Morphological variation and molecular study of the root lesion nematode Pratylenchus thornei

摘要

During a survey of plant-parasitic nematodes in the northern part of Iran, six populations of Pratylenchus thornei were studied by means of morphological and molecular characterisation. The results showed that body length has a highly significant correlation with all morphometric data indexed in the measurement table, except for the c' index and the dorsal pharyngeal gland opening. However, the highest correlation was detected between body length and 'a' index (r = 0.805). Furthermore, stylet length had a significant correlation with body length (r = 0.511), tail length (r = 0.300) and V (r = 0.324). On the study of ratios, the results revealed that b and a are more reliable to evaluate the species. A molecular study of the P. thornei populations using 28S rDNA showed close relationships of the Iranian and USA, Morocco, Moldova, Spain and United Kingdom populations extracted from NCBI Genbank. The results indicated monophyly of P. thornei. Measurement table, illustrations and phylogenetic analysis for this species are given.