en سایر موارد others پژوهشي Research <strong>Carbon nanotubes (CNTs) are known to have many unique physical and chemical properties. Because of these features, they accelerate the germination process, root growth, and photosynthesis rate that can result in increased crop productivity. In the present study, the effects of 4 multi-walled carbon nanotubes (MWCNTs) levels including 0 (control), 50 (low concentration), 100 (moderate concentration), and 200 (high concentration) mg/l were evaluated on morphological and anatomical characteristics of stem, root and leaf in two Okra cultivars namely Bamia and Emerald. </strong><strong>In </strong><strong>both cultivars, the value of height and biomass of shoot and root increased after addition of 50 and 100 mg/l MWCNTs. </strong><strong>Based on microscopic results, </strong><strong>the root and shoot diameters in both cultivars more affected by increased </strong><strong>cortex thickness and central cylinder </strong><strong>in 50 and 100 mg/l of MWCNTs treatments whereas </strong><strong>these parameters were </strong><strong>more affected by increased cortex thickness </strong><strong>in the high concentration of </strong><strong>MWCNTs. </strong><strong>Our study indicated that the thickness of mesophylls and spongy layers increased in low level of </strong><strong>MWCNT, </strong><strong>whereas these parameters were decreased in</strong> <strong>moderate and high levels of MWCNT </strong><strong>in both cultivars. </strong><strong>The</strong> <strong>statistical analysis showed that </strong><strong>Stomata size increased value in low and</strong><strong> moderate levels of MWCNT</strong><strong> in Bamia cultivar. In this study Stomata index measurement showed that this parameter was increased in moderate and high levels </strong><strong>of MWCNT</strong><strong> only in Emerald cultivar.</strong><strong> We observed that </strong><strong>diameter</strong><strong> of xylem</strong><strong> and phloem in the shoot were increased in </strong><strong>low (50 mg/l) and moderate (100 mg/lit) levels of MWCNTs</strong><strong> whereas these parameters were decreased in high MWCNT level. Although this study revealed that low treatments of MWCNTs caused an </strong><strong>increase of root xylem diameter in both cultivars</strong><strong>.</strong><br> &nbsp; anatomy. Biomass. Carbon nanotubes. Dried weight. Frish weight. Okra (Hibiscus escolentus L.). 27 36 http://jispp.iut.ac.ir/browse.php?a_code=A-10-90-4&slc_lang=en&sid=1 rashid jamei r.jamei@urmia.ac.ir Yes Academic staff soroush kargar khorrami s.kargarkhorrami@urmia.ac.ir No PhD.student Reza Darvishzadeh r.darvishzadeh@urmia.ac.ir No Academic staff Siavash Hosseini Sarghin s.hossieni@urmia.ac.ir No Academic staff