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The aim of our study was to evaluate the genetic relationship of Rhododendrons from Rhododendron collection at Tomaszkowice in Pogórze Wielickie. Leaves and leaf buds of three evergreen Asiatic species: R. aureum, R. brachycarpum, R. purdomii, six cultivars from Catawbiense Hybridum group (R. catawbiense): Catharine van Tol, Nova Zembla, Album Novum, Boursoult, Old Port, Hachmann’s Charmant and one cultivar from Yakushimanum Hybridum group: Koichiro Wada were investigated. Two plants from each accession were analysed. DNA was isolated by Ziegenhagen and Scholz [1998] protocol, dedicated to the difficult species in terms of high quality DNA extraction. After isolation, DNA was amplified with 19 RAPD primers. We obtained 255 RAPD markers and worked out a dendrogram, which illustrated the level of genetic diversity among the tested plants. Our study confirmed a close relationship between rhododendrons from Catawbiense Hybridum group. Another group was constituted by R. aureum and R. purdomii. The third group consisted of R. brachycarpum and Koichiro Wada cv.
Crosses between Betula nana and B. utilis 'Doorenbos' were undertaken in order to obtain interspecific hybrids which could be characterized by wide spreading stems, strong branching habit, decorative clear white bark and an interesting shape of purple leaves. The research purpose was to examine genetic diversity of the 16 F1 and F2 putative progenies by using the RAPD-PCR method and the ploidy analysis. A total of 242 RAPD markers were scored with 24 primers and 220 (90.9%) polymorphic bands were found. In the NJ dendrogram, cluster I consisted of the female parent - B. nana and 12 hybrids and cluster II grouped the male parent - B. utilis 'Doorenbos' with 4 hybrids (F2/2, F1/8, F1/7 and F2/1). The 2-D scaling by PCoA was in agreement with the similarity index, i.e. two hybrids (F1/8, F2/2) grouped with the male parent while others with female parent. Classification of the hybrid plants by chromosome counting demonstrated that 13 hybrids were confirmed with accurate chromosome counts as being diploid (2n=2x=28) and 3 plants (F1/7, F1/8, F2/2) as triploid with 42 chromosomes.
Background. The processing of tea leaves determines the contents of bioactive ingredients, hence it should be expected that each variety of tea, black, red or green, will represent a different package of compounds of physiological importance. Taste and aroma, as well as price and brand are the main factors impacting consumers’ preferences with regard to tea of their choice; on the other hand consumers less frequently pay attention to the chemical composition and nutritional value of tea. Objective. The purpose of the study was assessment of the nutritional value of black, green and white high-quality tea leaf from Chinese plantations based on the chemical composition of the dried leaves as well as minerals and caffeine content in tea infusions. Material and methods. The research material included 18 high-quality loose-leaf teas produced at Chinese plantations, imported to Poland, and purchased in an online store. The analyses included examination of the dried tea leaves for their chemical composition (contents of water, protein, volatile substances and ash) and assessment of selected minerals and caffeine contents in the tea infusions. Results. High-quality Chinese green teas were found with the most valuable composition of minerals, i.e. the highest contents of Zn, Mn, Mg, K, Ca and Al and the highest contents of protein in comparison to the other products. Chinese black teas had the highest contents of total ash and caffeine and white teas were characterized with high content of volatile substances, similar to the black teas, and the highest content of water and the lowest content of total ash. Conclusions. The three types of tea brews examined in the present study, in particular green tea beverages, significantly enhance the organism’s mineral balance by providing valuable elements.
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