Abstract
Dragon’s head (Lallemantia iberica) as an oilseed crop has been recently introduced to Iranian farmers and because of its tolerance to abiotic stresses has been acknowledged to be grown in drylands and rain-fed areas of the country in rotation with cereals and pulses. In this study, fifty Iranian L. iberica landrace were evaluated for the prevalent diseases under field conditions during 2019-2021 in Gonbad-Kavous, North of Iran. A spot lesion/blight symptom was observed in the field and the subsequent classical and molecular mycological studies identified Alternaria tenuissimaand A.atra as the causal agents. Subsequently, a complimentary experiment was conducted to screen genotypes for these disease agents under controlled conditions using the proposed scoring system invented in this study. Results showed a significant and negative strong correlation between Sclerotinia stem rot (SSR) with yield and plant height, while no relationship was observed between Alternaria spot/blight and agronomic traits. Nine and thirteen genotypes were identified as resistant and moderately resistant to SSR in the field and three of them showed additional resistance to Altarnaria spp. in the glasshouse. The resistant/high-yield genotypes identified through this research can be considered as valuable sources to be released as new cultivars or exploited in breeding programs.