Identification and characterisation of Mlo genes in pea (Pisum sativum L.) vis-à-vis validation of Mlo gene-specific markers

Pea is infected by a number of pathogens, and among them powdery mildew (PM) caused by Erysiphe pisi is an important fungal disease. This work was undertaken in silico to characterise the identified PM resistant genes of pea and design specific primers to be used in marker-assisted selection (MAS) of resistant and susceptible pea genotypes. Mlo gene sequences of A. thaliana and O. sativa were retrieved from different databases and used for a homology search of P. sativum EST databases. Each identified gene was used for a similarity search and phylogenetic classification with different crops. Four gene-specific primers were designed from the identified Mlo nucleotides and were amplified in different pea genotypes. Pea Mlo1 analogue of the ‘er’ gene was related to AtMlO2, AtMlO6, AtMlO12, and AtMlO3. Pea Mlo2 was related to AtMlo14 and Pea Mlo4. Pea Mlo3 gene was related to AtMlO15, AtMlO13, AtMlO4, and AtMlO11. The Pea Mlo4 gene was closely related with AtMlO8 and AtMlO7. In phylogenetic classification, two main clusters were formed; the first cluster possessed the 4 identified pea Mlo genes and the core conserved motifs. Validation of pea Mlo primers confirmed the effectiveness of PsMlo2 primer for use in MAS.