The two taxa Plantago major ssp. major and ssp. intermedia from different geographical regions were investigated karyologically. The separation of the two taxa depends mainly on seed number and size. The average karyotypic configuration for each population was used to contrast ideograms between populations from ssp. major and ssp. intermedia. The study revealed that the two taxa have distinct cytotypes which are somewhat correlated with seed number as an indication of taxonomic identity. The variation between two taxa is expressed by two main cytological groups based on the total form percentage (TF %) which measures the symmetry of the chromosomes over the whole karyotype. The study also revealed that the evolution of the P. major group may be in part due to chromosomal rearrangement. The study concluded that most major karyotypes are more symmetrical than those of intermedia, which may be an indication that intermedia is the derived type.
(2005), The Japan Mendel Society