Variability in Striga Resistance among a Collection of Diverse Rice Cultivars

Striga constitutes a major limitation to cereal crop production, and identifying cultivars that avoid or reduce the germination of the parasites' seeds is crucial. This study evaluated a diverse collection of 31 rice cultivars for Striga resistance and the role of cytochrome P450 genes in resistance or susceptibility. The phenotype of the resistant was characterized by the ability of the variety to support no or few emerging Striga. The presence or absence of the cytochrome P450 gene was determined by Multiplex PCR analysis. Upon examination, it became clear that five cultivars showed good resistance to Striga, while twenty exhibited intermediate resistance and six were very susceptible. In contrast, the resistant genotypes had few or no emerged Striga. Striga emerged early and rapidly in susceptible genotypes, supporting a higher number of emerged and attached Striga and Striga dry weight per plant. Multiplexed PCR analysis showed that 87.1% of the cultivars possessed the 93-11/Bala alleles, and 12.9% had the Nipponbare/Azucena alleles for strigolactone biosynthesis. Evaluating the variability of the 3 000 rice genomic data in these genes revealed similar results. The outcome of this research identified genotypes that are resistant, tolerant, and susceptible. This finding may be useful in breeding program for Striga resistance. The next steps for this research could involve testing the resistant genotypes in the field or using them as a starting point for a genetic experiment.