|BRADISH, CHRISTINE - North Carolina State University|
|FERNANDEZ, GINA - North Carolina State University|
|DOSSETT, MICHAEL - Agri Food - Canada|
Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2016
Publication Date: 5/1/2016
Citation: Bradish, C.M., Fernandez, G., Bushakra, J., Bassil, N.V., Finn, C.E., Dossett, M. 2016. Evaluations of sustained vigor and winter hardiness of black raspberry (Rubus occidentalis) grown in the Southeastern U.S. Acta Horticulturae. 1133:129-134.
Interpretive Summary: The Southeast United States is undergoing a surge in demand for fresh raspberries. Red and black raspberry plantings suffer in the region as a result of the high heat during the summer and fluctuating winter temperatures. We are using two populations of black raspberry to study the response of these plants to environmental conditions in two sites in North Carolina. The results from this three year study has shown that some offspring can exceed their parents in the ability to withstand temperature extremes and can therefore be useful for breeding cultivars adapted to the environmental conditions of the Southeast.
Technical Abstract: Demand for fresh berry products continues to grow on the East Coast; however commercial raspberry production in the Southeast is difficult because cultivars are not well adapted to the warm climate and fluctuating winter temperatures, where heat degrades plant vigor and fruit quality, and chilling requirements can be hard to meet. Recent research about the health benefits of a polyphenolic-rich diet has led to a resurgence of interest and breeding efforts in black raspberry, and is the driving factor for this particular research. Two half-sib populations, ORUS 4304 and ORUS 4305 (307 progeny total) were planted in Jackson Springs, North Carolina in 2012. From Fall 2012 - Spring 2015, a number of traits were measured on each plant, among them vigor, winter damage, and heat damage, analyzed in several different ways. Plant vigor increased or decreased over harvest seasons based on genetics primarily, but also showed correlations with temperature (i.e., less vigorous plants were more susceptible to damage by heat or cold). Overall, 4305 was less vigorous than 4304. As is the case with most raspberries grown in the Southeast, vigor in general is expected to decrease over time; however certain individuals show transgressive segregation for the trait. Linkage mapping for both populations is underway, and we will be able to identify and validate QTL for vigor, winter hardiness, heat tolerance, and other traits within black raspberry. Ultimately, we hope to gain a more complete understanding of black raspberry physiology and genetics to make breeding commercial quality cultivars a possibility in the Southeast.