The putative hybrid character of two Tilia varieties selected as avenue trees (‘Szent Istvan’ and‘K3’) should be clarified for further breeding activities. Their ancestor species should be identified by a genetic comparison with reference material (Tilia cordata, T. platyphyllos, T. dasystyla, T. × euchlora, T. × europaea and others). RAPD marker data were evaluated by UPGMA cluster and neighbour-joining analysis. The genetic comparison of the two selected clones with the collection of reference material offers insights into some systematic relationships within the genus Tilia. It was supplemented by a critical discussion of methods of RAPD data evaluation for taxonomic purposes.
Three problems in the taxonomy of Pancratium in Egypt are the lack of publications, a lack of clarity about the relationships between recently distinguished species, and the lack of markers for examining the levels and patterns of variation in rare and endemic species; the latter hinders work in plant conservation genetics. In this study we reassessed the taxonomic status of the Pancratium species of Egypt, and examined morphological and genetic variation within and between species, using specimens from different populations collected throughout its distribution range in the country. Our assessment was based on 38 macromorphological characters mainly representing vegetative parts, flowers, fruits and seeds, in addition to RAPD data. The results revealed five morphologically distinguished Pancratium species in Egypt, of which P. trianthum Herb. is newly recorded. Species identification was confirmed by two phenetic dendrograms generated with 26 quantitative morphological characters and RAPD data, while species delimitation was verified by principal component analysis. The diagnostic floral characters are those of the perianth, corona teeth, pistil, stamens, aerial scape, spathe, and number of flowers. The retrieved RAPD polymorphic bands show better resolution of the morphologically and ecologically closely allied Pancratium species (P. arabicum and P. maritimum), and also confirm the morphological and ecological divergence of P. tortuosum from the other studied species. These results are supported by the constructed UPGMA dendrogram.
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