Results of genotypic and phenotypic evaluation of barley cultivars for aluminum tolerance

This study compared the results of molecular genetic analysis using PCR markers (HVM68, 1kb-insertion, HvMATE-21indel) of ten barley (Hordeum vulgare L.) genotypes with a phenotypic evaluation of their aluminum tolerance. The objects of the study were barley cultivars ‘Novichok’, ‘Dina’, ‘Forvard’, ‘Bionik’, ‘Vitrum’, ‘Rodnik Prikamiya’, ‘Pamyati Dudina’ (Russia), ‘Zazerskij 85’ (Belarus), ‘Triumph’ (Denmark), ‘Tallon’ (Australia). It was established that the studied barley genotypes did not have the 1kb-insertion mutation (PCR product 1841 bp), which enhanced the expression of the HvAACT1 gene (PCR products with a size of 818 bp were obtained in all cultivars). The HvMATE-21indel deletion (PCR product 475 bp) was detected in the genome of three cultivars – aluminum-tolerant ‘Novichok’, ‘Bionik’ and acid-tolerant ‘Rodnik Prikamiya’. When using the HVM68 microsatellite marker, amplicons in the range of 175–220 bp were detected in barley cultivars. It is assumed that the studied barley genotypes have different mechanisms of regulation of the HvAACT1 gene and/or are characterized by its polymorphism, which requires further study. Among the PCR markers of barley aluminum tolerance used in the work, the most promising is the HvMATE-21indel marker. Based on the morphological evaluation of seedlings according to root length index (RLI), most of the cultivars (90 %) were classified as moderately tolerant (‘Forvard, ‘Novichok, ‘Vitrum, ‘Zazerskij 85’, ‘Tallon’) and tolerant (‘Dina’, ‘Bionik’, ‘Rodnik Prikamiya’, ‘Triumph’) genotypes. At the same time the HvMATE-21indel gene-specific marker was detected in only three cultivars, which indicated the need to expand the set of DNA markers used to identify mutations in the HvAACT1 gene and its regulatory regions. The method used for cytological evaluation of aluminum tolerance is promising for determining the genotype response to modeled aluminum-acid stress but requires further optimization. To characterize the aluminum tolerance of barley by phenotype it is advisable to use an integrated approach, including both field and laboratory analyses.