journal of kerbala university

An laboratory experiment was conducted to study the anatomical changes accompanied with Zn in removing B toxicity in different plant species that are different in their tolerance to B toxicity namely : mung bean (sensitive) , cucumber (moderately tolerant) and tomato (tolerant). Results were revealed that: boron toxicity caused changes in tissue measurements in leaves of mung bean, cucumber and tomato cuttings. It owere rgit caused decline of leaves thicknes, midrib, spongy layer, bundle length. In addition to an increases of palisade layer thickens , bundle width in mung bean and cucumber, and an increase of all the above parameters in Tomato leaves cutting. The toxic level of boron reduced the thickens of the hypocotyls ,cortex as wells vascular bundle number in mung bean and cucumber. Although, the measurements of vascular bundle increased in mung bean decreased in cucumber, whereas in tomato all the above measurements were increased. On the other hand, Zn supplied was improved the anatomical characteristics for leaves and basal part of cuttings. This means that Zn was lowering the reverse effect due to boron stress in anatomical structures of these plant spp.