Some histochemical observations on leaf abscission zone in Capsicum annuum L.

Abstract

The present observations were conducted on NP 46-A and Pusa jwala varieties of Capsicum annuum L. Investigations on changes in cell wall components of the cells of leaf abscission zone associated with the process of abscission were based on specific qualitative histochemical staining procedures. It was observed that the loss of pectic and cellulosic substances preceded the separation phase of abscission from middle lamella and cell walls of the cells of separation layer of abscission zone. The abscission zone was characterized by thin cutin deposition on epidermal cells and poor lignification in vascular elements of this region. Separation of senescent part of petiole was followed by deposition of suberin in cells of some outer layers of abscission zone and by the deposition of lignin in cells of the remaining layers of abscission zone to form a protection layer on exposed part of petiole stump. Development of tyloses, tannins and calcium oxalate crystals was not found associated with abscission in the present plant material.