Cytotaxonomy of medicinally important phyllanthus spp. in Bangladesh

Abstract

A combination of taxonomical analysis, cytogenetical method and molecular technique had done for authentic characterization of medicinally important five Phyllanthus L. species viz. P. acidus (L.) Skeels, P. emblica L. (small fruit form), P. emblica L. (large fruit form), P. niruri L., P. reticulatus Poir. and P. urinaria L. They were analyzed with several taxonomical parameters such as branching pattern, morphology of bark, leaves, flowers, fruits, seeds, flowering and fruiting time. Interphase nuclei and prophase chromosomes of these species showed notable variation and displayed the presence and distribution of both constitutive and facultative heterochromatin. Phyllanthus species, as studied here, showed variation in somatic chromosome counts such as 2n=2x=26 in P. acidus, P. niruri and P. reticulatus, 2n=6x=48 in P. urinaria and 2n=10x=100 in P. emblica (both small and large fruit forms), represented with multi-basic chromosome number. The karyomorphology of these Phyllanthus species showed that these species were more or less primitive in nature of which P. acidus, P. niruri and P. reticulatus were comparatively advanced than the others in evolutionary point of view. Formation of bivalent in addition with several multivalent at diakinesis and metaphase-I of P. emblica (both forms) indicated that this species has the possibility of being auto-allopolyploid or segmental-allopolyploid that are going through the process of diplodization. These five Phyllanthus species showed distinctiveness in their number, position, distribution and the percentage of GC- and AT-rich repetitive segments that allowed to analyze the reshuffled banded regions with the help of CMA and DAPIbanding method. RAPD analysis of five Phyllanthus spp. displayed that P. emblica and P. reticulatus were closely related whereas P. acidus and P. emblica were genetically distantly related. The two forms (small and large fruit forms) of P. emblica showed similarity in most important taxonomic parameters and somatic chromosome numbers and dissimilarity in some morphological characters.