Researchers have identified maize parental lines and hybrids with high levels of drought tolerance among the early and the extra-early maturing maize genotypes developed and conserved by IITA.
This successful identification has led to the availability and the possibility of sustainable development of more resilient maize varieties with dual characteristics of escaping and tolerating drought in the near future.
The discovery of a high level of drought tolerance among early maturing maize parental lines is also seen as ‘good news’ for farmers, especially in drought-prone areas of Africa where maize is a key staple.
Delivering a presentation on the topic, “Genetic Analysis and Molecular Characterization of Early Maturing Maize Inbred Lines for Drought Tolerance,” as part of the IITA Western Africa Hub monthly seminar series, Muhyideen Oyekunle said that 48 percent of the early maturing lines under study from IITA were drought tolerant with tolerance indices ranging from 0.17 (low) to 15.31 (high).
The study, which was supervised by Drs B. Badu-Apraku, IITA Maize Breeder; S. Hearne, CIMMYT Geneticist; and Prof. M.E. Aken’Ova, University of Ibadan, involved screening of over 150 early maturing maize inbred lines and hybrids for drought tolerance over a period of two years across six agroecological zones of Nigeria.
Other activities undertaken by researchers to spot the promising parental lines included assessment of early maturing drought tolerant hybrids under drought stress, molecular characterization of early maturing maize inbred lines, and genetic analysis of early maturing maize inbred lines for drought tolerance genes.
Oyekunle found that under drought conditions, hybrids performed better than open-pollinated varieties and could provide safety nets for farmers during bouts of drought. He also identified five diverse groups among the early maturing maize inbred lines studied and two inbreds as the best in terms of combining ability for future hybrid production.
Dr Badu-Apraku said the study would offer significant contributions to efforts to address drought effects on maize production.
Production of maize, one of the key staples in Africa, is being thwarted by the reccurrence of drought along the maize- growing belt of Africa with farmers reporting losses close to 90 percent in severe instances. Measures being adopted by researchers to prevent the negative consequences of drought include the development of early and extra-early maturing cultivars that complete their life cycles before the onset of drought, and the development of drought tolerant cultivars that possess drought tolerance genes.
Oyekunle explained that general considerations in breeding for drought tolerance in maize include information on genetic diversity among tropical maize lines and populations, hybrid performance, and inheritance of drought tolerance.
In collaboration with national programs, nongovernmental organizations (NGOs)/community-based organizations (CBOs), and seed companies, IITA has made early and extra-early maturing maize varieties and hybrids available to farmers in West Africa. These are being widely adopted to the extent that maize cultivation is largely replacing sorghum and millet in the savanna ecologies. Early and extra-early maize varieties fit into the hunger gap in the savanna zones that normally occurs before the year’s crops mature. They are also used for early planting and late planting when the rains are delayed, and fit very well into intercropping systems because they are less competitive with the component crops. These varieties are used as green maize in the forest zones and in peri-urban areas of West Africa.
For information, please contact: Godwin Atser, g.atser@cgiar.org
Communication Officer (West & Central Africa)