Development of supernumerary buds from the axillary meristem of pea, Pisum sativum (Fabaceae)

Abstract

Leaf axils of higher plants commonly contain vegetative axillary buds, which are derived from an axillary meristem. The persistence and continued organogenic activity of the axillary meristem has been studied experimentally in only two species. Pea (Pisum sativum L.) leaf axils contain up to four preformed axillary buds. Decapitating plants above Node 5 promoted the development of preformed buds at all nodes. Buds at each node were removed as soon as they began to grow. These manipulations eventually led to the growth of all the preformed buds and promoted the development of supernumerary buds in the axil of each leaf. Adventitious buds were not observed anywhere on these plants. Examination of leaf axil anatomy and external morphology indicated that new buds were derived from the axillary meristem. The axillary meristem at Node 2 was capable of forming at least six supernumerary buds. ‘Alaska’ plants (Rms-2) exhibited strong apical dominance whereas WL5951 plants (rms-2) contained branches at several nodes. Patterns of bud organogenesis and development were similar in both cultivars.