IITA scientists develop multiple stress tolerant maize hybrids with high levels of Pro-Vitamin A
Vitamin A deficiency is a major health problem in sub-Saharan Africa (SSA). Striga hermonthica (Giant Witchweed) and drought are two major constraints to maize production in the sub-region. Development and deployment of multiple stress tolerant maize hybrids with high levels of Pro-Vitamin A (PVA) offers a solution to food insecurity and malnutrition in SSA. The HarvestPlus Challenge Program has established 15 µg/g as the breeding target for PVA maize hybrids and open-pollinated varieties, however, only a few released PVA maize hybrids have attained this level of PVA.
A team of IITA maize scientists and molecular geneticists coordinated by the IITA early and extra-early Maize Program Lead, Baffour Badu-Apraku have developed extra-early PVA maize inbred lines and hybrids with very high levels of PVA. The chemical analysis carried out in the Food and Nutrition Science Laboratory in IITA-Ibadan has revealed the following results for the extra-early PVA maize inbred lines: TZEEIOR 202 (23.98 µg/g) and TZEEIOR 205 (22.58 µg/g).
Furthermore, crosses involving the high PVA maize inbred lines resulted in the development of PVA hybrids TZEEIOR 197 x TZEEIOR 205 (20.1 µg/g) and TZEEIOR 202 x TZEEIOR 205 (22.7 µg/g), containing about double the amount of PVA of the commercial PVA hybrid check, TZEE-Y Pop STR C5 x TZEEI 58 (11.4 µg/g).
Results of multilocation trials under drought, artificial Striga infestation, and optimal environments in Nigeria during the period 2015–2017 have shown outstanding agronomic performance of the PVA maize hybrids. The hybrid TZEEIOR 197 x TZEEIOR 205 with PVA level of 20.1 µg/g yielded 2723 and 4263 kg/ha across stress (Striga and drought) and non-stress environments, respectively. In contrast, TZEEIOR 202 x TZEEIOR 205 with PVA level of 22.7 µg/g yielded 1637 kg/ha across stress and 4051 kg/ha across non-stress environments.
The new PVA hybrids out-yielded the commercial PVA top-cross hybrid check; TZEE-Y Pop STR C5 x TZEEI 58 had a yield of 1205 across stress environments and 2611 kg/ha across non-stress environments. These interesting results open a great opportunity for breeding and releasing PVA maize hybrids with 50 percent higher levels of PVA than the target of 15 µg/g set by the HarvestPlus Challenge Program. Commercialization of these hybrids should contribute to food security and improved nutrition in West and Central Africa.
The collaborators on this research are Principal Scientist/Maize Breeder and Geneticist, Badu-Apraku; Research Administrative Manager, Abidemi O. Talabi; and Molecular Geneticists including Ana Luísa Garcia-Oliveira and Melaku Gedil.