Reaction of New Quality Protein Maize Genotypes to Striga asiatica

Abstract

Striga asiatica (L.) Kuntze, an obligate hemiparasite, can cause grain yield loss of 20 to 80% in cereal crops such as maize (Zea mays L.). In Sub‐Saharan Africa, maize breeding programs have focused on productivity of normal endosperm maize under Striga infestation while neglecting quality protein maize (QPM). This study aimed at determining levels of resistance or tolerance of eight new QPM genotypes and four non‐QPM checks to Striga asiatica in the field, pot, and agar gel experiments. Under field conditions, genotypes were evaluated in three different Striga‐endemic locations during the 2014–2015 and 2015–2016 cropping seasons using a four‐by‐three α‐lattice design with three replications. In the pot experiment, genotypes were arranged in 12 × 2 factorial treatments in a six‐by‐four α‐lattice design replicated four times. In the agar gel experiment, genotypes were arranged in a randomized complete block design replicated four times. In the field experiment, genotype × environment interaction was significant (p < 0.001) for grain yield, and MQ623, SC643, SC527, and SC535 were high yielding and more stable than non‐QPM genotypes. In the pot experiment, these genotypes also exhibited desirable Striga tolerance, whereas variation was significant (p < 0.05) for Striga treatments and genotype main effects, as well as for Striga × genotype interaction for root biomass and root/shoot biomass ratio. Five QPM genotypes (MH1416, MQ623, SC643, SC527, and SC535) produced higher and more stable grain yields than most of the non‐QPM checks in Striga‐infested fields. These genotypes provided alternative QPM sources that can perform relatively well in Striga‐endemic areas.