Option 1: F.C. Steward - F.C. Steward was a renowned plant biologist and made significant contributions to plant tissue culture. However, he did not start the work on plant tissue culture.

Option 2: P. Maheshwari - P. Maheshwari was an Indian botanist who played a crucial role in the study of plant reproduction and embryology. However, he did not begin the work on plant tissue culture.

Option 3: P.R. White - P.R. White was an Australian botanist who made significant contributions to the field of plant tissue culture. However, he did not initiate the work on plant tissue culture.

Option 4: Haberlandt - Correct Answer - Haberlandt, an Austrian botanist, is credited with starting the work on plant tissue culture. He pioneered the concept of in vitro culture of plant tissues in the late 19th century, laying the foundation for further advancements in the field.