Elicitation of resistance in pearl millet by oligosaccharides of Trichoderma spp. against downy mildew disease

In this study, we made an attempt to develop an ecofriendly management strategy against pearl millet (PM) downy mildew (DM) disease through seed priming with cell wall oligosaccharide of Trichoderma spp. Oligosaccharide treatment with mannitol significantly enhanced the seedling vigor when compared with the other controls. Significant reduction in DM disease was recorded in seeds treated with oligosaccharides extracted from Trichoderma virens and its efficacy was further increased when treated along with mannitol. At the biochemical level, increased activity of defense-related enzymes such as peroxidase and lipoxygenase was recorded followed by accumulation of signaling molecule Jasmonic acid in seedlings raised from seed treated with oligosaccharide (with or without mannitol) from T. virens. Under field conditions, oligosaccharide with mannitol provided a significant protection against the DM disease over other treatments. The possible utilization of oligosaccharide in inducing the systemic resistance against DM disease in PM is discussed.