Identification and resistance characterization of two traditional Chinese medicine plant species against Meloidogyne incognita

BACKGROUND: Root-knot nematodes are major plant pests responsible for global agricultural losses. However, systematic studies on host suitability of traditional Chinese medicine (TCM) plants for Meloidogyne species remain limited, leaving their resistance status unclear. This study aimed to evaluate the suitability of TCM plants as hosts for Meloidogyne incognita and characterize their resistance modes, with a single microplot trial providing supporting evidence. RESULTS: Of the 25 TCM species evaluated for host suitability for M. incognita, 23 were susceptible based on the reproduction factor. Taraxacum mongolicum developed root galls but produced no egg masses and was thus classified as highly resistant, whereas Plantago asiatica produced neither galls nor egg masses and was considered non-host. Although T. mongolicum supported high initial nematode penetration, nematode development was arrested, and the nematode population declined over time. In P. asiatica, significantly fewer penetrated nematodes, arrested development, and population reduction were observed. The number of root galls formed in T. mongolicum was comparable to that on susceptible hosts, but the galls were significantly smaller, with histological observations revealing inhibited giant cell formation. A single microplot trial provided supporting evidence that both T. mongolicum and P. asiatica reduced M. incognita populations in naturally infested soil compared to susceptible hosts. CONCLUSION: T. mongolicum was highly resistant and P. asiatica was a non-host to M. incognita, as both suppressed nematode development and reproduction. These species may be suitable for rotation with other susceptible medicinal crops to reduce M. incognita populations, providing a potential management strategy.