Leaf anatomy and carbon isotope composition in Coffea species related to photosynthetic pathway

possible presence of vascular bundle sheath cells and its relation to photosynthetic pathway, leaf anatomy and carbon isotope composition (d13c) were examined in six species of genus coffea: c. arabica (cvs. catuaí vermelho, mundo novo, bourbon vermelho and icatu amarelo), c. canephora (cvs. apoat？ and guarini), c. liberica, c. dewevrei, c. salvatrix and c. stenophylla. in all genotypes, the vascular bundle was surrounded by a layer of cells with numerous chloroplasts in a centrifugal position. visually no differences could be seen between the spongy parenchyma cells and the bundle sheath cells, neither in size nor in chloroplast number. the leaf d13c values ranged between a maximum of - 26.2 ？ in c. salvatrix and a minimum of -29.7 ？ in c. liberica. a strong correlation (r = 0.972, p = 0.001) between d13c and anatomical characteristics was observed in coffee species. c. salvatrix exhibited the highest d13c values and the most compact mesophyll, with more palisade and spongy parenchyma cells in contact with the vascular bundle sheath.