Content of diarylheptanoids in the bark of black (Alnus glutinosa (L.) Gaertn.) and grey alder (Alnus incana (L.) Moench) as an indicator of taxonomic and population variability

Abstract

Ovim istraživanjem obuhvaćene su dve populacije Alnus glutinosa (L.) Gaertn. (Prilički kiseljak i Rimski most) i dve populacije Alnus incana (L.) Moench (Golijska reka i Sastavci) uzorkovane na planini Goliji. Osnovni ciljevi bili su: 1) ispitivanje varijabilnosti i odnosa populacija unutar i između vrsta u odnosu na koncentraciju diarilheptanoida u kori prirodnih populacija A. glutinosa i A. incana; 2) ispitivanje sezonske varijabilnosti diarilheptanoida u kori vrsta A. glutinosa i A. incana; 3) procena hemotaksonomskog značaja diarilheptanoida u ispitivanim vrstama; 4) procena mogućnosti primene diarilheptanoida u detekciji spontanih hibrida između A. glutinosa i A. incana; 5) ispitivanje varijabilnosti oblika, veličine i nervature lista u populacijama A. glutinosa i A. incana; 6) procena spontane hibridizacije između ove dve vrste na osnovu morfologije lista. Koncentracija najzastupljenijih diarilheptanoida (hirsutanonol-5-O-β-D-glukopiranozida, oregonina, hirsutanonola, alnuzida A, platifilozida i rubranozida A) u etanolnim ekstraktima kore ispitivanih populacija određena je pomoću UHPLC-MS/MS. Međupopulaciona varijabilnost koncentracije diarilheptanoida ispitana je pomoću parametarskih (ANOVA) i neparametarskih (Kruskal-Wallis) testova, analize glavne komponente (PCA) i diskriminantne analize (DA). Prvi uvid u kvantitativnu distribuciju odabranih diarilheptanoida kod A. glutinosa i A. incana je procenjen na osnovu analize populacija Rimski most i Sastavci. DA je pokazala 100% diskriminacije između tri grupe individua koje je izdvojila PCA, na osnovu čega je postavljena hipoteza da je jedna grupa od četiri individue hibridogenog porekla. Diarilheptanoidi su se pokazali dobrim hemotaksonomskim markerima na interspecijskom nivou i utvrđena je njihova mogućnost primene u detekciji spontanih hibrida...In this study, two populations of Alnus glutinosa (L.) Gaertn. (Prilički kiseljak and Rimski most) and two populations of Alnus incana (L.) Moench (Golijska reka and Sastavci) were sampled on mountain Golija with the aims to investigate: 1) variability and relations of populations within and among species based on the concentration of diarylheptanoids in the bark of natural populations of A. glutinosa and A. incana; 2) seasonal variability of diarylheptanoids in the bark of A. glutinosa and A. incana; 3) the reliability of diarylheptanoids as chemotaxonomic markers in the studied species; 4) the reliability of diarylheptanoids for the detection of spontaneous hybrids between A. glutinosa and A. incana; 5) variability of leaf shape, size and venation in the populations of A. glutinosa and A. incana; 6) spontaneous hybridization between the studied species based on leaf morphology. Six diarylheptanoids (hirsutanonol-5-O-β-D-glucopyranoside, oregonin, hirsutanonol, alnuside A, platyphylloside and rubranoside A) were quantified in bark ethanol extracts of four Alnus spp. populations by UHPLC-MS/MS. Interpopulation variability of diarylheptanoid concentration was investigated with ANOVA, Kruskal-Wallis test, principal component analysis (PCA) and discriminant analysis (DA). Quantitative distribution of selected diarylheptanoids in the bark of A. glutinosa and A. incana was first analyzed in populations Rimski most and Sastavci, respectively. DA completely discriminates between three groups of individuals that were implied by PCA. Based on the results, a hypothesis is proposed that the group of four individuals is of hybridogenic origin. Diarylheptanoids proved to be good chemotaxonomic markers at the interspecific level and may also reveal hybrid species..