First Report of Pepper Damping-Off Caused by Fusarium Oxysporum in Uzbekistan
Abstract
Sweet and hot peppers (Capsicum annuum L.), widely cultivated vegetable and spice cultures worldwide are attacked by various pathogenic fungi and oomycetes. Among them Fusarium species, most often F. oxysporum, cause various diseases, including the damping-off. Fusarium diseases on Capsicum spp. and other vegetable crops were also reported in Uzbekistan, but pathogens were identified only morphologically, based on characteristics of their colonies and sporulation organs. However, it is currently required that morphological identification must necessarily be accompanied by molecular genetic identification and the fulfillment of Koch's postulates. The present study was conducted in order to identify damping-off pathogens of sweet pepper seedlings in Uzbekistan caused by species of the genus Fusarium, considering these requirements. In 2022, the incidence of seedling damping-off in a greenhouse nursery in the Andijan region of Uzbekistan was 12.5%. In the mycological analysis, Fusarium-like colonies grew out of 58% of the symptomatic plant parts. Two representative isolates, UZF-21 and UZF-23 have been morphologically identified as Fusarium oxysporum. Molecular genetic analysis of the partial sequences of the TEF-1α gene of these isolates and BLAST search have confirmed the results of morphological identification. The received sequences were deposited in the NCBI database under GenBank accession numbers OQ466308 and OQ466309, respectively. This is the first report of F. oxysporum as the cause of bell pepper damping-off, which identity was confirmed in Uzbekistan using both morphological and molecular analyses.