Effects of light quality on shoot proliferation ofPrunus cerasifera in vitroare the result of differential effects on bud induction and apical dominance

Abstract

SummaryThe morphogenic effect of different light qualities was investigated on in vitro shoot proliferation of Prunus cerasifera (clone Mr.S. 2/5) in relation to apical dominance and node formation. In intact microcuttings, leader stem length was not affected by light quality but blue and white light produced a higher number of nodes, with shorter internodes than red or far-red light or darkness. The proportion of nodes producing outgrowing lateral shoots was higher in red and far-red light than in white, blue or darkness. In decapitated microcuttings apical dominance was fully released in all the light treatments but not in darkness. Taken together the data show that the proliferation rate is a product of bud induction and release from apical dominance which are differentially affected by light quality. The much lower percentage outgrowth in white and blue light as compared with red light indicates a specific effect of blue light acting in the opposite direction to active (far-red light absorbing) form o...