Sporodochia formed by Fusarium oxysporum f. sp. fragariae produce airborne conidia and are ubiquitous on diseased strawberry plants in California

Sporodochia are dense masses of fungal hyphae bearing asexual conidia. For , sporodochia are known to produce airborne conidia and enhance the dissemination of this otherwise soilborne pathogen. Sporodochia are small and transient, and they are documented for only a few of . This study reports airborne conidia and sporodochia produced by f. sp. , the cause of Fusarium wilt of strawberry, in the Monterey Bay region of California. Sporodochia were discovered in 21 of 24 Fusarium wilt-diseased fields surveyed for this study, and were readily observed on symptomatic plants in these fields. Only necrotic tissues bore sporodochia, and they were most frequently observed on petioles and peduncles. Sporodochia covered significantly greater lengths of peduncles than petioles, extending from the base of the plant towards the upper part of the canopy. A stolon hosted the longest stretch of sporodochial growth, along its entire 35 cm length and on the base of the daughter plant. Macroconidia were produced by all sporodochia samples, and we did not find microconidia on any samples. An initial series of experiments confirmed the potential for conidia produced by sporodochia to disperse with wind over short distances. The prevalence of sporodochia producing airborne spores of f. sp. has great importance for disease management and biosecurity.