Demand-Driven Technologies for Sustainable Maize ... - IITA

62ConclusionThe results of this study showed that maize cultivation on acidsoils could lead to grain yield reduction of 60% or more in tropicalenvironments. Grain yield loss due to soil acidity could be minimizedby the development of hybrids from crosses between locally adaptedinbred lines and those introduced from CIMMYT Cali, Colombia acidsoil program.Al tolerance is under both additive and non-additive gene action.Therefore, two heterotic pools could be developed and used as sourcepopulations from which second generation inbred lines could beextracted to improve hybrid performance on acid soils. Inbred linesfrom IITA, Ibadan, Nigeria, and IRAD, Cameroon, could be screened forAl tolerance and recombined to form one of the pools. The second poolcould be developed by intermating selected lines from the numerousCIMMYT lines extracted from SA 3, SA 4, SA 6and SA 7populations.ReferencesBorrero, J.C., S. Pandey, H. Caballos, R. Magnavaca and A.F.C. Bahia Filho.1995. Genetic variances for tolerance to soil acidity in a tropical maizepopulation. Maydica 40:283–288.Ceballos, H., S. Pandey, L. Narro, and J.C. Perez-Valazquez. 1998. Additive,dominant and epistatic effects for maize grain yield in acid and non-acidsoils. Theor. Appl. Genet. 96: 662–668.Duque-Vargas, J., S. Pandey, G. Granados, H. Ceballos and E. Knapp. 1994.Inheritance of tolerance to soil acidity in tropical maize. Crop Sci. 34:50–54.Eticha, D., C. Thé, C. Welcker, L. Narro, A. Stab and W. Horst. 2005. Aluminiuminduced callose formation in root apices: inheritance and selection of traitfor adaptation of tropical maize to acid soils. Field Crop Res. (in press).Granados, G., S. Pandey and H. Ceballos. 1993. Response to selection fortolerance to acid soils in a tropical maize population. Crop Sci. 33:936–940.Lima, M., P.R. Furlani and J.B. Miranda Filho. 1992. Divergent selectionfor aluminium tolerance in a maize (Zea mays L.) population. Maydica37:123–132.Miranda Filho, L.T., P.R. Furlani, L.E.C. Miranda Filho and E. Sawazaki. 1984.Genetics of environmental resistance and super-genes: Latent aluminiumtolerance. Maize Genet. Coop. Newslet. 58:45–46Narro, L.A., J.C. Perez, S. Pandey, J. Crossa, F. Salazar, M.P Arias and J.Franco. 2000. Diallel and trialled analysis in acid soil tolerant maize (Zeamays L.) populations. Maydica 45:301–308.Pandey, S., H. Ceballos, R. Magnavaca, A.F.C. Bahia Filho, J. Duque-Vargasand L.E. Vinasco. 1994. Genetics of tolerance to soil acidity in tropicalmaize. Crop Sci. 34:1511–1514.