skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Flower-bud formation in explants of photoperiodic and day-neutral Nicotiana biotypes and its bearing on the regulation of flower formation

Journal Article · · Proceedings of the National Academy of Sciences of the United States of America; (United States)
;  [1]
  1. Michigan State Univ., East Lansing (United States)

The capacity to form flower buds in thin-layer explants was studied in Nicotiana of several species, cultivars, and lines of differing in their response to photoperiod. This capacity was found in all biotypes examined and could extend into sepals and corolla. It varied depending on genotype, source tissue and its developmental state, and composition of the culture medium, particularly the levels of glucose, auxin, and cytokinin. It was greatest in the two day-neutral plants examined, Samsun tobacco and Nicotiana rustica, where it extended from the inflorescence region down the vegetative stem, in a basipetally decreasing gradient; it was least in the two qualitative photoperiodic plants studied, the long-day plant Nicotiana silvestris and the short-day plant Maryland Mammoth tobacco, the quantitative long-day plant Nicotiana alata and the quantitative short-day plant Nicotiana otophora line 38-G-81, where it was limited to the pedicels (and, in some cases, the sepals). Regardless of the photoperiodic response of the source plants, the response was the same in explants cultured under long and short days. The capacity to form flow buds in explants is present in all Nicotiana biotypes studied supports the idea that it is regulated by the same mechanism(s), regardless of the plant's photoperiodic character. However, flower formation in the explants is not identical with de novo flower formation in a hitherto vegetative plant: it is rather the expression of a floral state already established in the plant, although it can vary widely in extent and spatial distribution. Culture conditions that permit flower-bud formation in an explant are conditions that maintain the floral state and encourage its expression; conditions under which no flower buds are formed reduce this state and/or prevent its expression. 14 refs., 5 figs., 3 tabs.

DOE Contract Number:
AC02-76ER01338
OSTI ID:
6246814
Journal Information:
Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 90:10; ISSN 0027-8424
Country of Publication:
United States
Language:
English