Suberization and bud formation in tobacco explants

Abstract

Wound‐healing and floral bud formation were studied in explants of Nicotiana tabacum L. Examination of sectioned material by conventional light microscopy, fluorescence microscopy and electron microscopy showed that suberin is formed in cells at the cut surface in close contact with the medium, after 4–7 days of culture. The number of cells depositing suberin depended on the agar concentration in the medium. In explants cultured on a medium with low agar concentration (0‐2 % agar), fewer cells showed suberin deposition and more callus cells without suberin were found. Explants cultured on a medium with high agar concentration (5 % agar) formed a complete layer of cells with suberin deposition. In tobacco explants floral determination occurred within 4 days after explantation. The inability of the explants to form floral buds after this period is probably due to barrier formation by suberin. Copyright © 1990, Wiley Blackwell. All rights reserved