Screening of Sorghum Mutant Lines in Vitro and Greenhouse Against Striga Hermonthica Infestation

The parasitic weed, Striga hermonthica (Del.) Benth is a major constraint to cereal productions such as sorghum. In Burkina Faso, sorghum is the first of the cereals, in terms of cultivated areas and human consumption per capita. This study aimed to identify resistant lines by screening 31 sorghum mutant lines. Experimental assays were carried out in vitro and under greenhouse. The results shown that mutant lines SbEMS0937-1, SbEMS3105-2 were low producers of Striga seeds germination stimulant in vitro. There was a positive and significant correlation (r = 0.72; p < 0.0001) between the germination maximum distance (GMD) and the germination rates (GR) of the different sorghum varieties and mutant lines. In the greenhouse conditions, the mutant SbEMS2311-1 was leading with two resistant controls to having significantly low numbers (5 plants/pot) of Striga 60 DAS (Days After Sowing) and featured the lowest number of Striga 90 DAS (10 plants/pot). The sorghum production variables that are the weights of the stems, panicles, and grains and the plant height at 21 days after sowing (DAS) and at the harvest were all positively related. However, the emergence date and the number of Striga plants which emerged at 90 DAS were negatively correlated (r = -0.21; p = 0.02). Otherwise, the GMD in vitro was positively correlated with the number of the Striga plants emerged at 60 DAS and 90 DAS in greenhouse. These results revealed that the mutagenesis of the sorghum lead to resistance or tolerance to S. hermonthica. Therefore, the growing of each of the three resistant mutants should contribute to reducing highly the density of this pest plant in the sorghum field. Furthermore, the transfer of gene (s) inducing this Striga-resistance/tolerance from mutant lines could improve Sorghum varieties preferred by local farmers.