Epidemic Identification of Fungal Diseases in Morchella Cultivation across China

Abstract

True morels (Morchella, Pezizales) are world-renowned edible mushrooms (ascocarps) that are widely demanded in international markets. Morchella has been successfully artificially cultivated since 2012 in China and is rapidly becoming a new edible mushroom industry occupying up to 16,466 hectares in the 2021–2022 season. However, nearly 25% of the total cultivation area has annually suffered from fungal diseases. While a variety of morel pathogenic fungi have been reported their epidemic characteristics are unknown, particularly in regional or national scales. In this paper, ITS amplicon sequencing and microscopic examination were concurrently performed on the morel ascocarp lesions from 32 sites in 18 provinces across China. Results showed that Diploöspora longispora (75.48%), Clonostachys solani (5.04%), Mortierella gamsii (0.83%), Mortierella amoeboidea (0.37%) and Penicillium kongii (0.15%) were the putative pathogenic fungi. The long, oval, septate conidia of D. longispora was observed on all ascocarps. Oval asexual spores and sporogenic structures, such as those of Clonostachys, were also detected in C. solani infected samples with high ITS read abundance. Seven isolates of D. longispora were isolated from seven selected ascocarps lesions. The microscopic characteristics of pure cultures of these isolates were consistent with the morphological characteristics of ascocarps lesions. Diploöspora longispora had the highest amplification abundance in 93.75% of the samples, while C. solani had the highest amplification abundance in six biological samples (6.25%) of the remaining two sampling sites. The results demonstrate that D. longispora is a major culprit of morel fungal diseases. Other low-abundance non-host fungi appear to be saprophytic fungi infecting after D. longispora. This study provides data supporting the morphological and molecular identification and prevention of fungal diseases of morel ascocarps.

Ultrastructure and Physiological Characterization of Morchella Mitospores and Their Relevance in the Understanding of the Morel Life Cycle

“…However, due to the weak research on their biological basis, cultivation has suffered serious instability [ 7 , 9 ]. For example, indoor cultivation in the United States has stagnated after a period of operation, and field cultivation in China has recently also suffered 70% non-profit situations in some areas [ 9 , 10 , 11 , 12 ]. As a consequence, there has recently been a comprehensive promotion of field cultivation based on deep knowledge development of basic biological foundations, such as the identification and characteristics of cultivable varieties [ 12 , 13 , 14 , 15 ], the identification of mating type genes [ 9 , 10 ], the characteristics of heterokaryons [ 16 , 17 , 18 , 19 , 20 , 21 ], nutritional metabolism [ 22 , 23 ] and “omics” technology [ 19 , 24 , 25 , 26 , 27 , 28 , 29 ].…”

Transcriptomic and Metabolomic Profiles Provide Insights into the Red-Stipe Symptom of Morel Fruiting Bodies

“…Nine cultivable species of morels are found in China, including M. sextelata , M. eximia , M. exuberans , M. importuna , M. owneri , M. rufobrunnea , M. tomentosa , Mel-13 , and Mel-21 [ 9 , 10 ]. Morel cultivation has achieved significant breakthroughs in China since 2012, with an area of 16,466 ha during the 2021–2022 season [ 11 ]. Meanwhile, morel biology has been recently extensively studied with important findings on its reproductive modes [ 7 , 12 , 13 , 14 , 15 , 16 ], nuclear and mitochondrial genome sequence and function [ 9 , 16 , 17 , 18 , 19 , 20 , 21 ], microbial community dynamics [ 22 , 23 , 24 , 25 , 26 ], nutrient metabolism [ 27 ], and fruiting body development [ 28 , 29 , 30 , 31 ].…”

“…Despite the rapid expansion of artificial morel cultivation in China, its cultivation industry is still facing several setbacks, including low spawn quality, spawn aging, environmental factors, mechanisms of exogenous nutrition, diseases, and management measures [ 5 , 7 , 11 ]. The large-scale, outdoor morel cultivation in an open environment infrastructure renders their ascocarps susceptible to pests and bacterial and fungal diseases [ 5 ].…”

“…Thus, preventing and controlling the disease spread is crucial for optimizing morel cultivation. It is estimated that 25% of the morel cultivation area has been affected by fungal infections, resulting in severe yield losses [ 11 ]. Several pathogenic fungi that infect morels have been identified, including Cladobotryum protrusum [ 32 ], Diploöspora longispora [ 33 ], the Fusarium incarnatum – equiseti species complex [ 34 ], Paecilomyces penicillatus [ 26 , 35 ], and Lecanicillium aphanocladii [ 36 ], have been identified.…”

“…Several pathogenic fungi that infect morels have been identified, including Cladobotryum protrusum [ 32 ], Diploöspora longispora [ 33 ], the Fusarium incarnatum – equiseti species complex [ 34 ], Paecilomyces penicillatus [ 26 , 35 ], and Lecanicillium aphanocladii [ 36 ], have been identified. Recently, ITS-amplicon sequencing and microscopic examination were performed on morel ascocarp lesions from 32 sites in 18 provinces across China, revealing that D. longispora was a major cause of morel fungus diseases [ 11 ].…”