Evaluation of Lens culinaris germplasm against ascochyta blight by applying phenotyping and defense genes attributes

Lentil Ascochyta blight (caused by Ascochyta lentis) is one of the most important limiting factors of lentil cultivation and production in most regions of the world. Introducing resistance sources against the pathogen is a suitable strategy to conquer this biotic stress. In this study, A. lentis-lentil pathosystem was inspected through the evaluation of 79 lentil genotypes in greenhouse conditions. Afterward, germplasm population structure as well as genomic regions conferring in differentiation of disease response types were determined by defense-genes related SSRs. Also, comprehensive analysis of the lentil defense system in facing A. lentis was done by measuring transcripts of defense-related genes of PR-2 and RBP-hnRNPs at 24, 48, and 72 h post inoculation. Non-parametric analysis of variance showed significant differences among studied genotypes regarding disease severity and AUDPC, where 69.62%, 21.51%, and 8.86% of them showed susceptible, moderate resistant, and resistant reactions, respectively. Genomic fingerprinting of genotypes by using 9 SSR loci specific to defense genes, manifested 51 alleles. Among the studied SSR loci, RRM1 with PIC values of 0.74 possessed the highest efficacy in evaluation of the lentil germplasm. Discriminant analysis of principle component analysis, showed efficacy of defense-genes related SSRs in prediction of R, S, and MR reactions that were determined phenotypically in greenhouse conditions. Combination of genetic algorithm with quadratic SVM as supervised machine learning method revealed allele PP2C-7 of gene PP2C (has act in pathway of plant stress signaling) as important feature for prediction of lentil reaction types against A. lentis. Study of molecular response against A. lentis showed overexpression of genes RBP-hnRNPs (transcriptional factor) and PR-2 (anti-fungal compound), especially at 48 hpi and 72 hpi for resistant genotype. In total, screening lentil germplasm is continuous work regarding the co-evolution of pathogens and resistant genes, and in this way, artificial intelligence through defense genes relevant SSRs could reliably identify resistance type genotypes. AB-resistant lentil genotypes respond rapidly and rigidly against infection compared with susceptible genotypes.