Ergot Susceptibility in Relation to Cytoplasmic Male Sterility in Pearl Millet

Abstract

The association of cytoplasmic male sterility with susceptibility to ergot (caused by Claviceps fusiformis) in pearl millet was studied in seven cytoplasmic male-sterile (CMS) lines (A lines), their corresponding maintainer lines (B lines), 10 pollinator lines (R lines), and 48 F1 hybrids (A × R and B × R). Four of the seven A lines were significantly more susceptible (90–97% severity) than their corresponding B lines (54–77% severity). All A × R hybrids except four were significantly more susceptible than their corresponding B × R hybrids, indicating the positive association of sterile cytoplasm with ergot susceptibility. The cytoplasmic effect on ergot susceptibility was significant in 20 of the 24 A/ B × R hybrids. The higher ergot susceptibility of A lines and A × R hybrids, compared with B lines and B × R hybrids, could be attributed to the cytoplasmic, nuclear, and cytoplasmic × nuclear factors affecting flowering events that influence ergot susceptibility. Implications of these findings in breeding CMS-based F1 hybrids are discussed