Foliar phenols and flavonoids level in pteridophytes: an insight to culturable fungal endophyte colonisation

There are many available reports of secondary metabolites as bioactive molecules from culturable endophytes, nevertheless, there are scarce research pertaining to the levels of metabolites in plants with respect to the incidence and colonisation of fungal endophytes in the same foliar tissues. Therefore, the study was focussed to examine whether fungal endophyte colonisation and the accumulation of secondary metabolites, such as flavonoids and phenols, in the plants are related in any way. For this reason, the study aims to analyse phenols and flavonoids from the fronds of eleven pteridophytes along with the culture-dependent isolation of fungal endophytes from the host plants subsequently assigning them to morphological category and their quantitative analysis and further resolving its identities through molecular affiliation. The results revealed that nine morpho-categories of fungal endophytes were allotted based on culture attributes, hyphal patterns and reproductive structural characters. Highest numbers of species were isolated from Adiantum capillus-veneris and least was recorded from Pteris vittata and Dicranopteris linearis. Maximum phenol content was analysed from the fronds of P. vittata and lowest was recorded in A. capillus-veneris. Highest flavonoid content was measured in D. linearis and lowest was detected in Christella dentata. Significant negative correlation was observed between phenol content of ferns and species richness of fungi. Moreover, significant positive correlation was observed with the relative abundance of Chaetomium globosum and flavonoid content of ferns and negative significant relation was found between relative abundance of Pseudopestalotiopsis chinensis and phenol content of pteridophytes. The occurrence and the quantitative aspects of endophytes in ferns and their secondary metabolites are discussed.