Wood Rot Associated Fungal Species in Low-Country Live-Wood Termite (Glyptotermes dilatatus) Infestation in Susceptible (TRI 4042) and Tolerant (TRI 3055) Tea Cultivars

Abstract

The Low-Country Live-Wood Termite (Glyptotermes dilatatus) is a major pest of tea cultivation in the Low Country Sri Lanka. They attack mostly on unhealthy tea bushes with die-back followed by wood rot. Understanding of the relationship between wood rot associated fungal species and LCLWT infestation is important to formulate alternative methods for managing LCLWT. This study was undertaken to identify wood rot associated fungal species in tea and to determine the relationship between wood rot associated fungal species and LCLWT infestation. The fungi from three stem portions of tea, both on LCLWT infested and non-infested susceptible and tolerant cultivars were isolated on sterilized PDA medium and identified following an identification key. Thirty nine fungal species were isolated from susceptible cultivar (TRI 4042). Among them, 81% was isolated on infested stems and 19% was isolated from non-infested stems. Many fungal species (39) were isolated from tolerant cultivar (TRI 3055). Among them, 38% was isolated from infested stems and 35% was isolated from non-infested stems. Acremonium spp. was the most prominent fungal species in both infested non-infested susceptible and tolerant cultivars followed by Verticillium spp and Nectria spp. There was high variation among fungal species isolated from tolerant and susceptible cultivars as well as infested and non infested stems. Remarkable difference was observed in the numbers of fungal species, isolated from infested and non-infested stems in susceptible cultivar. Number of fungal species isolated from the wood closer to the pruned surface was higher in both infested and non-infested branches of susceptible cultivar. Contrasting difference between fungal species in infested and non-infested bushes of susceptible cultivar provide a clue to develop new control strategies for LCLWT.