Resistance Evaluation of Pearl Millet- Male-Sterility Maintainer Populations against Downy Mildew Disease in Burkina Faso

Abstract

Pearl millet (Pennisetum glaucum [L.] R. Br.) is an important cereal crop in semi-arid regions, but its production is constrained by downy mildew caused by Sclerospora graminicola. The development of resistant male-sterility maintainer lines is important for improving the resistance of pearl millet hybrids. This study aimed to develop and screen pearl millet male-sterility maintainer populations for resistance to the Kamboinse downy mildew pathotype in Burkina Faso. Crosses were made between ICMB 177004, the maintainer parent of the hybrid ICMH 147007, and three maintainer lines used as sources of resistance, namely ICMB 177002, ICMB 93333 and SIVAREX-S3-45. Through self-pollination and backcrossing, thirty-four maintainer lines were developed and evaluated under greenhouse conditions. Analysis of variance showed highly significant differences among genotypes. Disease incidence ranged from 0.0% to 36.9%, with an overall mean of 5.26%. Among the thirty-four maintainer lines, twenty-one were classified as highly resistant, seven as resistant, four as moderately resistant and one as moderately susceptible. Six backcross-derived maintainers, BC3-B3, BC3-B4, BC3-B5, BC3-B6, BC3-B11 and BC3-B14, showed no disease symptoms under the screening conditions. These results indicate that several newly developed maintainer lines possess useful levels of resistance to the Kamboinse downy mildew pathotype and may serve as valuable parental materials for pearl millet hybrid development.