# Comparison of Three Biological Control Models of _Pycnoporus__sanguineus_ on Phytopathogenic Fungi
## 4 Discussion  
It has been demonstrated that certain components present in the _Pycnoporus_ genus possess antifungal properties [17]. Most of the studies in this regard have used complete extracts of _Pycnoporus_ fruiting bodies as an effective interaction model against various fungal species. These include species that are pathogenic to humans, such as _Candida albicans_, _Candida krusei_, _Aspergillus fumigatus_, _Mucor_ sp., _Microsporum gypyeum_, and _Trichoplytton metagrophytes_[24]. In the same way, some species impact economically important crops, including wood-degrading species, like _Trametes versicolor_, _Trametes feei_, _Trametes menizezizi_, _Lentinus_ sp., _Lentinus sajor-caju_, _Lentinus strigosus_, _Microporus affinis_, _Microporus xanthopus_, and _Gloeophyllum trabeum_[25]; species affecting various plants at the leaf level, such as _Pseudocerospora griseola_[26] and _Mycena citricolor_[27]; and species affecting different plant structures, including _Botrytis cinerea_, _Coniophora puteana_[20], and _Fusarium_ sp. [21]. Particularly, studies evaluating the effectiveness of _Pycnororus_ against _B. cinerea_ have utilized both antagonistic interaction models of the species _P. coccineus_[20] and complete spectrum extracts of the species _P. cinnabarinus_, with both solid and liquid cultures [18]. To date, only complete extract models of the species _P. sanguineus_ have been evaluated against _Fusarium_ sp. [21]. In all these studies, the effectiveness of _Pycnororus_ compounds against these phytopathogens has been demonstrated. This partially coincides with the results of the current study, which demonstrate the significant antifungal effectiveness of _P. sanguineus_. In the growth restriction of _B. cinerea_, this was observed with greater intensity under the treatment of PDA supplemented with the _P. sanguineus_ extract, as expressed as both a higher PIRG (74.34%) and a reduction in its GR (3.85 mm/day). This was even similar to the PIRG generated by captan and benomyl in some treatments (Table 1). However, although the treatment of PDA with the _P. sanguineus_ extract generated a considerable PIRG against _F. oxysporum_ (47.14%; Table 1), this was lower than what was observed against _B. cinerea_; overall, _F. oxysporum_ expressed greater resistance to the different treatments (Figure 2). Nonetheless, the results of the first model evaluated (antagonistic interaction model) did not show a significant difference in growth between the dual cultures of _P. sanguineus_ with _B. cinerea_ and _F. oxysporum_ compared to their respective control cultures (Tables 1 and 2). This contrasts with the strong antagonistic effect observed by [PERSON] et al. [20], where the species _Pycnororus coccineus_ was even able to replace its competitors by growing on them. This behavior is commonly associated with highly aggressive species used for the biological control of phytopathogens, such as several _Trichoderma_ species [28,29]. According to [PERSON] et al. [20], the antagonistic strategy used by _P. coccineus_ involves the growth restriction of its competitors through the release of enzymes (mainly lacases) rather than faster resource acquisition. This can even limit the growth rate of _P. coccineus_ itself. Although the present study cannot confirm the presence of this strategy in _P. sanguineus_, an increase in pigmentation of _P. sanguineus_ mycelia was observed in the contact zone with its competitors. This may be part of a growth restriction strategy against the advancing growth of this phytopathogen. Deeper physiological analysis could clarify this phenomenon, along with the pigments and metabolites involved. The second model of cinnabarin, and possibly to a lesser extent cinnabaric acid (Figure 1), showed the limited effectiveness of this compound in relation to the growth of the phytopathogens _B. cinerea_ and _F. oxysporum_.