Pathogen Identification And Resistance Screening Of Fusarium Basal Rot İn Taşköprü Garlic İn Türkiye

Abstract

Fusarium basal rot (FBR), caused by Fusarium spp., is a significant threat to garlic production globally, including in T & uuml;rkiye, where the unique Ta & scedil;k & ouml;pr & uuml; garlic is highly valued. This study investigated the diversity and aggressiveness of 77 Fusarium isolates obtained from disease surveys of FBR in Ta & scedil;k & ouml;pr & uuml; garlic and evaluated the yield and resistance of 20 garlic accessions, including 18 local landraces, the locally developed 'Ta & scedil;k & ouml;pr & uuml; 56', and the commercial Chinese variety 'ASCG'. Molecular identification using translation elongation factor 1-alpha (TEF1) and second largest RNA polymerase II B-subunit (RPB2) genes revealed F. oxysporum (67.5%) as the dominant species, followed by F. proliferatum (15.6%), F. solani (9.1%), F. redolens (5.2%) and F. clavum (2.6%), respectively. All isolates were pathogenic, but aggressiveness varied, with F. solani being the most aggressive, followed by F. redolens and F. oxysporum. While 'ASCG' exhibited the highest yield (3.15 ton/ha), it was highly susceptible to FBR (DSI = 97.50%). Conversely, the landrace ASTK2 displayed the highest resistance (DSI = 53.13%), but lower yield. Promisingly, several Ta & scedil;k & ouml;pr & uuml; landraces, such as ASTK6 and ASTK13, demonstrated both moderate resistance and promising yield potential. Surprisingly, 'Ta & scedil;k & ouml;pr & uuml; 56', despite being a locally developed variety, exhibited high susceptibility to FBR (DSI = 93.75%) and did not outperform many landraces in terms of yield. This study provides the first reports of F. redolens and F. clavum infecting garlic in T & uuml;rkiye, and the first molecular characterisation of F. solani as a garlic pathogen in the country, highlighting the potential of local landraces for breeding FBR-resistant, high-yielding cultivars.