In vitro culture: a simple and efficient way for salt-tolerant grapevine genotype selection

In order to quickly and efficiently evaluate the grapevine's salt tolerance, salinity tests were conducted on some grapevine varieties and rootstocks under in vitro conditions. Plant materials used in the salinity test were propagated using the axillary buds culture method. Single-node shoots were subjected to seven different NaCl concentrations (0, 20, 50, 100, 150, and 200 mM NaCl) in MS medium for 45 days. The different growth parameters analysed were: survival capacity, length of shoot, bud formation, and rooting capacity. Our results showed that salinity reduced in vitro growth and development of grapevine. Proliferation, growth, rooting and viability of explants decreased due to the increase in NaCl concentration. First symptoms of stress (leaves necrosis) appeared after 10 days of treatment with 80 mM NaCl, which may lead to total desiccation. It was determined that severity of salt treatment injury varied depending on the genotype and NaCl concentration. A positive correlation was found between the vigour of plants in saline medium and their faculty to tolerate salt. The most tolerant grapevine genotypes to salt treatment were Sejnene and Asli, followed by the moderately sensitive Saouadi and Sakasly genotypes, and last Razegui, 1103P, 41B, and SO4, which were particularity sensitive. Thus, grapevine's salt tolerance seems to be linked to the genetic background.