Risposta di genotipi di castagno al cinipide galligeno e strategie di lotta basate su meccanismi di resistenza.

The plant trade has favoured the introduction from Asia and the spread in Italy of the exotic pest D. kuriphilus, a serious threat for Castanea sativa. To cope with the emergency several lines of research were activated in Piedmont (Northwest Italy), including strategies aimed at the control of the gall wasp by breeding resistant genotypes. To this purpose cultivars and wild chestnuts were evaluated for susceptibility to the insect. During six years of observations, a large variability in the intensity of the infestation (No. galls/bud) across the genotypes was observed in some 60 cultivars from different geographic areas subjected to infestation under controlled conditions. Resistant response was also found in one hybrid cultivar C. sativa x C. crenata and in C. sativa. In addition, 12 seedlings from different European areas showed no infestation and were propagated by grafting for being checked under controlled conditions. To establish the yield loss due to the infestation by D. kuriphilus, 20 trees of cultivar ‘Marsol’ were chosen to study the relationship between production and infestation level. Data collected in 4 years were elaborated to produce an algorithm that will further be improved in coming years.