The use of rootless mutants for the screening of spontaneous androgenetic and gynogenetic haploids in Nicotiana tabacum: evidence for the direct transfer of cytoplasm

In crosses between a homozygous rootless mutant line of Nicotiana tabacum used as female and other Nicotiana tabacum lines, androgenetic haploids can be directly selected by their ability to form plantlets with a normal rooting system, whereas hybrid plants are killed few weeks after sowing. These androgenetic plants have the nucleus of the male parent into the cytoplasm of the female parent. In crosses where the homozygous rootless mutant line is used as a pollen donor, gynogenetic haploids can also be directly selected. Haploids can therefore be derived from male sterile plants using this approach. A generalization of this system for direct cytoplasm transfer and for the screening of spontaneous haploids in dicotyledons is proposed.