Assessment of Pearl Millet Genotypes for Downy Mildew Resistance and Agronomic Performance under Field Conditions in Senegal

Abstract

fields in Asia and Africa. In order to identify new sources of resistance to this disease, a set of 20 genotypes was assessed during the rainy season 2015 at Bambey, Nioro, Kolda and Sinthiou Maleme research stations in Senegal. Comparative survey between locations showed that the highest downy mildew incidence (100%) was recorded in Kolda. The 7042S, an international susceptible check, showed downy mildew incidence of 91.12%, IP22441 line was susceptible at Kolda (incidence = 30.5%), resistant at Sinthiou Maleme (incidence = 6.5%), moderately resistant at Bambey (incidence = 18%) and highly susceptible at Nioro (incidence = 70%). IP22295 line was susceptible at Kolda (incidence = 24.5%) but resistant at Bambey (incidence = 0%), Nioro (incidence = 3.5%) and Sinthiou Maleme (incidence = 0%). A hierarchical cluster analysis of these tested genotypes integrating agronomic parameters and response to downy mildew has identified four genotype groups characterized by downy mildew resistance, vegetative growth, panicle yield and flowering time. This study has shown the variability of S. graminicola populations from different tested locations. Genotypes IP22315, IP2295, SOSAT-C88-Sadore and SOSAT-C88-Pantacheru presented stable resistance to downy mildew across the tested locations. These genotypes can be used as parents for breeding pearl millet varieties resistant to the downy mildew disease under Senegal environments.