The 2012 ASHS Annual Conference

The objective of this study was to document and measure the pyrenes of North Carolina blackberry and raspberry selections relative to standard varieties previously documented.  Additionally, we explored how simple measurements of pyrenes could be utilized to identify the possible source of blackberry or raspberry cultivar. The fruit of twelve blackberry cultivars (APF-45, Arapaho, Chester, Natchez, Navaho, NC 430, NC 537, ORUS 1350-2, ORUS 1939-4, Ouachita, Triple Crown, and Tupy) and ten raspberry cultivars (Autumn Britten, Caroline, Himbo Top, Mandarin, Moutere, Nantahala, Nantahala×Abliss, Nantahala×Cherokee, Octavia, and Redeva 96-3) were harvested from research plots in Salisbury, Laurel Springs, and Mills River, NC in 2010 and 2011 and their pyrenes extracted. These cultivars include primocane fruiting or thornless blackberries and floricane or primocane fruiting raspberries.  Measurements of length, width, and depth were taken with an electronic digital caliper and weights per pyrene were measured in milligrams with an analytical balance. Qualitative observations of the shape of the raphe (lower edge) of the pyrene and pyrene shape were also recorded to assign cultivars to groups based on specifications such as concave, straight, or convex raphae and oval, half-circle, and/or triangular pyrenes. Using SAS software, the physical characteristics of blackberry and raspberry pyrenes were analyzed to identify if there was adequate variance among cultivars to warrant the use of these characteristics as a means of identification of an unknown cultivar. This study showed that weight, length, width, depth, shape (length/width), and flatness (length/depth) were significant indicators of cultivar for both blackberries and raspberries. Variations of weight per unit measurement were also significantly related to cultivar; however, this is likely due to the strong relationship between these ratios and weight itself. The pyrene of an unknown cultivar may be characterized by raphe shape and pyrene shape and then further differentiated from other cultivars by its weight, length, width, depth, shape (length/width), and flatness (length/depth).