Cytogenetic studies of Argyreia pilosa and Argyreia sharadchandrajii (Convolvulaceae) from Western Ghats of Maharashtra, India

The genus Argyreia is known for its ecological and genetic diversity, yet cytogenetic studies remain limited for many of its species. The present study reports a karyotypic analysis of two species, A. pilosa and A. sharadchandrajii, from the Western Ghats of India. Both species exhibited a diploid chromosome number of 2n=30, consistent with most Argyreia species. A. pilosa displayed a karyotypic formula of 11 median region centromeric chromosomes (m) and 4 submetacentric chromosomes (sm), whereas A. sharadchandrajii displayed a karyotypic formula of 14m+1sm. Minor variations in karyotypic parameters, such as dispersion index (DI), centromeric asymmetry (MCA), and coefficient of variation (CVCL and CVCI), were observed, with A. sharadchandrajii exhibiting greater karyotypic symmetry. The karyotype analysis of the two species revealed symmetrical karyotypes classified under Stebbins’ 1A category. These findings contribute to the taxonomic and evolutionary understanding of Argyreia, highlighting the role of cytogenetic data in species differentiation.