Diversity of phylloplane microflora in certain tea cultivars of Assam, North-East India

摘要

The phylloplane is considered as the hostile environment for microbial growth. Phylloplane microflora plays important role affecting the plant-microbe interactions in leaf surface and thereby contribute significantly for beneficial plant growth and disease suppression. Qualitative and quantitative composition of phylloplane microflora depends on change in various parameters such as host characteristics, leaf architecture, chemical environment of the corresponding leaf surface and altering micro and macro climatic conditions. In the present investigation, the qualitative and quantitative estimation of fungi and quantitative estimation of bacteria and actinomycetes were carried out in the phylloplane of certain tea cultivars of Assam like TV 1, TV 18, TV 25, Teenali 17, T.3E/3, S.3A/1, S.3A/3 and Clone 663 using a culture-based approach. The study revealed the existence of more bacterial populations over fungi irrespective of the tea clones. Quantitatively the density of bacteria in young leaves (3 rd leaf) ranged between 7.0x10 4 cfu/ml to 90x10 4 cfu/ml while the fungal population ranged from 1.0x10 4 cfu/ml to 37x10 4 cfu/ml respectively. Irrespective of the methods used, the actinomycetes population was found to be scarce. Microbial density was maximum in February and minimum in June. Leaf surface of TV 1 showed maximum microbial occurrence. Qualitatively a total of 10 fungal genera were isolated throughout the investigation of which Aspergillus and Penicillium were recorded as the dominant mycoflora.