Comparative Study of the Rates of Organogenesis of Normal and Cecidial Shoots in Shorea curtisii Dyer ex King (Dipterocarpaceae)

Abstract

In the neoformational epiphyllous bud-gall of Gallacoccus anthonyae Beardsley (Eriococcidae), the growth of the cecidial shoot occurs in two developing periods induced by the insect. These two organogenic periods are separated by a resting period which corresponds to the molting and moving stage of the insect. During each of the developing periods, 12 leaves are formed in distichous arrangement. The leaves appear at 6-day intervals. At the end of the second organogenic period, the gall-apex becomes parenchymatous. In the bud-gall of Gallacoccus secundus Beardsley, the development of the cecidial shoot occurs in only one organogenic period. The neoformational apex produces 3 leaves in distichous arrangement and then aborts. The interval between two leaf initiations is less than 10 days. As regards the rate of organogenesis (one leaf every 6 days) and the fate (degeneration) of the apex, the cecidial buds and the terminal bud of the seedling, which is stimulated into hyperactivity after transplantation, are comparable. However, the distichous arrangement in the cecidial buds and the existence in the gall of G. anthonyae of two successive developing periods recall the behavior of the plagiotropic normal buds of Shorea curtisii.