efficient marker-assisted backcrossing strategy for enhancing barley (Hordeum vulgare L.) production under acidity and aluminium toxicity

• Published in: Molecular breeding Vol. 31; no. 4; pp. 855 - 866
• Main Authors: Soto-Cerda, Braulio J, Peñaloza, Enrique H, Montenegro, Adolfo B, Rupayan, Annally R, Gallardo, Milton H, Salvo-Garrido, Haroldo
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.04.2013; Springer Netherlands; Springer Nature B.V
• Subjects: acid soils; Acidic soils; Acidity; Agricultural economics; Aluminum; backcrossing; Barley; Biomedical and Life Sciences; Biotechnology; Breeding; chromosome mapping; Crop production; Crops; Cultivated lands; Cultivation; Deoxyribonucleic acid; Developing countries; DNA; Embryos; Food; Food production; Food security; Gene mapping; genes; Genetic control; Genomes; Hordeum vulgare; introgression; LDCs; Life Sciences; microsatellite repeats; Molecular biology; physiology; Plant biology; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Seeds; Soil stability; Strategy; Toxicity; Barley; Acid soil; Aluminium toxicity; Food security; Marker-assisted backcrossing
• ISSN: 1380-3743; 1572-9788
• DOI: 10.1007/s11032-013-9839-7

To feed the predicted extra two billion people by 2050, crop production must increase on existing cultivated land at a rate that challenges our current capability. Acid soils and aluminium (Al³⁺) toxicity restrict productivity worldwide but also offer the greatest opportunity for increases in global food production. Our understanding of the physiology, genetic control and the identification of genomic regions underlying Al resistance in important staple crops has increased greatly over the past 20 years, enabling the application of molecular breeding. In this study, we report the application of an efficient marker-assisted backcrossing (MAB) strategy for the introgression of the HvAACT1 gene which confers Al resistance in barley (Hordeum vulgare L.). We conducted foreground and background selection using microsatellite (SSR) markers linked to HvAACT1 and SSR-based linkage maps, along with embryo rescue and a cost-effective DNA preparation method shortening the breeding cycle to ~18 months. The MAB strategy enabled the development of homozygous (BC₃F₂) Al-resistant lines with the smallest introgressed region and 98.7 % of the recurrent parent genome. The Al-resistant line yielded significantly more seeds (121 %) than its isogenic line in soil-based assays containing 12 % of Al saturation. This MAB strategy could be extended to other staple crops with similar molecular toolboxes, expanding their cultivation onto acid soils, and contributing to greater yield stability and food security, particularly in developing countries.