Plant development, leaf, cell and stomata dimension are related with inducing different vigour in peach rootstocks

Three peach seedling rootstocks diverse in inducible growth vigour, 'P.S. A6' (vigorous), 'P.S. B2' (intermediate vigour) and 'P.S. A5' (semi-dwarfing vigour), have been selected by DCDSL of Pisa University to control the canopy size of grafted cultivars. Studies were conducted from seed germination to pot and under field conditions, to assess the relationship of plant growth and some leaf traits, such as area, stomata and epidermal cell dimensions. Plants exhibited different development from the first year of growth onwards. Trunk cross-sectional areas, number of lateral shoots, total shoot length and internode length were related to the genotypic capacity of each rootstock to regulate vigour. The rootstock inducing lowest vigour, 'P.S.A5', has lowest values for all growth parameters, except for density and index of stomata, and for cell epidermal density. The most vigorous rootstock, 'P.S. A6', has the highest values for all growth parameters including leaf dimensions.