Abstract
When the shoot apex of Helianthus annuus cv. Peredovic is bisected surgically, two new apices are regenerated, each of which, 3 weeks after the operation, contains a quiescent central zone similar to that of the original apex. The operation destroys some cells of the original zone and stimulates others to become active in DNA synthesis. Regenerating apices, supplied with [H3] thymidine and autoradiographed at the end of the 2nd day after the operation, reveal no evidence of a quiescent zone. Evidence for the establishment of quiescence appears by the end of the 3rd day and becomes clearer on the 4th and 5th days after the operation. There is no evidence that the residual zone cells play any particular role in regeneration. It is suggested that quiescence in regard to DNA synthesis and mitosis appears sooner than the cytological features associated with quiescence in the sunflower shoot apex.
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.
