Interactions between galling insects and plant total phenolic contents in Rosa canina L. genotypes

This study aimed to determine interactions between gall induction by Diplolepis sp. and leaf total phenolic content in Rosa canina genotypes. A total 20 R. canina genotypes with and without insect damage has been selected in different parts of Northeast Anatolia and the leaf samples collected in July 2009. Total phenolic content was estimated by the Folin-Ciocalteu colorimetric method and expressed as gallic acid equivalents (GAE) in mg/g dry weight. The results showed that seven genotypes without insect damage had significantly greater total phenol content in its leaves compared to insect damaged R. canina plants. These results clearly indicate that total phenolic content in R. canina genotypes that had no galling insect damage may have an important part of chemical defense of R. canina plants against Diplolepis sp. This may have also suggested that these resistant genotypes against galling insect are important for sustainable and organic rose hip production.