Morphological and molecular identification of potato cyst nematodes Globodera rostochiensis and Globodera pallida in Bulgaria

Kostadin Trayanov, Hаrry Samaliev, Milena Kostova, Bojin Bojinov and Ani Besheva

Abstract: The potato cyst nematodes (PCNs), Globodera rostochiensisand Globodera pallida are economically important parasites of the potato and are recognized as quarantine pests. In Bulgaria G. rostochiensis was identified for the first time in 1978, while G. pallida in 1992. Identifications of PCNs populations have been based only on morphological characters and G.rostochiensis is prevailing species in potato fields. The present work was aimed to introduce a faster and more reliable method for identifying and differentiating the PCN species in three potato-producing regions in Bulgaria. For the morphological identification of both PCN species, 30 cysts and 30 second-stage juveniles (J2S) were studied. For a more accurate and rapid identification of G. rostochiensis and G. pallida, polymerase chain reaction (PCR) based method was applied. Multiplex PCR reaction was performed with primers designed for a small region between internal transcribed spacer 1 and the 5.8 S ribosomal RNA gene regions in order to identify the Globodera species. The mean morphometric values of the 30 experimental cysts and J2S were common within the expected range for G.pallida and G. rostochiensis with some variations observed. The present results demonstrate the occurrence of both species of PCNs, as G. pallida was identified in 24 from the soil samples and G. rostochiensis in 6 of them. The correct and rapid identification of PCN species in Bulgarian potato fields is essential for adopting more effective measures for its control.

Keywords: cyst nematodes; Globodera pallid; Globodera rostochiensis; PCR identification; potato

Date published: 2020-04-30