The "falcifolia" syndrome of Oenothera. First communication

Summary Reciprocal crosses between Oe. lamarckiana and Oe. suaveolens lead to an off-spring, part of which is crippled. According to Harte 1948 this characteristic malformation is called falcifolia (sickle-shaped leaf). It is restricted to certain sectors of the plant and appears in various plants at different stages of their development. For this reason the percentage of falcifolia-plants increases gradually during the vegetative period. Reciprocal crosses show a clear quantitative difference in regard to the percentage of crippled plants as well as to the degree of crippling. At maturity the percentage of falcifolia-plants is approximately as follows: Oe. lamarckianaxOe. suaveolens: 90–100% Oe. suaveolensxOe. lamarckiana: 20–40% Selfing of normal and crippled hybrids leads to an F₂ which consists of both types; the percentage varies. In general a crippled plant produces more falcifolia-progeny than a normal plant. Backcrossing with Oe. lamarckiana leads to an offspring with less than 20% falcifolia whilst backcrossing with Oe. suaveolens produces more than 50% crippled plants. This large difference appears in every backcross, regardless whether the F₁-plant is normal or crippled, and whether it functions as seed-parent or pollen-parent. Furthermore it does not matter whether the F₁ has been obtained with Oe. lamarckiana or with Oe. suaveolens as seed-parent. The peculiar inheritance appears to be independent of nuclear and plastid genes (genome and plastome), but is in fact a non-mendelian one. Falcifolia cannot be produced by grafting Oe. lamarckiana and Oe. suaveolens reciprocally. It seems to be caused by the interaction of different plasmotypes.

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Herrn Professor Dr. Dr. h. c. Friedrich Oehlkers zum 80. Geburtstag gewidmet.