Taxonomic significance of transverse sections of roots of six Citrus species
Chinelo A. Ezeabara
Nnamdi Azikiwe University, P.M.B. 5025 Awka, Nigeria
13 Jul 2015
15 May 2016
13 Jun 2016
Citrus, root anatomy, secondary wood, transverse section, intercellular canals, axial parenchyma
Transverse sections (T/S) of the roots of Citrus aurantifolia (Christm.) Swingle, C. grandis Osbeck, C. limon (L.) Burm.f., C. paradisii Macf., C. reticulata Blanco and C. sinensis (L.) Osbeck were investigated using standard plant anatomical procedures. The pores of roots of all the species were oval in shape. The sizes of the pores found in C. sinensis were the lowest range (117–27 µm in length; 108–27 µm in width). The distributions of axial parenchyma were confluent parenchyma in Citrus aurantifolia, C. grandis, C. paradisii, C. reticulata and C. sinensis, whereas it was vasicentric aliform parenchyma in C. limon. Citrus limon, therefore, possessed an advanced feature which indicated that it evolved at a different rate compared with others. The study revealed anatomical characters of these Citrus species and hence shed light on their affinity. The characters of secondary wood, therefore, could be applied as additional characters by plant taxonomists in resolving the ongoing controversy in the taxonomy of Citrus.