Striga resistance and compatibility of maize genotypes to a biocontrol agent, Fusarium oxysporum f.sp.strigea

ABSTRACT

Striga presents a major threat to cereal crop production in sub-Saharan Africa. A combined use of host resistance and biological control agents holds promise as a key strategy for sustainable, integrated Striga management in maize (Zea mays L.) production. The objective of this study was to determine resistance against Striga asiatica (L.) Kuntze and compatibility of selected maize genotypes to a biocontrol agent, Fusarium oxysporum f.sp. strigae (FOS), for integrated Striga management. Eighteen maize genotypes were evaluated under glasshouse and field conditions using three treatments: 1) maize genotypes sown without Striga infestation and FOS treatment (control), 2) maize genotypes grown under Striga infestation and; 3) FOS-treated maize genotypes grown under Striga infestation. The results showed that genotype-by-FOS interaction significantly (P < 0.05) affected all traits, except anthesis-to-silking interval, ear aspect score and Striga emergence count at 8 weeks after planting. All maize and Striga traits were significantly affected by FOS treatment (P < 0.001), although the efficacy of FOS seemed to be maize genotype dependent. Mean grain yield was 4.2 t ha⁻¹ for the control, 2.63 t ha⁻¹ for the FOS-treated and 2.17 t ha⁻¹ for the untreated genotypes. Overall, the combined effect of host resistance and inoculation of seed with FOS reduced parasitic infestations and Striga damage symptoms, resulting in improved agronomic performance. Five genotypes (ZM1523, ZM 1423, ZM 1421, NC QPM and Colorado) showed resistance to S. asiatica and compatibility to FOS. The study demonstrated the efficacy of host resistance and biological control in integrated management of S. asiatica in maize.

KEYWORDS:

• Biocontrol
• breeding
• Fusarium oxysporum f.sp. strigae
• maize
• Striga resistance

Acknowledgments

The authors thank the National Research Foundation (NRF) of South Africa and the World Academy of Science (TWAS) for financial support of the study. The International Institute of Tropical Agriculture (IITA) is acknowledged for providing some of the germplasm used in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.