Vol.:(0123456789) 1 3 Archives of Virology https://doi.org/10.1007/s00705-018-3702-4 BRIEF REPORT Physiological traits of endornavirus‑infected and endornavirus‑free common bean (Phaseolus vulgaris) cv Black Turtle Soup S. Khankhum 1  · R. A. Valverde 2 Received: 21 July 2017 / Accepted: 25 November 2017 © Springer-Verlag GmbH Austria, part of Springer Nature 2018 Abstract This study evaluated the physiological traits of eight lines of common bean (Phaseolus vulgaris) cv. Black Turtle Soup, four of which were double-infected with Phaseolus vulgaris endornavirus 1 and Phaseolus vulgaris endornavirus 2, and four of which were endornavirus-free. Plants from all eight lines were morphologically similar and did not show statisti- cally signifcant diferences in plant height, wet weight, number of days to fowering and pod formation, pods per plant, pod thickness, seed size, number of seeds per pod, and anthocyanin content. However, the endornavirus-infected lines had faster seed germination, longer radicle, lower chlorophyll content, higher carotene content, longer pods, and higher weight of 100 seeds, all of which were statistically signifcant. The endornaviruses were not associated with visible pathogenic efects. Common bean (Phaseolus vulgaris) is the most important grain legume for human consumption and represents a rich source of protein, vitamins, minerals, and fber [6]. Com- mon bean originated in central Mexico, but its domestication took place in two geographical locations, Mesoamerica and the Andes [4]. Currently, this crop is grown worldwide. In the feld, common bean is often infected by plant pathogens which can cause economically important diseases [27]. Plant viruses are in a parasitic relationship with the host and, in most cases; this interaction negatively afects host morphology and physiology resulting in disease. However, there are increasing reports of plant viruses, called persistent viruses, which do not cause apparent symptoms [22]. Persis- tent plant viruses include some members taxonomically clas- sifable within the families Amalgaviridae, Chrysoviridae, Endornaviridae, Partitiviridae, and Totiviridae [7, 11, 16, 23, 24]. Members of the Endornaviridae family have an RNA genome that ranges from 9.8 to 17.6 kb in length and have been reported as infecting plants, fungi, and oomycetes [11, 29]. Currently endornaviruses are classifed in two gen- era, Alphaendornavirus, which includes viruses that infect plants, fungi, and oomycetes, and Betaendornavirus, which includes viruses of ascomycete fungi [1]. Plant endorna- viruses are distributed throughout all plant tissues but are transmitted only through the gametes with indirect evidence suggesting that they lack cell-to-cell movement capabilities [11, 18, 20, 31]. Economically important crops infected by endornaviruses include common bean, melon, pepper, and rice among others [10, 20, 21, 25]. In most cases, only some cultivars of a particular crop have been shown to be endornavirus-infected. In the case of common bean cul- tivars of Mesoamerican origin most tested cultivars have been shown to be double-infected by two endornaviruses, Phaseolus vulgaris endornavirus 1 (PvEV-1) and Phaseolus vulgaris endornavirus 2 (PvEV-2) [14]. Although endorna- viruses have been reported in economically important crops, their efect to the host has not been fully evaluated. This is mainly because a practical inoculation method has not been developed. In an attempt to obtain information about the efect that these viruses may have in common bean, we conducted comparative experiments using eight lines of the cultivar Black Turtle Soup (BTS): four double-infected with PvEV-1 and PvEV-2 and four endornavirus-free. We Handling Editor: Sead Sabanadzovic. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00705-018-3702-4) contains supplementary material, which is available to authorized users. * R. A. Valverde ravalve@lsu.edu 1 Department of Biology, Faculty of Science, Mahasarakham University, Khamriang, Kantarawichai, Maha Sarakham, Thailand 2 Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, USA