Identification of Root Rot Pathogens on Polygonatum cyrtonema in Fujian

  Objective   Pathogens that caused the root rot disease on Polygonatum cyrtonema Hua in Fujian were identified.

  Methods   Based on the survey of P. cyrtonema root rot disease in three planting areas in the province, infected plants and rhizomes were sampled to isolate the microbes. Suspected pathogens were examined morphologically and molecular biologically prior to a pathogenicity test for a confirmed identification.

  Results  Approximately 10.50% the typical disease symptoms appeared on the seedlings, and 17.65% on the rhizomes at harvest. Based on the morphological characteristics, FOF1/FOR1 and F8/R8 PCR amplification of specific primers, and sequences of translation elongation factor-1α (tef-1α) gene, the pathogens that caused the infection were identified to include Fusarium oxysporum, F. solani,> and F. fujikuroi from 98 isolates. The frequency of isolating F. oxysporum from the collected samples was 75.51%, 20.41% on F. solani, and 4.08% on F. fujikuroi. Inoculating the isolated pathogens on healthy rhizomes reproduced the same symptoms as observed in the field and followed Koch’s rules.

  Conclusion   F. oxysporum, F. solani, and F. fujikuroi were identified to be the pathogens of the root rot disease on P. cyrtonema in Fujian. F. fujikuroi was the first time to be associated with the outbreak in China.