies with the aim of identifying the type of tannins present in each plant. The study included colour tests and paper chromatography of both the free sugars and phenolic aglycones. The plants recorded here are those ranging fromAceraceae toFlacourtiaceae.

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Zusammenfassung In Fortsetzung dieser Reihe wurden die Blätter- und Rindermaterialien von 31 Pflanzen, gesammelt aus den botanischen Gärten in Kairo, auf ihre Gerbstoffe untersucht. Mit Hilfe der Papierchromatographie wurden sowohl die freien Zucker als auch die phenolischen Komponenten dieser Pflanzen identifiziert.In dieser Mitteilung wurden die Untersuchungsergebnisse der Pflanzen der Familien Aceraceae bis Flacourtiaceae gegeben.

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Résumé En poursuivant nos études précédentes, les feuilles et les écorses de 31 plantes cueillies dans les jardins de Caire, ont été soumises à des études détaillées. En vue d'identifier le type des tannins présent dans chaque plante, les études contenaient des expériments par chromatographie sur papier concernant les sucres natifs et les aglycones phénoliques. Les plantes qui ont été rapportées ici sont celles des familles Aceraceae à Flacourtiaceae.

     

Assessment of Transmission Ability of Barley Yellow Dwarf Virus-PAV Isolates by Different Populations of Rhopalosiphum padi and Sitobion avenae

Populations of two aphid species from different geographic regions of Morocco were tested for their ability to transmit five barley yellow dwarf virus-PAV (BYDV-PAV) type isolates using Clintland 64 oat as the test plant. Transmission efficiencies were determined for 10 sub-populations of Rhopalosiphum padi and 12 sub-populations of Sitobion avenae. After a short acquisition access period (AAP) of 4h, all populations transmitted the virus but with different efficiencies. R. padi (Rp-S) and S. avenae (Sa-S) collected in the Settat region were the most efficient vectors, with transmission rates of 38% and 27%, respectively. R. padi (Rp-C) collected at Chaouen and S. avenae (Sa-B) at Berkane, were poor transmitters with respective vectoring abilities of 20% and 16%. These four sub-populations were chosen to study the acquisition of BYDV-PAV and the retention of virus within aphids in more detail. The transmission after two AAPs of 4h and 48h were compared. Starved aphids given a 4h AAP had significantly higher transmission efficiencies than non-starved aphids. However, after a 48h AAP, no difference was observed in the transmission between starved and non-starved aphids. Intraspecific variability was also detected by means of serial transfers of individual aphids after the given AAP. Following the first day of serial transfers, no differences were observed in transmission efficiency and virus titers for sub-populations within each species acquiring the virus during 48h, but there was significant variation when the virus was acquired in 4h. The levels of PAV antigen retained by aphids fed on healthy plants declined rapidly during the first day after acquisition, but remained fairly constant during the next 5–7 days depending on the length of the AAP. Virus antigen could be detected by ELISA in Rp-S and Sa-S for up to 11 days of serial transfer, but it was shown that aphids could retain and transmit BYDV-PAV for at least 3 weeks.     

Impact of some alternative methods to chemical control in controlling aphids (Hemiptera: Sternorrhyncha) and their side effects on natural enemies on young Moroccan citrus groves

Aphid control in Moroccan citrus orchards is based mainly on carbamate and neonicotinoid sprays, especially methomyl and imidacloprid. The extensive use of these insecticides may have side effects on natural enemies and environment quality and raises human health concerns. This research aimed to assess the control of aphids with insecticidal soap, kaolin and augmentative biological control using the indigenous predator Adalia decempunctata L. (Coleoptera: Coccinellidae). The insecticides were applied and the predators were released in April 2009 and 2010. Under field experimentation, the methomyl and imidacloprid foliar pulverization were very effective against aphids. In contrast, the insecticidal soap and kaolin application were less efficient while A. decempunctata adults were effective only in the first week after release. The side effects on beneficial insects were also assessed and discussed. The possibility of employing A. decempunctata in an integrated pest management package in citrus groves is discussed in relation to effectiveness and side effects on beneficial arthropods.     

Design and implementation of an electronic mobile poultry production documentation system

Documentation is a major component of any traceability system where traceability is defined in the ISO Regulation 8402:1994 as the ability to trace the history, application and location of what is under consideration. Traceability systems are record keeping systems designed to track the flow of product or product attributes through the production process or supply chain. All international supply chains are forced to comply with traceability requirements. In this paper, we develop and implement an end-to-end mobile application prototype that traces the poultry production. This application consists of front-end and back-end systems. At the front-end, the worker uses a GPRS enabled handheld device (cell phone, PDA, etc.) to capture information on poultry operations collected at a remote chicken farm and transmit it to a back-end server in the main office. Through customized application the back-end server analyses all information received from the front-end and based on a built-in business process and business rules, intelligently updates various stakeholders of any breach of bio-security measures that requires immediate attention. The proposed system administrators can also access this application via Internet for management decision making. The back-end system consists of web server, defined business application logic and database server.     

Biochemical and histological alterations of cellular metabolism from jerboa (Jaculus orientalis) by 2,4-dichlorophenoxyacetic acid: Effects on d-3-hydroxybutyrate dehydrogenase

2,4-Dichlorophenoxyacetic acid (2,4D) is one of the widely used herbicide of the phenoxy family with possible startling number of adverse effects on species other than the weeds which is designed to kill. The effects of 2,4D were investigated in jerboa (Jaculus orientalis), a wild animal of subdesert highlands. The jerboas have been daily treated intraperitonally with 2,4D 3 mg/kg body weight for 4 weeks. Plasmatic markers, and antioxidants defences systems were assessed and histological alterations were evaluated. The in vivo and in vitro effects of 2,4D on the mitochondrial d-3-hydroxybutyrate dehydrogenase (BDH) were also determined. Our results showed a strong decrease of triglycerides level and HDL cholesterol and an increase in GOT level and LDL cholesterol. The microscopic evaluation showed that 2,4D induced necrosis of seminiferous tubules cells in testis, hyperplasia of hepatocytes in liver and presence of multinucleated giant cells in brain. The results show also an inhibitory effect on BDH in terms of activity and kinetic parameters. All of these results show that 2,4D induces toxicity which affects energy metabolism, morphological perturbation and oxidative stress.     

Enhancing Wheat Production Under Arid Climate Stresses Using Bio-Elicitors

Arid climate has contributed to crops yield production decrement in many regions due to water shortage and soil salinization. The main target of this research is to enhance wheat production under arid climate stresses by utilizing bio-elicitors. Two common wheat assortments i.?e. cv. Gemmiza 10 and Sakha 93 accomplished tolerant to these stresses utilizing bio elicitors include Acremonium coenophiulum, Streptomyces griseus, Trichoderma harzanium, T. viride, Rhodotorula glutinis, Paenibacillus polymyxa, Bacillus subtilis, B. megaterium, Pseudomonas putida, P. fluorescens compared with natural elicitors as methyl jasmonate (MJ), chitosan (CHI), ascorbic acid and putrescein (PUT). Varieties were planted in two progressive seasons in recently reclaimed lands, where two fields were selected the first is located in North Sinai while the second is situated to the south of Behira Governorate. Bio elicitors reduced abiotic stress and enhance physiological characteristic expressed as Proline, soluble carbohydrates %, Chl.a, Chl.b, Chl.a + b; Chl.a/Chl.b; Carotenoids and increased the concentration of Crude protein, N, P and total soluble carbohydrates in wheat grains. Using P. fluorescens exhibted increment in grain yield of wheat plants, cv sakha 93 amounted by 68.3% in Sinai region, while in Behira region the increement reached (45.5%) with P. polymyxa treatment. The response of Gemmiza 10 variety to the Bio-elicitors was less compared to Sakha 93 variety in both regions, where the highest increments due to P. putida treatment were18.9 and 19.7% in Sinai and beheirwa regions, respectively, compared to the control in each region. A remarkable increments of wheat growth, development and extended survival under salt and water limiting and restricting conditions. These findings demonstrate that wheat plants can display improved stress tolerance through bio-elicitors, and recommend that innovation may be useful in reducing effects of climate change and environmental stress on other crops and expanding agricultural production onto marginal lands.     

Benzo-(1,2,3)-thiadiazole-7-carbothioic S-methyl ester (BTH) stimulates defense reactions in <Emphasis Type="Italic">Xanthosoma sagittifolium</Emphasis>

The root rot disease caused by Pythium myriotylum is responsible for about 70% of cocoyam production loss in Cameroon. The potential of benzo-(1,2,3)-thiadiazole-7-carbothioic S-methyl ester (BTH) to trigger resistance in cocoyam (Xanthosoma sagittifolium) plants against P. myriotylum was investigated. Under controlled conditions, BTH was an efficient elicitor of some defense reactions in cocoyam. Application of 0.2 mg ml⁻¹ of BTH on leaves 7 days before inoculation of roots with P. myriotylum enhanced the activities of peroxidase (Pox) and polyphenoloxidase (PPO) as well as the total phenolic content. This resistance was noted as a decrease in disease incidence and severity in BTH-treated plants. This increase in Pox activities was correlated with two new isoforms in a white (sensitive) cultivar inoculated after stimulation. In a yellow (resistant) cultivar, stimulation was characterized by the appearance of one isoform. Qualitative analysis of phenolic compounds by HPLC showed an increase of hydroxycinnamic and flavonoid derivatives after inoculation. We also observed the appearance of a new caffeoylshikimic acid derivative after stimulation followed by inoculation of both cultivars. The findings indicated that the pattern of induction is different and depends on the variety.