HORMONE-INDEPENDENT ROOT ORGAN-CULTURES OF RYE (SECALE-CEREALE)

This work describes the growth of rye root organ cultures which were c apable of being repeatedly subcultured in hormone-free medium. They sh owed morphological characteristics, growth rate, inability to produce shoots, and response to auxins and cytokinins similar to those of the Agrobacterium rhizogenes (Ri plasmid) transformed hairy root cultures of tobacco and red beet which were used for comparison. The root cultu res of rye were initiated from callus produced on a medium containing the growth regulators (plant hormones) 2,4-D and kinetin, then transfe rred to hormone-free medium. However not all rye explants gave rise to callus that would differentiate into stable hairy root cultures and r ye seedling root explants did not grow if placed directly on a hormone -free medium. Rice and wheat produced callus and roots on a medium con taining hormones but root organ cultures could not be maintained on a hormone-flee medium.