Interesting new facts on Heterodera schachtii (Nematoda: Heteroderidae) from South Africa

Abstract

In January 2017 Heterodera schachtii Schmidt, 1871 was collected from a potato field, formerly planted to cabbage, in the Tarlton area of South Africa. As H. schachtii from South Africa has never been studied molecularly, this short communication is the first of its kind for this country. Two PCR amplification primers that amplify the ITS region, including the 5.8S ribosomal gene, as well as short parts of the 18S and 28S ribosomal genes, were used for the molecular study. According to the MP consensus tree the South African population is closely related to an H. schachtii population from the Netherlands. The GenBank accession number of the ITS-rDNA sequence of the specimen is MF 754150. As voucher specimens, the terminal patterns of two cysts and four infective juveniles with accession numbers 50551 and 50552 have been deposited in the National Collection of Nematodes (NCN) at the Nematology Unit, ARC-PHP, Pretoria, South Africa. The present study includes interesting scanning electron micrographs (SEM) of the external morphology of the cyst cone, as well as the presence of the second stage juveniles in the gelatinous egg sac of the cysts. This is novel information since, according to literature, to date only eggs have been found in the egg sac of this species.