Heterothallic Type of Mating System forCordyceps cardinalis

Abstract

Cordyceps cardinalis successfully produced its fruiting bodies from multi-ascospore isolates. However, subcultures of multi-ascospore isolates could not produce fruiting bodies after few generations. Fruiting body production also differed from sector to sector of the same isolate. Single ascospore isolates were then co-inoculated in combinations of two to observe the fruiting characteristics. Combinations of certain isolates produced perithecial stromata formation, whereas other combinations did not produce any fruiting bodies. These results show that C. cardinalis is a heterothallic fungus, requiring two isolates of opposite mating types for fruiting body production. It was also shown that single ascospore isolates are hermaphrodites.

Effects of MAT1-2 Spore Ratios on Fruiting Body Formation and Degeneration in the Heterothallic Fungus Cordyceps militaris

“…However, these fruiting bodies are incomplete due to the lack of perithecia (the flaskshaped fruiting structure) and ascospores [11]. This phenomenon was also discovered in some haploidic MAT1-1 strains of C. takaomontana and C. cardinalis [12,13]. In our study, monokaryotic strains H8 and M5 harboring the MAT1-1 mating-type locus were more stable for fruiting body formation than heterokaryotic strains G12, B12, and HQ1 through successive culturing generations (Figure 1).…”

“…In the fifth generation, fruiting body formation in these strains was completely impaired (Figure 1B). Although sexual reproduction in heterothallic Cordyceps species usually requires both MAT1-1 and MAT1-2 for fruiting body production [9,[11][12][13], Zheng et al (2011) also indicated that the sequenced C. militaris strain (Cm01) carrying only MAT1-1 without an opposite mating-type partner in its genome is still able to form fruiting bodies (stromata). However, these fruiting bodies are incomplete due to the lack of perithecia (the flaskshaped fruiting structure) and ascospores [11].…”

“…Deletion of MAT1-1 or MAT1-2 resulted in impairment of the fruiting body formation in C. militaris [9]. Strikingly, some single MAT1-1 mating-type strains of C. militaris, Cordyceps takaomontana, and Cordyceps cardinalis can also form fruiting bodies, but these stromata are sterile, without perithecia or ascospores [11][12][13]. The molecular mechanism for this phenomenon is still not known yet.…”

“…Successive subculturing of mycelia or spores for several generations in filamentous fungi and mushrooms causes degeneration [12][13][14][15][16][17][18]. Strain degeneration in C. militaris is characterized by the reduction in fruiting body formation, mycelial growth rate, pigmentation, and production of bioactive metabolites [19,20].…”

Detection of a PCR‐based mating type for native intraspecific Beauveria bassiana isolates

“…Whether ascomycetes mating systems are outcrossing or selfing is largely determined by the genomic organization of the MAT gene. In addition, the mating type of fungi can clarify the biological species concept (Havenga et al, 2020; Sung et al, 2010).…”