Abstract: The antagonistic yeast Pichia guilliermondii Y35-1, isolated from loquat fruit was evaluated for its inhibitory activity against postharvest anthracnose infection in loquat fruit. Also, the application of liquid and solid-state cultures of strain Y35-1 as preservatives for loquat fruit was investigated. The results showed that the P. guilliermondii Y35-1 could inhibit spore germination in Colletotrichum gloeosporioides as an anthracnose pathogen for loquat fruit; Y35-1 could inhibit parasitize its hyphae and inhibit its growth. Non-contact culture confrontation test showed that strain Y35-1 could significantly inhibit the expansion and growth of C. gloeosporioide. Both the liquid biocontrol agent and freeze-dried powder of Y35-1 could significantly inhibit decay incidence of loquat fruit during the postharvest storage period. The decay index was only 2.25% and 3.60%, respectively, at day 20 of storage. And these two biocontrol agents played a positive role in the maintenance of fruit firmness, mass loss, soluble solids content, cell membrane permeability in pericarp, total sugar content, total acid content and vitamin C content of loquat fruit. The best storage temperature was 4 ℃ for the liquid biocontrol agent and ?20 ℃ for the freeze-dried powder. Trehalose played a positive role in maintaining the viability and biocontrol efficacy of the freeze-dried powder of Y35-1. In summary, these results showed that Y35-1 had an obvious inhibitory effect on postharvest anthracnose infection in loquat fruit, and both biocontrol agents of Y35-1 could preserve the postharvest quality of loquat fruit.

Key words: postharvest loquat fruit, antagonistic yeast, Pichia guilliermondii, Colletotrichum gloeosporioides, biocontrol agent, microbial quality preservation