Submitted to: American Phytopathology Society
Publication Type: Abstract Only
Publication Acceptance Date: 3/16/2000
Publication Date: 6/1/2000
Citation: Wilson, J.P., Gates, R.N., Panwar, M.S. 2000. Theory and observations of the dynamic multiline population strategy for resistance gene management. Phytopathology 90:S84.
Technical Abstract: The dynamic multiline population breeding strategy integrates attributes of the gene-stacking and multiline strategies. Isogenic lines of pearl millet Tift 23DB developed with rust resistance from 3 wild pearl millets, 18 landraces, and 2 elite inbreds were combined to form a base population. Four cycles of open pollination were made and cytoplasmic male-sterile (CMS) counterparts were advanced with the B population. Hybrids with Tift 383 were produced on CMS cycles C1-C4. Frequency of seedlings with resistance to single-uredinium isolates of Puccinia substriata var. indica averaged 18 to 38% in C1 and C4 hybrids, respectively. The hybrid populations and Tifleaf (TL)1 and TL 2 were evaluated in 3 yield trials in 1998-99. Disease-free forage dry matter yields did not differ. Across trials, AUDPCs of TL 1 and TL 2 averaged 1307, C1 and C 2 averaged 914, and C3 and C 4 averaged 604. Final severities of TL1 and TL2 averaged 67%, C1 and C2 averaged 47%, and C3 and C4 averaged 30%. When analyzed by regression analysis, AUDPC was reduced 12.2%, final rust severity was reduced 13.4%, and dry matter yield was increased 3% per cycle.