[6] Tiwari was born in Jabalpur and obtained his PhD in genetics from Indian Agriculture Research Institute and further completed postdoc from National Institute of Agricultural Botany, Cambridge, UK.

[7] Tiwari created a rapid method for plant anatomy using fluorescence microscopy in 1986.

[13] He was instrumental in preparing an in-depth report on the state of plant genetic resources available for food and agriculture for the FAO (United Nations).

[15][16][17] He served as Chairman of the National Biodiversity Authority under the Ministry of Environment, Forests and climate change, Government of India, Expert Committee on Normally Traded Commodities from 2005 to 2007.

[18] He also served as board member of Acharya N. G. Ranga Agricultural University, Hyderabad, from 2005 to 2008.