Morphological and molecular characterisation of grapevine endophytic Trichoderma asperellum and in vitro bioefficacy against Colletotrichum gloeosporioides and Xanthomonas citri pv. viticola

A total of ten Trichoderma isolates were purified from different plant parts of grapevine cultivars for their antagonistic potential. All the ten Trichoderma isolates exhibited light green to dark green coloured colony characteristics. The PCR amplification of the ITS region yielded amplicons of ∼600 bp. Likewise, translation elongation factor (TEF-1α) and actin (ACT) genes of these isolates showed an amplification of ∼507 bp and ∼480 bp size amplicons, respectively. Sequence information of the ITS region, TEF-1α and ACT genes showed 98–100% similarity with available sequences of Trichoderma asperellum. Additionally, in vitro bioefficacy of these isolates was evaluated against Xanthomonas citri pv. viticola and Colletotrichum gloeosporioides. Results showed the maximum inhibition of Xcv and C. gloeosporioides achieved by NRCG-7 with 81.34–94.44% and 31.27–66.11%, respectively followed by NRCG-3 (78.87–92.22%); (28.86-60.55%), and NRCG-5 (76.49–93.33%); (26.45–58.33%) isolates. This study will strengthen biointensive disease management strategies under field conditions.