[4] His graduate studies were completed in Botany (1959)[4] from the University of Madras following which he obtained masters (1964)[4] and doctoral degrees (1968)[4] in Cytogenetics, under the supervision of renowned botanist, M. S. Swaminathan, from the Indian Agricultural Research Institute (IARI).
[1][5] His career started at his alma mater, the Indian Agricultural Research Institute, as a cytogeneticist in 1968,[6][1][5] a post he held till 1976 when he was promoted as the Senior Scientist.
[4][1] The next move was to Indian Council of Agricultural Research (ICAR), New Delhi as the Deputy Director General of the Crop Science Division.
[5] In 1997 Siddiq was honored as the National Professor of ICAR and in 2002,[1][6] he took charge of the Centre for DNA Fingerprinting and Diagnostics (CDFD) as the Distinguished Chair.
[1] He sits in the Board of Members of the International Rice Research Institute as well as the Executive Committee of the Agri Biotech Foundation.
[8] Siddiq is the chairman of the Farm and Rural Science Foundation of The Federation of Andhra Pradesh Chambers of Commerce and Industry.
[5] On the organizational front, Siddiq has collaborated with the World Bank/FAO as consultant and advisor and has prepared many project proposals for programs in Egypt, Sri Lanka, India, Indonesia and the Philippines.
[4] In 2011, the Government of India included him in the Republic day honours, listing him for the fourth highest civilian award of Padma Shri.