Resistance Mechanisms to Vine Cicada (Psalmocharias alhageos) in Four Grapevine Rootstocks

Vine cicada (Psalmocharias alhageos) is one of the important pests of grapevines that is existing in Iran, Afghanistan, southern regions of Russia, Turkey and Iraq. The aim of the present research was to determine the resistance mechanisms to vine cicada in four grapevine rootstocks, Spoota, Nazemiyeh, Kober 5BB, and CH1. This research was carried out using randomized complete block design with three replications and three vines in each experimental unit at the Takestan grapevine research station from 2021 to 2023. The highest pest establishment was observed in the roots of Spoota (6.1%) and Nazemiyeh (5.8%) rootstocks. The highest total phenol was recorded in CH1 rootstock (4.86 mg gDW-1) and the lowest in Nazemiyeh rootstock (3.1 mg gDW-1). The highest root vascular cylinder was belonged to CH1 rootstock (72.6 μm). Considering that the cicada nymphs could not establish (only few nymphs) on the root of the Kober 5BB rootstock, therefore, the resistance mechanism in this grapevine rootstock was antibiosis. However, in the Nazimiya, Spoota and CH1 rootstocks, the cicada was established and fed from their roots, but they did not show any stagnating growth, therefore, the resistance mechanism in these rootstocks identified as tolerance.