Genetic Variation in Resistance to Valsa canker is Related to Arbutin and Gallic Acid Content in Pyrus bretschneideri

Abstract

Pear Valsa canker is a fungal trunk disease caused by Valsa pyri. Phenolic compounds are ubiquitous in plants and usually contribute to plant resistance against biotic stress. To investigate the association between phenolic compounds and level of resistance to V. pyri, we quantified the contents of individual phenolic compounds in the cortex and phloem of stems from 8 cultivars of Pyrus bretschneideri. Significant variation in the levels of all compounds was found among the cultivars. Correlation analysis revealed an inverse correlation between levels of arbutin and gallic acid with the degree of canker resistance. This suggested that these phenolic compounds are beneficial to V. pyri infection. These data could be valuable for breeding cultivars of P. bretschneideri with greater resistance to V. pyri. Keywords: Pyrus bretschneideri, phenolic compound, resistance, Valsa canker, LC–MS