Study On The Quality Formation Characteristics And Suitable Harvesting Period Of Blue Honeysuckle

‘Lanjingling’,‘Wulan’,and ‘Beilei’ are three blue honeysuckle(Lonicera caerulea L.)species independently cultivated by Professor Huo Junwei,the director of the Small Berry Engineering Center at Northeast Agricultural University.Its fruit has a rich taste,high yield,strong resistance,and great market potential,but they have small fruit hardness,are prone to decay,and have short storage time,which greatly limits its planting area and promotion.This experiment conducted from 2021 to 2022 investigated and analyzed the physicochemical indicators and nutritional substances of fruit from these thre e varieties at different harvest times,determined the optimal harvest period,and conducted comparative storage experiments on fruit harvested at different periods.The changes in fruit quality and the characteristics of metabolite accumulation were compa red and analyzed,providing a theoretical basis for their quality breeding,cultivation technology,and scientific storage.The main research results are as follows:(1)Changes in the appearance of blue honeysuckle during development: the fruits of the three varieties showed a ‘fast-slow-fast-slow’ growth trend in transverse and longitudinal diameter and single fruit weight,with slow fruit growth at maturity and no significant differences;the fruit color changed from green to blue,and was a blue of similar degree at maturity,which was difficult to distinguish.Fruit hardness showed a decreasing trend,with‘Lanjingling’ and ‘Beilei’ showing a steep decrease in hardness at the late stage of color change(40 d after flowering)and early ripening period(47 d after flowering),respectively,and a large decrease in ‘Wulan’ during the early ripening period(46 d after flowering).(2)The metabolic characteristics of the fruit during the development o f ‘Lanjingling’:the node that determines the sugar and acidity of the fruit is 40 d after flowering whe n it enters the sugar accumulation stage and organic acids begin to decrease.The accumulation of most amino acids and their derivatives was greatest at 23 d after flowering and gradually decreased as the fruit matured.The content of flavonols and dihydro flavonoids gradually increased at 40 d after flowering,and the content of flavonoids gradually decreased at 40 d after flowering.(3)The optimum harvesting period of blue honeysuckle is determined: according to the principal component analysis of the nut ritional indicators of blue honeysuckle and the characteristics of low-temperature storage,the optimal harvesting period for ‘Lanjingling’ is52 d after flowering for long-distance transportation,54 d for ‘Wulan’,and 57 for ‘Beilei’after flowering.For short-distance transportation or local sale,the optimal harvesting period was 57 d after flowering for ‘Lanjingling’,58 d after flowering for ‘Wulan’,and 67 d after flowering for ‘Beilei’.