References
[1] Ji, Q., Xu, X., Wang, K. (2013). Genetic transformation of major cereal crops. Int. J. Dev. Biol., 57: 495-508.
[2] CIMMYT and IITA. (2010). Maize-Global alliance for improving food security and the livelihoods of the resource-poor in the developing world. Draft proposal submitted by CIMMYT and IITA to the CGIAR Consortium Board. El Batan, Mexico, p. 91.
[3] Central Statistical Agency (CSA). (2020). Agricultural Sample Survey 2019/2020: Report on Area and Production of Major Crops (Private Peasant Holdings, Meher Season) Statistical Bulletin, Volume 1, CSA, Ethiopia.
[4] FAOSTAT. (2020). Statistical Database of the Food and Agriculture of the United Nations. Retrieved from http://www.fao.org/faostat/en/.
[5] Abate, T., Shiferaw, B., Menkir, A., Wegary, D., Kebede, Y., Tesfaye, K., Kassie, M., Bogale, G., Tadesse, B., Keno, T. (2015). Factors that transformed maize productivity in Ethiopia. Food Sec., 7(5): 965-981.
[6] Amegbor, I. K., Badu-Apraku, B., Gloria B. Adu, G. B., Adjebeng-Danquah, J., and Toyinbo, J. (2020). Combining Ability of Extra-Early Maize Inbreds Derived from a Cross between Maize and Zeadiploperennis and Hybrid Performance under Contrasting Environments. Agronomy, 10(8): 1-18.
[7] Badu-Apraku, B., Obisesan, O., Olumide, O.B., and Toyinbo, J. (2021). Gene Action, Heterotic Patterns, and Inter-Trait Relationships of Early Maturing Pro-Vitamin A Maize Inbred Lines and Performance of Testcrosses under Contrasting Environments. Agronomy, 11(7): 1-24.
[8] Sprague, G. F. and Tatum, L.A. (1942). General vs specific combining ability in single crosses of corn. Journal of the American Society of Agronomy, 34: 923-932.
[9] Stuber, C. W. (1994). Heterosis in plant breeding. Plant Breed Rev., 12: 227-251.
[10] Hayman, B. I. (1954). The theory and analysis of diallel crosses. Genetics, 39: 789-809.
[11] Griffing, B. (1956). Concept of general and specific combining ability in relation to diallel crossing systems. Aust. J. Biol. Sci., 9: 463-493.
[12] Comstock, R. E. and Robinson, H. F. (1948). The components of genetic variance in populations of bi-parental progenies and their use in estimating the average degree of dominance. Biometrics, 4: 254-266.
[13] Kempthorne, O. (1957). An introduction to genetic statistics. John Wiley, New York.
[14] Barata, C. and Carena, M. (2006). Classification of North Dakota maize inbred lines into heterotic groups based on molecular and testcross data. Euphytica, 151: 339-349.
[15] Fan, X. M., Zhang, Y. D., Yao, W. H., Bi, Y. Q., Liu, L., Chen, H. M., and Kang, M. S. (2014). Reciprocal diallel crosses impact combining ability, variance estimation, and heterotic group classification. Crop Sci., 54: 89-97.
[16] Fan, X. M., Bi, Y., Zhang, Y., Jeffers, D., Yin, X., and Kang, M. (2018). Improving breeding efficiency of a hybrid maize breeding program using a three heterotic-group classification. Agronomy Journal, 110: 1-8.
[17] Badu-Apraku, B., Oyekunle, M., Fakorede, M. A. B., Vroh, I., Akinwale, R. O., and Aderounmu, M. (2013). Combining Ability, heterotic patterns and genetic diversity of extra-early maturing yellow inbreds under contrasting environments. Euphytica, 192: 413-433.
[18] Fan, X. M., Zhang, Y. M., Yao, W. H., Chen, H. M., Tan, J., Xu, C. X., Han, X. L., Luo, L. M., and Kang, M. S. (2009). Classifying maize inbred lines into heterotic groups using a factorial mating design. Agron J., 101: 106-112.
[19] Akinwale, R. O., Badu-Apraku, B., Fakorede, M. A. B., and Vroh-Bi, I. (2014). Heterotic grouping of tropical early-maturing maize inbred lines based on combining ability in Striga-infested and Striga-free environments and the use of SSR markers for genotyping. Field Crops Res., 156: 48-62.
[20] Badu-Apraku, B., Fakorede, M.A.B., Gedil, M., Talabi, A.O., Annor, B., Oyekunle, M., Akinwale, R.O., Fasanmade, Y., Akaogu, I.C., and Aderounmu, M. (2015). Heterotic responses among crosses of IITA and CIMMYT early white maize inbred lines under multiple stress environments. Euphytica, 206: 245-262.
[21] Cochran, W. G. and Cox, G. M. (1960). Experimental designs. John Wiley & Sons Inc., New York, USA.
[22] R Core Team. (2019). R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria.
[23] RStudio Team. (2020). RStudio: Integrated Development Environment for R. RStudio, PBC, Boston, MA, USA.
[24] Singh, R. H. and Chaudhary, B. D. (1985). Biometrical methods in quantitative genetic analysis. New Delhi-Ludhiana, India: Kalyani Publishers.
[25] SAS Institute Inc. (2011). Base SAS® 9. 3 Procedures Guide.SAS Institute Inc, Cary, NC.
[26] Baker, R. J. (1978). Issues in diallel analysis. Crop Science, 18: 535-536.
[27] Badu-Apraku, B., Fakorede, M. A. B., Talabi, A. O., Oyekunle, M., Akaogu, I. C., Akinwale, R. O., Annor, B., Melaku, G., Fasanmade, Y., and Aderounmu, M. (2016). Gene action and heterotic groups of early white quality protein maize inbreds under multiple stress environments. Crop Science, 56: 183-199.
[28] Badu-Apraku, B., Annor, B., Oyekunle, M., Akinwale, R. O., Fakorede, M. A. B., Talabi, A. O., Akaogu, I. C., Melaku, G., Fasanmade, Y. (2015). Grouping of early maturing quality protein maize inbreds based on SNP markers and combining ability under multiple environments. Field Crops Res., 183: 169-183.
[29] Nasser, L. M., Badu-Apraku, B., Gracen, V. E., and Mafouasson, H. N. A. (2020). Combining Ability of Early-Maturing Yellow Maize Inbreds under Combined Drought and Heat Stress and Well-Watered Environments. Agronomy, 10(10): 1-26.
[30] Abu, P., Badu-Apraku, B., Ifie, B.E., Tongoona, P., Ribeiro, P. F., Obeng-Bio, E., Offei, S. K. (2021). Genetics of extra-early-maturing yellow and orange quality protein maize inbreds and derived hybrids under low soil nitrogen and Striga infestation. Crop Science, 61: 1052-1072.
[31] Menkir, A., Melake-Berhan, A., The, C., Ingelbrecht, I., and Adeboju, A. (2004). Grouping of tropical and mid-altitude maize inbred lines on the basis of yield data and molecular markers. TheorAppl Genetics., 108: 1582-1590.
[32] Annor, B., Badu-Apraku, B., Nyadanu, D., Akromah, R., and Fakorede, M. A. B. (2020). Identifying heterotic groups and testers for hybrid development in early maturing yellow maize (Zea mays) for sub-Saharan Africa. Plant Breed., 139(4): 708-716.
[33] Annor, B. and Badu-Apraku, B. (2016). Gene action controlling grain yield and other agronomic traits of extra-early quality protein maize under stress and non-stress conditions. Euphytica, 212: 213-228.
[34] Legesse, B. W., Pixley, K. V., and Botha, A. M. (2009). Combining ability and heterotic grouping of highland transition maize inbred lines. Maydica, 54: 1-9.
[35] Badu-Apraku, B., Fakorede, M. A. B., Gedil, M., Annor, B., Talabi, A. O., Akaogu, I. C., Oyekunle, M., Akinwale, R. O., and Fasanmade, T. Y. (2016). Heterotic patterns of IITA and CIMMYT early-maturing yellow maize inbreds under contrasting environments. Agronomy Journal, 108: 1321-1336.
[36] Mageto, E. K., Makumbi, D., Njoroge, K., and Nyankanga, R. (2017). Genetic analysis of early-maturing maize (Zea Mays L.) inbred lines under stress and non-stress conditions. Journal of Crop Improvement, 31(4): 560-588.
[37] Vasal, S. K., Srinivasan, G., Pandey, S., Córdova, H. S., Han, G. C., and Gonzalez Ceniceros, F. (1992). Heterotic patterns of ninety-two white tropical CIMMYT lines. Maydica, 37: 259-270.
[38] Meseka, S., Menkir, A., Bossey, B., Mengesha, W. (2018). Performance Assessment of Drought Tolerant Maize Hybrids under Combined Drought and Heat Stress. Agronomy, 8(14): 1-17.
[39] Bhatnagar, S., Betrán, F. J., and Rooney, W. L. (2004). Combining ability of quality protein maize inbreds. Crop Sci., 44: 1997-2005.
[40] Machida, L., Derera, J., Tongoona, P., and MacRobert, J. (2010). Combining ability and reciprocal cross effects of elite quality protein maize inbred lines in subtropical environments. Crop Sci., 50: 1708-1717.
[41] Melchinger, A., Geiger, H., Seitz, G., and Schmidt, G. (1987). Optimum prediction of three-way crosses from single crosses in forage maize (Zea mays L.). Theoretical and Applied Genetics, 74: 339-345.
[42] Hallauer, A. R. and Miranda, J. B. F. (1988). Quantitative genetics in maize breeding, 2nd ed. Iowa State University Press, Ames.
[43] Simmonds, N. W. (1979). Principles of Crop Improvement. Longman, London.
[44] Gethi, J. G. and Smith, M. E. (2004). Genetic responses of single crosses of maize to Strigahermonthica (Del.) Benth. and Strigaasiatica (L.) kuntze. Crop Sci., 44: 2068-2077.
[45] Fan, X. M., Chen, H. M., Tan, J., Xu, C. X., Zhang, Y. D., Luo, L. M, Huang, Y. X., and Kang, M. S. (2008). Combining abilities for yield and yield components in maize. Maydica, 53: 39-46.
[46] Menkir, A., and Ayodele, M. (2005). Genetic analysis of resistance of grey leaf spot of mid-altitude maize inbred lines. Crop Sci., 45: 163-170.
[47] Adebayo, A. M., Menkir, A., Blay, E., Gracen, V., and Danquah, E. (2017). Combining ability and heterosis of elite drought-tolerant maize inbred lines evaluated in diverse environments of lowland tropics. Euphytica, 213(2): 1-12.
[48] Keno, T., Worku, M., and Zeleke, H. (2017). Combining ability and heterotic orientation of mid-altitude sub-humid tropical maize inbred lines for grain yield and related traits. African Journal of Plant Science, 11(6): 129-239.
[49] Wegary, D., Vivek, B. S., and Labuschagne, M. T. (2014). Combining ability of certain agronomic traits in quality protein maize under stress and non-stress environments in Eastern and Southern Africa. Crop Sci., 54: 1004-1014.
[50] Amegbor, I. K., Badu-Apraku, B., and Annor, B. (2017). Combining ability and heterotic patterns of extra-early maturing white maize inbreds with genes from Zeadiploperennis under multiple environments. Euphytica, 213: 1-16.
[51] Agbaje, S. A., Badu-Apraku, B., and Fakorede, M. A. B. (2008). Heterotic patterns of early maturing maize inbred lines in Striga-free and Striga-infested environments. Maydica, 53: 87-96.
[52] Nepir, G., Wegary, D., and Zeleke, H. (2015). Heterosis and combining ability of highland quality protein maize inbred lines. Maydica, 60: 1-12.