Susceptibility levels of some chestnut cultivars and genotypes to the chestnut gall wasp in Turkey

The Asian chestnut gall wasp (ACGW) is one of the most important pests threatening most Castanea species. The best management strategy against this pest can be establishing new orchards with resistant cultivars along with biocontrol (parasitoid Torymus sinensis Kamijo (Hymenoptera: Torymidae)). In Turkey, ACGW was first detected in 2014 at Gac?k village of Yalova province. Bursa, ?stanbul, Sakarya, Kocaeli, Bal?kesir, Bilecik, D?zce, Giresun, Bart?n, Zonguldak, Sinop and ?zmir provinces are also infected with ACGW. This study was carried out to determine the levels of susceptibility of chestnut cultivars/genotypes to ACGW. The study was carried out in Yalova province between 2016 and 2018. In total, 15 cultivars/genotypes were involved in the study, including European (C. sativa) chestnuts (Albayrak, Alt?nay, ?Erfelek?, ?Osmano?lu?, Sal?pazar?, ?Serdar?, ??nal?), interspecific hybrids (?Marigoule? and BDB-L) and complex hybrids (?Aky?z?, ?Macit 55?, ?Ali Nihat?, A9, A55, A56) were tested in the study. In April 2016, five- to seven-year-old seedlings were ?bark? grafted, and susceptibility to the ACGW was evaluated by recording the ratio of infected buds (%), visual assessment of the damage (severity), and calculations of an infestation index. Among the cultivars and genotypes tested in the study, the ?Aky?z? cultivar was determined to exhibit the highest resistance against the ACGW. To fully understand the resistance mechanism of the ?Aky?z? cultivar, molecular and biochemical studies should be done and compared with other results.