|Pastor Corrales, Marcial - Talo|
Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2014
Publication Date: 1/28/2015
Citation: Khankhum, S., Valverde, R., Pastor Corrales, M.A., Osorno, J., Sabanadzovic, S. 2015. Phaseolus vulgaris endornavirus 1 and Phaseolus vulgaris endornavirus 2 infecting common bean Phaseolus vulgaris genotypes show differential infection patterns between gene pools. Archives of Virology. 160:1131-1137. Interpretive Summary: Endornaviruses are double-stranded RNA viruses occurring in economically important crops including common bean. Two distantly related endornavirus species, PvEV-1 and PvEV-2, have been recently reported occurring in various common bean market classes. We investigated the occurrence of these viruses in current varieties, landraces, and wild common beans collected from the Mesoamerican and Andean centers of domestication. We included other closely related species. PvEV-1 and PvEV-2 were detected mostly in beans of Mesoamerican origin but rarely in those of Andean origin. These viruses were not detected in other Phaseolus species. The incidence of the viruses diminished significantly in landraces and wild beans. They were not detected in wild beans of Andean origin. The results suggest that these endornaviruses most likely originated from infected wild Mesoamerican beans that were selected during domestication and were introduced by breeders to some Mesoamerican cultivars. This research, which can be added to the body of evidence supporting the existence of two divergent gene pools and to the uniqueness of each gene pool in common bean, is important to scientists using the information to study the diversity and evolution of the common bean to improve the common bean crop.
Technical Abstract: We investigated the occurrence of two plant endornaviruses, Phaseolus vulgaris endornavirus 1 (PvEV-1) and Phaseolus vulgaris endornavirus 2 (PvEV-2), in breeding-lines, cultivars, landraces, and wild genotypes of common bean (Phaseolus vulgaris) as well as other Phaseolus species collected from two centers of common bean domestication: Mesoamerica and the Andes. Plants were tested for the presence of viral dsRNA by gel electrophoresis and RT-PCR using virus-specific primers. The two endornaviruses were detected in most P. vulgaris genotypes of Mesoamerican origin but rarely in genotypes of Andean origin. These viruses were not detected in other Phaseolus species. PCR products of selected P. vulgaris genotypes were sequenced and compared to corresponding sequences of PvEV-1 and PvEV-2. Double-infections of the endornaviruses were detected in 63 of 68 (93%) common bean genotypes of Mesoamerican origin. In contrast, with one exception, only single-infections were detected in 4 of 42 (9%) genotypes common bean of Andean origin. In land races of Mesoamerican and Andean origin these endornaviruses were detected in 14 of 36 (39%) and 3 of 42 (7%), respectively; while only 9 of 59 (15%) wild P. vulgaris genotypes of Mesoamerican origin were infected. The endornaviruses were not detected in wild P. vulgaris of Andean origin. The results obtained in this investigation suggest that these two endornaviruses were introduced into the Mesoamerican modern genotypes during common bean domestication and provide more evidence that support the existence of two divergent gene pools of common bean.