Systematic reinstatement of highly sacred Ficuskrishnae based on differences in morphology and DNA barcoding from Ficusbenghalensis (Moraceae)

Abstract

Ficuskrishnae is considered as native to India and is well-known for the peculiarity in nature of its cup-shaped leaves where both the vernacular name (Krishna Fig) and specific epithet were derived. The taxonomic status of Ficuskrishnae is still unclear and currently treated as a subspecies or variety under Ficusbenghalensis. In the present study, morphological characters and molecular analysis were employed to address their species delimitation. The spacer markers ITS2 and trnH-psbA were used for constructing phylogenetic trees along with morphometric analysis. Ficuskrishnae distinctly differs from Ficusbenghalensis by having cup-forming leaves and the nature of the aerial roots, stipules, petioles, ostiolar bracts of the receptacle, DNA content, chromosome differences and nodal anatomy. The results showed that the highest divergence is observed in trnH-psbA (20.8 ± 12.2), followed by ITS2 (5.7 ± 3.2). The phylogenetic tree construction using Bayesian analysis showed a divergent boundary between the two species suggesting that F.krishnae could be an independent species, not a variety of F.benghalensis. The present study's findings support the view that these two floras can be treated as different species.

Keywords: Bayesian analysis; Ficus; ITS2 region; conspecifics; species delimitation.

Figure 1.

Typical morphology of Ficusbenghalensis and Ficuskrishnae. A1, A2Ficusbenghalensis twig and figs (PC: Jana Venkata Sudhakar) B1, B2Ficuskrishnae twig and figs (PC: Jana Venkata Sudhakar)

Figure 2.

Maximum Clade Credibility (MCC) tree from Bayesian analysis using two DNA barcode markers (ITS2+trnH-psbA) with posterior probabilities values in percentage that are shown at nodes.

Figure 3.

Total evidence MCC tree from Bayesian analysis of the two DNA markers and morphology. The Posterior Probabilities values in percentage are shown at the nodes.