biologia plantarum

Biologia plantarum 36:553, 1994 | DOI: 10.1007/BF02921177

Axillary bud proliferation and ethylene production as controlled by radiation of different spectral composition and exogenous phytohormones

M. Panizza¹, F. Tognoni¹, B. Lercari¹

¹ Dep. Biologia delle Piante Agrarie, University of Pisa, Pisa, Italy

The effect of radiation of different spectral composition on axillary proliferation of lavandin (Lavandula officinalis Chaix ×Lavandula latifolia Villars cv. Grosso) was studied in combination with application of exogenous benzyladenine (BA) and putrescine (Put) and endogenous ethylene production. The effect of BA was predominant over the radiation. Continuous far-red showed a fluence rate-dependent promotion of shoot proliferation in the presence of BA. On BA-free medium, shoot number was enhanced under blue, white, and red radiation, at low photon fluence rates. BA, however, could reduce the inhibiting effect of blue and ultraviolet radiation, at high photon fluence rates. Exogenous Put stimulated axillary bud proliferation under some radiation treatments in the presence of BA. Moreover, Put, analogously to BA, could overcome the detrimental effect of ultraviolet radiation. A positive correlation between biotic ethylene production and shoot formation was evidenced under far-red at high photon fluence rate in the presence of BA, and under white, red and blue radiation at low photon fluence rate in the BA-free medium. However, when abiotic ethylene (released from the agarized medium) was stimulated by UV, no improvement of shoot formation was observed.

Received: June 23, 1993; Accepted: September 30, 1993; Published: December 1, 1994  Show citation