Fruit bagging reduces the postharvest decay and alters the diversity of fruit surface fungal community in ‘Yali’ pear

Author:Congcong Gao , Yang Zhang , Huimin Li , Qi Gao , Yudou Cheng , Solabomi Olaitan Ogunyemi and Junfeng Guan

Background: Fruit bagging is an efective technique for fruit protection in the orchard management. Bagging can
      create a micro-environment for fruit growth and afect fruit quality during storage, in which the diversity of microorganisms may play an important role. Therefore, various methods including biochemistry, analytical chemistry, and
      bioinformatics methods were used to reveal the infuences of fruit bagging on postharvest fruit quality, physiological
      characters, decay and surface fungal community of ‘Yali’ pear fruit were investigated in this study.
      Results: Fruit bagging signifcantly decreased the postharvest decay after 15days of ambient storage. There were
      no signifcant diferences in fruit frmness, titratable acid and ethylene production rate between the fruit-bagging
      and non-bagging group after 15days of storage, while the soluble solids contents (SSC) and respiration rate in nonbagging fruit was signifcantly higher than that in fruit-bagging after 15days of storage. Furthermore, the surface
      microbes of pear were collected and determined by the new generation sequencing technology. The alpha diversity
      of fungi in non-bagging fruit decreased signifcantly after 15days of storage, while there were no signifcant changes
      in bagging fruit. Ascomycota and Basidiomycota were the two major phyla detected in the bagging fruit, and the
      dominant fungal genera were Alternaria (23.7%), Mycosphaerella (17.25%), Vishniacozyma (16.14%), and Aureobasidium (10.51%) after 15days of storage. For the non-bagging pear, Ascomycota was the only phylum detected, and
      the dominant genera was Pichia (83.32%) after 15days of storage. The abundance of Pichia may be regarded as the
      biomarker to indicate the degree of fruit decay.
      Conclusions: This study showed that fruit bagging could signifcantly reduce postharvest fruit decay and respiration
      rate of ‘Yali’ pear. Signifcant diferences were found in fungal composition between bagging and non-bagging pear
      after storage for 0 or 15days. Fruit bagging maintained the diversity of fungi on the fruit surface, increased the abundance of non-pathogenic fungi, and even antagonistic fungi such as Aureobasidium, Vishniacozyma, and Mycosphaerella. A reduction in the abundance of pathogenic fungi and incidence of postharvest decay during the storage of ‘Yali’
      pear were also recorded. In conclusion, fruit-bagging changed the fungal diversity on fruit surface of ‘Yali’ pear, which
      had signifcant efect on reducing postharvest fruit decay, and thus prolong the storage period of ‘Yali’ pears. The future thrust of this study will focus on the isolation of fungi or bacteria from pear fruit surface and identify their roles
      in causing fruit decay and changing fruit quality during storage.

Key words:Postharvest decay, Fruit bagging, Fungal community, ‘Yali’ pear, Pichia