Verticillium wilt in spinach seed production

• Published in: Plant disease Vol. 89; no. 1; pp. 4 - 11
• Main Authors: Toit, L.J. du, Derie, M.L, Hernandez-Perez, P
• Format: Journal Article
• Language: English
• Published: St. Paul, MN American Phytopathological Society 2005
• Subjects: Biological and medical sciences; disease transmission; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fusarium oxysporum; Fusarium oxysporum f. sp. spinaciae; host plants; new geographic records; new host records; pathogenicity; Phytopathology. Animal pests. Plant and forest protection; plant pathogenic fungi; seed productivity; seeds; spinach; Spinacia oleracea; vegetable crops; Verticillium dahliae; Verticillium wilt; New Zealand; Denmark; Netherlands; United States; Washington; Plant pathology; Microbiology; Plant pathogen; Fusarium oxysporum f. sp. spinaciae; Spinacia oleracea; premature senescence; Chenopodiaceae; Fungi; Vegetable crop; Dicotyledones; Angiospermae; Verticillium; Spermatophyta; Fungi Imperfecti; Thallophyta; f. sp
• ISSN: 0191-2917; 1943-7692
• DOI: 10.1094/PD-89-0004

There are no previous reports of Verticillium wilt in fresh and processing spinach (Spinacia oleracea) crops in the United States. In 2002, a hybrid spinach seed crop in the Pacific Northwest developed late-season wilt symptoms. Assays of the harvested seed and stock seed of the male and female parents revealed 59.5, 44.0, and 1.5%, respectively, were infected with Verticillium dahliae. Assays of 13 stock or commercial seed lots grown in 2002 and 62 commercial lots harvested in 2003 in Denmark, Holland, New Zealand, and the United States revealed the prevalence of Verticillium spp. in commercial spinach seed. Sixty-eight lots (89%) were infected with Verticillium spp. at incidences ranging from 0.3 to 84.8%. Five spinach seed isolates of V. dahliae were pathogenic on each of three spinach cultivars by root-dip inoculation. V. dahliae was detected on 26.4% of the seed from 7 of 11 inoculated plants but on none of the seed from 6 control plants, demonstrating systemic movement of V. dahliae. Seed-to-seed transmission was also demonstrated by planting naturally infected seed lots. This is the first report of Verticillium wilt of spinach in the primary region of spinach seed production in the United States.