EXPERIMENTAL-EVIDENCE FOR THE AUTONOMY OF RAY DIFFERENTIATION IN FICUS-SYCOMORUS L

Wounding or partial girdling leaving only a narrow cambial bridge resu lted in changes in the xylem structure in stems and branches of Ficus sycomorus. Wounding inhibited the formation of fibre bands, induced ty losis and differentiation of narrow vessels, and resulted in partially differentiated tissues. Partial girdling of mature trunks resulted in the formation of either a strip of traumatic xylem or a parenchymal s trip in which all axial components failed to differentiate but the rad ial system was not affected and the rays continued to form. The differ entiation of rays without an axial system is indicative of the autonom y of the radial signal system that participates in the regulation of r ay formation.