Balancing visual comfort and building energy efficiency remains challenging for existing curtain adjustment methods in office buildings, especially under practical implementation constraints. This study proposes an energy-saving curtain adjustment method (ECAM) that includes an energy-oriented baseline mode (ECAM-B) and an extended comfort mode (ECAM-C). Specifically, ECAM-B fully deploys or retracts the curtain according to the trade-off between air-conditioning and lighting energy consumption. ECAM-C is built upon ECAM-B by searching discretized candidate curtain retraction rates under daylight glare probability (DGP) and daylight illuminance constraints to determine the control command. A coupled luminous-thermal prediction model, validated against full-scale experimental data, was applied to estimate DGP, indoor daylight illuminance, and cooling load. ECAM was then evaluated on a representative summer day using these predicted luminous-thermal indicators and the derived energy consumption indicators. Across all transmittance cases in the south-facing room with low lighting power density, ECAM reduced daily total energy consumption relative to the traditional curtain adjustment method (TCAM), while ECAM-C maintained the predicted DGP below 0.35. At the optimal curtain transmittance of 20%, ECAM-C achieved daily energy-saving rates of 20.8% and 19.5% compared with the no-curtain and TCAM cases, respectively. In the simulated west-facing office with high lighting power density, ECAM-C further improved the indoor luminous-thermal environment. Moreover, ECAM-C provided an additional daily energy saving of 184.6 Wh compared with ECAM-B, while improving the indoor visual environment. These results may inform practical occupancy-responsive curtain control and retrofit-oriented shading automation in office buildings.

Entomopathogenic fungi are recognized as environmentally sustainable biological control agents and are widely utilized in integrated pest management programs. However, their efficacy under field conditions is frequently constrained by limited conidial production capacity and susceptibility to environmental stresses, particularly ultraviolet (UV) radiation and elevated temperatures. In this study, we identified Beauveria bassiana strain RCEF5280 naturally infected with Beauveria bassiana chrysovirus 1 (BbCV1) and subsequently obtained an isogenic virus-free strain through single-conidium isolation. Comparative phenotypic analysis revealed that BbCV1 infection significantly enhanced conidial production by approximately 65% compared to the virus-free counterpart. Furthermore, following exposure to UV-B irradiation or heat shock, conidia from BbCV1-infected strains exhibited markedly higher germination rates than those from virus-free strains. To evaluate the reproducibility of these beneficial effects across different genetic backgrounds, BbCV1 was horizontally transmitted to two additional virus-free B. bassiana strains (RCEF383 and RCEF385) via hyphal anastomosis. Virus-infected derivatives of both recipient strains demonstrated substantial improvements in sporulation capacity (63-168% increase) and enhanced tolerance to UV radiation and heat stress. Molecular analysis indicated that these phenotypic changes were associated with upregulation of genes involved in conidiation, DNA damage repair, and heat shock response. Additionally, BbCV1 infection did not compromise fungal virulence against Galleria mellonella larvae or alter vegetative growth characteristics. These findings demonstrate that BbCV1 functions as a beneficial mycovirus that enhances key fitness traits relevant to the commercial production and field application of B. bassiana-based biopesticides.

Mycoviruses play diverse ecological roles ranging from conferring hypovirulence to establishing mutualistic symbioses. While these agents are vital for biocontrol, their genomic diversity within basal fungi is still poorly understood. In this study, we identified and characterized two novel double-stranded RNA (dsRNA) viruses co-infecting the basal fungus Conidiobolus macrozygosporus isolate RCEF7522. Complete genome sequences of the two viruses were determined by high-throughput sequencing and rapid amplification of cDNA ends (RACE). CmzV1 contains a dsRNA genome of 5,086 bp (G + C content: 48.3

Internal shading technologies, as an essential strategy for improving the indoor optic-heat environment and reducing building energy consumption, still lack effective energy-saving regulating methods. In this study, a heat gain, daylight illuminance, and energy consumption model for office buildings was established based on the energy balance principle. Using the model, a curtain regulating strategy with high energy performance was developed. In this strategy, an energy-saving curtain regulating method (ECRM) was proposed, distinct from the traditional curtain adjustment method (TCAM), to improve the energy performance of buildings. Furthermore, a simplified internal shading optic-heat ratio (n) was utilized to evaluate the shading performance and support curtain optical-property selection under the studied conditions. The energy consumption characteristics of office buildings were analyzed under various electric lighting power and curtain surface reflectivity (pc) conditions. The energy-saving potential of the ECRM was also explored. The results show that the energy-saving potential in offices with curtains is greater than that in offices without curtains, and that the surface reflectivity significantly affects the internal shading optic-heat ratio (n). In buildings with higher electric lighting power, the optimal optical reflectivity of the curtains was between 60% and 80%. On a typical summer design day, the ECRM in the office was consistently more energy-saving than the TCAM. Simulation results predict that, on a typical summer design day, ECRM can reduce the office energy consumption by up to 26.6% compared with TCAM when the curtain reflectivity is 80%. Even for office buildings with lower electric lighting power, ECRM was predicted to have greater energy-saving potential than TCAM.

Beauveria bassiana is an entomopathogenic ascomycete widely utilized in biological pest control. However, its effectiveness is often limited by low conidiation rates, sensitivity to environmental stresses, and delayed insecticidal activity. In this study, we identify and characterize a mycovirus, Beauveria bassiana polymycovirus 4-2 (BbPmV4-2), which markedly enhances the fitness and may modulate virulence of its fungal host. BbPmV4-2 comprises eight double-stranded RNA segments, among which three are unique and have not been previously detected in related mycoviruses. Infection with BbPmV4-2 nearly doubles conidial yields and upregulates key conidiation-related genes, facilitating enhanced dispersal of both the host fungus and the mycovirus itself. Additionally, BbPmV4-2 infected strains exhibit increased tolerance to ultraviolet (UV) irradiation and elevated temperatures, and may also exhibit increased virulence against the greater wax moth, Galleria mellonella. The potentially increased virulence is attributed to increased conidial hydrophobicity, adhesion, and cuticle penetration capabilities. Functional analysis reveals that the viral open reading frame ORF5 plays a critical role in conferring hypervirulence and stress tolerance by interacting with host proteins BbGAP1, a GPI-anchored membrane protein, and BbSDU1, a deubiquitinating enzyme. These interactions elucidate a molecular mechanism by which a mycovirus that enhances environmental adaptability and potentially influences host pathogenicity. Our findings provide significant insights into mycovirus-host interactions and suggest potential strategies for optimizing biological pest control applications.

Here, we present the identification and complete genome sequences of two novel double-stranded RNA (dsRNA) viruses coinfecting the basal fungus Conidiobolus lii isolate RCEF7535. The viruses, named Conidiobolus lii ootivirus 1 (ClOV1) and Conidiobolus lii totivirus 1 (ClTV1), exhibit distinct genomic characteristics. The genome of ClOV1 is 5,909 nucleotides in length and contains two open reading frames (ORFs). ORF1 encodes a 724-amino-acid capsid protein (CP) with a molecular weight of 80.80 kDa that shows 25.11% sequence identity to the CP of Conidiobolus lamprauges totivirus 1. ORF2 encodes a 743-amino-acid RNA-dependent RNA polymerase (RdRp) with a molecular weight of 83.22 kDa that shares 42.03% sequence identity with the RdRp of Conidiobolus chlamydosporus totivirus 2. The genome of ClTV1 is 4,653 nucleotides in length and contains two ORFs, with ORF1 encoding a 690-amino-acid hypothetical protein (HP, 78.18 kDa) and ORF2 encoding a 799-amino-acid RdRp (90.95 kDa). Both ORFs of ClTV1 display high sequence similarity to hypothetical proteins of Wuhan insect virus 27, with 70.25% identity in the HP and 68.76% identity in the RdRp. Phylogenetic analysis based on RdRp sequences showed that ClOV1 grouped with viruses of the genus Ootivirus within the family Ootiviridae, while ClTV1 clustered with viruses of the genus Totivirus of the family Orthototiviridae. This discovery enhances our understanding of mycovirus diversity, particularly in basal fungi, by identifying novel viruses infecting members of the genus Conidiobolus.

Penicillium exsudans strain RCEF7900, obtained from leaf litter, was found to harbor two double-stranded RNA (dsRNA) elements, designated as dsRNA1 and dsRNA2, with lengths of 1,816 bp and 1,625 bp, respectively. dsRNA1 encodes a 572-amino-acid RNA-dependent RNA polymerase (RdRp) protein (65.29 kDa), while dsRNA2 encodes a 503-amino-acid coat protein (CP) (56.73 kDa). A BLASTp search indicated that dsRNA1 and dsRNA 2 together constitute the genome of a novel partitivirus, which we have named "Penicillium exsudans partitivirus 1" (PePV1). Phylogenetic analysis based on RdRp amino acid sequences revealed that these genome segments belong to a member of a new species within the proposed genus "Zetapatitivirus" of the family Partitiviridae, with the RdRp showing the most sequence similarity (79.72% identity) to that of Sonifin virus. This is the first report of a zetapatitivirus from P. exsudans, expanding our understanding of mycoviral diversity in this fungal species.

Conidiobolus sensu lato, a genus within the family Ancylistaceae, encompasses a diverse range of fungal species that are widely distributed in plant debris and soil. In this study, we identified three double-stranded RNA (dsRNA) viruses coinfecting a strain of Conidiobolus taihushanensis. These viruses were identified as Conidiobolus taihushanensis totivirus 1 (CtTV1), Conidiobolus nonsegmented RNA virus 1-2 (CNRV1-2), and Conidiobolus taihushanensis virus 1 (CtV1). Through high-throughput sequencing and RNA-ligase-mediated rapid amplification of cDNA ends (RLM-RACE), we determined their complete genome sequences. The genome of CtTV1 is 6,921 nucleotides in length, containing two open reading frames (ORFs). ORF1 encodes a 1,124-amino-acid capsid protein (CP) with a molecular weight of 125.07 kDa, and ORF2 encodes a 780-amino-acid RNA-dependent RNA polymerase (RdRp) with a molecular weight of 88.05 kDa. CNRV1-2, approximately 3.0 kb in length, also contains two ORFs, which are predicted to encode a 186-amino-acid hypothetical protein (HP) and a 758-amino-acid RdRp. CtV1 has a smaller genome consisting of 3,081 base pairs (bp) with two ORFs: one encoding a 244-amino-acid HP (26.85 kDa) and the other encoding a 707-amino-acid RdRp (80.64 kDa). Phylogenetic analysis based on RdRp sequences revealed that CtTV1 shows the highest similarity to Phytophthora pluvialis RNA virus 1, with 38.79% sequence identity, and clusters with members of the family Orthototiviridae, and it is most closely related to Utsjoki toti-like virus. In contrast, CtV1 formed a unique branch and might represent a new genus. The genome sequence of CNRV1-2 is 99.74% identical to that of the previously described Conidiobolus non-segmented RNA virus 1 (CNRV1). Our findings indicate that CtTV1 and CtV1 are distinct novel viruses, while CNRV1-2 appears to be a variant of CNRV1. This study enhances our understanding of the genetic diversity and evolutionary relationships among mycoviruses associated with C. taihushanensis.

In this study, we identified a novel partitivirus, named "Cordyceps militaris partitivirus 1" (CmPV1), in Cordyceps militaris strain RCEF7506. The complete genome of CmPV1 comprises two segments, dsRNA1 and dsRNA2, each encoding a single protein. dsRNA1 (2,206 bp) encodes an RNA-dependent RNA polymerase (RdRp), and dsRNA2 (2,256 bp) encodes a coat protein (CP). Sequence analysis revealed that dsRNA1 has the highest similarity to that of Bipolaris maydis partitivirus 2 (BmPV2), whereas dsRNA2 shows the highest similarity to human blood-associated partitivirus (HuBPV). Phylogenetic analysis based on RdRp sequences suggests that CmPV1 is a new member of the genus Betapartitivirus of the family Partitiviridae. This is the first documentation of a betapartitivirus infecting the entomopathogenic fungus C. militaris.

We investigated the prevalence and species diversity of dsRNA mycoviruses in Beauveria bassiana isolates from the China's Guniujiang Nature Preserve. Among the 28 isolates analyzed, electropherotyping revealed viral infections in 28.6 % (8 out of 28) of the isolates. Metatranscriptomic identification and RT-PCR confirmed the presence of six putative virus species, including two novel species: Beauveria bassiana victorivirus 2 (BbV-2) and Beauveria bassiana bipartite mycovirus 2 (BbBV-2). Four previously characterized mycoviruses were also identified: Beauveria bassiana polymycovirus 4 (BbPmV4), Beauveria bassiana partitivirus 1 (BbPV-1), Beauveria bassiana bipartite mycovirus 1 (BbBV-1), and Beauveria bassiana chrysovirus 2 (BbCV-2). BbPmV4 was found to be the prevailing mycovirus among the infected isolates, and three isolates showed co-infection with both BbPmV4 and BbBV-2. This study enhances our understanding of fungal viral taxonomy and diversity, providing insights into mycovirus infections in B. bassiana populations in China's Guniujiang Nature Preserve. Furthermore, the study on the diversity of B. bassiana viruses lays the foundation for recognizing fungal viruses as potential enhancers of biocontrol agents.

Penicillium oxalicum, an important biocontrol fungus in China, has been a subject of extensive study due to its role in combating various pathogenic fungi. Despite the prevalence of mycoviruses with double-stranded (ds) RNA genomes in filamentous fungi, there has been no screening of mycoviruses in P. oxalicum. In this report, we describe the identification and characterization of a novel dsRNA virus isolated from P. oxalicum, designated as "Penicillium oxalicum partitivirus 1" (PoPV1). The genome of PoPV1 consists of two dsRNA segments, dsRNA1 (1,770 bp) and dsRNA2 (1,584 bp), each containing a single open reading frame (ORF): ORF1 and ORF2. Comparative analysis revealed that the RdRp and CP amino acid sequences of PoPV1 share the highest identity (89.18% and 73.97%, respectively) with those of Penicillium aurantiogriseum partitivirus 1 (PaPV1). Motif analysis based on RdRp amino acid sequences places PoPV1 in the genus Gammapartitivirus within the family Partitiviridae, with a distinctive motif VI (R/KV/ILGDD). Phylogenetic analysis further established a close relationship of PoPV1 to PaPV1, forming a unique clade among the gammapartitiviruses. Consequently, we propose that Penicillium oxalicum partitivirus 1 represents a new species in the genus Gammapartitivirus. This is the first report of a dsRNA virus in P. oxalicum.

An airborne microflora isolate, Aspergillus ochraceopetaliformis RCEF7483, was found to harbor seven dsRNA elements, indicating co-infection with a novel chrysovirus and a known partitivirus. Sequence analysis and RT-PCR confirmed dsRNA5-7 as components of Aspergillus ochraceous virus (AOV), a member of the Partitiviridae family. In light of its distinct host, we have designated it Aspergillus ochraceopetaliformis partitivirus 1 (AoPV1). The dsRNA segments, named dsRNA1-4, with lengths of 3706 bp, 3410 bp, 3190 bp, and 3158 bp, respectively, constitute the genome of a novel chrysovirus designated Aspergillus ochraceopetaliformis chrysovirus 1 (AoCV1). The dsRNA1-4 segments contain five open-reading frames (ORF1-5). Specifically, ORF1 encodes a putative RNA-dependent RNA polymerase (RdRp) with a length of 1112 amino acids, and ORF2 encodes a putative coat protein (CP) spanning 976 amino acids. Additionally, ORF3-5 encode hypothetical proteins (HP1, HP2, and HP3) with lengths of 108, 843, and 914 amino acids, respectively. Comparative analysis revealed the highest similarity of dsRNA1-4 with corresponding proteins in Aspergillus terreus chrysovirus 1 (AtCV1) (RdRp, 66.58%; CP, 51.02%; HP2, 61.80%; and HP3, 41.30%). Due to falling below the threshold for a new species in the Chrysoviridae, we propose that dsRNA1-4 in A. ochraceopetaliformis strain RCEF7483 constitute the novel chrysovirus AoCV1. Moreover, phylogenetic analysis using RdRp amino acid sequences placed AoCV1 within the Alphachrysovirus genus of the Chrysoviridae family, clustering with AtCV1 and other alphachrysoviruses. Our study contributes to the understanding of mycoviruses in A. ochraceopetaliformis and expands our knowledge of the diversity and evolution of chrysoviruses in fungal hosts.

Metarhizium anisopliae is a well-studied entomopathogenic fungus that is widely used in biological control programs. The presence of polymycoviruses in this fungus is common, but their effects on fungal development and stress tolerance are not well understood. In this study, we report the discovery of a novel double-stranded RNA virus, named Metarhizium anisopliae polymycovirus 1 (MaPmV1), which comprises four dsRNAs ranging from 2.4 to 1.4 kbp in length. Phylogenetic analysis revealed that MaPmV1 belongs to the Polymycoviridae family. Biological comparison between MaPmV1-infected (Vi) and -free (Vf) isogenic lines showed that MaPmV1 remarkably enhances the growth rate and conidiation of the host fungus. The upregulation of growth- and conidiation-related genes in Vi strains supports this finding. In addition, MaPmV1 increases the sensitivity of the host to UV-B irradiation, which is evidenced by the downregulation of DNA damage repair genes in Vi strains. However, MaPmV1 does not appear to have any significant impact on the virulence of M. anisopliae . Furthermore, overexpression of individual viral proteins in M. anisopliae did not result in any significant phenotypic alterations, indicating that MaPmV1-mediated changes are not related to a single viral protein. Overall, our findings suggest that mycoviruses can be exploited to enhance fungal development in entomopathogenic fungi, which may lead to improved conidium production on a large scale.

Mycoviruses are widely present in all major groups of fungi but those in entomopathogenic Metarhizium spp. remain understudied. In this investigation, a novel double-stranded (ds) RNA virus is isolated from Metarhizium majus and named Metarhizium majus partitivirus 1 (MmPV1). The complete genome sequence of MmPV1 comprises two monocistronic dsRNA segments (dsRNA 1 and dsRNA 2), which encode an RNA-dependent RNA polymerase (RdRp) and a capsid protein (CP), respectively. MmPV1 is classified as a new member of the genus Gammapartitivirus in the family Partitiviridae based on phylogenetic analysis. As compared to an MmPV1-free strain, two isogenic MmPV1-infected single-spore isolates were compromised in terms of conidiation, and tolerance to heat shock and UV-B irradiation, while these phenotypes were accompanied by transcriptional suppression of multiple genes involved in conidiation, heat shock response and DNA damage repair. MmPV1 attenuated fungal virulence since infection resulted in reduced conidiation, hydrophobicity, adhesion, and cuticular penetration. Additionally, secondary metabolites were significantly altered by MmPV1 infection, including reduced production of triterpenoids, and metarhizins A and B, and increased production of nitrogen and phosphorus compounds. However, expression of individual MmPV1 proteins in M. majus had no impact on the host phenotype, suggesting insubstantive links between defective phenotypes and a single viral protein. These findings indicate that MmPV1 infection decreases M. majus fitness to its environment and its insect-pathogenic lifestyle and environment through the orchestration of the host conidiation, stress tolerance, pathogenicity, and secondary metabolism.

A number of viruses have recently been discovered in all major fungal phyla using high-throughput sequencing. However, basal fungi remain among the least-explored organisms with respect to the presence of mycoviruses. In this study, we characterized two mycoviruses coinfecting the basal fungus Conidiobolus adiaeretus, which we have named "Conidiobolus adiaeretus totivirus 1" (CaTV1) and "Conidiobolus adiaeretus totivirus 2" (CaTV2). Due to their similar sizes, the genomic RNAs of these two viruses comigrated as a single band in 1.5% agarose gel electrophoresis but could be distinguished and characterized by next-generation sequencing and RT-PCR. Like those of other totiviruses, the genomes of both CaTV1 and CaTV2 have two discontinuous open reading frames: ORF1 and ORF2, encoding a putative capsid protein and a putative RNA-dependent RNA polymerase (RdRp), respectively. The RdRps of CaTV1 and CaTV2 have 62.73% and 63.76% amino acid sequence identity, respectively, to Wuhan insect virus 26 and have 62.15% amino acid sequence identity to each other. A maximum-likelihood phylogenetic tree based on RdRp amino acid sequences showed that both CaTV1 and CaTV2 clustered in a clade with members of the genus Totivirus. Therefore, we propose that CaTV1 and CaTV2 are two new members of the genus Totivirus in the family Totiviridae.

Abstract Penicillium oxalicum, an essential biocontrol fungus in China, has been a subject of extensive study due to its role in combating various pathogenic fungi. Despite the prevalence of mycoviruses with double-stranded (ds) RNA genomes in filamentous fungi, no instances of mycovirus infection have been reported in P. oxalicum. In this investigation, we present the identification and characterization of a novel dsRNA virus isolated from P. oxalicum, designated as "Penicillium oxalicum partitivirus 1" (PoPV1). The genome of PoPV1 consists of two dsRNA segments, dsRNA1 (1,770 bp) and dsRNA2 (1,584 bp), each hosting a single open reading frame (ORF): ORF1 and ORF2. Comparative analysis revealed that PoPV1's RdRp and CP sequences share the highest identity (89.18% and 73.97%, respectively) with Penicillium aurantiogriseum partitivirus 1 (PaPV1). Motif analysis based on RdRp amino acid sequences places PoPV1 in the genus Gammapartitivirus within the familyPartitiviridae, with a distinctive motif VI (R/KV/ILGDD). Phylogenetic analysis further establishes PoPV1's close relationship with PaPV1, forming a unique clade within gammapartitiviruses. Consequently, we propose that Penicillium oxalicum partitivirus 1 represents a novel species in the genus Gammapartitivirus, marking the first reported case of dsRNA in P. oxalicum.

In this study, a novel double-stranded (ds) RNA mycovirus, named Cordyceps chanhua alternavirus 1 (CcAV1), was detected in the entomogenous fungus Cordyceps chanhua in China and characterized. The complete genome of CcAV1 is composed of three dsRNA segments: dsRNA 1 (3,512 bp), dsRNA 2 (2,655 bp), and dsRNA 3 (2,415 bp). Each of the three dsRNAs possesses a single open reading frame (ORF). dsRNA 1 encodes a putative RNA-dependent RNA polymerase (RdRp), and dsRNA 2 and dsRNA 3 encode hypothetical protein 1 (HP 1) and hypothetical protein 2 (HP 2), respectively. The predicted amino acid sequences of the putative RdRp, HP 1, and HP 2 had the highest identity of 66.99%, 49.30%, and 56.91%, respectively, to those of Aspergillus foetidus dsRNA mycovirus. A maximum-likelihood phylogenetic tree based on RdRp amino acid sequences showed that CcAV1 clustered with members of the proposed family "Alternaviridae". Hence, we propose that Cordyceps chanhua alternavirus 1 is a novel member of the proposed family "Alternaviridae".

There are four dsRNAs segments present in the entomopathogenic fungus Metarhizium brunneum strain RCEF0766. The genomic segments dsRNA1 and dsRNA3 are of a novel virus, “Metarhizium brunneum bipartite mycovirus 1” (MbBV1), while dsRNA2 and dsRNA4 are the components of the Metarhizium brunneum partitivirus 2 (MbPV2), a member in genus Gammapartitivirus of the family Partitiviridae based on molecular analysis and RT-PCR. This suggests that the strain RCEF0766 was co-infected by two different mycoviruses. The complete genome sequence of MbBV1 was elucidated by high-throughput sequencing and RLM-RACE. MbBV1 consists of two dsRNAs (1987 and 1642 bp) encode open-reading frames (ORFs). The ORF1 in dsRNA 1 encode is a putative RNA-dependent RNA polymerase (RdRp) with the molecular weight of 68.08 kDa, while ORF2 in dsRNA 2 encodes a hypothetical protein with the molecular weight of 33.07 kDa. The deduced proteins of ORF1 and ORF2 have the highest identity to those of Erysiphe necator-associated bipartite virus 1 (76.88% and 65.30%). Based on the amino acid sequence of RdRp, MbBV1 is phylogenetically clustered together with the unassigned mycoviruses and represents a distinct lineage. Our study proposes that MbBV1 is a novel mycovirus with bisegmented dsRNA genomes and should be considered a new member of the unassigned group.

Cicada flower, scientifically named Cordyceps chanhua, is an important and well-known Chinese cordycipitoid medicinal mushroom. Although most mycoviruses seem to induce latent infections, some mycoviruses cause host effects. However, the effects of mycovirus on the fungal development and stress tolerance of C. chanhua remain unknown. In this study, we report a novel mycovirus designated Cordyceps chanhua partitivirus 1 (CchPV1) from C. chanhua isolate RCEF5997. The CchPV1 genome comprises dsRNA 1 and dsRNA 2, 1784 and 1563 bp in length, respectively. Phylogenetic analysis using the aa sequences of RdRp revealed that CchPV1 grouped with members of the genus Gammapartitivirus in the family Partitiviridae. We further co-cultivated on PDA donor strain RCEF5997 and recipient C. chanhua strain RCEF5833 (Vf) for 7 days, and we successfully obtained an isogenic line of strain RCEF5833 with CchPV1 (Vi) through single-spore isolation, along with ISSR marker and dsRNA extraction. The biological comparison revealed that CchPV1 infection slows the growth rate of the host, but increases the conidiation and formation of fruiting bodies of the host. Furthermore, the assessment of fungal tolerance demonstrated that CchPV1 weakens the multi-stress tolerance of the host. Thus, CchPV1 infection cause changes in fungal development and multi-stress tolerance of the host C. chanhua. The findings of this study elucidate the effects of gammapartitivirus on host entomogenous fungi and provide a novel strategy for producing high-quality fruiting bodies of C. chanhua.

Penicillium citrinum is a commonly occurring filamentous fungus with a worldwide distribution. However, no sequence data for viruses in P. citrinum have been reported. Here, we characterized a novel dsRNA virus from the hospital indoor air fungal strain P. citrinum RCEF 7060, which we have named "Penicillium citrinum non-segmented dsRNA virus 1" (PcNRV1). The genome of PcNRV1 dsRNA is 2,895 bp in length and contains two open reading frames encoding a protein with an unknown function in ORF1 and a putative RNA-dependent RNA polymerase (RdRp) in ORF2. Sequence comparisons and phylogenetic analysis showed that PcNRV formed a well-supported independent clade together with members of the proposed genus "Unirnavirus" and was most closely related to Penicillium miczynskii RNA virus 1 (PmRV1), with 76.45% amino acid sequence identity in the RdRp. Thus, PcNRV1 is a novel non-segmented dsRNA mycovirus belonging to the proposed genus "Unirnavirus" and is the first characterized viral sequence from P. citrinum.