ABSTRACT
Pasteurella multocida [P. multocida] is an important pathogen of various domestic animals. The outer membrane proteins [OMPs] play a major role in pathogenesis and immunogenicity of P. multocida. The aim of the study was to develop indirect enzyme linked immuno sorbant assay [ELISA] based on OMPs to ascertain the antibody titers in animals post-infection or to gauge the potency of vaccine. The OMPs were extracted and purified from P. multocida P: 52 [vaccine strain] and P. multocida B: 2 isolated from natural outbreak of Haemorrhagic septicaemia [HS] and analyzed on SDS PAGE and through western blot. The OMPs profile of the vaccine strain and the isolate from the natural outbreak of HS were found to be similar. Optimization of various components viz. coating antigens, anti-species conjugate, etc. were carried out against both anti-P. multocida hyper immune and pre immune serum. Validation of OMP based indirect ELISA assay to measure immune response against P. multocida in bovine revealed 91% diagnostic sensitivity [DSN] and about 100% diagnostic specificity [DSP] at 25% cut off. OMP based indirect ELISA was found to be more specific, but less sensitive as compared to WCL based assay
ABSTRACT
The status of colonization of Arbuscular Mycorrhizal Fungi [AMF] in the roots and AMF spore population in the rhizosphere soils of Turmeric [Curcuma domestica Vahl.] were assessed with the samples collected from Dashmail, Kantaji and Ramsagar of Dinajpur district; Thengamara of Bogra district and Boalmari of Faridpur district. Roots were assessed for AMF colonization after staining in aniline blue and rhizosphere soil samples were assessed for AM fungal spore population following wet sieving and decanting methods. Turmeric roots collected from different locations were found mycotrophic and the rhizosphere soil samples contained a large number of AMF spores. Significant variation of biodiversity of colonization and spore population were recorded in the present investigation. The range of AM colonization varied from 34% to 52% with the highest AM colonization was recorded from Kantaji [52%] and the lowest from Thengamara [34%]. The range of mycelial, vesicular and arbuscular colonization was recorded as 34-52%, 24-48% and 26-40% respectively. Poor, moderate and abundant intensity was recorded as 51-71%, 21-40% and 5-22% for mycelial colonization; 34-67%, 21-54% and 4-24% for vesicular colonization and 54-81%, 17-39% and 2-22% for arbuscular colonization respectively. Total range of spore population was recorded as 54-154 with the highest from Boalmari [154] and the lowest from Dashmail [54]. No correlation was found between percent colonization and the spore population. Glomus was dominant among the available AM fungal genera. Biodiversity of structural colonization in the roots and AM fungal genera in the rhizosphere soil samples of turmeric growing areas indicate the applicability of AM fungal technology in turmeric growing areas
Subject(s)
Mycorrhizae , Fungi , Curcuma , Zingiberaceae , Plant RootsABSTRACT
Neem is one of the most valuable multi-purpose tree. This tree is very important culturally, medicinally and pesticidally and has gained worldwide recognition for its pharmaceutical and pesticidal properties. Our knowledge about the diseases of Neem is quite insufficient and fragmentary. Only leaf spots caused by Cercospora subsessilis are recorded from Bangladesh. The present work was undertaken to record the occurrence of powdery mildew on Neem leaves that has not been recorded earlier from Bangladesh. The symptoms of the disease were observed thoroughly under field conditions and the infected samples were brought to the laboratory for the detection of the causal organism from the diseased leaves. The causal organism of powdery mildew disease of Neem was observed in the laboratory and was identified as Oidium azadirachtae sp. nov. Initial infection in the leaf surface was found as a tiny powder mass and with the progress of the disease the whole area of the leaf was covered with a powder mass. The infection was also found on the lower surface of the mature leaves. The leaf becomes susceptible to infection when it is half the normal size and remains so till senescence. The disease was more prevalent in mature or old leaves than the young leaves. Because of leaf surface coverage with the powdery mass the photosynthetic activities are reduced and severe fungal attack results in defoliation. The spread of the diseases is favoured by high humidity, low temperature and mist. The specimens with typical powdery mildew symptoms were preserved in the laboratory