ABSTRACT
In Winter 2016, root and soil samples were collected from the rhizosphere soil at 10 to 15 cm depth of turfgrass, in the yard of a complex of houses in Caxias, a region near Lisbon, Portugal. The grass (dominated by tall fescue) showed yellow patches, stunting, and poor growth. Several specimens of a ring nematode (50-60 nematodes/100 ml soil) were recovered from soil and identified as Mesocriconema xenoplax (peach ring nematode) based on morphological and morphometrical analysis of females. The observed morphological features were with previous descriptions. Species identification was confirmed through sequencing of the fragment spanning D2/D3 domain of the 28S rDNA gene. Phylogenetic analysis revealed that the Portuguese isolate grouped with M. xenoplax isolates (98% similarity), supporting its identification as M. xenoplax. This is the first report of M. xenoplax from turfgrass in Portugal and in Europe contributing with additional information on the distribution of this phytoparasite.In Winter 2016, root and soil samples were collected from the rhizosphere soil at 10 to 15 cm depth of turfgrass, in the yard of a complex of houses in Caxias, a region near Lisbon, Portugal. The grass (dominated by tall fescue) showed yellow patches, stunting, and poor growth. Several specimens of a ring nematode (50-60 nematodes/100 ml soil) were recovered from soil and identified as Mesocriconema xenoplax (peach ring nematode) based on morphological and morphometrical analysis of females. The observed morphological features were with previous descriptions. Species identification was confirmed through sequencing of the fragment spanning D2/D3 domain of the 28S rDNA gene. Phylogenetic analysis revealed that the Portuguese isolate grouped with M. xenoplax isolates (98% similarity), supporting its identification as M. xenoplax. This is the first report of M. xenoplax from turfgrass in Portugal and in Europe contributing with additional information on the distribution of this phytoparasite.
ABSTRACT
Platypus cylindrus is an important wood borer of cork oak trees (Quercus suber) in the Mediterranean region, namely Portugal, Morocco and Algeria where its presence has drastically increased in the past few decades. On the contrary, the insect is not a relevant pest in Tunisia. The aim of this work is to analyze morphological and genetic differences among Tunisian and Portuguese populations in order to understand their role in the diverse population dynamics (e.g., aggressiveness) of the insect. The information could be used as a novel tool to implement protective measures. Insects were collected from cork oak stands in Tunisia (Ain Beya, Babouch and Mzara) and Portugal (Chamusca and Crato). Morphological traits of female and male mycangial pits were determined, using scanning electron microscopy but no significant differences were found. Genetic differences were analyzed using nuclear (internal simple sequence repeat polymerase chain reaction) and mitochondrial (cytochrome oxidase I (COI)) molecular markers. The results showed a very low level of intraspecific polymorphism and genetic diversity. The alignment of COI sequences showed high percentage of identical sites (99%) indicating a very low variation in nucleotide composition. Other variables related with the ecology of the insect and its associated fungi must be studied for a better understanding of the differences in the insect population's dynamic in Mediterranean countries.
