Abstract:

The study aims to clarify the causes of wheat plant death, leaf dryness and spots in main wheat production areas in Tacheng of Xinjiang, determine the pathogen, and lay a foundation for the effective disease control in field. In this study, the pathogenic bacteria of diseased plants were isolated and purified by conventional tissue isolation method. The pathogenicity was determined by needle inoculation; the pathogen species were identified by morphological observation and rDNA-ITS and EF-1 gene sequence analysis; and the biological characteristics of the identified pathogens YE9 and YE10 were studied. After isolation and identification, Alternaria and Fusarium were obtained, including 20 Fusarium equiseti and 20 Fusarium acuminatum respectively, and the isolation frequency was 13%. The optimum carbon source of F. equiseti and F. acuminatum was soluble starch, and the best illumination condition was 24 h. The optimum nitrogen source of F. equiseti was beef paste, and the optimum growth temperature was 28℃, the lethal temperature was 53℃, and the optimum growth pH was 6.5. The optimum nitrogen source of F. acuminatum was yeast extract powder, the optimum growth temperature was 20℃, the lethal temperature was 50℃, and the optimum growth pH was 7.5. The experiment confirmed that Fusarium could infect wheat leaves and cause the symptoms of wheat leaf blight, which was reported for the first time in China and laid a foundation for the effective control of the disease in field.

Key words: wheat, pathogen, Fusarium, pathogen identification, leaf blight, biological characteristics