Anatomical and molecular characterisation in four Nigerian Physalis (Solanaceae) Species

Abstract

High morphological similarities among Physalis species often lead to misidentification, hindering their breeding, utilisation and  conservation. This study characterised four Nigerian Physalis species using anatomical traits and matK molecular markers to clarify their  genetic relationships. Leaf transverse sections revealed starch granules in the species studied except P. pubescens, with arc-shaped  grains unique to P. angulata and P. peruviana, and polygonal grains specific to P. micrantha. Styloids were diagnostic for P. peruviana.  Stem anatomy showed that P. angulata had a polygonal outline, thick cuticle, absence of trichomes and sclerenchyma cells,  distinguishing it from others. All species were woody except P. pubescens. Pore and ray types were taxonomically significant, and P. pubescens had a conjoint, bicollateral vascular bundle. Anatomical cluster analysis separated P. angulata, a tetraploid, from the diploid  species, grouping P. pubescens with P. micrantha, while P. peruviana was closely related to them. Molecular analysis yielded 100%  successful PCR amplification, with sequences ranging from 774–870 bp and GC content varying between 33.1% and 36.1%. BLAST analysis  showed speciesspecific similarities and phylogenetic analysis separated P. micrantha from others. This study revealed that the four  Physalis species are genetically distinct with low genetic diversity.