Scientists Track Down Important Primocane Fruiting Trait in Blackberries

A national team of horticulture scientists has made a big discovery in blackberry genetics. They now have evidence pointing to the single genetic region that controls primocane-fruiting, or the ability to flower and fruit on first-year canes.

The primocane-fruiting trait has fueled the rapid growth of the fresh‑market blackberry industry over the past two decades, enabling fruit to be grown in warmer climates and to be produced outside the traditional harvest window. Still, scientists didn’t fully understand its genetic basis, says Margaret Worthington, Director of the Fruit Breeding Program for the University of Arkansas Division of Agriculture’s research arm, the Arkansas Agricultural Experiment Station.

Published in the Genetics journal, the study by Worthington and her co-authors explains how genome-wide association identified a single genomic region on chromosome Ra03 that is strongly associated with primocane fruiting.

The new research can speed development of improved varieties with better yield, fruit quality and regional adaptability, she says.

“The world’s first primocane-fruiting blackberries were developed here in the Arkansas Fruit Breeding Program, and we are continuing to breed new primocane-fruiting varieties with high yield potential, fruit quality and adaptation to the Southeast as part of our ‘Prime-Ark’ series,” Worthington says. “So, it is gratifying that we are able to lead the charge to resolve some of the mysteries behind its genetic control and develop useful markers for the global blackberry community.”

To validate the result, the researchers conducted genetic linkage mapping in a separate biparental population, which independently confirmed that the same chromosomal region controls the trait.

Within the mapped region, the team identified 10 candidate genes potentially involved in flowering regulation. Follow‑up analysis narrowed the list to two high‑priority candidates that have known roles in plant developmental timing.

For more, continue reading at uaex.uada.edu.