Detection of a hypersensitive reaction in the chestnut hybrid ‘Bouche de Bétizac’ infested by Dryocosmus kuriphilus Yasumatsu

The purpose of the study was the identification of the mechanisms of resistance to Dryocosmus kuriphilus Yasumatsu in the hybrid-resistant cultivar ‘Bouche de Bétizac’ (Castanea sativa × Castanea crenata). Larvae and eggs of the insect are found in the buds of this cultivar at the end of winter, but there is no gall development after budburst. The hypothesis of the presence of a hypersensitive reaction (HR) in the buds was tested using diaminobenzidine (DAB) to detect H2O2 and by Real Time PCR (RT-PCR) to evaluate the expression of a germin-like protein gene. The results support the hypothesis of the occurrence of an HR in ‘Bouche de Bétizac‘ as response to the cynipid infestation, resulting in cell and larvae death.