Location: Crop Germplasm Research
Project Number: 3091-22000-034-04-I
Project Type: Interagency Reimbursable Agreement
Start Date: Aug 15, 2018
End Date: Aug 14, 2021
Aim 1. Uncovering resistance sources present in the SAP. Aim 2. Mining the NPGS sorghum collection for new resistance alleles. Aim 3. Gene expression profile of anthracnose resistant accessions. Aim 4. Validation of anthracnose resistant loci in sweet sorghum germplasm.
Experimental Design. Sorghum Association Panel (SAP) with SC748 as resistant check and BTx623 and PI609251 as susceptible checks will be evaluated for resistance against C. sublineola. Seed from the SAP lines will be obtained from the USDA-ARS, Plant Genetic Resources Conservation Unit, Griffin, Georgia. The anthracnose evaluations will be conducted at the Texas AgriLife Experiment Station, near College Station, Texas. In the trials, lines will be planted in a randomized complete block design, with each line replicated thrice. Seed will be planted in 6 m rows at 0.31 m spacing between rows. Inoculum preparation, inoculation method, and disease assessments will be as detailed by Prom et al (2009). Briefly, at the 8 leaf stage (approx. 30 d after planting), C. sublineola-colonized sorghum grains (approx. 10 seeds) will be placed into the leaf whorl of each plant. Disease assessment will be conducted 30 days post-inoculation and thereafter on a weekly basis for four consecutive weeks and based on a scale of 1 to 5 (Prom et al., 2009). The symptom types will be categorized into two reaction classes: ratings 1 or 2 as resistant; ratings 3, 4 or 5 as susceptible. The presence of acervuli on the leaves, which indicates successful reproduction of the pathogen, will be used to define anthracnose susceptible response. Data will be subjected to analysis of variance using PROC GLIMMIX (SAS version 9.4, SAS Institute, Cary, NC) to determine anthracnose disease response for the lines. Means comparison will be based on Tukey-Kramer at the 5% probability level.