History, Contribution, and Future of Quantitative Genetics in Plant Breeding: Lessons From Maize

Abstract

ABSTRACTThe time frame of the history of quantitative genetics is similar to Mendelian genetics. The rediscovery of Mendel's laws of inheritance in 1900 was the basis for determining the inheritance of quantitative traits and for developing plant breeding and selection methods. Because of the differences expressed by many of the leading geneticists relative to importance of continuous vs. discontinuous variation in evolution, the acceptance of the concepts for the study of quantitative genetics was delayed. R.A. Fisher, S. Wright, and J.B.S. Haldane were the primary early contributors for developing the theory and methods for studying the inheritance of quantitative traits. Greater interest in the inheritance of quantitative traits in plants occurred after 1946, primarily because of the heterosis expressed in maize (Zea mays L.) hybrids. During the past 50 yr, extensive research has been conducted to determine the relative importance of different genetic effects in the inheritance of quantitative traits for most cultivated plant species. Quantitative genetic research has contributed extensive information to assist plant breeders in developing breeding and selection strategies. Directly and/or indirectly, the principles for the inheritance of quantitative traits are pervasive in developing superior cultivars to meet the food, feed, fuel, and fiber needs the world demands. The principles of quantitative genetics will have continued importance in the future, but at different levels. Information from molecular genetics research will be integrated with our current knowledge at the phenotypic level to increase the effectiveness and efficiency of plant breeding.