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• New microvines combining Vitis vinifera and V. labrusca genetic backgrounds have be obtained. • The Vvgai1 mutation results in similar behaviours in V. labrusca than in V. vinifera . • The genetics of sex type and opposite-to-leaf trait are differentially governed. • Vvgai1 disturbs microvine C source/sink delaying shoot maturation but not reproductive development. In order to develop new genotypes to explore grapevine adaptation to climate, we introduced the Vvgai1 mutation in V. vinifera x V. labrusca hybrids. Vvgai1 mutation induced a strong miniaturisation of leaf and shoot length, as a result of a significant reduction of internodes size and an increase of the phyllochron. The lignification of the main shoots was delayed in the microvines in comparison to their macrovine counterparts while the leaf C assimilation rate was not impacted by the mutation. The shift from the alternate spiral (juvenile) to distichous (adult) phyllotaxis and the appearance of the first tendril occurred at lower node rank in macrovines. However, while macrovines did not produce any reproductive organs during the first vegetative cycle, microvines displayed the first perfect flowers on the main shoot from the internode 18, only a few months after embryo rescue and acclimation. The segregation of the sex type confirmed that the sex determining locus of the V. labrusca cv. Isabella is heterozygous. Conversely, the proportion of opposite-to-leaves organs following a labrusca - versus vinifera -type distribution suggested a more complex genetic determinism for this trait. These experiments provide a new set of microvine genotypes and phenotypic data for studying the response of V. labruscana to abiotic and biotic factors and open new questions about how phytohormones control the development of the grapevine liana.