Screening lentil germplasm for resistance against Ascochyta lentis under field and controlled conditions

Lentil (Lens culinaris) is the third most important grain legume in the world after chickpeas and peas. Ascochyta blight (AB) caused by Ascochyta lentis, is one of the most damaging diseases of this crop worldwide. In this study response of ۱۶۹ lentil genotypes against AB was appraised in the greenhouse and field conditions based on randomized complete block design (RCBD). Field screening was carried out in the growing season of ۲۰۱۹-۲۰۲۰ at Shirvan-Chardavol Agricultural Research Station, Ilam province, Iran. Conidial suspension with concentration of ۱×۱۰۶ spore per mL was used for artificial infection in the greenhouse condition. Analysis of variance discovered significant differences among studied genotypes in response to the pathogen. There were no detected resistant genotypes among the studied lentil germplasm against AB in either environments. In the field condition, the majority of genotypes were identified as resistant while in the greenhouse condition most of the genotypes retained susceptible responses. Regarding AUDPC and disease severity characteristics, genotypes “G۱۲۱”, “G۱۳۲”, and “G۱۳۹” were recognized as resistant in both field and greenhouse coditions. Classification of lentil genotypes by using Ward algorithm in both conditions resulted in ۴ heterotic groups. The identified resistant genotypes can be useful in the breeding program of interested susceptible lentil genotypes by the backcross approach. Also, the identified heterotic groups can consider in parental selection for mapping QTLs related to resistance to the disease.