Abstract
Two experiments were conducted to examine the response of Rudbeckia hirta to limited inductive photoperiodic treatments. Plants of R. hirta were grown to maturity under short days (SD). In the first experiment, mature plants were placed under LD for 0, 8, 16, 24 or 32 LD before being returned to SD with one group remaining under LD as a control. In the second experiment, mature plants remained under LD for 0, 4, 8, 12, 16, 20, 24, or 28 days before they were returned to SD. Meristems were sampled 0, 4, 8, or 12 days after return to SD and histologically examined. Plants receiving 32, 36, 40 or 44 LD were used as a continuous LD control. As the number of inductive cycles was increased, plant height and branch number increased. Plants receiving only 4 LD never progressed beyond floral initiation. After 8 LD, the meristems continued to develop even when returned to SD. Once involucral bract primordia initiated, the meristem was committed to flower whether in LD or SD conditions. Plants receiving 24 or more LD reached anthesis earlier than plants receiving fewer LD.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
