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Study on viruses infecting black pepper indicated that infection of Cucumber mosaic virus (CMV) and Piper yellow mottle virus (PYMoV) either alone or as mixed infections was prevalent in cultivated areas of Idukki and Wayanad districts of Kerala. Highest disease incidence (DI) was observed in Poothadi (45.50 %) of Wayanad and lowest in Karunapuram (21.62 %) of Idukki district. Highest vulnerability index (V.I.) was recorded in Panamaram (61) of Wayanad and lowest in Pampadumpara (32) of Idukki. Serological technique DAS-ELISA was used for detection of these viruses along with molecular detection using coat protein specific primers. The isolates of PYMoV from different locations ofIdukki and Wayanad showed similarity in ORF III to other reported PYMoV sequences. [ABSTRACT FROM AUTHOR]

Chemical fungicides used in plant disease management may have deteriorative effects on humans, animals, and the environment. The use of native strains of Trichoderma spp. against plant diseases may help to reduce the dependence on chemical fungicides. In this study, eleven novel isolates of Trichoderma spp. from virgin forest soils of different agro-climatic zones of Kerala were characterized and evaluated for their efficacy against damping off disease of tomato caused by Pythium aphanidermatum under in vitro and in vivo; and also, against wilt pathogen, Fusarium oxysporum under in vitro conditions. Dual culture assay showed that all the Trichoderma isolates were found to inhibit the growth of P. aphanidermatum and F. oxysporum under in vitro conditions with multiple modes of action. The mycelial colour, texture, and conidial characters varied among all the isolates. The volatile metabolites by isolates of Trichoderma spp. also showed in vitro inhibition of the pathogens. Seed treatment (20 g kg-1) and potting medium addition @ 2 % (w/w) of isolates TRMW-2, TRKR-2, TRPN-3, TRPN-11 and TRPN-17 could effectively reduce pre- and post-emergence damping off of tomato. Among them, isolates TRMW-2, TRKR-2, and TRPN-11 were the most effective ones in reducing pre- and post-emergence damping off to about 72 and 90 percent respectively. Molecular identification of the isolates of Trichoderma spp. using ITS universal primers revealed similarity with certain reference strains of the NCBI Genbank database. [ABSTRACT FROM AUTHOR]

Cardamom plantations are subjected to constant threat due to the Fusarium rot disease caused by Fusarium oxysporum Schlecht which is pronounced during summer months. The current study deals with the identification of an effective and ecofriendly management practice for the disease through the use of biocontrol agents. Survey conducted between February and May 2019 revealed maximum disease severity and incidence in Pampadumpara panchayat of Nedumkandam block (84.40% and 100%) and minimum in Erattayar panchayat of Kattappana block (50.40% and 60.00%). A pot culture experiment was conducted to study the effect of three bioagents (Glomus fasciculatum, Trichoderma asperellum and Pseudomonas fluorescens) individually as well as in combinations. Root inoculation of G. fasciculatum with basal application and spray with P. fluorescens as well as root inoculation of G. fasciculatum along with basal application of T. asperellum and P. fluorescens spray were identified to be effective against the disease. Disease suppression by the above bioagents was facilitated by reduced pathogen antagonist ratio in the soil, high level of mycorrhizal colonization in the roots and enhanced biochemical activity of defense enzymes like peroxidase, poly phenol oxidase and phenylalanine ammonia lyase in the plants. [ABSTRACT FROM AUTHOR]

Trichoderma spp. are long been recognized as efficient fungal biocontrol agents for the control of plant disease and for their ability to increase plant growth and development. Management of soil borne diseases has become very much important since it causes high crop yield losses. The present study was carried out to isolate Trichoderma spp. from soil samples collected from different locations of Kerala and to test their in vitro efficacy against soil borne pathogens viz., Pythium aphanidermatum and Rhizoctonia solani. The Trichoderma spp. was isolated on Trichoderma Selective Medium (TSM) and observed that the isolates differed in radial growth and colony characters such as colony colour, texture and sporulation. In vitro studies revealed the potential of Trichoderma isolates against soil borne pathogens. Isolates TRPN3 and TRPN7 exhibited no sporulation and white mycelial colour. Isolates which completed their growth at four days after inoculation include TRKR1, TRPN3, TRPN7, TRPN10 and TRPN18. Biocontrol activities against different pathogens resulted in inhibition of pathogens. Maximum inhibition percentage was observed by the isolates TRPN7, TRPN15 and TRKR2 against both the pathogens. The maximum inhibition exhibited against both the pathogens is due to the antagonistic property displayed by the isolates. [ABSTRACT FROM AUTHOR]

Basal stem rot and blight disease incited by Sclerotium rolfsii resulted in significant crop loss in vegetable cowpea. Among the different levels of pH tested under in vitro conditions, pH 6.0 was revealed to be optimum for the mycelial growth, whereas pH 7.0 supported maximum sclerotia formation. Soil moisture of 35 to 50 per cent was ideal for early disease expression and establishment. A minimum level of two per cent fungal inoculum multiplied in sand oats medium resulted in complete disease incidence. Among the botanicals tested in vitro, garlic bulb extract (1%) and garlic creeper leaf extract (5%) revealed cent per cent inhibition of mycelial growth and sclerotia formation of the fungus. Both the extracts also inhibited the mycelial regeneration from sclerotia. Thus, garlic bulb and garlic creeper were revealed to be potent botanicals which can be used as effective alternatives to soil fumigants for the management of S. rolfsii. [ABSTRACT FROM AUTHOR]

A study was undertaken during December 2020 to February 2021 to evaluate the suitability of oyster mushrooms in different agro-ecological zones of Kerala viz., coastal plains, midland laterites, foothills, high hills and Palakkad plains. The oyster mushroom species selected were Pleurotus florida, Pleurotus djamor, Hypsizygus ulmarius, Pleurotus sajor-caju and Pleurotus citrinopileatus. The sporocarps of five species of oyster mushrooms were studied based on the size, texture and colour of sporocarp, gill arrangement, stipe length and colour of pinhead. Performance of all the species were evaluated based on yield and growth characteristics. H. ulmarius was found to be best suited oyster mushroom species for cultivation in coastal plains with biological efficiency (BE) of 102.99 per cent, foot hills (92.73 per cent BE) and high hills (123.30 per cent BE). In midland laterites and Palakkad plains, highest BE of 82.70 per cent and 103.80 per cent respectively were obtained from P. djamor. Earliness in primordial initiation and less crop duration was observed in P. djamor from all the five agro-ecological zones of Kerala. From the present study it was evident that H. ulmarius was adapted to the climatic conditions prevailing throughout Kerala. P. djamor performed well in areas having higher temperature (more than 280C), lesser rainfall and lesser humidity (80 per cent). [ABSTRACT FROM AUTHOR]

We have recently reported significant association of non-polio enteroviruses (NPEVs) with acute and persistent diarrhea (18-21% of total diarrheal cases), and non-diarrheal Increased Frequency of Bowel Movements (IFoBM-ND) (about 29% of the NPEV infections) in children and that the NPEV-associated diarrhea was as significant as rotavirus diarrhea. However, their diarrhea-causing potential is yet to be demonstrated in an animal model system. Since the determination of virus titers by the traditional plaque assay takes 4-7 days, there is a need for development of a rapid method for virus titer determination to facilitate active clinical research on enterovirus-associated diarrhea. The goal of this study is to develop a cell-based rapid detection and enumeration method and to demonstrate the diarrhea-inducing potential of purified and characterized non-polio enteroviruses, which were isolated from diarrheic children. Here we describe generation of monoclonal and polyclonal antibodies against purified strains belonging to different serotypes, and development of an enzyme-linked immuno focus assay (ELIFA) for detection and enumeration of live NPEV particles in clinical and purified virus samples, and a newborn mouse model for NPEV diarrhea. Plaque-purified NPVEs, belonging to different serotypes, isolated from children with diarrhea, were grown in cell culture and purified by isopycnic CsCl density gradient centrifugation. By ELIFA, NPEVs could be detected and enumerated within 12h post-infection. Our results demonstrated that Coxsackievirus B1 (CVB1) and CVB5 strains, isolated from diarrheic children, induced severe diarrhea in orally-inoculated 9-12 day-old mouse pups, fulfilling Koch's postulates. The methods described here would facilitate studies on NPEV-associated gastrointestinal disease., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Lymphatic filariasis is a parasitic disease of tropical countries. This is a disfiguring and painful disease contracted in childhood, but the symptoms become apparent only in later years. Diagnosis of filarial infection is very crucial for the management of the disease. The main objective of this study was to develop a filarial antigen-based immunological assay for the diagnosis and surveillance of the disease. Monoclonal and polyclonal antibodies were raised to the recombinant protein Brugia malayi vespid allergen homologue (VAH). Capture enzyme-linked immunosorbent assay (ELISA) was standardized utilizing various combinations of antibodies and evaluated with serum samples of endemic normal (EN, n= 110), microfilaraemic (MF, n= 65), chronic pathology (CP, n= 45) and non-endemic normal (NEN, n= 10) individuals. Of the 230 samples tested, VAH capture assay detected circulating antigen in 97.91% of bancroftian and 100% of brugian microfilaraemic individuals, and 5% of endemic normal individuals, comparable to the earlier reported SXP-1 antigen detection assay. However, the combination of VAH and SXP-1 (VS) capture ELISA was found to be more robust, detecting 100% of microfilaraemic individuals and with higher binding values. Thus an antigen capture immunoassay has been developed, which can differentiate active infection from chronic infection by detecting circulating filarial antigens in clinical groups of endemic areas.