PLANT-REGENERATION FROM CALLUS-CULTURES OF SWITCHGRASS

Regeneration from cells or tissues cultured in vitro is a fundamental requirement for most applications of plant biotechnology. The objective of this study was to develop protocols in which plants could be regenerated with ease and in high numbers from tissue cultures of switchgrass (Panicum virgatum L.). Mature caryopses and young leaf segments of the cultivar Alamo were explanted onto agar solidified Murashige and Skoog medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP). BAP at 45 mu M for mature caryopses and at 5 mu M for leaf explants in combination with 22.5 mu M 2,4-D produced high frequency plantlet regeneration by both organogenesis and somatic embryogenesis. The mode of regeneration was documented by light and scanning electron microscopy. One thousand regenerated plants have been established in the field for observation and evaluation.