Relation Between Metal Accumulation and Surface Characteristics of Leaves and Stems in Two Cultivars of Sweet Potato Ipomoea Batatas (L.) Lam. ‘Commensal' and ‘Salyboro' Under Salt Stress

Axillary bud cultures of two cultivars of sweet potato Ipomoea batatas (L.) Lam. “commensal” and “salyboro” were subjected to salt stress under in vitro conditions for 8weeks.  Relative salt concentrations ranged from 0 to 150 mM.  Samples  were collected after 2, 4 and 6 days after exposure to salt. Another sampling was done at the end of the growing period. The present work reports the results on the early effects up to 6 days. Observations were made on stems and leaves using scanning electron microscopy. Metal analysis was carried out by ICP-Ms.   SEM Analysis  revealed that in both cultivars stomata distribution and the guard cells shape was affected by salt above 50mM. Trichome distribution and shape was also affectd. Accumulation of metals, especially micronutrients like Fe ,Mn, Cu and Zn as well as levels of K have some correlation with the morphological changes. These and other results are further discussed in relation to salt tolerance mechanisms of these two cultivars of sweet potato.