Identification of AFLP and microsatellite markers linked with an aluminium tolerance gene in barley (Hordeum vulgare L.)

Abstract

Barley is the most sensitive among the cereals to aluminium (Al) stress and breeding for more tolerant cultivars is a priority. To enhance selection efficiency for Al tolerance in barley, PCR-based AFLP and microsatellite markers linked to a locus conferring tolerance to aluminium were identified. The study used F(2) progeny derived from a single cross between Yambla (moderately tolerant of Al) and WB229 (tolerant of Al) and developed hydroponic pulse-recovery screening methods to assess tolerance of phenotypes based on root growth. The segregation ratios of tolerant and sensitive genotypes and F(3) progeny testing suggest that a single major gene controlled Al tolerance ( Alt). In order to determine the chromosomal location of the Alt gene, we used the AFLP technique coupled with bulk segregant analysis. We evaluated tolerant and sensitive bulks using 30 combinations of EcoRI/ MseI primers, and 12 of these permitted differentiation of the sensitive and tolerant bulks. More than 1,000 amplified fragments were obtained, and 98 polymorphic bands were scored. AFLP analysis of wheat-barley chromosome addition lines indicated that the Alt gene was located on barley chromosome 4H. Four chromosome 4H-specific microsatellite markers (Bmac310, Bmag353, HVM68 and HVMCABG) were tightly linked to Alt. The large allelic variation detected with microsatellite marker Bmag353 allowed us to implement this marker for routine marker-assisted selection for Al tolerance, and 396 plants could be screened on a single gel.

Characterization of Newly Developed Wheat/Barley Introgression Lines in Respect of Aluminium Tolerance

“…Nevertheless, the high root growth found in lines containing the 4H chromosome of barley, irrespective of the parents, indicated the presence of quantitative trait loci (QTL) for root elongation on chromosomes 4H. A similar association was found previously by Raman et al [19], Jefferies et al [28] and Ellis et al [29] under different stress conditions. When evaluating the Al tolerance level of these introgression lines and parental genotypes, similar results were found by monitoring root growth and by the haematoxylin test.…”

“…They encode transport proteins responsible for malate and citrate release. Nevertheless, several minor QTLs controlling Al tolerance were also identified on chromosomes 2A, 5A, 3B and 5D in wheat and 2H, 3H, 5H and 6H in barley, indicating the multigenic trait of Al tolerance [19][20][21]. In addition, crosses between different genotypes or species have demonstrated that the presence of alien chromosomes may affect the Al tolerance of introgression lines.…”

Aluminium tolerance in barley (Hordeum vulgare L.): Physiological mechanisms, genetics and screening methods

“…All eight tolerant barley cultivars ranked by Minella and Sorrells (1992) were six-row cultivars. Two row barleys having Al tolerance have also been reported (Raman et al, 2002).…”

Mapping of genomic regions associated with net form of netblotch resistance in barley

“…Healthy leaf samples from these were used for validation of 4 microsatellite markers (EBmac0906, Bmac0310, Bmag0353, Bmac0181), which mapped within 10 cM of the locus conferring NFNB resistance in Sloop/ Halcyon. These markers have been reported to map closely in barley populations derived from Lina/Canada Park, WB229/Yambla, and Dayton/Harlan Hybrid (Ramsay et al 2000;Raman et al 2002Raman et al , 2003. Deoxyribonucleic acid was extracted in 2 mL Eppendorf tubes as described previously (Raman and Read 2000).…”