## 3 Results
### In Vivo Interaction between Endophytes and C. acutatum  
The capacity of both endophytes _A. pullulans_ and _S. summerbelli_ to reduce the incidence (AUDpci) and severity (AUDPCs) of anthracnose, caused by the pathogen _C. acutatum_, was evaluated by artificial inoculation of detached olives. The results show that _A. pullulans_ significantly reduced (\(p<0.001\)) the progress curve for the incidence (up to 10-fold) and severity (up to 35-fold) of anthracnose in comparison with olives inoculated solely with _C. acutatum_ (Figure 3). On day 15, 100% incidence was reached in olives inoculated solely with _C. acutatum_, while in the _A. pullulans + C. acutatum_ treatment, the incidence was 20% and remained practically stable until the end of the bioassay. Similarly, olives inoculated with _A. pullulans_ and _C. acutatum_ did not exceed the severity index of 2 (25-50% of the infected area) until the end of the bioassay, while olives inoculated with _C. acutatum_ reached the severity index of 5 by the end of the bioassay. An interesting delay by 15 days in the appearance of disease symptoms was also observed in the presence of _A. pullulans_ as opposed to 3 days in the _C. acutatum_ control. Figure 1: Inhibition (%) of _Colletotrichum acutatum_ growth by the endophytes _Aureobasitium pullulans_ (**a**) and _Sarcaladium summerbelli_ (**b**), after 2, 4, 7, 8 and 10 days of interaction. Box plots depict medians (central horizontal lines), inter-quartile ranges (boxes) and 95% confidence intervals (whiskers). Asterisks indicate statistical significance compared with the control (\(n=5\)), at ***\(p<0.001\) and ***\(p<0.01\), within each day of interaction. ns: not significant. Figure 2: Sporulation (**a**) and spore germination (**b**) of _Colletotrichum acutatum_ in co-culture with _Aureobasitium pullulans_ (Ap + Ca) or _Sarcaladium summerbelli_ (Ss + Ca) and in control (single culture of _C. acutatum_, Ca control), after 10 days of interaction. Bars with different lowercase letters indicate significant differences (\(p<0.05\), \(n=5\)). The endophyte _S. summerbelli_ did not reduce the disease progression rate compared to the control (i.e., olives inoculated solely with _C. acutatum_), either for incidence (_p_ = 0.766) or severity (_p_ = 0.371). Indeed, both the incidence and severity of anthracose in olives inoculated with _S. summerbelli_ + _C. acutatum_ increased steadily throughout the 21 days of olive fruit monitoring and at the same rate as that in olives inoculated with _C. acutatum_ (Figure 3). In both treatments, 100% incidence and a severity index of 5 were reached by days 15 and 21, respectively, with characteristic anthracose symptoms (i.e., mass of orange conidia) starting to show from the ninth day. At the end of the olive bioassay, both the sporulation and germination of _C. acutatum_ in the presence of _A. pullulans_ and _S. summerbelli_ were evaluated and compared to those of the control (olives solely inoculated with _C. acutatum_). The results show great differences among the two endophytes in their capacity to inhibit both the sporulation and germination of _C. acutatum_ in olives (Figure 4). _A. pullulans_ significantly (_p_ < 0.05) reduced the sporulation and germination of _C. acutatum_, by 90% and 70%, respectively, in relation to the control. In contrast, no significant difference in the sporulation (_p_ = 0.497) and germination (_p_ = 0.099) of _C. acutatum_ was observed among the _S. summerbelli_ + _C. acutatum_ treatment and control. Figure 3: Area under the disease progress curve of incidence (AUDPCi; (**a**)) and severity (AUDPCs; (**b**)) of anthracose in olive fruits for the different treatments, over 21 days of post-inoculation with the pathogen _Colletotrichum acutatum_. Treatments: fruits inoculated with Tween 80 (mock-inoculated), with the pathogen (control) and with the endophyte and, 3 days later, with the pathogen (_A. pullulans_ + _C. acutatum_ or _S. summerbelli_ + _C. acutatum_).