## 1 Introduction  
The constantly growing awareness of consumers regarding the need for healthy eating and consuming food with health-promoting properties leads to the search and characterization of new species with this direction of utilization. Species belonging to the genus _Lonicera_ such as _Lonicera caerulea_ var. _edulis, L. caerulea_ var. _kamtschatica, L. caerulea_ var. _altaica, L. caerulea_ var. _byarnikowae_ and _L. caerulea_ var. _emplyllocalyx_, as well as their hybrids, collectively known as _Lonicera caerulea_ L., also known as haskap, blue honeysuckle, honeyberry or sweet berry honeysuckle, are representative of such plants. The fruits of this species, like strawberry, blueberry, blackberry or blackcurrant, belong to the so-called super fruits--fruits, which due to the presence of bioactive compounds, are very desirable in the human diet [1,2]. Health-promoting properties of the haskap berries include protective effects against cardiovascular and neurodegenerative diseases, osteoporosis, type 2 diabetes as well as antimicrobial, anticarcinogenic and anti-inflammatory activity [3]. Combining biological traits of individual species allowed us to obtain cultivars with large fruits without a bitter taste, not falling off the bush after ripening, fertile, more resistant to diseases, suitable for mechanical harvestingand storage, as well as significantly different in terms of phytochemical content. The assessment of the content of health-promoting phytochemical compounds, such as phenolic acids, flavonoids and anthocyanins has so far been performed usually for a small group of cultivars. [PERSON] et al. [4] studied 14 cultivars, [PERSON] et al. [5] 7 cultivars, [PERSON] et al. [6] 4 cultivars, [PERSON] et al. [7] 7 cultivars, [PERSON] et al. [8] 3 cultivars, [PERSON] et al. [9] 19 cultivars, [PERSON] et al. [10] 8 cultivars, [PERSON] et al. [11] 3 cultivars and [PERSON] et al. [12] 6 cultivars. So far, the largest group of 30 cultivars has been analyzed by [PERSON] et al. [13]. The level of the analyzed phytochemical properties, as indicated by numerous authors [12; 14; 15; 16] depends, on one hand, on the properties of the cultivar (genotype), while on the other hand, it is the result of many environmental factors (soil, fertilization, etc.). The analysis of the influence of each of these factors allows us to determine the extent to which a given phytochemical property results from the impact of genetic factors, and to which it is a result of the effect of the environment, which can be expressed by the heritability coefficient, and which has not been presented so far for this species. The attractive biological value of _Lonicera_ fruits, which consists of the values of individual cultivars, causes a rapid increase in the cultivation area of this species. According to the available data, the global cultivation area in 2017 amounted approximately to 5500 ha. The largest planted area was in China and North Korea, in total, 2000 ha, Poland--1800 ha, Canada--1000 ha, Russia--400 ha and Japan--160 ha [17]. The cultivation area of this species is constantly growing and, for example, in Russia, this area increased to 735 ha in 2019 and its further increase to about 2000 ha is planned in 2022 [18]. Poland, with a cultivation area of approximately 4000 ha in 2019, is a world leader in the production of haskap berries [19]. The Commission Implementing Regulation (EU) 2018/1991 of 13 December 2018 authorizing the introduction of _Lonicera caerulea_ L. berries to the market as a traditional food from a third country in accordance with the Regulation of the European Parliament and of the Council (EU) 2015/2283 [20] is likely to support a further increase in the cultivation area of this species.