Location: Tropical Crops and Germplasm ResearchTitle: Inheritance and molecular mapping of anthracnose resistance gene present in the differential line PI533918
Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2014
Publication Date: N/A
Technical Abstract: Anthracnose (Collectrotichum sublineolum) is considered one of the most destructive diseases of sorghum (Sorghum bicolor L. Moench) because it infects all aerial tissues of the plant. The best strategy to control the disease is the incorporation of resistance genes. At present, eighteen sorghum lines have been established to differentiate anthracnose pathotypes based on their disease reaction response. Nevertheless, the genetic control underlying these resistance responses is known for only one of these lines, which makes stacking of resistance genes difficult. Therefore, the genetic inheritance of anthracnose resistance present in the sorghum differential line PI533918 (SC112) was determined as a single dominant gene by the analysis of F2 individuals and F2-3 families. This resistance gene was mapped to the distal region of Chromosome 5 flanked by a serial of SSRs markers within a 10cM recombinant region. High resolution mapping delimited the gene to a 1.1Mbp genomic region flanked by two SSRs markers at 4.5cM to each other. This genomic region is characterized by the presence of a cluster of two resistance genes belonging to the NBS-LRR resistance gene family. Comparative analysis of the region confirmed that it is not associated with the previously anthracnose resistance gene mapped on the same chromosome. The identification and mapping of multiple resistance genes is imperative for the development of new varieties with broader anthracnose resistance. Genetic markers developed through this project will allow the employment of marker assisted selection to stack different anthracnose resistance genes into elite sorghum lines.