AN INVESTIGATION ON CALLUS FORMATION STAGES IN ST. JOHN'S WORT, HYPERICUM PERFORATUM L . , IN CULTURE MEDIUM
St. John's wort is a valuable medicinal plant that has been used for more than 2000 years and is known globally as one of the best medicines in the context of neurological diseases and skin health. As the leading sciences worldwide, plant tissue culture and micropropagation by genetic engineering methods are important indicators of agricultural biotechnology. The fact that undifferentiated plant cells can potentially turn into a complete plant can lead to the conclusion that a new gateway has been opened for biologists. As such, it considerably accelerates the time for the implementation of breeding programs in comparison to traditional plant breeding methods and allows inter-genera crosses in plants. In addition, other basic applications of tissue culture by plant microsamples include maintenance of genetic reserves, production of virus-free plants, and paying economic and practical attention to the production of haploid plants. The present research briefly investigates on callus formation stages of St. John's wort in culture medium (MS).