Protocol for rye anther culture

Rye (Secale cereale L.) is a cross-pollinated cereal, which has a strong self-incompatibility system. Population varieties of rye are highly heterozygous. Genes for self-fertility can, however, be introduced from wild relatives for purposes of hybrid rye breeding. In population breeding, selfing is detrimental, as rye suffers from severe inbreeding depression. The protocol for rye anther culture was developed for cross-pollinating rye for purposes of population breeding and genetic marker research. Rye has been generally considered to be recalcitrant to anther culture. The source of self-compatibility, a weedy wild relative S. vavilovii (L), has shown better response (Immonen, 1999). However, the use of a self-fertile species in population breeding would be problematic and therefore a protocol was needed for cultivated rye. The motivation for developing a broadly applicable rye anther culture protocol for rye is three-fold: in hybrid rye production homozygous doubled haploids could facilitate the process because, although the time needed for testing the combining ability cannot be reduced, the differentiation of quantitative traits is more effective with DH lines; in marker studies DH materials make development of mapping populations faster and mapping easier than is otherwise the case with obligatory cross-breeding crops; in population breeding doubled haploids could be a potential means for fixing a trait or increasing its prevalence in the population, providing that the trait can be selected for either visually or through marker-assisted selection at plantlet stage, or self-incompatibility could be circumvented. The latter could be reached through a recurrent selection scheme provided that the DH method to be used in subsequent cycles is economical and efficient, and the restrictions of self-incompatibility are overcome.