The potato virus "X": Its strains and reactions

Abstract

The virus, the subject-matter of the following study, is known under several names: the X virus of Dr Kenneth M. Smith (1931), the common mosaic of Quanjer (1923), the healthy potato virus of Johnson (1925), which he also called tobacco ringspot (a name now given to a quite distinct virus, viz. that described by Wingard (1928) and others (Thung, 1936), and potato virus 1, the name now given by Smith (1937). The extensive work which Smith, the writer and his colleagues, have done on this virus during the last four years has led to the appellation of the X virus being generally adopted as the most convenient, as well as the least committal, of its synonyms, and it is the one which will be adhered to in this paper. Smith drew attention to the variation in virulence of the symptoms exhibited by the virus infection he then called tobacco ringspot, induced by the inoculation of the juice of a potato suffering from what appeared to be simple mosaic.

Potato virus Y (PVY) and potato virus X (PVX) resistance breeding in Kenya: applicability of conventional approaches

“…Sources of virus resistance used for breeding for PVY and PVX resistance: Recognition of potato viruses as a serious problem in potato production in 1930's triggered a lot of research on the characterization of numerous virus resistance genes and phenotypes in Solanum species (Salaman, 1938;Cockerham, 1970;Solomon and Barker, 2001;Rahman et al, 2010). Before recognition of this virus problem, selection for virus resistance within the tuberosum gene pool was done by selecting cultivars that were able to withstand virus degeneration better than others (Cockerham, 1943).…”

Infection of Solanum laciniatum Ait. with potato viruses X and Y

“…During 1977-78 a crop of 'Arran Banner' potatoes had been grown adjacent to this plant, and a self-sown potato showing rugose mosaic virus symptoms grew in contact with it. Sap from the infected S. laciniatum and potato leaves was inoculated to Nicotiana tabacum L. and produced symptoms typical of those induced by mixed infection with potato viruses X and Y: the characteristic spot-necrosis symptoms resulting from a synergistic interaction between viruses X and Y, first described by Smith (1931) and examined further by Salaman (1938) using six strains of virus X. This reaction on tobacco remains one of the most useful biological tests for mixed infection with the two viruses.…”