Assessment of interspecific hybridization between wild beet Beta vulgaris L. subsp. maritima and cultivated sugar beet under Moroccan conditions

Obtaining a viable and fertile beet hybrid resulting from wild and cultivated sugar beet crosses under Moroccan conditions is challenging. To deal with hybridization, barriers in sugar beet, such as concordance of flowering period between biannual and annual subspecies, flowering aptitude according to vernalization requirement, genotype incompatibility and hybrid sterility, should be overcome. In our study, interspecific hybrids were obtained from crosses between 17 cultivated sugar beet Beta vulgaris subsp. vulgaris and 17 Beta vulgaris subsp. maritima, collected in different regions of Morocco. Twenty-two agro-morphological traits were used for the evaluation of 208 hybrid plants, under greenhouse conditions. CH and WH hybrids were collected on cultivated and wild parents separately. Most of the hybrids behaved as annual plants, of which 83.17% were able to flower and produce seeds without any vernalization requirements. All WH hybrids and 57.06% of CH hybrids were morphologically similar to their wild parent. However, 24% of CH hybrids were phenotypically similar to their cultivated parent. The remaining CH hybrid plants were behaving as intermediate genotypes between both wild and cultivated parents. Our results showed the success of interspecific beet crosses and emphasized the high variability among hybrid genotypes. This is of great importance for sugar beet improvement and breeding programs and interspecific crosses patterns understanding.