Phytoplasmas associated with disease of coconut in Malaysia: phylogenetic groups and host plant species     

N. Nejat  K. Sijam  S. N. A. Abdullah  G. Vadamalai  M. Dickinson 《Plant pathology》2009,58(6):1152-1160

Coconut palm ( Cocos nucifera ), oil palm ( Elaeis guineensis ), Bermudagrass ( Cynodon dactylon ) and Madagascar periwinkle ( Catharanthus roseus ) with symptoms indicative of phytoplasma disease were collected from different locations in Malaysia. PCR assays employing phytoplasma universal rRNA gene primers P1/P7 alone or P1/P7 followed by R16F2n/R16R2 detected phytoplasmas in eight out of 20 Malayan Red Dwarf (MRD), nine out of 12 Malayan Yellow Dwarf (MYD) and 12 out of 12 Malayan Tall (MT) coconut palms displaying coconut yellow decline symptoms. Positive detections were also obtained from six out of six oil palm seedlings showing symptoms of yellowing and necrosis, from 10 out of 10 Bermudagrass samples with white leaf symptoms, and from eight out of eight periwinkle plants showing phyllody, virescence, little leaf, proliferation and foliar yellowing. Phytoplasmas were not detected in any of the symptomless plants tested. Sequencing and phylogenetic analysis of PCR products determined that phytoplasmas infecting both MRD and MT coconuts and Bermudagrass in Serdang, Selangor State, were all members of the 16SrXIV ' Candidatus Phytoplasma cynodontis' group, whereas isolates in periwinkle in Serdang were all members of the 16SrI ' Ca. Phytoplasma asteris' group. However, the phytoplasmas detected in MYD coconuts and oil palms from Banting, Selangor State, and in periwinkle from Putrajaya were collectively very similar (99%), but shared <97·5% similarity with 16S rDNA sequences of all other known phytoplasmas, indicating that they represent a novel taxonomic group. Thus, at least two phylogenetically distinct phytoplasmas are associated with the coconut yellow decline syndrome in Malaysia, both of which were also detected in other plant species.  相似文献   

Current status and future strategy in breeding grasspea (Lathyrus sativus)     

C. G. Campbell  R. B. Mehra  S. K. Agrawal  Y. Z. Chen  A. M. Abd El Moneim  H. I. T. Khawaja  C. R. Yadov  J. U. Tay  W. A. Araya 《Euphytica》1993,73(1-2):167-175

Efforts in grasspea (Lathyrus sativus) improvement have increased since the development of lines that are very low in the neurotoxin Beta-N-oxalyl-L-alpha-beta-diamino propionic acid (ODAP); also referred to as Beta-N oxalyl-amino-L-alanine (BOAA). Many programs now address several related aspects of improvement simultaneously. These include reduced ODAP concentrations, insect and disease resistance, nitrogen fixation, agronomic practices, fodder and forage production, and components for increased yielding ability. The coordinated, multidisciplinary approach now being applied to the genetic improvement of grasspea should allow the potential of this largely neglected grain legume to be fully realized.  相似文献   

Thermal,swelling and stability kinetics of chitosan based semi-interpenetrating network hydrogels     

Muhammad Omer Aijaz  Sajjad Haider  Fahad S. Al-Mubaddel  Rawaiz Khan  Adnan Haider  Abdulaziz Abdullah Alghyamah  Waheed A. Almasry  Mohammad Sherjeel Javed Khan  Muhammad Javid  Wajahat Ur Rehman 《Fibers and Polymers》2017,18(4):611-618

The present study is focused on studying the swelling kinetics, thermal and aqueous stabilities, and determination of various forms of water in the chitosan (CS) and polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). CS/PAN blend hydrogel films were prepared by solution casting technique. The blend film with optimum swelling properties was selected for the synthesis of sIPN. CS in the blend was crosslinked with the vapors of Glutaraldehyde (GTA) to prepare sIPN. The fabricated CS/PAN blend and sIPN hydrogels films were characterized with Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and field emission scanning electron microscope (FESEM). The kinetics of swelling, bound and unbound waters and aqueous stability were determined experimentally. FESEM showed good miscibility between CS and PAN, FTIR showed no chemical interaction between CS and PAN; however, it did show a doublet for the sIPN, TGA showed improved thermal stability and swelling kinetic followed second order kinetics. The degree of swelling of the sIPN hydrogels samples at room temperature varied from ~2200 % (with a fair degree of stability (~30 %)) to ~1000 % (with high degree of aqueous stability (43 %)) with increase in the crosslinking time. The calculated unbound water (W_UB) max., for the blend was 52.3 % whereas for the bound (W_B) the max., was 41.9 %. However, for sIPN hydrogel films, the W_UB water decreased (max. 21.0 %) where as the W_B increased (max. 52.0 %). The decrease in W_UB and increase in the W_B is attributed to the formation of a compact structure and increase in the contact area between the water and polymers in sIPN hydrogels due to the induction of new water contacting point in these hydrogel films, respectively.  相似文献   

Evaluation of mechanical properties of jute/glass/carbon fibers reinforced hybrid composites     

M. A. Abd El-baky 《Fibers and Polymers》2017,18(12):2417-2432

A study on the tensile and flexural properties of jute-glass-carbon fibers reinforced epoxy hybrid composites in inter-ply configuration is presented in this paper. Test specimens were manufactured by hand lay-up process and their tensile and flexural properties were obtained. The effects of the hybridization, different fibers content and plies stacking sequence on the mechanical properties of the tested hybrid composites were investigated. Two-parameter Weibull distribution function was used to statistically analyze the experimental results. The failure probability graphs for the tested composites were drawn. These graphs are important tools for helping the designers to understand and choose the suitable material for the required design and development. Results showed that the hybridization process can potentially improve the tensile and flexural properties of jute reinforced composite. The flexural strength decreases when partial laminas from a carbon/epoxy laminate are replaced by glass/epoxy or jute/epoxy laminas. Also, it is realized that incorporating high strength fibers to the outer layers of the composite leads to higher flexural resistance, whilst the order of the layers doesn’t affect the tensile properties.  相似文献   

Effects of carbohydrate source and polyethylene glycol on maturation and germination of somatic embryos in walnut (<Emphasis Type="Italic">Juglans regia</Emphasis> L.)     

Maryam Aflaki Jalali  Hassan Bahrami Sirmandi  Abdullah Hatamzadeh 《Journal of Crop Science and Biotechnology》2017,20(1):29-35

Low efficiency of somatic embryo maturation, germination, and conversion to plantlets is a major problem in many species including J. regia L. Germination efficiency of somatic embryos is very low in walnut. In this study, effects of two carbohydrate sources, sucrose and maltose (each at 3% and 6%), and two kinds of PEG (4000 and 6000) (each at four levels of 1.5%, 3%, 5% and 7.5%) on maturation and germination of walnut embryos were tested. The number of somatic embryos increased conspicuously on medium containing PEG. Furthermore, higher levels of PEG-4000 (7.5%) could remarkably enhance the morphogenesis of somatic embryos and the number of embryos produced. PEG-4000 stimulated somatic embryo maturation of walnut. This stimulatory effect was dependent on the carbohydrate source used. Sucrose in combination with PEG-4000 produced 50% of cotyledonary and normal somatic embryos. Different concentrations of PEG were effective on the number of embryos with a shoot meristem. PEG-4000 7.5% and sucrose 3.0% produced the highest rate (50.0%) of normal shooting embryos. However, PEG (4000, 6000) and maltose caused an unfavorable effect and increased the frequency of abnormal shaped somatic embryos.  相似文献   

Chemical Composition of Urban Wet Deposition in Amman,Jordan     

Jaradat  Qasem M.  Momani  Kamal A.  Jiries  Anwar G.  El-Alali  Abdullah  Batarseh  Mufeed I.  Sabri  Tayel G.  Al-Momani  Idrees F. 《Water, air, and soil pollution》1999,112(1-2):55-65

Precipitation events were collected during the period from October 1996 to April 1997 from two sites in the city of Amman, Jordan. The samples were analyzed for major cations (Na+, K+, Ca2+, Mg2+ and NH4+), major anions (F-, Cl-, NO3- and SO42-), in addition to heavy metals (Cu2+, Cd2+, Zn2+, and Pb2+). High levels of Ca2+ and SO42- were observed. The results were comparable with some regional values and they indicate that about 58% of Na+ and Cl- are of marine origin, while Ca2+, K+ and a large fraction of SO42- are of soil dust origin. Heavy metals were detectable in most of the samples, zinc showed the highest concentrations. Significant correlation was obtained between zinc and lead, which may indicate automobile emission source.  相似文献   

Biochemical effect of selenium and vitamin E/selenium administration on some trace elements in clinically normal suckling buffalo calves     

H A Amer  T K el-Neweehy  S A Abd el-Salam 《Archiv fuer experimentelle veterinaermedizin》1985,39(6):847-851

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Biochemical effect of naturally and experimental induced nutritional muscular dystrophy on copper and iron levels in plasmas of suckling Egyptian buffalo calves     

T K el-Neweehy  H A Amer  S A Abd el-Salam 《Archiv fuer experimentelle veterinaermedizin》1985,39(6):859-863

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Influence of induced disease states on the disposition kinetics of imidocarb in goats   总被引：2，自引：0，他引：2  

A Salam Abdullah  J D Baggot 《Journal of veterinary pharmacology and therapeutics》1986,9(2):192-197

The influence of fever, induced by different agents, on the disposition kinetics of imidocarb was determined in goats. Escherichia coli endotoxin (0.2 microgram/kg), Trypanosoma evansi (10(7) in 1 ml sterile glucose citrate), and Infectious Bovine Rhinotracheitis virus (10(6.5)TCID50) were the agents administered to induce the febrile state. In control and febrile animals the two-compartment model was used to describe the disposition kinetics of the drug. Fever caused significant changes to occur in the apparent volume of distribution and the body (systemic) clearance of imidocarb, but the half-life remained unchanged. The statistical significance of the changes in these pharmacokinetic parameters varied with the etiology of the febrile state. E. coli endotoxin and IBR virus caused corresponding decreases in apparent volume of distribution and clearance of imidocarb, while fever induced with T. evansi caused highly significant increases in both pharmacokinetic parameters. It was concluded that the alterations in the disposition kinetics of imidocarb that occurred in the febrile goats were related not only to the febrile reaction per se but also to the pathophysiology of the disease condition.  相似文献   

Blood and tissue concentrations of trimethoprim following its administration alone and in combination with josamycin.     

M G el-Sayed  M I Abd el-Aziz  A M Abd el-Azem 《DTW. Deutsche tier?rztliche Wochenschrift》1992,99(4):154-156

Following a single oral dose of trimethoprim (10 mg/kg b. wt.) in normal fowls, the highest serum concentration achieved 4 hours post-administration with value of 0.64 microgram/ml. The absorption half-life time was 0.64 hours. The elimination half life was 4.73 hours. During repeated oral administration of 10 mg/kg b. wt., once daily for five consecutive days, trimethoprim peaked in serum, 4 h after each dose. Trimethoprim persisted in all fowl's tissues for 96 hours after stopping of drug administration. After oral administration of josamycin (18 mg/kg b. wt.) and trimethoprim (10 mg/kg b. wt.) in normal fowls, a maximum serum concentration of trimethoprim was recorded at 2 hours with half-life of absorption (t0.5(ab)) valued 0.74 hour. The elimination half-life (t0.5 beta) was 4.37 hours. During repeated oral administration of josamycin (18 mg/kg b. wt.) and trimethoprim (10 mg/kg b. wt.) once daily for five consecutive days in normal fowls, the highest plasma concentrations of trimethoprim occurred 2 hours post each dose. The daily maximum plasma concentrations during the repeated oral administration of both tested drugs were nearly constant.  相似文献