Fragmentchromosomen bei Crepis capillaris

Zürich

1960

S. 93-106

16 Abb., 5 Tab., 17 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200150969

1. Partially heterochromatic fragment chromosomes have been found in a small population of Crepis capillaris. Their cytogenetics was studied. 2. Seedsetting of selfeld plants is lowered in the presence of f-chromosomes. The same is true for fXO-crosses compared with crosses of the OXO- and OXf-type. But seedfertility increases if both, seed- and pollen-plant, contain f-chromosomes. 3. F1-generations of the crosses OXf and fXO are composed of more than 80 % plants carrying f-chromosomes, which demonstrates that in these crosses both male and female gametes containing f-chromosomes are favoured. Crosses of the type fXf confirm these results. 4. Embryos and endosperms of some seeds revealed dicentric f-chromosomes. Int their mitosis single and, following parallel separation of dicentrics, double bridges occurred which lead to irregular distribution and deviation of f-chromosomes.