DIVERSITY OF ADAPTATION, AGRONOMIC POTENTIAL AND FRUIT QUALITY OF LONICERA CAERULEA L.

Abstract

Blue honeysuckle (Lonicera caerulea L.) is a novel perennial fruit crop with northern climatic adaptation. Its extreme winter hardiness, early-season fruiting, high antioxidant content and unique flavour profiles have brought it attention as a niche-crop. Breeding for temperate regions that are suited to large-scale horticultural production is relatively recent. Barriers to large-scale commercial production include a low chilling requirement, resulting in early bud break, winter damage and poor pollination in temperate climates; modest yields, irregular fruit shapes and agronomic traits that limit harvestability and marketability; and a low sugar to acid ratio with questionable claims of potential human health benefits due to widely varying reports of antioxidant activity. With the long-term objective of expanding the commercial potential of the crop, germplasm evaluation in a major fruit production region, the Fraser Valley, British Columbia, Canada, assessed phenological adaptation to a temperate climate, fruit morphological traits associated with agronomic potential and fruit biochemical characteristics related to fruit quality and nutritional content. Direct comparison of phenology and biochemistry to three globally important commercial crops, highbush blueberry, red raspberry and June-bearing strawberry, were conducted over two years with biological replication across multiples sites. Genetic diversity was characterized between three foundation germplasm groups, and the potential to make genetic progress was assessed in three improved groups. Physiological and genetic complexity was elucidated for economically important phenotypic responses to the target environment through comparison of improved germplasm with their parental foundation genotypes. This work demonstrates that there is sufficient variation in phenology to permit crop adaptation to a temperate climate, which will make it possible to broaden the range of the crop into major fruit production regions. It shows that diversity in fruit morphological features can be used to breed for large-scale commercial agronomic potential. It characterizes fruit biochemical diversity, signifying commercially marketable fruit quality paired with high nutritional content related to potential human health benefits. This fundamental information on crop genetic resources and the genetic control of important traits will inform breeding strategies that will transform blue honeysuckle from a niche to commercial crop.