Comparison of anonymous and targeted molecular markers for the estimation of genetic diversity in ex situ conserved Lactuca

The anonymous marker systems microsatellites (simple sequence repeats), amplified fragment length polymorphisms and sequence-specific amplified polymorphisms were compared with the targeted marker systems sequence-related amplified polymorphisms, target region amplification polymorphisms and nucleotide binding site profiling for their ability to describe the genetic diversity in a selected set of 80 Lactuca accessions. The accessions were also described morphologically, and all characterisation methods were evaluated against the genetic diversity assessed by a panel of three crop experts. The morphological data showed a low level of association with the molecular data, and did not display a consistently better relationship with the experts’ assessments in comparison with the molecular data. In general, the diversity described by the targeted molecular markers did not differ markedly from that of the anonymous markers, resulting in only slight differences in performance when related to the expert-based assessments. It was argued that markers targeted to specific gene sequences may still behave as anonymous markers and that the type of marker system used is irrelevant when at low taxonomic levels a clear genetic structure is absent due to intensive breeding activities

In vitro propagation of the wild carrot Daucus carota L. subsp. halophilus (Brot.) A. Pujadas for conservation purposes

Daucus carota subsp. halophilus, is a wild crop relative of domestic carrot. It is an aromatic plant widely used in folk medicine due to recognized therapeutic properties of its essential oils. Experiments were carried out to evaluate the potential of in vitro propagation techniques to the conservation of this endemic and endangered taxon. The results showed that shoot tips of in vitro germinated seeds were able to proliferate in the presence of benzyladenine, with the best results being achieved using 4.4μM, both in the first and second cultures. Shoots rooted after being transferred to 1/2- Murashige and Skoog basal medium. The results indicated that the concentration of benzyladenine used during the multiplication phase did not interfere with the rate of root formation. The obtained plantlets were morphologically and anatomically identical to those obtained by seeds. Some of the in vitro produced shoots developed flowers that produced viable pollen. Plant regeneration was also achieved by somatic embryogenesis induction in cotyledons and root segments cultured in the presence of 4.5μM 2,4-dichlorophenoxyacetic acid. Somatic embryos converted into plantlets in a medium without growth regulators. Plants obtained either by shoot proliferation or somatic embryogenesis were acclimatized and are now growing at the Coimbra Botanical Garden. The first attempts to reintroduce these plants in the original habitat were successful. It can be concluded that the protocols developed are a useful approach to the conservation of this endemic species