sampling, and age of plant on leaf chemical composition of red raspberry ( Rubus idaeus L.) J. Amer. Soc. Hort. Sci. 97 740 742 John, M.K. Daubeny, H.A. Chuah, H.H. 1976 Factors affecting elemental composition of red raspberry leaves J. Sci. Food Agr. 27
Gina E. Fernandez and James R. Ballington
al., 2008 ). Season extension techniques are used to advance or delay the fruiting season of many small fruit crops including raspberry ( Rubus idaeus ) and blackberry ( Pritts, 2008 ; Pritts et al., 1992 ; Strik and Thompson, 2009 ; Strik et al
Ivan dos Santos Pereira, Luciano Picolotto, Michél Aldrighi Gonçalves, Gerson Kleinick Vignolo, and Luis Eduardo Corrêa Antunes
Blackberry ( Rubus spp.) production and consumption is increasing worldwide ( Antunes et al., 2014 ; Fachinello et al., 2011 ; Strik et al., 2007 ; Strik and Finn, 2012 ). The increase in consumption is mainly due to the high antioxidant
Jianying Gu, Michele Warmund, and Milon George
Floral buds of `Royalty' purple raspberry and `Heritage' red raspberry were used to develop a cryopreservation method without loss of viability. The effects of prefreezing (PF), cooling rate, thawing rate, and cold storage at -7°C were tested. No survival was observed in samples immersed directly in LN2 whereas `Heritage' and `Royalty' had 90 and 97% survival after holding the samples at -22°C (`Heritage') or -18°C (`Royalty') for one week before immersion in LN2. In all cases, fast thawing resulted in a higher survival rate than slow thawing. Rapid cooling rate decreased the buds survival in LN2, however the effect was diminished when the samples were stored at the PF temperature for one week. The effect of both thawing and PF storage became less critical with bud dehydration. Differential thermal analysis (DTA) was conducted on buds without any PF treatment and buds that were subjected to PF and cold storage. DTA samples that did not receive PF exhibited LTEs, while LTEs were absent in samples subjected PF for one week. Thus, the slow removal of intracellular water to extracellular ice appears to be associated with subsequent survival of Rubus buds in LN2.
Derek N. Peacock and Kim E. Hummer
During research to develop a new germination protocol for Rubus being conducted at the National Clonal Germplasm Repository in Corvallis, we observed mixed responses to sodium hypochlorite (NaOCl) as a seed scarifying agent. For R. parviforus Nutt., scarification with NaOCl resulted in 34% germination. Fewer than 1% of the seedlings showed any negative effects after exposure to 2.6% NaOCl for 24 hours. But in R. ursinus Cham. & Schldl., R. multibracteatus A. Leveille & Vaniot, R. swinhoei Hance, and R. setchuenensis Bureau & Franchet, the percentage of injury observed ranged from 40% to 100%. In these cases, although embryonic tissue did not appear necrotic, the radicle and plumule failed to elongate after emergence. The epicotyl or primary leaves did not develop, and the radicle failed to form root hair. The cotyledons, apparently unaffected, opened and were a healthy green. NaOCl did not kill the embryo, but deterred development of the embryonic axis. As a result of the NaOCl scarification the cotyledons expanded yet the seedlings eventually died.
Angela K. Anderson and Chad E. Finn
Morphological variation was examined in 20 populations of Rubus ursinus subsp. macropetalus from British Columbia, Washington, and Oregon grown in a common garden. There was significant variability between and within populations for most traits studied. Principal component analyses separated populations along geographical clines for traits of horticultural significance. PC1 represented a general vigor component in all trials, and formed a negative correlation with elevation in four of five analyses (r = 0.60, 0.58, 0.50, 0.49; P < 0.05). Autumn leaf senescence tended to increase from west to east and with elevation. With higher elevation, there was a tendency for fruit weight to decrease, for later vegetative budbreak and fruit ripening, and for a shorter budbreak to first flower interval. From north to south, budbreak became somewhat earlier, cane spot susceptibility decreased, and budbreak to first flower interval increased. Characterization of this species will assist breeders to identify possible sources of cold hardiness, disease resistance, improved vigor, and acceptable fruit traits for the improvement of cultivated trailing blackberry.
P.J. Macdonald and Margie Luffman
A collection of indigenous North American red raspberry (Rubus strigosus Michx.) was evaluated in an unreplicated field planting at the Canadian Clonal Genebank, Trenton, Ont. The accessions originated in British Columbia (B.C.) and the United States. Useful characteristics in the collection have been identified under B.C. conditions; however, field performance in Ontario has not been reported. Cultivars originating from B.C., Manitoba, and Ontario were included in the planting as standards. Overwintering injury ranged from slight to severe. Indigenous accessions were vigorous, with cane height comparable to standards; however, in some cases, primocane production was excessive. Most B.C. accessions flowered and fruited equivalent to, or earlier than, the earliest cultivar (`Boyne'), while R. strigosus from other locations were mid-season to late. Primocane fruiting was typical in B.C., but was not consistent in Ontario. Fruit were small, but had good color and structure. Accessions showed resistance to powdery mildew [Sphaerotheca macularis (Wallr.:Fr.)], but were very susceptible to late yellow rust [Pucciniastrum americanum (Farl.) Arth.].
Jianfeng Liu, Bowen Yang, Yuetong Ming, Yuchu Zhang, and Yunqing Cheng
Rubus idaeus is a red-fruited species of Rubus L. and has remarkable economic and cultural value. This genus is distributed over both the hemispheres and is commonly cultivated in temperate regions ( Sønsteby and Heide, 2009 ). Its berry has
Kim E. Hummer, Chad E. Finn, and Michael Dossett
small fruit and berry crops. The second is to emphasize his efforts on Rubus including his development of thornlessness, pigment mutation, and interspecific crosses. In addition, Burbank’s efforts will be integrated into current work on small fruit and