Anther culture is the process of using anthers to culture haploid plantlets. The technique was discovered in 1964 by Guha and Maheshwari. This technique can be used in over 200 species, including tomato, rice, tobacco, barley and geranium. In experiments using Datura innoxia, induction frequencies of almost 100% and a yield of more than one thousand plantlets or calluses have occurred under optimal conditions from one anther. Success can be determined within 24 hours as cells begin to divide.