Abstract
Seasonal and diurnal variations of airborne basidiomycetous spores concentrations (basidiospores, smuts and rust spores) were studied using Burkard Volumetric Spore Traps in three major coastal cities viz., Dammam, Jeddah and Jizan in Saudi Arabia. The distance between the sites was approximately 1600 km from East to West. In addition to numerous airborne deuteromycetous spores identified at all sites, a considerable concentration of basidiomycetous spores were also recorded. The data revealed that basidiospores constituted a maximum of 17% of the total air spora in Jizan, while the maximum for Dammam and Jeddah was 11% each. Spores from smuts constituted the highest percentages of all basidiosmycetous spores ranging between 9-33% and 12-33% respectively in Dammam and Jizan. In Jeddah, it constituted between 14-26%. In contrast, rusts were less frequent at all sites. Maximum concentration of basidiospores showed that at certain months the level reached between 1000-6000 m super(-3). The data did not exhibit any seasonal pattern in their maximum appearance. Maximum concentration of smuts were much higher compared to basidiospores and the level fluctuated between 500-4000 m super(-3). Rusts were low in concentration (<150 m super(-3)). The diurnal pattern of basidiospores concentration for at least one site (Jizan) averaged over the year showed a nocturnal trend consistent with basidiospores active discharge. The other two sites had no such trend. Diel periodicities of smuts and rusts spores did not exhibit any clear pattern. The study suggests that even in coastal regions having the same climatic conditions with a slightly different geography, show variation in basidiospores concentrations.