Isolation of Main Pathogens Causing Postharvest Disease in Fresh Codonopsis pilosula during Different Storage Stages and Ozone Control against Disease and Mycotoxin Accumulation

Abstract

Codonopsis pilosula is an important Chinese herbal medicine. However, fresh C. pilosula is prone to decay during storage due to microorganism infections, seriously affecting the medicinal value and even causing mycotoxin accumulation. Therefore, it is necessary to study the pathogens present and develop efficient control strategies to mitigate their detrimental effects on the herbs during storage. In this study, fresh C. pilosula was collected from Min County in Gansu Province, China. The natural disease symptoms were observed during different storage stages, and the pathogens causing C. pilosula postharvest decay were isolated from the infected fresh C. pilosula. Morphological and molecular identification were performed, and pathogenicity was tested using Koch’s postulates. In addition, the control of ozone was examined against the isolates and mycotoxin accumulation. The results indicated that the naturally occurring symptom increased progressively with the extension of storage time. The mucor rot caused by Mucor was first observed on day 7, followed by root rot caused by Fusarium on day 14. Blue mold disease caused by Penicillum expansum was detected as the most serious postharvest disease on day 28. Pink rot disease caused by Trichothecium roseum was observed on day 56. Moreover, ozone treatment significantly decreased the development of postharvest disease and inhibited the accumulations of patulin, deoxynivalenol, 15-Acetyl-deoxynivalenol, and HT-2 toxin.

Ozone Application Suppressed the Blue Mold Development and Maintained the Main Active Ingredients Content of Postharvest Fresh Codonopsis pilosula during Storage

“…Our previous studies suggested that P. expansum is the main pathogen causing fresh C. pilosula blue mold during the postharvest storage period, which seriously impairs the quality of the fresh C. pilosula after harvest [ 19 ]. In this study, it was found that 2 mg L −1 ozone fumigation treatment significantly reduced the disease incidence of the blue mold of C. pilosula , inhibited the development of the blue mold of C. pilosula , reduced the accumulation of patulin, and alleviated the weight loss of C. pilosula to some extent.…”

“…The samples were collected every 7 days for patulin analysis. Patulin accumulation was determined based on the method by Lv [ 19 ].…”

Effects of Ozone Treatment on Postharvest Mucor Rot of Codonopsis pilosula Caused by Actinomucor elegans

“…A. elegans was previously isolated and purified from tissues affected by C. pilosula mucor rot disease in the laboratory. The identification was carried out through morphological and molecular biological methods [14]. The isolated A. elegans was stored at 4 • C on PDA (potato dextrose agar) culture medium for future use.…”

Effects of Microbial Inoculants Combined with Chemical Fertilizer on Growth and Soil Nutrient Dynamics of Timothy (Phleum pratense L.)

“…Field experiments were carried out from April 2022 to November 2022 at Kaishengyuan Agricultural Professional Cooperative, Minxian County, Dingxi City, Gansu Province, China (103 • 48 ′ 25 ′′ E, 34 • 29 ′ 20 ′′ N, elevation 2603.15 m). The research site is located in the transition zone from a temperate semi-humid climate to an alpine humid climate, with an average annual temperature of 5.5 • C. The annual precipitation is 635 mm, the annual precipitation is 635 mm, and the average sunshine duration is 2214.9 h. The soil type is black soil with a pH of 7.97, alkaline-dissolved nitrogen of 94.52 mg•kg −1 , 21.80 mg•kg −1 quick phosphorus, 41.11 mg•kg −1 quick potassium, and 24.11 g•kg −1 organic matter [13].…”