A Comparative Analysis of the Microbiome of Kiwifruit at Harvest Under Open-Field and Rain-Shelter Cultivation Systems.

Yuan Sui,Qianhua Zhao,Zhenshuo Wang,Mingguo Jiang,Qiya Yang,Qinhong Liao,Hongyin Zhang,Jianbin Lan,Jia Liu,Junyang Yue,Jing Liu,Qi Wang

doi:10.3389/fmicb.2021.757719

Abstract

The composition of microbial communities can directly affect fruit quality, health status, and storability. The present study characterized the epiphytes and endophytes of “Hongyang” and “Cuiyu” kiwifruit at harvest under grown under open-field (OF) and rain-shelter (RS) cultivation systems. Disease incidence in kiwifruit was significantly lower (p < 0.05) under the RS system than it was under the OF system. High-throughput sequencing [16S V3-V4 ribosomal region and the fungal internal transcribed spacer (ITS2)] was conducted to compare the composition of the epiphytic and endophytic microbial community of kiwifruit under the two cultivation systems. Results indicated that the abundance of Actinobacteria, Bacteroidetes, Enterobacteriales, Acetobacterales, Sphingomonas, Pseudomonas, and Sphingobacterium was higher under the RS system, relative to the OF system, while the abundance of Capnodiales, Hypocreales, Vishniacozyma, and Plectosphaerella was also higher under the RS system. Some of these bacterial and fungal taxa have been reported to as act as biocontrol agents and reduce disease incidence. Notably, the α-diversity of the epiphytic bacterial and fungal communities on kiwifruit was higher under RS cultivation. In summary, RS cultivation reduced natural disease incidence in kiwifruit, which may be partially attributed to differences in the structure and composition of the microbial community present in and on kiwifruit.

Highlights

Kiwifruit, known as the "king of fruits," has a high nutraceutical value
The disease incidence at harvest was assessed in the two cultivars growing under the two cultivation systems (OF and RS) in 2 different years (2018 and 2019)
We characterized the epiphytic and endophytic community composition in the two different cultivars grown under two different cultivation systems (OF and RS) to determine if there was an association between the composition of the microbial community and the observed levels of disease incidence

Summary

Introduction

Known as the "king of fruits," has a high nutraceutical value. Kiwifruit is rich in bioactive compounds with antioxidant properties and is a major source of vitamin C (Richardson et al, 2018). In order to reduce disease incidence in plants and increase their economic value, rain-shelters (RS) have been used in the cultivation of several different fruits, including pear (Zhang et al, 2020), grape (Meng et al, 2012), and cherry (Tian et al, 2019). Studies have demonstrated that RS cultivation prevents excessive rainfall and hail damage to flowers and fruits and reduces disease occurrence, providing significant protection (Tian et al, 2019). Meng et al (2012) reported that RS cultivation significantly reduced the incidence of grape diseases, delayed fruit ripening, and promoted the accumulation of quercetin-3-O-glucose-7-O-rhamnoside in grape skin peels during grape ripening. RS cultivation was used to reduce the occurrence of kiwifruit natural disease and to explore the impact of RS cultivation on the microbiome of kiwifruit

Methods

Results

Discussion

Conclusion