Macro-, micromorphological characters and DNA fingerprinting markers on three Ruprechtia species (Polygonaceae) in Egypt

Abstract

Macro-,micromorphological characters and DNA fingerprinting markers have been used to differentiate the threeRuprechtia C. A. Meyer species growing in Egypt (R. exelsa, R. polystachya, and R. salicifolia). Interestingly,the macro- and micromorphological criteria of the vegetative organs showed no fundamental characters todiscriminate between the three examined species. However, the data obtained from the seed coat surface (usingLM and SEM) revealed some variability among the tested species. Seed coat surface was colliculate in (R.excelsa), pusticulate in (R. polystachya) and reticulate–scalariform in R. salicifolia. Accordingly, the seed coatsurface can be used as a fundamental criterion to discriminate between the species of this study. The RAPD–PCR electrophoretic profile, showed unique RAPD markers some of which were species-specific. Speciesspecificmarkers were recorded by using primers OPA-01, OPA-02 and OPA-05 respectively. Two RAPDmarkers specific to R. polystachya and R. salicifolia were recorded. The two markers for the former species havea molecular size of 1800 and 2600 bp using primer OPA-01. While those specific to the latter species have amolecular size of 300 and 400 bp using primers OPA-02. For R. excelsa, one specific RAPD marker wasrecorded, it has a molecular size 800 bp using primer OPA-05. The RAPD markers may be considered as validcriteria to discriminate between the three Ruprechtia species used in this investigation. However, the similarityin the banding profile of RAPD-PCR and the morphological criteria justify the maintenance of the three speciesin the same genus.