Preliminary observations on adaptation and nutraceutical values of blue honeysuckle (Lonicera caerulea) in Oregon, USA

Blue honeysuckle (Lonicera caerulea L) is a polymorphic species widely ranging over northern regions of both Eurasia and North America. Berries have long been harvested from wild plants in regions of Russia, China, and Japan where superior edible forms are native. During the past several decades, research in Russia and Japan has resulted in cultivars being selected for commercial production. However, this species-is virtually unknown in North America as an edible berry. Over the past four years, germplasm has been introduced into Oregon, USA from northeastern China, Siberia, and Hokkaido, Japan. Evaluations were made for plant growth, time of flowering and fruit maturity, fruit traits, and adaptability to a relatively mild, maritime climate. Plants from Siberia and northern China exhibit four negative traits associated with a short dormancy period; very early bloom, early fall leaf senescence, fall flowering, and winter die-back of annual shoots. Because these factors negatively affect yields, plants from these cold regions are not adapted to western Oregon. However, plants from Hokkaido, Japan and the Kurile Islands may have potential for cultivation in this region. They bloom 2-3 weeks later, hold their leaves until late in fall, do not flower in fall, and do not die back in winter. Therefore, future selection and breeding efforts in Oregon will be directed towards plants from these regions. Analyses of 11 fruit samples from different subspecies revealed high content of anthocyanins (116 to 339 mg/100gm fresh weight) and phenolics (427 to 1142 mg gallic acid/100gm fresh weight). Total anti-oxidant capacity was measured as oxygen radical absorbing capacity (ORAC) with values of 18 to 104 mumol Trolox equivalent per g fresh weight and ferric reducing antioxidant power (FRAP) with values of 37 to 113 mumol Trolox equivalent per g fresh weight. Antioxidant capacity was correlated with both anthocyanin and total phenolic content.