Histological and in vitro seed culture studies on Biancaea sappan (L.) Tod. (Caesalpiniaceae)

Abstract

Establishment of a tissue culture protocol for clonal regeneration is an essential prerequisite for the potential and economically important plant species Biancaea sappan (L.) Tod. (syn. Caesalpinia sappan L.; Caesalpiniaceae). This plant is a valuable dye-yielding legume shrub native to Indomalayan and is used in India by the local people of Kerala and Tamil Nadu States for its biological potential. The present study evaluated seed development both in vivo and in vitro through histological analysis. The mature seed was used as explants and cultured on modified Murashige and Skoog (MS) medium supplemented with 2, 4-D, BAP, GA3 and IBA. The cultures showed direct regeneration of shoots from nodular structures in the shoot apical meristem (SAM) region. During in vitro regeneration, the callus cells exhibited ballooning of cells, and the morphogenetic seed developed parenchymatous, polygonal cells filled with polyphenols. Histological studies indicated that in vitro plant regeneration involved the organogenic pathway that leads to de novo shoot primordia development.