Interaction of e-Brassinolide and Unicanzole on the Salt Stress in Two Cultivars of Sweet Potato

Brassinosteroids are growth regulators that enhance plant growth and development .  While natural brassinosteroids are not yet reported from many plants including  sweet potatoes, external application  of brassinosterods is shopwn to alleviate abitoc stress in plants. Unicanazole [UCZ], a fungicide, blocks the synthesis of naturally occurring brassinosteroid biosynthesis.  The present work has been carried out to confirm  the effects of external supply of brassinosteroids on  alleviating the salt stress in sweet potato and  to examine if  unicanazole reverses these effects. Two cultivars of sweet potato [ Ipomoea batatas L.]  Salyboro and Commensal were used and the experiments . Experiments were carried under in  vitro conditions using nodal cultures.  We confirm our previous studies that e-Brassinolide has a positive effect on  reducing  the salt stress effects  .  UCZ 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 brassinosteroids as growth regulators for sweet potato.