Location: National Germplasm Resources LaboratoryTitle: Loquat is a new natural host of apple stem grooving virus and apple chlorotic leaf spot virus
|LIU, QIYAN - Southwest University|
|XUAN, ZHIYOU - Southwest University|
|WU, YUANJIAN - Southwest University|
|LI, MIN - Southwest University|
|ZHANG, SONG - Southwest University|
|WU, DI - Southwest University|
|CAO, MENGJI - Southwest University|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2019
Publication Date: 7/19/2019
Citation: Liu, Q., Xuan, Z., Wu, Y., Li, M., Zhang, S., Wu, D., Li, R., Cao, M. 2019. Loquat is a new natural host of apple stem grooving virus and apple chlorotic leaf spot virus. Plant Disease. https://doi.org/10.1094/PDIS-04-19-0721-PDN.
Interpretive Summary: Loquat (Eriobotrya japonica) is an evergreen tree species in the family Rosaceae that is cultivated in Asia and Europe as a fruit and ornamental tree. In this study, two common apple viruses, apple stem grooving virus (ASGV) and apple chlorotic leaf spot virus (ACLSV), were found in loquat trees with disease symptoms by using high-throughput sequencing. The complete genomic sequences of both ASGV and ACLSV isolates were determined. An additional 54 loquat field trees were tested for both viruses; a moderate percentage (13-39 %) were infected. This is the first report of either ACLSV or ASGV naturally occurring in loquat. Further studies are needed to determine the viral effects on loquat production and/or whether this plant is a reservoir from which the viruses can spread to other hosts.
Technical Abstract: Natural infections of apple stem grooving virus (ASGV) and apple chlorotic leaf spot virus were identified from loquat (Eriobotrya japonica) trees with leaf curl symptom by high-throughput sequencing. The complete genomic sequences of two ASGV isolates and one ACLSV isolate were determined. Sequence analysis showed that ASGV-L2 was most closely related to citrus isolate MTH (90.7%), while ASGV-L3 had the highest sequence identity with hawthorn isolate HH (91.4%). Phylogenetic analyses grouped L2 with MTH and five other isolates in a cluster and L3 with HH and two other isolates in another cluster. ACLSV-L1 was most closely related to pear isolate SY02. A total of 54 more samples were tested by RT-PCR, and results showed that infection rates were 39% for ASGV-L2, 28% for ASGV-L3 and 13% for ACLSV-L1. To our knowledge, this is the first report of ASGV and ACLSV in the loquat.