Lentil (Lens culinaris Medik.), a small edible grain legume belonging to the Fabaceae family, is a self-pollinating, cool-season crop with needle-like leaves and white to pale purple or dark purple flowers1. It was domesticated by humans about 10,000 years ago in the Mesopotamian part of the Fertile Crescent and quickly spread to the New World, including the Mediterranean Basin and Central Asia, and later it was naturalized to the Americas2. The world lentil cultivation area is about 5.5 million hectares with production of 6.6 million tons3. Türkiye ranks 4th in lentil production after Canada, India, and Australia. Lentil cultivation in Türkiye is very important and accounts for 6.7% of world production. Türkiye's total lentil production is 474,000 tons and is produced in at least 40 provinces4. About 89.5% of Türkiye's lentil production constitutes red and green lentils, which constitute 10.5% of the winter crop in the Southeastern Anatolia Region. The rest of the crop is grown as summer crops. Yozgat (39.5%), Konya (23.7%), Kırşehir (16.3%), Çorum (7.6%), and Ankara (2.9%) provinces largely contribute to the green lentil production4. Lentil production can be limited by biotic and abiotic stress factors. Frost and drought are the most common abiotic stress factors in summer green lentil production5. Fungal diseases like wilt, root, and crown rot complex caused by Ascochyta lentis, Rhizoctonia solani, R. bataticola, Aphanomyces euteiche, Pythium, and Fusarium species are the most important fungal diseases, which cause a combination of diseases including damping-off, seedling blight, wilt, and root rot, depending on the timing of infection, host susceptibility, and meteorological conditions6,7,8.
Fusarium is a filamentous imperfect fungus found in soil, plants, and organic substrates and is a cosmopolitan genus among these pathogens9. It causes various diseases such as Fusarium wilt, root, and root collar rot, as well as Fusarium head blight in wheat, Fusarium wilt in cucurbits, and root rot in most legumes, including lentils10,11,12. Vascular wilt, root, and root collar rot caused by Fusarium spp. is the most important disease of lentils in many lentil cultivation areas globally10. Fusarium oxysporum is the most common Fusarium species associated with wilt, root, and root collar rot in lentils. Globally, wilt, root, and crown rot diseases are caused by F. graminearum, F. sporotrichioides, F. equity, F. acuminatum, F. redolent, F. avenaceum, F. culmorum, F. solani, and F. verticillioides in lentil planting areas7. Wilt, root and crown rot diseases caused by Fusarium spp. occur in both seedling and adult stages and cause sudden wilting, drying, and eventual death of the leaves. Symptoms of the disease include seed rot, root rot, wilting upper leaflets, stunting, shrinkage, and curling of leaves. In the middle and late pod-filling stages, seeds are usually shrunken, and root symptoms include stunted growth, brown discoloration, damaged taproot tips, and proliferation of secondary roots. Discoloration of the vascular tissue may not be seen in all cases13.
In the Central Anatolia Region, studies on the status of wilt and root rot diseases in lentils have been conducted in limited numbers. Yozgat has a mild and moderate climate with abundant rainfall in winter when compared to summer and is classified as Dsb (Warm, humid terrestrial climate) by Köppen and Geiger14. The mean temperature is 9.6 °C with an average precipitation of 512 mm. Yozgat is located in the northern hemisphere. Summer occurs in June, July, August, and September. It is very important to have information about the regional epidemiology and etiology of the phytopathogenic fungal agents that cause the disease for developing different control strategies against soil-borne Fusarium spp., to control disease15. In this context, the objectives of the present study are to determine and identify - the disease parameters (disease prevalence, incidence, and severity) of wilt, root, and crown rot diseases in lentils by conducting a survey in Yozgat province, where approximately 40% of the total green lentil production is done singly, the pathogenic Fusarium species that cause wilt and root rot in lentils by morphological and molecular analyses, and to determine the individual virulence levels of the Fusarium species by carrying out pathogenicity tests.