In vitroinduced floral reversion in switchgrass (Panicum VirgatumL.)

Abstract

Switchgrass (Panicum Virgatum L.) is a warm-season perennial grass native to North America, it was used as forage and vegetative filter strips in early days, and have developed into a bioenergy crop in recent years. In this study, we found that the switchgrass cultivar ‘Alamo’ at elongation stage 4 have developed inflorescences about 1 cm in length, and in vitro incubation of the shoot apexes harboring inflorescences on Murashige and Skoog’s basal medium supplemented with 3 mg/L 6-benzylaminopurine generated multiple shoot clumps. Anatomical study showed that some of the regenerated shoots originated from axillary buds on the explants, some of them originated from adventurous buds and some of them originated from young florets. Further study of shoots originated from young florets found that the floral organs degenerated or developed into leaf-like organs, and the flower terminal transformed into a vegetative shoot apical meristem, that’s to say these shoots arise from flower reversion. In vitro induction of floral reversion provided a novel protocol to manipulate flower development in switchgrass, which might contribute a fundamental for flower development study in switchgrass and other plants.