Allelopathic activity of Sorghum bicolor root parts and exudates on Bipolaris sorokiniana

Abstract

Sorghum Sorghum bicolor L. releasing allelochemicals in the soil through their root exudation that functional their associated soil microorganisms and can help in building disease control strategy for increasing sustainability. The obtained results of sorghum rhizospheric exudates exhibited markedly effect on bacterial count in rhizosphere soil. The extract of root exudates profile was tested by two prepared concentrations; 500 ppm and 1000 ppm against the Bipolaris sorokiniana compared to untreated control. The reduction percentages were calculated after four and seven days of fungus growth, the results represented that the reduction over control were 17.53, 45.63% after four days, however after seven days the reductions over control were 17.28, 36.40%. For sorghum root parts, the reduction increase with increasing concentration ranged from 49.71 to 71.67%, the highest reduction was afforded by conc. 1600 ppm while the lowest reduction by 200 ppm. The analysis to identify sorghum allelochemicals was conducted by LC-MS/MS and FTIR afforded; proline, coumaric acid, cinnamic acid, hydroxycoumarin, benzoxazolone, ferulic acid and sorgoleone. While, sorghum root parts extract compounds were; coumaric acid, cinnamic acid, vanillic acid, luteolin3-Hydroxycoumarin, gallic acid, ferulic acid and sorgoleone. It could be used sorghum root exudates and root parts extract in disease bio-control due the effect of secreted biochemical molecules as step toward sustainable agriculture.

Keywords

• sorghum
• allelochemicals
• root exudates
• rhizosphere
• lc-ms/ms
• ftir