|Ramanjulu, Valluru - PENNSYLVANIA STATE UNIV.|
|Christ, Barbara - PENNSYLVANIA STATE UNIV.|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 2000
Publication Date: N/A
Technical Abstract: There has been an increased amount of potato tuber blight associated with the emergence of new, aggressive strains of Phytophthora infestans. A diploid hybrid Solanum phureja x S. stenotomum F1 population segregating for foliar blight was evaluated for tuber blight under laboratory conditions. Two parental and 179 F1 clones and one cultivar were inoculated with a US-8 genotype of P. infestans by placing 25 microliters of 6 x 10-4 sporangia/ml in an incision and incubating in the dark at 12 C, RH >90% for 14 days. The experimental design was a randomized complete block with 2 replications repeated twice. Lesions were measured daily from 5-14 days after inoculation. Percentage of lesion area (severity) was assessed visually and penetration was measured on day 14. There were significant differences among the F1 clones for lesion diameter, rate of lesion expansion, penetration and severity. There were positive correlations among lesion diameter, rate of lesion expansion and severity. The distributions of each variable were skewed towards resistance. There are clones that have tuber resistance and high levels of foliar resistance. A genetic linkage map will be developed with molecular markers to determine the quantitative loci associated with resistance.