001 Viruses Associated to Alstroemeria Varieties and Epidemiology of Tomato Spotted Wilt in cv. `Rosario'

Abstract

Viruses associated to eight Alstroemeria varieties and the relationship of thrips density and environmental factors with Tomato Spotted Wilt (TSW) intensity as well as the TSW effect on yield were studied in `Rosario' in Central Mèxico. Using hosts range the viruses detected were Tomato Spotted Wilt Tospovirus (TSWV), Impatiens Necrotic Spot Tospovirus (INSV), Alstroemeria Mosaic Potyvirus (AlMV), Alstroemeria Streak Potyvirus (ASV), Arabis Mosaic Nepovirus (ArMV), and Cucumber Mosaic Cucumovirus (CMV). With serology it was confirmed the presence of TSWV in `Jubilee', `Rosario', and `Regina' varieties; INSV in `Anabel', `Jubilee', and `Red Sunset'; and AlMV in `Rosario', `Red Sunset', `Rosita', `Yellow King', `Jubilee'. and `Rojo Sangria'. TSWV and AlMV were found coinfecting `Rosario' plants. Five percent of plants were serologically positive to TSWV in the first flower harvest (25 Jan.-5 Apr.), 10% in the second (12 Ap.-21 June), and third (5 July-13 Sept.), and 18% in the last harvest (23 Sept.-6 Dec.). The highest peak density of thrips (520 to 630 individuals per sticky trap) were registered when the maximum temperature was higher than 35 °C and the relative humidity was between 40% to 60%. However, such peak density was not correlated with a significant increase of TSW incidence. Number and quality of inflorescences and the stem growth rate were significantly higher (P = 0.05) in plots with asymptomatic plants than that with plants showing putative symptoms of TSW.