Dr. Ratul Nath Key Note Speaker INFES- 2019

Ratul Nath

Former INSPIRE Fello, DST India

Assistant Professor, Deptt. of Botany, Biswanath College, Chariali,

Biswanath, Assam, India

Title of presentation: Evaluation of biofertilizer potential of Endophytic microbial consortium isolated from tea bush (Camellia sinensis L.)


At present, the tea cultivation in India, especially in Assam is highly dependent on agrochemicals including chemical fertilizers and pesticides. These agrochemicals are usually applied beyond the permissible limit and hence causing a remarkable adverse effects to the ecosystem. Because of excess use of agrochemicals, quality of Indian tea is declining gradually and sometimes the foreign markets reject the tea from India because of high chemical residues present in it. To regain the quality, production of organic tea is one of the best ways. The organic agriculture needs a high amount of biofertilizers and biopesticides. Though lots of biofertilizers are introduced in the market, most of them are prepared from microorganisms isolated from soil. Soil microorganisms are not native to the plant system and hence they may have some negative effects to the plant health leading to low production. Hence, we have to search for new sources of biofertilizers which are more native to the plant system.Endophytic microorgaisms are the microbes present inside the plant tissues without showing any visible effects to the plant system and exhibits very good role in plant growth. As they are present inside the plant system, they are much more native to the plant in comparison to the rhizosphere microbes. Hence, there is every possibility that biofertilizers derived from endophytes may work better in comparison to others. In this study we have isolated endophytic bacteria from tea roots, leaves and stems and were screened for their in vitro plant growth promoting potentials including plant growth hormone production (Indole Acetic acid and Giberellin), mineral solubilization (Phosphate, zinc and potassium) and siderophore production activities. Antimicrobial activities of the isolates were tested against some established plant pathogens. A total of four endophytic bacteria were identified as best in terms of their plant growth promotion and antimicrobial activities and were subjected to pot culture experiment. The experiment exhibited significant growth promotion by the consortium prepared from endophytic bacteria and hence may be used as potential biofertilizer for tea.

Key words: Endophytic microorganism, Biofertilizer, plant growth promotion.


Dr. Nath has completed his M.Sc. from Department of Life sciences, Dibrugarh University with first class first position in 2009 and completed his doctorate from Assam University, Silchar in Endophytic Microbial Biotechnology under the guidance of Prof. G. D. Sharma, Vice-Chancellor, Bilaspur University and Prof. Madhumita Barooah, Assam Agricultural University in 2015 with INSPIRE fellowship from DST India. Dr. Nath is one of the pioneer workers of endophytic microbial ecology of tea and presently working as Assistant Professor in Botany at Biswanath College, Assam. He is the Coordinator of UGC b. Voc. Course in “small tea garden management” in the same college as well as Principal investigator of a DBT sponsored research project on Traditional rice beer of Deori community of Assam”.