Pre Inoculation Research Articles

Soil Enzyme Activity and Nutrient Uptake as Influenced by Arbuscular Mycorrhizal Fungi in Tobacco Rhizosphere under Parasitic Weed Stress Condition

The present study assessed the effect of Arbuscular mycorrhizal fungi on nutrient uptake and soil enzyme activity of tobacco rhizosphere under parasitic weed stress condition. The experiment was carried out in Orobanche infested soils of Belagavi district during 2018-19. During the investigation different inoculation methods of Arbuscular mycorrhizal fungi were screened for their ability to improve the nutrient uptake and soil enzyme activity i.e. (pre inoculation of nursery seedlings; direct soil application and the combination of both). The present experimental results revealed that soil enzyme activities like dehydrogenase, phosphates and urease activity was highest in treatments received planting of pre colonized tobacco seedling with STD AMF along with soil application at the time of planting and second highest was recorded in the treatment received pre colonized UASDAMFT plus soil application. Furthermore nutrient uptake like N, P, K and micronutrients were found to be the highest in the plots received mycorrhization compare to the rhizosphere of non mycorrhized plants. In mycorrhizosphere the activity of mycorrhizal fungi and other beneficial microorganisms could be a source for different soil enzyme needed for biochemical reaction in the plant rhizosphere.

Comparative evaluation of immune-responsiveness in indigenous and exotic breeds of chicken

In this research we conducted a comparative study of immune responsive traits for the two exotic chicken breeds viz. Australorp and Cornish with one of the indigenous Kadaknath chicken breeds. Immune response to Sheep Red Blood Cells (SRBC) was measured in terms of Haemagglutination Titre (HA) and Haemagglutination Inhibition titre (HI) at five stages viz; 0 (pre inoculation), 3rd , 6th , 9th and 12th days post primary inoculation (PPI) of SRBC. The HA titre was significantly (P

Pectin oligosaccharide (POS) induce resistance in Arabidopsis thaliana through salicylic acid-mediated signaling pathway against Pseudomonas syringae pv.tomato DC3000

To investigate the disease resistance effect of pectin oligosaccharide (POS) in Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), different concentrations of POS (25, 50, 100, 200 mg L−1) were used. Results demonstrated that 25 mg L−1 POS treatment at 3 DPI (days pre inoculation) showed the most effective resistance against Pst DC3000 by enhancing salicylic acid (SA) content and SA pathway mediated genes (PR1, PR2 and PR5) expression. Furthermore, 25 mg L−1 POS pretreated plants also showed significant production of reactive oxygen spices (ROS) and nitric oxide (NO). So, our results suggest that POS induces resistance to Pst DC3000 in Arabidopsis by activating SA pathway.

CONTROL OF LASIODIPLODIA THEOBROMAE ON AVOCADO IN EGYPT

This study was performed during 2015-2016 seasons to identify fungal species associated with dieback, grafting failure process during vegetative propagation in commercial nursery and stem-end rot of avocado(Persea americana Mill.).Lasiodiplodia theobromae (syn. Botryodiplodia theobromae, Diplodia natalensis) was the most pathogenic as well as the most frequently isolated fungi whereas, the other isolated fungi (Alternaria solani, Fusarium moniliforme, F. solani, Aspergillus niger and Rhizopus stolonifer) were negligible. Hass and Fuerte were the most susceptible cultivars to dieback and stem-end rot diseases, followed by Eitinger, Duke and Reed, while Bekon and Benkerton recorded the lowest percentages of infection. Hass and Fuerte were susceptible to grafting failure process. All tested fungicides suppressed completely the avocado dieback infection when shoots were sprayed at the same time of inoculation with L. theobromae, followed by 7 days pre inoculation. On the other hand, spraying the avocado shoots 7 days post inoculation with L. theobromae was the least effective treatment in controlling the disease under greenhouse conditions. Dipping the scions in the tested fungicides before dipping it in spore suspensions of L. theobromae during grafting increased the percentage of success of grafted seedlings. Dipping avocado fruit after harvest in the tested fungicides before placing mycelial agar discs (5 mm diameter) of L. theobromae into a hole on the pedicel (stem) that was made with a 5-mm-diameter cork borer reduced the infection of stem-end rot. Generally, KemaZed, Amistar Top,Topsin M70 and Occidor were the most effective in controlling the avocado three diseases. This study confirms that stem-end rot and failure grafting followed by dieback of avocado can be initiated by fungus causing branch dieback and stresses the importance of controlling branch dieback.

Efficacy of Biological Control Agents for Management of Postharvest Black Rot Pathogen Aspergillus carbonarius in Grapes

Grape berries were treated with different biological agents to test their efficacy in reducing post harvest incidence of black mould rot and minimize the loss. The agents Pseudomonas, Bacillus, Trichoderma and yeast isolates were individually screened against the black rot pathogen Aspergillus carbonarius. B. subtilis strains EPC-8 and EPCO-16 and T. harzianum (Th Co) showed high mycelial growth suppression of A. carbonarius in vitro . The effective biological control agents were tested in pre, post and combined inoculation studies against A. carbonarius in grape berries. In the pre inoculation, B. subtilis (EPC-8) showed 57.80 per cent reduction in the incidence of A. carbonarius followed by T. harzianum (Th Co) (48.43 percent). The same trend of effectiveness was also found in the post-inoculation and combined inoculation tests under storage conditions at room temperature in grape berries.

Efficacy of different biological control agents against major postharvest pathogens of grapes under room temperature storage conditions.

Normal 0 14 false false false IT ZH-TW X-NONE MicrosoftInternetExplorer4 Grapes were treated post harvest with a variety of biological agents to determine their effcacy in reducing yield loss. The agents Pseudomonas , Bacillus , Trichoderma and yeast isolates were individually screened against a number of postharvest pathogens including Aspergillus carbonarius , Penicillum expansum , and Fusarium moniliforme . B. subtilis strains EPC-8 and EPCO-16 showed high mycelial growth suppression of A. carbonarius and P. expansum in vitro . The fungal antagonist Trichoderma viride strain (Tv Tvm) was the most effective, inhibiting mycelial growth by 88.8 per cent. The biological control agents were tested in pre, post and combined inoculation studies against postharvest pathogens of grapes. In the pre inoculation, B. subtilis (EPC-8) reduced the disease incidence of A. carbonarius causing rot, T. harzianum (Th Co) was effective against P. expansum , and T. viride (Tv Tvm) was effective against F. moniliforme . The same trend of effectiveness was also found in the post-inoculation and combined inoculation tests.

Evidence that the Fc region of autologous rabbit IgG isolated before and after hyperimmunization is structurally different: recognition by rheumatoid factor and monoclonal antibodies

Autologous hyperimmune (HI) and pre-inoculation (PI) rabbit Fc gamma populations were found to be conformationally different by spectroscopic measurements, and antigenically different by measurements which examined rheumatoid factor (RF) and monoclonal antibody (MoAb) binding specificity for both populations in ELISA. Circular dichroism spectra of HI rabbit Fc gamma (prepared from animals after hyperimmunization with streptococcal vaccine) were both qualitatively and quantitatively different, particularly in the 225-228 nm range, in comparison to both homologous normal and autologous PI Fc gamma. Binding studies in ELISA showed that affinity constants obtained for reactions of both rabbit RF and various murine MoAb with HI IgG and Fc were approximately 10-fold higher relative to those observed for PI IgG and Fc. Enzymatic deglycosylation of HI and PI Fc gamma led to elimination of CD spectral differences. Further, association constants obtained for RF and MoAb reactions with deglycosylated (sialic acid and galactose removed) PI Fc gamma were equivalent to those obtained in the presence of untreated HI Fc gamma. Together, these results suggest the complex oligosaccharide structure of rabbit IgG may play a significant role in the expression of Fc gamma determinants, and alteration of this structure under hyperimmune or other conditions may be related to induction of an RF response.

Antibody response to Ehrlichia risticii and antibody reactivity to the component antigens in horses with induced Potomac horse fever

The antibody response and the antibody reactivity to component antigens of Ehrlichia risticii were studied in horses with induced Potomac horse fever. These horses had no detectable antibodies to E. risticii in their preinoculation (PrI) sera by indirect fluorescent-antibody assay and enzyme-linked immunosorbent assay (ELISA). All the horses exhibited typical disease features following experimental infection and responded with specific antibodies, as measured by ELISA and indirect fluorescent-antibody assay. A primary antibody response was detected in 70% of the horses, while a secondary-type antibody response was detected in 30% of the horses by ELISA. In the primary antibody response, a distinct titer was observed at 2 weeks postinoculation (PI), when the immunoglobulin M (IgM)/IgG ratio was 2 to 5, and the overall antibody titer peaked at 6 to 8 weeks PI. The secondary-type antibody response exhibited a characteristic titer at 1 week PI, the IgM and IgG titers were about equal at 2 weeks PI, and the overall antibody titer peaked at 6 weeks PI. A transient depression in the IgG response at 4 weeks PI was observed in both response types. The antibody was maintained at a high titer for over a year in all horses. Western immunoblot reactivity showed that the antisera collected from these infected horses at 4 to 5 weeks PI recognized some or all of the six major E. risticii component antigens (70, 55, 51, 44, 33, and 28 kilodaltons), all of which were apparent surface components. The 6- to 8-week PI antisera recognized up to 16 component antigens, including 9 major antigens (110, 86, 70, 55, 51, 49, 44, 33, and 28 kilodaltons). However, the PrI sera of these horses showed reactivity at various intensities with one to seven of the component antigens. There was no apparent correlation between this reactivity pattern and the subsequent antibody response types.

Hyperimmunization alters Fc gamma antigenicity. Linkage to glycosylation.

Rabbits were hyperimmunized with streptococcal vaccine to produce hyperimmune (HI) IgG, and both HI IgG and autologous preinoculation (PI) IgG were used to prepare Fc gamma. mAb raised against these, and deglycosylated PI Fc gamma preparations were subsequently used to determine if antigenic differences existed between autologous HI and PI Fc gamma. Although the majority of mAb examined did not discriminate between the two sources of Fc gamma, several mAb exhibited remarkable specificity for autologous HI Fc gamma. We did not detect any mAb which exhibited the converse specificity. Of the mAb chosen for study, all except one appeared specific for determinants located in C gamma 2; the exception specifically reacted with pFc', and did not discriminate between the two Fc preparations. Importantly, partial deglycosylation of autologous PI Fc gamma led to equivalent reactivity with previously HI-specific mAb. The results of this study provide immunologic evidence that abnormal C gamma 2 structures exist prior to and reach serologically detectable levels during the hyperimmune response in these animals, apparently as a result of glycosylation pattern alterations within the Fc region. Such autoantigenic differences could account for the induction of RF under these conditions, and perhaps in certain human arthritic diseases as well.

Phenols in Cotton Seedlings Resistant and Susceptible to Alternaria macrospora

AbstractIn healthy cotton seedlings, stems have a lower phenol content than leaves, but resistant plants have an altogether relatively higher phenol content than susceptible plants. Phenols extracted from infected plants can inhibit the growth of A. macrospora in vitro. In cotton plants infected with A. macrospora, phenols are oxidized by polyphenoloxidase rather than peroxidase and catalase. The main oxidative activity was around the developing necrotic area but activity was detected far from, necrosis as well. Though pre–inoculation mechanical injuries operated the phenol oxidation mechanism in the plant, they neither prevented nor encouraged the increase in disease severity. Isozyme pattern showed that contribution of all participants in the pathological interaction to the oxidative mechanism occurred in the diseased plant. A negative linear correlation was found between polyphenoloxidase activity, phenol accumulation and resistance. This study suggests that the phenol oxidative mechanism, participates in cotton plant resistance to A. macrospora.