Infusion, development and improvement of highland maize germplasm in Eastern Africa
Twumasi-Afriyie, S.
Infusion, development and improvement of highland maize germplasm in Eastern Africa - Nairobi (Kenya) : CIMMYT : KARI, 2004. - Printed
Maize is a major crop in eastern Africa in terms of production, consumption and income generation for both resource- constrained men and women. Maize research, therefore, ranks first in ASARECA 's regional research priorities. A significant proportion of maize in the region is produced in the highland zone, which represents a very favorable maize growing environment. However, maize production is affected by major biotic constraints (leaf blight E. turcicum, common rust Puccinia sorghi, Fusarium ear rot, stalk borers and stalk lodging) and abiotic stresses (frost, hail and waterlogging on vertisols). In spite of these constraints, highland maize breeding had received little attention since the introduction of Ecuador 573 into Kenya in 1959. It was in the recognition of these factors that the Highland Maize Gene Pools Project was initiated in October 1997 with the objectives to introduce, develop and improve the highland maize. Six countries in the region (Ethiopia, Kenya, Tanzania, Uganda, Rwanda and Burundi) directly participated in the project. About 1,200 items of local germplasm were collected in the six countries in 1998 and were evaluated in the respective countries. More than 4,000 lines of CIMMYT mid-altitude and highland transitional zone maize were evaluated at a regional highland nursery at Ambo, Ethiopia with emphasis on screening for the major biotic and abiotic stresses and general adaptation. Selected inbred lines were top crossed to three regional testers [Kitale Synthetic II, Ecuador 573 and Kuleni (Pool 9A)] and evaluated in the region. Line x tester analysis was carried out to determine the combining ability and the heterotic groups of selected lines. The CIMMYT transitional highland maize germplasm entries were much earlier in maturity than the earliest locally available materials in the region. The transitional zone materials derived from Pool 9A had good adaptation to the regional highland zone. Pool 9A lines topcrossed to the three local testers produced significantly higher grain yield than the testers indicating good levels of heterosis. Line x tester analysis showed that the three testers were effective in separating the lines into heterotic groups based on their SCA effects. The data were used to group the CIMMYT transitional and mid-altitude lines into three distinct heterotic groups based on the Ecuador-Kitale pattern and on Kuleni. Germplasm products generated from the project and made available to collaborators included inbred lines classified into heterotic groups, hybrids and local landraces.
Text in English
970-648-120-6
Maize
Highlands
Combining ability
Hybrids
CIMMYT KARI
Infusion, development and improvement of highland maize germplasm in Eastern Africa - Nairobi (Kenya) : CIMMYT : KARI, 2004. - Printed
Maize is a major crop in eastern Africa in terms of production, consumption and income generation for both resource- constrained men and women. Maize research, therefore, ranks first in ASARECA 's regional research priorities. A significant proportion of maize in the region is produced in the highland zone, which represents a very favorable maize growing environment. However, maize production is affected by major biotic constraints (leaf blight E. turcicum, common rust Puccinia sorghi, Fusarium ear rot, stalk borers and stalk lodging) and abiotic stresses (frost, hail and waterlogging on vertisols). In spite of these constraints, highland maize breeding had received little attention since the introduction of Ecuador 573 into Kenya in 1959. It was in the recognition of these factors that the Highland Maize Gene Pools Project was initiated in October 1997 with the objectives to introduce, develop and improve the highland maize. Six countries in the region (Ethiopia, Kenya, Tanzania, Uganda, Rwanda and Burundi) directly participated in the project. About 1,200 items of local germplasm were collected in the six countries in 1998 and were evaluated in the respective countries. More than 4,000 lines of CIMMYT mid-altitude and highland transitional zone maize were evaluated at a regional highland nursery at Ambo, Ethiopia with emphasis on screening for the major biotic and abiotic stresses and general adaptation. Selected inbred lines were top crossed to three regional testers [Kitale Synthetic II, Ecuador 573 and Kuleni (Pool 9A)] and evaluated in the region. Line x tester analysis was carried out to determine the combining ability and the heterotic groups of selected lines. The CIMMYT transitional highland maize germplasm entries were much earlier in maturity than the earliest locally available materials in the region. The transitional zone materials derived from Pool 9A had good adaptation to the regional highland zone. Pool 9A lines topcrossed to the three local testers produced significantly higher grain yield than the testers indicating good levels of heterosis. Line x tester analysis showed that the three testers were effective in separating the lines into heterotic groups based on their SCA effects. The data were used to group the CIMMYT transitional and mid-altitude lines into three distinct heterotic groups based on the Ecuador-Kitale pattern and on Kuleni. Germplasm products generated from the project and made available to collaborators included inbred lines classified into heterotic groups, hybrids and local landraces.
Text in English
970-648-120-6
Maize
Highlands
Combining ability
Hybrids
CIMMYT KARI