Development of blackberry cultivars with novel plant architecture

M.L. Worthington, J.R. Clark
Blackberry (Rubus subgenus Rubus) germplasm with novel plant architecture is being developed for landscape/garden and commercial purposes in the University of Arkansas (UA) breeding program. Genotypes with novel architecture have shorter internodes, reduced plant stature, and a compact, columnar form. The novel phenotype was first observed in 2002 in a single seedling plant in a family derived from a cross of two of the first UA primocane-fruiting selections that also yielded the cultivar ‘PrimeArk® 45’. The first novel selection, APF-44, had short internodes and grew only approximately 70 cm tall with no tipping, though all its siblings had normal internodes and standard height. While the genetic control of novel plant architecture in blackberry is not understood, the trait is heritable. The novel phenotype has been recovered in offspring of APF-44 and in other crosses. Today, at least four blackberry cultivars with novel plant architecture developed from UA germplasm are commercially available around the world. These cultivars include ‘Sharon’s Delight’ with Ozeki Blueberry Nursery Company in Japan, ‘Baby Cakes®’ in the Bushel and Berry® line of Star® Roses and Plants in the US, and ‘Black Cascade™’ and ‘Purple Opal™’ from Hargreave’s Plants in the UK. These ornamental cultivars are all marketed toward home gardeners, but blackberries with novel plant architecture may also have commercial applications, particularly for substrate production. Combining fruit firmness and storability with novel architecture is a major breeding objective currently in the UA program. Additionally, systems of managing the novel-architecture plants are needed to further develop their commercial fruit production potential.
Worthington, M.L. and Clark, J.R. (2020). Development of blackberry cultivars with novel plant architecture. Acta Hortic. 1277, 159-164
DOI: 10.17660/ActaHortic.2020.1277.23
Rubus, dwarf, columnar, plant architecture, internode length, ornamental

Acta Horticulturae