Validation of in vitro grafting using indigenous wild grapevines as rootstock with commercial scion varieties

Abstract

Wild progenitors of grapevine constitute a diverse source of genetic variability which have been used as a potential rootstock to cope with different abiotic and biotic stresses. In Pakistan, wild grapevine accessions locally called Dakh, Fatati, Toran, Zarishk, and Kishmish naturally exist in mountainous and sub-mountainous regions of humid and sub-humid areas. However, many vineyards that are cultivated as own rooted crops have been affected by many environmental or edaphic conditions. To cope with these adverse conditions, it is the utmost need to cultivate highly productive Vitis varieties with suitable rootstocks, but compatibility is a major concern between these grafted plants. In the present study, in vitro cleft grafting was used to evaluate the compatibility of these wild grapevine accessions as rootstocks with other commercial scion varieties like King’s Ruby and Flame Seedless. Wild grapevine accessions Dakh, Kishmish, and Toran showed a relatively improved rate of compatibility with commercial scion varieties compared to Zarishk and Fatati accessions. Initially, a slower but stable process of graft compatibility between wild grapevine accessions and scion varieties was observed at 10 days after grafting. Differentiation of parenchymatous cells into vascular bundles started at 15 days after grafting, whereas complete formation of vascular bundles at graft junctions of wild grapevine accessions and commercial scion varieties was observed at 21 days after grafting. This initiation of vascular layers at the initial stage helped the improvement of shoot growth of scion varieties grafted on wild grapevine accessions Dakh and Kishmish. Moreover, a higher rate of root growth was observed in grafted wild grapevine accessions Dakh, Zarishk, and Kishmish compared to Fatati and Toran. Among both commercial scion varieties, King’s Ruby resulted (54–59%) as more effective when grafted with wild grapevine accessions.