Research paperAnatomically assisted cherry rootstock selection

- Cherry rootstocks belonging to P. cerasus and P. fruticosa were anatomically surveyed.
- Selection goal was growth control capacity and potential drought adaptability.
- Genotypes SV2-7 and OV14 are expected to be size-controlling.
- Genotypes SV7, OV32-34 could be suitable for areas with limited precipitation or irrigation.

Main goal of this study was the establishment of unequivocal selection protocol in breeding size-controlling rootstocks with possible drought adaptability. Plant material, consisted of 'oblačinska' sour cherry (Prunus cerasus L. - OV) and ground cherry genotypes (Prunus fruticosa Pall. - SV), was propagated by softwood cuttings under controlled mist system. Analysis included detail anatomical investigation of fine and skeletal roots and rootstock stems. Each constituent contributed to the overall rootstock size-control capacity and potential drought adaptability. Fine roots contribution was estimated trough the active root surface area that significantly varied within and between investigated species, indicating different absorption capacities. Ratio between active-fine-roots surface area responsible for radial solution sinking and total root surface area, comprised of non-sinking skeletal roots and fine roots served as coefficient for reduced water uptake in theoretical hydraulic conductance calculations. Simultaneous examination of root system water capacity, axial conductance capacity corrected by radial sink capacity, and rootstock stem capacity, defined by anatomical characteristics, wood formation and thickening dynamics was established as reliable selection protocol for size-controlling capacity and hypothesized adaptability. Based on stated protocol greatest size-controlling effect is expect to be achieved within ground cherry genotypes - SV1, SV2, SV4, SV5 and SVKK, followed by 'oblačinska' cherry genotypes OV13, OV14, OV22, OV23, and OV24. Following the same approach, genotypes SV2-7 and OV14 are presumed to be the best adapted to drought and embolism caused by freezing/thawing and hydration/dehydration cycles.