The 2012 ASHS Annual Conference

Brassinosteroids are growth regulators that enhance plant growth and development. In addition, they also alleviate abiotic stress responses like salt stress.  Natural brassinosteroids are not yet reported from sweet potatoes.   Propicanazole  [PCZ] blocks the synthesis of naturally occurring brassinosteroid biosynthesis.  The present work has been carried out to understand the effects of external supply of brassinosteroids on sweet potato and also to determine if  propicanazole reverses these effects. Two cultivars salyboro and commensal were used and the experiments were carried under in vitro conditions using nodal cultures.  Morphological characters including shoot height, leaf area, leaf color, and root formation were  measured. We show that e-Brassionolide has a positive effect on the growth of both cultivars by increasing the leaf chlorophyll and leaf size . PCZ  inhibited the root growth, leaf chlorophyll and shoot height  and reversed  some of the positive effects of e-Brassinolide.  These results will be discussed in relation to possible use of brassionsteroids as growth regulators for sweet potato.