APS Homepage

POSTERS: Genetics of resistance

Phenotyping the sorghum nested association mapping (NAM) parents for charcoal rot resistance
Afsana Noor - Dept. of Plant Pathology, Kansas State University. Christopher Little- Dept. of Plant Pathology, Kansas State University, Geoffrey P. Morris- Dept. of Agronomy, Kansas State University

Sorghum charcoal rot, caused by Macrophomina phaseolina (MP), is an economically significant disease in Kansas. An effective strategy to control this disease is to understand the genetic variation underlying charcoal rot resistance. The lack of accurate phenotyping and environmental variation has constrained genetic improvement of charcoal rot resistance. The sorghum NAM parents (ten diverse global lines crossed with an elite breeding line) have been used as a powerful population for trait dissection. The objective of this study was to phenotype the sorghum NAM parents for charcoal rot resistance. Sorghum NAM parental lines have been phenotyped against MP in the greenhouse using stalk injections with liquid cultures at 14 days after flowering (DAF). Mock-inoculated checks were injected with phosphate buffer (10 mM). Plant height, yield parameters, lesion length (measured from split stalks), and nodes crossed by the lesion were collected at 56 DAF. The results showed no significant difference between P898012, SC1345, SC971, Ajabsido, and Segaolane based on mean lesion length. However, comparison with the other six parents suggested the aforementioned lines are susceptible. SC1103 showed the lowest lesion length. Phenotyping will be repeated from greenhouse and field for confirmation. Based on phenotyping, transcriptome analysis will be performed to understand and dissect the molecular mechanisms of charcoal rot resistance using a NAM parental population.