Genetic diversity and pathotype determination of Colletotrichum sublineolum isolates causing anthracnose in sorghum

Abstract

Amplified fragment length polymorphism (AFLP) based genetic diversity was analyzed for 232 Colletotrichum sublineolum isolates collected between 2002 and 2004 from three geographically distinct regions of Texas, and from Arkansas, Georgia, and Puerto Rico. Results revealed significant levels of polymorphism (59%) among the isolates. Even so, genetic similarity between isolates was high, ranging from 0.78 to 1.00. Clustering of similar isolates did not correlate with either geographic origin or year of collection. Pathotypes of 20 of the isolates were determined using 14 sorghum lines previously used in Brazil and the United States and 4 from Sudan. Seventeen new pathotypes were established from the 18 isolates that gave uniform and consistent reactions on all host differentials over 2 years of greenhouse testing. Differentials BTx378 and QL3 were resistant to all isolates while BTx623 and TAM428 were universally susceptible both years. Each of these lines had shown differential responses in prior studies indicating that the pathogen population has sufficient diversity to adapt rapidly to changes in resistant host lines deployed. When the 2-step pathotype classification scheme was used, the 18 isolates examined in this study were placed in four Eur J Plant Pathol (2012) 133:671-685

Sequencing of an Anthracnose‐Resistant Sorghum Genotype and Mapping of a Major QTL Reveal Strong Candidate Genes for Anthracnose Resistance

“…Numerous sources of genetic resistance to anthracnose have been identified, but consistency of resistance is a function of not only specific resistance sources but also the pathotype and environment of evaluation (Mehta et al, 2005). Sorghum line SC748‐5, a grain sorghum, has been identified as strongly resistant to the disease (Prom et al, 2012; Rosenow and Frederiksen, 1982). To determine the genetic mechanism of anthracnose resistance, SC748‐5 was crossed with the now fully sequenced, anthracnose‐susceptible line BTx623.…”

Assessment of sorghum genetic resources of Ethiopia for anthracnose (Colletotrichum sublineolum Henn.) resistance and agronomic traits

“…Colletotrichum sublineolum, the causal agent of sorghum anthracnose is a serious biotic stress limiting sorghum production and productivity (Prom et al, ; Tesso et al, ). Developing anthracnose‐resistant cultivars are key for yield gains in sorghum.…”

“…The pathogen was first reported in Togo, West Africa in 1902 (Thakur & Mathur, ). Anthracnose is prevalent in most sorghum growing areas of the world (Crouch & Beirn, ; Prom et al, ; Tesso et al, ). Disease infection and development is the highest in tropical and subtropical regions where high temperatures and humidity are common (Burrell et al, ; Crouch & Beirn, ; Marley, Diourte, Neya, & Rattunde, ; Mathur, Thakur Neya, Marley, & Casela, ; Mehta et al, ; Ngugi, King, Abayo, & Reddy, ; Patil et al, ).…”

“…There is a continuous need to identify new sources of resistance among available genetic stocks and landraces through artificial and natural inoculation for resistance breeding. This should be followed by genetic recombination and selection for effective disease management and to enhance sorghum productivity (Prom et al, ; Resende, Milagres, Rezende, Aucique‐Perez, & Rodrigues, ; Sharma, Upadhyaya, Manjunatha, Rao, & Thakur, ).…”

Sustainable Agriculture Reviews

“…Currently scientists (Prom et al 2012 ) are developing real-time PCR primers for two downy mildews that are considered to be threat to sorghum production along with PCR-based tags genes for resistance to head smut, anthracnose, downy mildew and grain mold. These molecular tags will be useful for breeding cultivars with more durable resistance and for cloning specifi c resistance genes.…”