Effect of some Yew endophytes on vegetative growth and phytochemical variation of Stevia rebaudiana B.

<strong>Purpose:</strong> Due the importance of taxol and based on the confirmed role of certain endophytes of Yew tree in the production of this vital compound, the present study was designed to investigate the effect of isolated endophytic fungi on vegetative and qualitative characteristics of stevia plant. <strong>Research method:</strong> The experiment included five different endophytic fungi isolated from Yew tree. In order to do that, rooted cuttings of stevia were transferred to the pot after being inoculated with different isolated endophytic fungi (TB2, TB2-3, TB20, TB55) of Yew tree in four replications as a completely randomized design and were kept in outdoor conditions. To isolate endophytic fungi, root samples were collected from the yew trees in the Ziyarat forest located in Golestan province, Iran. <strong>Main findings:</strong> The results of the study revealed the positive effect of Yew tree endophytes as biotic agents on the growth and physiological parameters of stevia. Also, the fungal pathogenicity effect on stevia was not observed. In addition, the main stem diameter, internode spacing, leaf area and other measured parameters were affected by studied endophytes. Among of the five used isolates fungi, three were classified as stevia plant grows stimulator. Also, due to the highest total sugar and antioxidant activity of stevia, rest two isolates were classified as “bio-elicitor”. <strong>Limitations:</strong> There was no limitation to report. <strong>Originality/Value:</strong> The findings of the present study suggest that stevia, as a medicinal and economical herb, is capable of coexistence with yew endophytes. If taxol producer endophytes successfully transfer to stevia, it is possible to study the production of taxol in herbaceous plants, thereby opening the new door to easier and cheaper access to Taxol.