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Development of a pearl millet Striga-resistant genepool: Response to five cycles of recurrent selection under Striga-infested field conditions in West Africa

2013; Elsevier BV; Volume: 154; Linguagem: Inglês

10.1016/j.fcr.2013.07.008

1872-6852

Boubacar A. Kountche, C. Tom Hash, Harouna Dodo, Oumarou Laoualy, Moussa Sanogo, Amadou Timbeli, Yves Vigouroux, Dominique This, Randy Trinity Nijkamp, Bettina I. G. Haussmann,

Genetic and Environmental Crop Studies

Striga hermonthica (Del.) Benth. is a persistent threat to pearl millet [Cenchrus americanus (L.) Morrone, comb. nov.] production, especially in West Africa. This study aimed at evaluating the response of a diversified pearl millet genepool to five cycles of recurrent selection targeting Striga resistance and panicle yield, and to a lesser extent downy mildew [Sclerospora graminicola (Sacc.) J. Schroet.] resistance. Two-hundred full-sib families (FS) representing the C5 selection cycle were evaluated together with the genepool parental landraces, experimental varieties derived from previous cycles and local checks in Striga-infested fields at Sadoré (Niger) and Cinzana (Mali). Substantial and mostly significant selection progress could be documented. The accumulated percentage gain from selection amounted to 51%/1% lower Striga infestation (measured by area under Striga number progress curve, ASNPC), 46%/62% lower downy mildew incidence, and 49%/31% higher panicle yield of the C5-FS compared to the mean of the genepool parents at Sadoré/Cinzana, respectively. Experimental varieties selected from previous cycles also revealed lower ASNPC and mostly higher yield compared to genepool parents at their selection sites. Significant genetic variation among the C5-FS and operative heritabilities of 76% (Cinzana), 84% (Sadoré) and 34% (combined across locations) for ASNPC will enable continued selection gain for Striga resistance. High genotype × environment interaction variances for all target traits suggest that different experimental varieties need to be extracted from the genepool for different sites. The genepool-derived varieties will be further validated on-farm and are expected to contribute to integrated Striga control in pearl millet in West Africa.