Figure 1.

Johann Gregor Mendel (1822–1884). Mendel cultivated as many as 27,000 garden pea plants during his famous crossing experiments (1854–1863) at the St Thomas monastery in Brno (Orel, 1971). Since peas are self-pollinating, Mendel had to emasculate the flowers before manual cross-pollination. In the winter of 1885, Mendel reported on his pea experiments and presented the general law of inheritance in two lectures in Brno. A year later, the edited lectures were published as his famous article “Experiments on Plant Hybrids” (1866). A, Pea flower, original photograph from Flickr (https://www.flickr.com/photos/wheatfields/2670660145/), by allispossible.org.uk, CC BY 4.0. B, diagram of pea floral structure. C, Mendel at work, images courtesy of Mendel University in Brno.