Gene-specific Markers for Acid Soil/Aluminium Tolerance in Barley

One of the major problems in barley production is acid soil/aluminium tolerance. When the soil pH decreases (below 5.5), aluminium becomes soluble and toxic to plant growth resulting to poor nutrient absorption and less water intake. Thus, scientists use genetic modification and molecular marker-assisted selection in the development of barley cultivars with acid soil/aluminium tolerance. Dr. Miao Ban from Huazhong Agricultural University and other scientists mapped a major complex trait for acid soil tolerance from the CIMMYT barley variety Svanhals and developed a PCR-based gene-specific marker for marker-assisted breeding.

The team used the gene encoding an aluminium-activated citrate transporter HvMate to develop gene-specific molecular markers to detect acid soil/aluminium tolerance based on PCR. Through sequence analysis of the gene, the 21-bp indel (insertion–deletion) between the tolerant and sensitive cultivars were identified. Furthermore, the new marker was mapped to the quantitative trait loci (QTL) region on chromosome 4H for acid tolerance which accounted for 66.9 percent of phenotypic variation in the doubled haploid population. Polymorphism was confirmed in other tolerant varieties which have been widely used as source of acid soil tolerance in Australian breeding programs. Based on the study, the new marker is an effective and simple molecular tool for choosing the acid soil tolerance gene from several tolerance sources.

Read the abstract at http://link.springer.com/article/10.1007/s11032-013-9859-3.