Análisis morfológico y molecular de los blenios de agua dulce: una nueva especie del género Salaria Forsskål, 1775 (Actinopterygii, Blennidae) en Marruecos.

The North African freshwater fish fauna is scarce compared to other regions of the world, probably due to historical and climatic factors. The western part of North Africa is more diverse than central or eastern areas. Populations of freshwater blennids that have been traditionally ascribed to the species Salaria fluviatilis nowadays inhabit the Sebou basin in Morocco. In this study we demonstrated morphologically and molecularly that these Moroccan populations constitute a new species, for which we provide a formal description. The following diagnostic characters distinguish the newly described species from other freshwater blennids: head without diagonal rows of dark dots or blotches on cheeks; supra-ocular tentacle thick and simple (not branched); 13-15 teeth on the upper jaw and 14-16 on the lower jaw; 16-17 soft anal fin rays; short pre-orbital distance (cephalic index: 2.9-3.8); height of the anterior (spiny) part of the dorsal fin short (dorsal fin index: 0.8-1.3) and 34 vertebrae. Mitochondrial and nuclear genetic distances between the new Salaria species and either S. economidisi or S. fluviatilis are high, especially in the mitochondrial control region (18%), while these genetic distances range from 2 to 3% when the nuclear S7 marker is compared. These morphological and molecular characters differentiate the new species from the remaining freshwater species of the genus (Salaria economidisi and S. fluviatilis). The new species is confined to a small restricted area of the Sebou basin in Morocco and should be considered endangered (EN) according to the IUCN Red List.La fauna de peces de agua dulce del norte de África es escasa comparada con otras regiones del mundo debido fundamentalmente a factores históricos y climáticos. El oeste del norte de África es más diverso que las regiones del centro y del este. En la cuenca del río Sebou habitan actualmente poblaciones de blenios de agua dulce que han sido tradicionalmente adscritas a la especie Salaria fluviatilis. En este estudio demostramos morfológica y molecularmente que estas poblaciones marroquíes constituyen una nueva especie, para la cual proveemos una descripción formal. Los siguientes caracteres diagnósticos distinguen a la nueva especie descrita del resto de especies de blenios de agua dulce: cabeza sin una fila diagonal de puntos oscuros o manchas en las mejillas; tentáculo supraocular grueso y simple (no ramificado); 13-15 dientes en la mandíbula superior y 14-16 en la inferior; 16-17 radios blandos en la aleta anal; distancia preorbital corta (índice cefálico: 2.9-3.8); altura de la region anterior de la aleta dorsal corta (índice dorsal: 0.8-1.3) y 34 vértebras. Las distancias genéticas mitocondriales y nuclear entre la nueva especie de Salaria y las otras dos especies son altas, especialmente en la región control (18%), mientras que estas distancias genéticas variaron entre 2-3% para el gen nuclear S7. Estos caracteres morfológicos y moleculares diferencian a la nueva especie del resto de blenios de agua dulce del género (Salaria fluviatilis y S. economidisi). La nueva especie está confinada a la cuenca del río Sebou en Marruecos y debería ser considerada como En Peligro (EN) de acuerdo a las categorías de la lista roja

Pathotypic diversity of Rhynchosporium secalis (Oudem) in Tunisia

Scald, caused by Rhynchosporium secalis (Oudem), is an important disease of barley in Tunisia particularly in northern, northwestern and central parts of the country where the climate is usually cold and wet during most of the barley growing season. Pathogenic variability of the barley scald pathogen in Tunisia was determined by testing the pathogenicity of 100 isolates from 5 different regions on 19 host differentials. Pathotypic diversity was high, with 93 R. secalis pathotypes identified on two differential sets (one comprising 9 and the other 10 barley lines) containing known resistance genes. A few pathotypes comprised 2% of the isolates; however, the majorities were represented by a single isolate. None of the differential lines was resistant to all isolates. The differential cultivar “Astrix” was the least compatible with the scald pathotypes followed by the differential cultivars “Atlas” and “Abyssinia”. Compatibility of the pathotypes on “Rihane” (69%) was close to that on “Osiris” (73%) and “La Mesita” (61%). None of the pathotypes was found in all the five regions of Tunisia surveyed. Some pathotypes were specific to a single region while others were found in several regions. The incidence of pathotypes varied considerably among regions, with region 3 (northwestern Tunisia) comprising the largest number of pathotypes. Virulent pathotypes were recovered in all regions but more pathotypic variability (44%) was observed in the semi-arid region 3. Differential cultivars allowed classification of R. secalis in four virulence groups. Canonical discriminant analysis showed no apparent association between virulence and geographical origin of the populations. Pathogenic variability in R. secalis in Tunisia was found not to be associated with geographical region, hence, the necessity for deployment of different resistance sources in major barley growing areas.Key words: Rhynchosporium secalis, barley, virulence groups, pathotypic variation