Interspecifc in vitro hybridization in genus Centaurium and identifcation of hybrids via fow cytometry, RAPD, and secondary metabolite profles

Abstract

Most of the species from the genus Centaurium Hill readily hybridize between themselves in natural habitats. Artificialinterspecific hybrid plants were obtained under in vitro conditions using reciprocal crosses between 4 species: Centaurium erythraea,C. littorale, C. maritimum, and C. pulchellum. Among 76 crossing experiments performed, 3 types of crosses produced seeds and gave20 interspecific hybrid plants. Nuclear DNA quantification, fingerprinting of molecular markers, and determination of variation inmain secondary metabolite content were employed to confirm their hybrid nature. All 3 approaches were capable of detecting hybridplants. RAPD molecular markers proved to be the most reliable, always placing the hybrids between their parents in dendrograms,while secoiridoid glycoside content also showed intermediate profiles in the hybrid plants in relation to the parents. Hence, each ofthe techniques employed can be recommended for elucidating the mechanisms of interspecific hybridization in natural populations ofCentaurium species in further studies. This could help to comprehend their breeding system and recognize interspecific hybridizationas one of the crucial steps in polyploid formation and speciation in this genus.