Ditylenchus rafiqi n. sp. from pomegranate (Punica granatum L.) from India with a tabular key for the species known from India

Abstract

Summary Ditylenchus rafiqi n. sp. was recovered from the rhizosphere of pomegranate in New Delhi (India), and it is characterised by morphological, morphometrical and molecular methods. The new species is characterised by having a body length of 553-901 μm, delicate stylet (7-10 μm long), longer conus length (5.0-5.5 μm in females and 4.5-5.5 μm in males) with small round knobs sloping backward, seven lateral lines at the mid-body, median bulb well developed with thickening of lumen walls, a post-uterine sac well developed (27-47 μm), tail long, elongate conoid with an almost round terminus (45-74 μm) and male spicule of 15-17.5 μm, gubernaculum simple, leptoderan type of bursa enveloping the tail almost >50% of its tail length. A detailed study based on morphological and morphometrical methods clearly demarcates that D. rafiqi n. sp. differs from other known species of Ditylenchus. The molecular characterisation was done using D2-D3 of 28S rRNA and ITS rRNA markers. Molecular characterisation shows that the new species is closely related to D. acutus, D. gilanicus (D2-D3 marker), and D. medicaginis (ITS rRNA markers). Based on phylogenetic analyses using D2-D3 of LSU and ITS rRNA markers, D. rafiqi n. sp. forms an intermediate clade between the D. triformis and D. dipsaci groups.