First Report of Iris yellow spot virus Infecting Allium tuberosum in India

Abstract

Allium tuberosum L., commonly known as garlic chives, is an important spice in northeastern India as well as in many other parts of the world. Iris yellow spot virus (IYSV; genus Tospovirus, family Bunyaviridae) is an important pathogen of onion (4) and other related Alliums such as garlic (3) and leek (2). During April 2013, symptoms potentially induced by IYSV such as chlorotic and straw-colored spindle-like lesions were observed on leaves of A. tuberosum accession Hanzong Winter (CGN 20779) plants in the wild species garden at the Directorate of Onion and Garlic Research (DOGR), Rajgurunagar, Pune, Maharashtra, India. Ten plant samples of A. tuberosum were randomly collected from the wild species garden and the upper, middle, and lower portions of the leaves were pooled and tested by double-antibody sandwich (DAS)-ELISA using a commercially available kit (Agdia Inc., Elkhart, IN) for IYSV. All of them showed positive results for IYSV incidence. Total RNA from the ELISA positive leaf samples of A. tuberosum was extracted using the RNeasy Plant Mini kit (Qiagen GmbH, Hilden, Germany). The primer pair IYSV-F (5′-TCAGAAATCGAGAAACTT-3′) and IYSV-R (5′-TAATTATATCTATCTTTCTTGG-3′) (1) was used for RT-PCR. The primer pair was specific to amplify 797 bp of the nucleocapsid (N) gene of IYSV. The amplified product derived from A. tuberosum isolate was purified by QIAquick PCR Purification Kit (Qiagen) and cloned using the vector pDrive (Qiagen). The recombinant clone was sequenced (Accession No. KF624624). Sequence analysis performed on CLC Main Workbench Version 6.8.4 confirmed that the fragment was of IYSV. Nucleotide sequence comparison of our virus with other IYSV isolates revealed that the highest nucleotide identity (99%) was with the IYSV garlic isolate (HM173691) from India. Further, maximum 96% protein identity was with IYSV onion isolate (ACA09432) and garlic isolate (ADK56108) from India. To our knowledge, this is the first report of IYSV naturally occurring on A. tuberosum in India. It is evident from previous studies that IYSV causes significant losses in onions (1) and from this study, that its symptoms have direct impact on quality of garlic chives. Further detailed studies are required to assess the magnitude of the impact of IYSV infection on yield and quality of A. tuberosum. References: (1) A. Bulajic et al. Plant Dis. 93:976, 2009. (2) M. C. Córdoba-Sellés et al. Plant Dis. 91:1365, 2007. (3) S. J. Gawande et al. Plant Dis. 94:1066, 2010. (4) B. Mandal et al. Plant Dis. 96:468, 2012.

Newly identified host range of viruses infecting species of the genus Allium and their distribution in six habitats in the Czech Republic

“…The presence of INSV and IYSV in alliums is probably due to their adaptation to new crops, the importation of infected bulbs, and the transmission from infected nearby crops and volunteer plants that contribute to disease spread by acting as reservoirs for the virus and the vector (Cooper & Jones, 2006). In addition to the cultivated alliums (e.g., garlic, leek, and onions), previous studies reported only small surveys of virus incidence in some wild and ornamental species (Bampi et al, 2015; Cramer et al, 2011; van Dijk, 1993; Dovas et al, 2001; Gawande et al, 2014; Paduch‐Cichal & Bereda, 2017; Scrace et al, 2015; Ward et al, 2009). Among the species identified as hosts of carla‐, poty‐, allexi‐ or orthotospoviruses, several have not been reported previously.…”

“…Some earlier studies investigated viruses in wild plants based on the idea that natural vegetation may serve as a reservoir for the disease (Cooper & Jones, 2006). To date, the occurrence of viruses, especially in cultivated crops such as garlic, onion, leek, and shallot has been well investigated worldwide (Chen et al, 2001; Chodorska et al, 2014; Conci et al, 2003; Cramer et al, 2011; Dovas et al, 2001; Godena et al, 2020; Klukáčková et al, 2007; Mahmoud et al, 2008; Ward et al, 2009) but viral infection of wild and ornamental Allium species in both natural and agricultural ecosystems is only occasionally tested (Bampi et al, 2015; Cramer et al, 2011; van Dijk, 1993; Dovas et al, 2001; Gawande et al, 2014; Paduch‐Cichal & Bereda, 2017; Scrace et al, 2015; Ward et al, 2009). Although viruses tend not to damage wild plants (Cooper & Jones, 2006), the abundance of Allium viruses in nature and their ability to move between hosts should be further explored for disease resistance (Khandagale et al, 2020).…”

Development of a sensitive Luminex xMAP-based microsphere immunoassay for specific detection of Iris yellow spot virus

“…IYSV was firstly recorded in onion crops in Idaho, USA in 1989 [ 4 ] and then in the Netherlands in 1992, where it was characterized to be a new, distinct orthotospovirus from Iris hollandica [ 5 ]. Subsequently, IYSV was found to occur in [ 6 ] Brazil [ 7 ], Australia [ 8 ], Japan [ 9 ], Chile [ 10 ], Spain [ 11 ], Guatemala [ 12 ], Peru [ 13 ], India [ 14 ], and Egypt [ 15 ].…”

Sequence analysis of Indian iris yellow spot virus ambisense genome segments: evidence of interspecies RNA recombination

“…IYSV was first reported in the USA in 1989 [12], after which the virus was reported in many other countries [11]. In India, it was first reported in onions in 2006, in garlic in 2010, and in chives in 2014 [9,10,23].…”