Submitted to: International Pearl Millet Improvement and Seed Production Workshop Proceedings
Publication Type: Book / Chapter
Publication Acceptance Date: 11/19/2006
Publication Date: N/A
Interpretive Summary: not required
Technical Abstract: The primary diseases and pests in the southeastern U.S. generally differ from those found throughout much of Asia and Africa. Targets for resistance breeding include rust (Puccinia substriata var. penicillariae), pyricularia leaf spot (Pyricularia grisea), stalk rot, grain mold, root-knot nematodes (Meloidogyne incognita and M. arenaria), and chinch bug (Blissus leucopterus leucopterus). Downy mildew (Sclerospora graminicola) and ergot (Claviceps fusiformis) are not yet found on pearl millet in the western hemisphere, although there is some controversy over this claim. For most of the target pests, controlled evaluations of potential sources of resistance are performed to positively identify resistance in donor parents. Confirmed resistance donors are used as parents in crosses with agronomically elite lines. Subsequent selection nurseries are designed to promote disease and pest establishment and increase for evaluation of segregating progeny in diverse environments over years. Finally, advanced selections are evaluated in controlled tests to confirm that resistance has been transferred to the resulting selected progeny. The techniques used to identify resistance can vary greatly depending upon the specific disease or pest in question. Resistance is required to develop genotypes that are compatible with mechanized agriculture and suitable for use in regional cropping systems. To be most effective, resistance breeding must be well-integrated into the overall variety improvement program and the objectives should help to determine the configuration and time of planting of screening nurseries. Sufficient program resources should be allocated to address the most important constraints, but opportunities exist to select for resistance to other secondary constraints with little additional cost.