Micropropagation of Vitis vinifera L. cv. Hibernal Using Chitosan, Meta-Topolin and Silicon Supplementation

Abstract

The aim of this protocol is to present an optimized in vitro micropropagation procedure for Vitis vinifera L. cv. Hibernal, focusing on shoot multiplication, rooting, and plant quality under supplementation with chitosan, meta-topolin (mT), and silicon (Actisil) in Woody Plant Medium (WPM). Nodal shoots excised from vineyard-grown stock plants are surface-disinfected and established on hormone-free WPM, followed by multiplication on media enriched with different concentrations of chitosan, mT, and Actisil. Low chitosan concentration (10 ppm) promotes root elongation and high-quality shoots without visible phytotoxicity. In contrast, higher mT levels suppress both shoot and root formation, underlining the need for careful cytokinin dosage. Actisil applied at 50 µL L⁻¹ slightly improves root length and plant resilience, confirming the supportive role of silicon in stress tolerance. Leaf colour parameters measured in the CIE Lab system reflect changes in pigmentation and potentially chlorophyll content in response to mT and chitosan. The protocol provides a reproducible platform for efficient micropropagation of ‘Hibernal’ and can be adapted to other wine grape cultivars.