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United States Department of Agriculture

Agricultural Research Service

Research Project: Evaluation and Genetic Analyses of Sorghum Genetic Resources for Key Agronomic Traits

Location: Tropical Crops and Germplasm Research

Title: Inheritance and Molecular Mapping of Anthracnose Resistance Genes Present in Sorghum Line SC112-14

Authors
item Cuevas, Hugo
item Prom, Louis
item Erpelding, John

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 7, 2014
Publication Date: N/A

Interpretive Summary: Anthracnose (Colletotrichum sublineolum) is one of the most destructive diseases of sorghum (Sorghum bicolor L. Moench) affecting all aerial tissues of the plant. The identification of resistance genes is the most effective strategy for disease control. Herein, anthracnose resistance present in the line SC112-14 was characterized as a single dominant gene located on sorghum chromosome five. Molecular markers associated with this resistance gene were developed and evaluated in segregating progenies. These markers can be used for marker assisted selection in sorghum breeding programs to develop new sorghum varieties with anthracnose resistance.

Technical Abstract: Anthracnose (Colletotrichum sublineolum) is one of the most destructive diseases of sorghum (Sorghum bicolor L. Moench) affecting all aerial tissues of the plant. The most effective strategy for its control is the incorporation of resistance genes. Therefore, the anthracnose resistance response present in the sorghum line SC112-14 (Cs-SC112) was studied against pathotypes from Puerto Rico, Texas, Arkansas, and Georgia using F2 progenies and recombinant inbred lines. The results determined that a series of nearest single locus at the distal region of chromosome 5 are controlling the resistances response against pathotypes from Puerto Rico, Texas, and Arkansas. Resistances loci against pathotypes from Texas and Puerto Rico are tightly linked and flanked by SSR markers Ch5-55.0 and Ch5-56.1, while resistance locus against pathotypes from Arkansas is 9.5 cM below SSR marker Ch5-56.1. The resistance locus against pathotypes from Georgia is not located in the distal region of chromosome 5, and its location could not be determined. Comparative analysis confirmed that the region associated with these three loci is not associated with the anthracnose resistance locus Cg1, which was previously mapped in the distal region of the same chromosome. The dominant mode of action against pathotypes from Puerto Rico suggests these resistances sources can be beneficial for sorghum hybrid production. The durability of anthracnose resistance in sorghum depends on the adequate use of multiple resistance sources. Thus, the knowledge and genetic markers developed herein provides the tools to initiate the pyramid of multiple anthracnose resistance loci through marker assisted selection.

Last Modified: 11/24/2014
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