Identification of Potato Cyst Nematodes (Globodera rostochiensis) on Potato in Yunnan Province

PurposeTo identify the specific species of Globodera spp., which was found in individual potato plantations in Yunnan Province, providing a basis for formulating disease control measures.

MethodsThe symptoms of aboveground and underground damaged roots of plants were observed in the field, and the rhizosphere soil and damaged roots were collected as research samples. Potato cyst nematode (PCN) were isolated from the samples, and the species was identified by morphological and molecular biological methods.

ResultsMorphological identification showed that the morphological characteristics and measurements of the cysts and the second stage juveniles (J2) were consistent with those of G. rostochiensis. Molecular identification showed that the PCR amplification products of 28S rDNA-D2/D3 region was 784 bp, the DNA sequences of 28S rDNA-D2/D3 were 99.11%-100.00% similar to those of G. rostochiensis in NCBI database; the mtDNA-CoX1 region amplified product was 447 bp, the DNA sequences of mtDNA-cox1 were 99.28%-99.33% similar to those of G. rostochiensis in NCBI database. Phylogenetic trees showed that the 28S rDNA-D2/D3 region sequence and mtDNA-cox1 region sequence of this nematode clustered in the same branch with 100% support. The specific primers ITS5/PITSr3 identified G. rostochiensis with fragment size 430 bp, which was consistent with the reported in the past.

ConclusionIt is confirmed that the PCN found in individual potato plantations in Yunnan Province are G. rostochiensis. This nematode is a worldwide plant quarantine species, and strict measures should be taken to avoid further spread of this nematode disease.