ABSTRACT
Gregor Mendel found that the plant’s respective offspring retained the essential traits of the parents, and therefore were not influenced by the environment. This simple test gave birth to the idea of heredity. He established the basic laws of heredity: Hereditary factors do not combine, but are passed intact; each member of the parental generation transmits only half of its hereditary factors to each offspring; and different offspring of the same parents receive different sets of hereditary factors. This understanding of a gene proved to be useful for plant breeding throughout many decades and contributed to significant breeding progress in major crop species. Later, new insights from molecular genetics brought considerable changes to the concept of the gene and subsequently to plant breeding.
By the late nineteenth century, farmers still rely on advanced local landraces. However, commercial breeders, who established a dominating presence, for example, in Germany, wanted a single variety of each crop for the whole country—universal varieties. Breeders brought their new understanding of genetics to the traditional techniques of self-pollinating and cross-pollinating plants. Yields could be significantly increased by utilization of modern crossing and selection methods after 1900. The development of specific crossing techniques as well as methods of selection determined the breeding progress during the first half of the twentieth century. The second half is characterized by strong growth of biochemical, physiological, molecular, and statistical advances in biology. This made genetic analyzes more transparent and led to more efficient selection procedures, which even led to a so-called “Green Revolution.”
