RECENT PROGRESS IN BRAMBLE BREEDING AT BELTSVILLE, MARYLAND

In developing hardier thornless blackberries, recent efforts have centered on plant, disease, and fruit characterization of named cultivars, selections, seedlings and potential parent germplasm.
Our germplasm collection has been expanded.
Cane samples have been exposed to controlled laboratory freezing tests to determine clonal and cane area differential sensitivity.
Winter temperatures have been monitored in Ohio to determine the extremes and cold duration patterns to which thornless blackberries may be exposed.
Spur blight and cane blight have been identified as potentially devastating pests of thornless blackberries.
Eastern U. S. thornless blackberries appear to have potential juice production capabilities.
Cooperative work on trellising methods, herbicide evaluations, and mechanization schemes has been initiated in our selection planting.
Segregating and non segregating progenies for thornlessness continue to be screened at Wooster, Ohio.
Five hardy heterozygous thorny selections have been made recently to serve as parents.
Five thornless selections have been rated as superior hardy parents at both Wooster and Beltsville.
Selection for hardy transgressive segregants among intercrosses of partially hardy thornless materials is promising now.
This may prove faster than introgression of hardiness from thorny blackberries.
Introgression of hardiness from red raspberries is an exciting possibility.

Symposium on Breeding and Machine Harvesting of Rubus

G.J. Galletta, A.D. Draper, R.G. Hill Jr

https://doi.org/10.17660/ActaHortic.1980.112.12