Hybridization between hexaploid triticale and Triticum monococcum L. II. The F1 generation AuAbBR

摘要

F1 plants from a cross between hexaploid triticale (AUAUBBRR) and Triticum monococcum (AbAb) can be obtained, only by means of embryo culture. Mostly, they are weak and about 40 percent of them died after planting in soil, and about 20 percent in the course of an in vitro cloning. All F, plants had somatic chromosome numbers of 28. A chromosome doubling by colchicine treatment was impossible. The expression of the Abgenome in the tetraploid F, is visible in many morphological traits, e.g., in stalk length, the occurrence of cilia near the leaf ground, glaucousness, and colour of spikes. Although all of the involved T. monococcum accessions were resistant to mildew, some of the F1 plants were susceptible. This indicates differences in the genetic background of resistance to mildew. On average, 3.81 percent of living pollen grains (ascertained by the fluorescein diacetate test) in the anthers of F1 plants were observed (range 0 to 10.68 %). However, all the anthers remained indehiscent and selfing was always impossible. Consequently, only backcrosses to triticale were possible. The average seed set in this backcross was 0.40 percent.