First Report of Meloidogyne incognita on Daylily (Hemerocallis citrina) in Shaanxi, China

HomePlant DiseaseAhead of PrintFirst Report of Meloidogyne incognita on Daylily (Hemerocallis citrina) in Shaanxi, China PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Meloidogyne incognita on Daylily (Hemerocallis citrina) in Shaanxi, ChinaP. Y. Wei, S. Pan, D. L. Peng, Z. J. Chen, B. Hong, F. Zhang, and Y. M. LiP. Y. WeiShaanxi Key Laboratory of Plant Nematology, Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi’an 710043, ChinaSearch for more papers by this author, S. PanShaanxi Key Laboratory of Plant Nematology, Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi’an 710043, ChinaSearch for more papers by this author, D. L. Penghttps://orcid.org/0000-0002-6759-577XState Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaSearch for more papers by this author, Z. J. ChenShaanxi Key Laboratory of Plant Nematology, Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi’an 710043, ChinaSearch for more papers by this author, B. HongShaanxi Key Laboratory of Plant Nematology, Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi’an 710043, ChinaSearch for more papers by this author, F. ZhangShaanxi Key Laboratory of Plant Nematology, Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi’an 710043, ChinaSearch for more papers by this author, and Y. M. Li†Corresponding author: Y. M. Li; E-mail Address: [email protected]https://orcid.org/0000-0001-7257-276XShaanxi Key Laboratory of Plant Nematology, Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi’an 710043, ChinaSearch for more papers by this authorAffiliationsAuthors and Affiliations P. Y. Wei1 S. Pan1 D. L. Peng2 Z. J. Chen1 B. Hong1 F. Zhang1 Y. M. Li1 † 1Shaanxi Key Laboratory of Plant Nematology, Bio-Agriculture Institute of Shaanxi, Shaanxi Academy of Sciences, Xi’an 710043, China 2State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China Published Online:22 Jun 2023https://doi.org/10.1094/PDIS-10-22-2397-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleDaylilies (Hemerocallis citrina Baroni) are ornamental herbaceous perennials. In China, they are important cash crops for their roots, leaves, and flowers as both food and medicine (Guo et al. 2022). Dali County, Shaanxi Province, is a major daylily producer; the cultivation area is 43,330,000 m2 and the output is 227,000 kg, worth more than $109,120,000. In July 2021, many daylilies (cv. Shayuan) had chlorotic leaves and stunted growth in a Dali field. The area investigated was ∼2,000 m2, and root-knot nematode (RKN) disease incidence was >90%. Inflorescences of diseased plants decreased by nearly 30%, which seriously affected yield. Diseased plants had obvious galling on the roots, typical of RKN infection. Second-stage juveniles (J2) densities were 300 to 350 in 100 g of the 10 to 20 cm soil layer. RKNs were collected from root samples (n = 15) and were found in all diseased plant samples. Female perineal patterns (n = 20) showed a high dorsal arch and wavy stria, mostly lacking obvious lateral lines. Morphometrics of adult females (n = 20) were: body length (BL) = 668.99 ± 24.56 (487.57 to 897.84) μm, body width (BW) = 433.73 ± 12.84 (343.71 to 551.61) μm, stylet length = 15.64 ± 1.45 (10.86 to 28.26) μm, dorsal pharyngeal gland orifice to stylet base (DGO) = 2.57 ± 0.20 (1.41 to 3.68) μm, vulval slit length = 20.44 ± 0.91 (16.00 to 24.22) μm, and vulval slit to anus distance = 18.05 ± 1.06 (14.58 to 24.90) μm. Males had a trapezoidal labial region, with a high head cap concaved at the center of the top end in lateral view; stylet knobs were prominent, usually demarcated from the shaft. Morphometrics of males (n = 7) were: BL = 1,124.56 ± 53.97 (998.37 to 1,336.52) μm, BW = 33.60 ± 0.79 (30.21 to 36.52) μm, stylet length = 23.63 ± 0.78 (20.14 to 26.37) μm, DGO = 3.04 ± 0.09 (2.69 to 3.38) μm, spicule length = 25.72 ± 0.57 (23.97 to 28.33) μm. The key morphometrics of J2s were: BL = 439.13 ± 6.52 (398.32 to 481.33) μm, BW = 15.14 ± 0.26 (13.91 to 16.66) μm, stylet length = 13.44 ± 0.29 (10.96 to 14.60) μm, DGO = 2.13 ± 0.18 (1.22 to 3.10) μm, tail length = 57.46 ± 4.89 (38.85 to 101.33) μm, hyaline tail terminus = 16.93 ± 0.97 (11.45 to 22.54) μm. These features match the description of Meloidogyne incognita (Eisenback and Hirschmann 1981). The DNA of 11 females was extracted using species-specific primers Mi2F4/Mi1R1 (5′-ATGAAGCTAAGACTTTGGGCT-3′/5′-TCCCGCTACACCCTCAACTTC-3′) for M. incognita identification (Kiewnick et al. 2013). A 300 bp fragment was amplified, confirming the RKNs as M. incognita. To confirm identification, the NADH dehydrogenase subunit 5 (nad5) from the mitochondrial DNA region was amplified by primers NAD5-F/R (5′-TATTTTTTGTTTGAGATATATTAG-3′/5′-CGTGAATCTTGATTTTCCATTTTT-3′; Janssen et al. 2016). A 611 bp fragment was obtained with a sequence (GenBank OP115729) 100% identical to a sequence of M. incognita (MT683461). The ITS region was amplified by primers rDNA-F/R (5′-TTGATTACGTCCCTGCCCTTT-3′/5′-TTTCACTCGCCGTTACTAAGG-3′) (Vrain et al. 1992). The 768 bp sequences (OP095037) were 100% identical to a sequence of M. incognita (MH113856). A greenhouse infection test was run. Eighteen 5-week-old healthy daylilies (cv. Shayuan) were individually grown in 9 liter pots of autoclaved soil and inoculated with 3,000 J2s. Six uninoculated plants were negative controls. After 60 days, all inoculated plant roots had galling symptoms similar to those in the field; RKNs extracted from roots were identified as M. incognita with the primers Mi2F4/Mi1R1. No obvious symptoms were observed on controls. An average of 9,635 J2s were recovered from inoculated plants (reproductive factor = 3.21), confirming pathogenicity. Although daylily was reported as a host of M. incognita in Florida (Inserra et al. 1995), to our knowledge, this is the first case of M. incognita naturally infecting daylily in China. This disease reduces daylily yield and may cause serious economic losses; further studies should focus on the occurrence and effective control of the disease.The author(s) declare no conflict of interest.References:Eisenback, J. D., and Hirschmann, H. 1981. J. Nematol. 13:513. ISI, Google ScholarGuo, A., et al. 2022. Sci. Hortic. 293:110682. https://doi.org/10.1016/j.scienta.2021.110682 Crossref, Google ScholarInserra, R. N., et al. 1995. Nematol. Circ. 211. Google ScholarJanssen, T., et al. 2016. Sci. Rep. 6:22591. https://doi.org/10.1038/srep22591 Crossref, ISI, Google ScholarKiewnick, S., et al. 2013. Nematology 15:891. https://doi.org/10.1163/15685411-00002751 Crossref, ISI, Google ScholarVrain, T. C., et al. 1992. Fund. Appl. Nematol. 15:563. Google ScholarFunding: This research was funded by the Key R&D Project of Shaanxi Province (2020ZDLNY07-06), Science and Technology Program of Shaanxi Academy of Sciences (2022K-02), and Key Research and Development Program of Shaanxi Province (2022NY-128).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Just PublishedSubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Published: 22 Jun 2023First Look: 23 Jan 2023Accepted: 16 Jan 2023 Information© 2023 The American Phytopathological SocietyFundingKey R&D Project of Shaanxi ProvinceGrant/Award Number: 2020ZDLNY07-06Shaanxi Academy of SciencesGrant/Award Number: 2022K-02Key Research and Development Program of Shaanxi ProvinceGrant/Award Number: 2022NY-128KeywordsdaylilyMeloidogyne incognitaShaanxiThe author(s) declare no conflict of interest.PDF download