The transition from vegetative to reproductive development in switchgrass (Panicum virgatum L.) has been described as a photoperiod-mediated process. With its extensive native range, photoperiod response varies widely within the species. To synchronize flowering among cultivars of distinct origin, disparities in light-driven developmental responses often require breeders to develop elaborate photoperiod regimens. The objective of this research was to identify a simple photoperiod treatment that could be used to evoke sexual reproductive development for three upland cultivars of switchgrass: Cave-In- Rock (origin 37°N), Sunburst (origin 42°N), and Dacotah (origin 46°N). To evaluate photoperiod sensitivity, switchgrass clones were grown in the greenhouse under various local natural ambient photoperiods, as well as under a 24-h low-irradiance daylight extension. Despite previously being described as a short-day plant, these upland cultivars of switchgrass were induced to flower under 24-h low-irradiance daylight-extended photoperiod. This daylight extension method was valid for use in addition to any ambient photoperiod. These results identified a simple system that used inexpensive equipment (common fluorescent bulbs) and required no alternating light and dark periods to promote panicle production in switchgrass. This system will be useful for improving seed yield components, via controlled pollination in the greenhouse, most especially when the ambient photoperiods are not favorable for floral induction.
ASJC Scopus subject areas
- Agronomy and Crop Science