A Biochemical Approach to identify Resistant Tea Cultivars to Low Country Live Wood Termite (Glyptotermes dilatatus)

Pest damage to the tea bush is a serious issue for Sri Lankan tea industry. Low Country Live Wood Termite (LCLWT), Glyptotermes dilatatus is one of the most economically important pests as they attack the low grown teas which have the highest contribution to the Sri Lankan tea production. Introducing resistant cultivars with high yield is the most promising method among various methods of controlling this pest. Therefore, screening new cultivars is important to introduce resistant cultivars to the grower. This research was conducted to study the feasibility of using caffeine, total catechin and total polyphenol contents as biochemical markers to identify resistant cultivars for LCLWT. Healthy and rotted stems of four cultivars (TRI 4042, TRI 4049, TRI 3025, TRI 3069) which were susceptible and resistant to LCLWT were collected separately. Caffeine content had increased in all cultivars upon infestation. Resistant cultivars had high caffeine in the healthy stems. Total catechin and total polyphenol content decreased in all the cultivars upon infestation and high amounts were observed in resistant cultivars in healthy stems. There were two clusters according to the biochemical parameters considered in hierarchical cluster analysis. Resistant and susceptible cultivars to LCLWT are divided into clusters separately in k-means cluster analysis. This confirms that the caffeine, total catechin and total polyphenol contents in healthy tea stems can be used as biochemical markers to identify resistant cultivars for LCLWT.