Molecular identification of Meloidogyne species isolated from potato in China and evaluation of the response of potato genotypes to these isolates

Summary Root-knot nematodes ( Meloidogyne spp.) are one of the most economically important groups of plant-parasitic nematodes on potato ( Solanum tuberosum ), but there has been little study regarding their occurrence on potato in China. In this study, the nematodes in two nematode-infected potato samples collected from Yunnan Province were identified as Meloidogyne spp. Amplicon sizes with species-specific PCR primers indicated that one sample was M. javanica and the other was M. incognita . Cultures established from these two isolates were used to screen 28 potato genotypes in China. All genotypes were susceptible to both M. javanica and M. incognita . However, the mean root galling index and number of egg masses were generally higher for M. javanica than M. incognita . Variable susceptibility was demonstrated among the tested potato genotypes. No available resistant potato cultivars plus a rapid spread of Meloidogyne spp. will result in a potential threat to potato production in China.