Gametic and somatic embryogenesis through in vitro anther culture of different Citrus genotypes

Abstract: In vitro tissue culture represents a useful technique for advancing Citrus breeding and propagation. Among in vitro regeneration systems, anther culture is commonly used to produce haploids and doubled haploids for a fast-track producing homozygous lines, in comparison with the traditional self-pollination approach, which involves several generations of selfing. In addition, anthers culture can produce somatic embryos that can also be used for clonal propagation. In this study, two thermal shocks were applied to the anthers of six Citrus genotypes (two clementine and four sweet oranges), just after they were put in culture. The response obtained was different depending on the genotype: both clementines, namely Hernandina and Corsica, produced homozygous and triploid regenerants (microspore-derived embryos), whereas all of the analyzed regenerants from sweet oranges, three cultivars of Tarocco and Moro, produced heterozygous and diploid regenerants similar to the parental genotypes (somatic embryos).