Characteristics of Nazmieh and Spota grape rootstock resistant to crown and root gall disease

Abstract

Crown and root gall are the most common bacterial diseases in Iranian vineyards. Commercial cultivars of V. vinifera spp. are highly susceptible to them. Due to the presence high lime in most of the soils of Iran, a breeding program started 14 years ago to obtain a cultivar crown and root gall disease resistant and soil lime tolerant. Crossbreeding was performed with four parents of American species (male) and four parents of Iranian seeded grape cultivars (Vinifera sp. – female) which made it possible to obtain 16 hybrids. Two hybrids were selected as NAZ6 (V. vinifera ‘Jighjigha’ × Riparia “Gloire”) and NAZ4 (V. vinifera ‘Qaraouzum’ × Kober 5BB), respectively. In 2018, these two rootstocks received the necessary approval after being examined by the Iranian Research Institute of Registration and Certification of Seeds and Plant, and were named Nazmieh (AZ6) and Spota (NAZ4). Both Agrobacterium vitis resistance causing crown and root gall more than 86%, tolerance to soil lime (up to 30%) as well as cold tolerance were determined in both rootstocks. The results showed that Nazmieh induced high vigor while Spota is a dwarfing rootstock. Both rootstocks were also evaluated for their graft-compatibility and for the influence exerted on the production and quality of the bunches.