Characterization of phylloplane microflora of tomato (Solanum lycopersicum L.) and their role against major foliar fungal diseases
| dc.contributor.advisor | Rajest, T. | |
| dc.contributor.author | Hajong, Monika | |
| dc.date.accessioned | 2023-02-09T08:20:25Z | |
| dc.date.available | 2023-02-09T08:20:25Z | |
| dc.date.issued | 2020-07 | |
| dc.description.abstract | Phylloplane is a leaf surface, which harbours a diverse kind of microbial populations. Foliar disease management was not as successful as compared in rhizosphere as the microbial growth on leaves are restricted by severe environmental conditions. Phylloplane microflora play a vital role in agricultural and environmental process as they can impact the ecological balance, plant growth, suppress or stimulate colonization and infection of the plant pathogens. Therefore, the aim of this investigation was to isolate and evaluate the potential strains from tomato phylloplane against the major foliar fungal diseases namely early blight, late blight and Septoria leaf spot. The surveys were conducted from different tomato growing areas of 7 districts namely Ri-bhoi, East Khasi Hills, West Jaintia Hills, East Jaintia Hills, East Garo Hills, West Garo Hills and South West Garo Hills of Meghalaya for the collection of tomato leaf samples. Total, 173 bacteria and 96 fungi were isolated from collected samples by following 3 different methods. Out of 3 different isolation methods, leaf impression method recovered the maximum microbial populations followed by leaf washing and without dilution plating method and leaf washing and serial dilution plating method. Bacteria were found predominant in tomato phylloplane compared to fungi. All the bacterial and fungal isolates were tentatively identified and grouped based on morphological and biochemical tests. The predominant bacteria tentatively identified were whitish colony (102 isolates) followed by yellow-pigmented bacteria (28 isolates), bacteria with cream colonies (20 isolates), fluorescens bacteria (10 isolates), pink-bacteria (8 isolates) and branching-like bacteria (5 isolates). The predominant fungi found were Phoma sp. followed by Trichoderma sp., Pythium sp., Penicillium sp., Fusarium sp., Acremonium sp., Aspergillus sp., Chaetomium sp., Cladosporium sp. Rhizopus sp., Botryodiplodia sp., Alternaria sp. and Camarosporium sp. Out of 173 bacterial isolates only 10 isolates were found effective by showing at least 50% growth inhibition of foliar pathogens under in vitro condition. The results of present investigation suggested that majority of the phylloplane fungi isolated from tomato are pathogenic in nature and only Penicillium sp. and Trichoderma sp., were found most effective by showing at least 50% growth inhibition of pathogens under in vitro condition. Only 10 bacterial and 10 fungal isolates were selected as antagonists against the pathogens based on their in vitro tests such as dual culture assay, antimicrobial and PGP traits. These 10 bacterial strains were further identified based on molecular method using 16S rDNA gene sequenced. The fungal strains were identified by National Centre for Fungal Taxonomy (NCFT), New Delhi. Among these 20 strains, only 2 best strains namely B. altitudinis ASH2 and P. chrysogenum ALH1L were further selected for talc-based bioformulation preparation. These talc-based bioformulations were further evaluated under pot and field condition against the late blight disease of tomato (P. infestans). Various mode of bioformulation delivery was used either in individual as seed treatment or soil treatment or root-dip treatment or foliar spray and in combination. Total 15 treatments were used under field condition including the control, and it was found that the combination treatment of B. altitudinis ASH2 and P. chrysogenum ALH2L (seed + soil + root-dip + foliar spray) was most effective in managing the late blight disease by recording only 8.33% and 41.67% disease incidence as compared to negative control (58.33%) even on 90th DAT. Also, maximum yield was recorded with these 2 treatments (48.36 and 46.28 t/ha/plot) as compared to negative control plot (23.94 t/ha/plot). Similarly, combination treatment with both the bioformulations respectively under pot experiment in both the seasons were also found the lower disease incidence with higher yield as compared to the control plant. | en_US |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810193521 | |
| dc.language.iso | English | en_US |
| dc.pages | [30], 252p. | en_US |
| dc.publisher | College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam | en_US |
| dc.sub | Plant Pathology | en_US |
| dc.subject | Tomato | en_US |
| dc.subject | Fungal diseases | en_US |
| dc.theme | Academic Research | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | Characterization of phylloplane microflora of tomato (Solanum lycopersicum L.) and their role against major foliar fungal diseases | en_US |
| dc.type | Thesis | en_US |