Photoregulation of adventitious and axillary shoot proliferation in menthol mint, Mentha arvensis

A direct and indirect methodology for efficient shoot proliferation and reg eneration from various explants of Mentha arvensis has been developed by st udying the interactive effect of plant growth regulator and light colour. N odal explants cultured on Murashige and Skoog's (MS) medium supplemented wi th 10 muM thidiazuron and incubated under red light, proliferated an averag e of 50 shoots after 30 days, whereas internodal explants cultured in modif ied MS medium supplemented with 40 muM 6-benzylaminopurine and 0.5 muM alph a -naphthaleneacetic acid and exposed to red light, regenerated an average of 200 shoots after 60 days. Among the six cultivars tested, internodal exp lants of cv, Gomti regenerated about 90 shoots after 20 days of culture. Un der the above conditions, leaf explants were observed to regenerate an aver age of 60 shoots after 60 days of culture, which was preceded by callus dev elopment. The protocol standardized for high efficiency shoot proliferation and regeneration in M, arvensis from nodal, internodal and leaf explants i s suitable for micropropagation, genetic transformation and for obtaining s omaclonal variants in this essential oil-yielding crop plant.