Identification of Interspecific Hybrids Between B. vulgaris L. and Species of Procumbentes Section Using RAPD Markers

Sugar beet pests and diseases are the main factors decreasing root yield and sugar content. Sugar beet wild relatives especially section Procombentes have some resistance genes against pests and diseases, and therefore are important in sugar beet breeding programs. Interspecific hybridization between B. vulgaris and these wild relatives is a routine approach to obtain resistant varieties. In this research, interspecific hybridization was carried out between a tetraploid B. vulgaris as female and two species of Procumbentes section as male parents. Embryo rescue technique was used to develop hybrid plants. RAPD markers were used to identify the hybrids. Genomic DNA extracted from parents and hybrids and followed by PCR reactions using random primers OPX15 and OPX2. The sequences of these two primers are recognized to be specific for the Procumbentes genomes. The results showed that there are some bands to identify real hybrids. These hybrids had three common bands with their parents in PCR reactions products with OPX15 primer. Two bands (700 bp and 2600bp) came from Procumbentes and one band (1100bp) from B. vulgaris. PCR product of OPX2 primer showed that hybrids have two common bands (600bp and 990bp) with cultivated and wild parents, respectively. A third band (1900bp) was common in all parents and hybrids. Molecular studies showed that hybrid plants have similar bands to both wild and cultivated species and, therefore, are interspecific hybrids. This indicates that this technique can be useful to identify different species within beet germplasm and their inter-specific hybrids.