Detection of self-incompatible oilseed rape plants (Brassica napus L.) based on molecular markers for identification of the class I S haplotype.

The selection of desirable genotypes with recessive characteristics, such as self-incompatible plants, is often difficult or even impossible and represents a crucial barrier in accelerating the breeding process. Molecular approaches and selection based on molecular markers can allow breeders to overcome this limitation. The use of self-incompatibility is an alternative in hybrid breeding of oilseed rape. Unfortunately, stable self-incompatibility is recessive and phenotype-based selection is very difficult and time-consuming. The development of reliable molecular markers for detecting desirable plants with functional self-incompatible genes is of great importance for breeders and allows selection at early stages of plant growth. Because most of these reliable molecular markers are based on discrimination of class I S-locus genes that are present in self-compatible plants, there is a need to use an internal control in order to detect possible PCR inhibition that gives false results during genotyping. In this study, 269 double haploid F2 oilseed rape plants obtained by microspore embryogenesis were used to verify the applicability of an improved PCR assay based on the detection of the class I SLG gene along with an internal control. Comparative analysis of the PCR genotyping results vs. S phenotype analysis confirmed the applicability of this molecular approach in hybrid breeding programs. This approach allows accurate detection of self-incompatible plants via a different amplification profile.