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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #281090

Title: Comparison of methods for late leaf spot phenotyping in peanut

item GILL, R - University Of Georgia
item CULBREATH, A - University Of Georgia
item Holbrook, Carl - Corley
item OZIAS-AKINS, P - University Of Georgia

Submitted to: American Peanut Research and Education Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2012
Publication Date: 2/1/2013
Citation: Gill, R., Culbreath, A.K., Holbrook Jr, C.C., Ozias-Akins, P. 2013. Comparison of methods for late leaf spot phenotyping in peanut. Proceedings American Peanut Research and Education Society. 44:37-38.

Interpretive Summary: not required

Technical Abstract: A field study was conducted in 2011 to characterize late leaf spot resistance in a recombinant inbred line (RIL) population developed from a cross between Gregory, a virginia type cultivar and Tifguard, a runner type cultivar. Gregory has been previously characterized as susceptible and Tifguard is reported as moderately resistant to the disease. This biparental population consisted of 78 F7:8 lines and was grown with the parents in three replications in a non-sprayed field trial. The leaf spot intensity was assessed four times during the season using the traditional Florida 1-to-10 severity scale and twice using the novel combination of lateral stem assay (LSA) and image analysis. Three lateral stems were randomly collected from each plot across the three replications in the field and the leaves were then subjected to imaging by a flatbed scanner. The image analysis and manual phenotyping on these lateral stem samples yielded data on percent defoliation, percent area covered by disease, number of lesions per unit area etc. Correlation between the Florida scale rating and the lateral stem assay data is being evaluated. If adequate correlation is found between these, LSA could serve as an objective method for detailed disease phenotyping.