Molecular mapping of genomic regions harboring QTLs for stalk rot resistance in sorghum

• Published in: Euphytica 2008, Vol.159 (1-2), p.191-198
• Main Authors: Srinivasa Reddy, P, Fakrudin, B, Rajkumar, Punnuri, S. M, Arun, S. S, Kuruvinashetti, M. S, Das, I. K, Seetharama, N
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; chromosome mapping; Crop diseases; Disease resistance; Economic importance; Fundamental and applied biological sciences. Psychology; fungal diseases of plants; genetic markers; Genetics and breeding of economic plants; Genomics; grain sorghum; internodes; Life Sciences; linkage groups; Lodging; Macrophomina phaseolina; microsatellite repeats; Pest resistance; phenotypic variation; Plant Genetics and Genomics; Plant pathogens; Plant Pathology; Plant Physiology; Plant resistance; Plant Sciences; quantitative trait loci; random amplified polymorphic DNA technique; signs and symptoms (plants); Soil-borne diseases; Sorghum; Sorghum bicolor; stalk rot; Varietal selection. Specialized plant breeding, plant breeding aims
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-007-9472-9

Stalk rot, also called as charcoal rot in India, caused by Macrophomina phaseolina, is an economically important, soil borne disease in major sorghum growing areas across the world. A population of F₉ generation recombinant inbred lines (RILs), derived from IS22380 (susceptible) x E36-1 (resistant), along with parents were phenotyped in sick plots at two locations (Dharwad and Bijapur, Karnataka, India). A total of 85 polymorphic marker loci (62 nuclear and 4 genic SSRs, 19 RAPDs) was available for the construction of genetic map, spanning 650.3 cM in all the ten linkage groups. Analysis with QTL Cartographer (2.5b), adopting composite interval mapping method (LOD > 2.0) at both locations, revealed 5 QTLs at Dharwad and 4 QTLs at Bijapur locations for the component traits of charcoal rot disease resistance. QTLs for number of internodes crossed, length of infection and per cent lodging accounted for 31.83, 10.76 and 18.90 per cent at Dharwad location and 14.87, 10.47 and 26.44 per cent phenotypic variability at Bijapur location, respectively. The QTLs for number of internodes crossed by the rot, length of infection and percent lodging were common across two locations. These QTLs, consistent over environments for the component traits, are likely to assist in marker-assisted selection (MAS) for charcoal rot resistance in sorghum.