Polymorphism of wild species of р. Malus MILL. according to powdery mildew resistance genes

Abstract

Powdery mildew (Podosphaera leucotricha (Ell. E tEv.) Salm.) – is one of the most widespread apple diseases in world. Identification of forms, carrying resistance genes, is an important stage in breeding programs aimed at obtaining powdery mildew resistant apple varieties. Diagnostic DNA markers of target genes will increase reliability of identification and efficiency of apple breeding for the creation of resistant genotypes. The purpose of this study was molecular genetic testing of wild species of genus Malus Mill. According to Pl-1, Pl-w and Pl-d powdery mildew resistance genes for revealing polymorphism of the studied loci and identification of valuable genotypes for breeding. The study subjects were the wild species of genus Malus Mill. of different ecological and geographic origin. The Pl-1 gene was identified using AT20-SCAR marker, Pl-w gene - EM M02 marker, Pl-d gene - EM DM01 marker. AT20-SCAR marker (Pl-1 gene) was identified in 37.3 % of genotypes. EM M02 marker (Pl-w gene) was detected in 16.4 % of the studied forms. EM DM01 marker (Pl-d gene) is present in 10.4 % of the analyzed forms. At least one of the studied molecular markers is present in the genome of 52.2 % of apple wild species. The Pl-1 gene in apple wild species is most spread in Baccatae series, the Pl-w gene - in Baccatae and Sieboldinae series, the Pl-d gene - in Orientalis series. Wild species M. baccata 2319, M. mandshurica 41947, M. sachalinensis 85, M. sachalinensis 97, M. purpurea v. pendula 2396 are characterized by combination of Pl-1 and Pl-w genes; M. turkmenorum 13283 and M. turkmenorum 29 421 - Pl-1 and Pl-d genes; M. denticulata 29416 - Pl-w and Pl-d genes, which allows to recommend them as promising complex sources of high powdery mildew resistance for breeding.