Jorge E. Campos

Clonal and genetic structure of two Mexican oaks: Quercus eduardii and Quercus potosina (Fagaceae)

Quercus eduardii and Q. potosina are dominant oak species in Sierra Fría, Aguascalientes, Mexico. These species have been exploited for multiple purposes since the 16th century. Both species produce clonal offspring through root suckering and acorns through sexual reproduction. To understand clonality for the implementation of the most adequate actions for the conservation of these species, we addressed the following questions: (a) what is the spatial clonal structure of both species? (b) How much clonal and genetic diversity is maintained in these species? Random Amplified Polymorphic DNAs (RAPDs) were used as molecular markers for these analyses. Genets of both species have few ramets and these grow close the parent tree. Autocorrelation analyses at the ramet level showed an aggregated distribution at short distances and a random spatial distribution at larger distances. Also, at the genet level the autocorrelation analyses showed a random distribution. Clonal diversity was high in both species (Q. eduardii: D=0.963, G/N=0.60; Q. potosina: D=0.985, G/N=0.65). Genetic diversity was high within populations (Q. eduardii: He=0.33±0.11; Q. potosina: He=0.35±0.11). Low levels of genetic differentiation among populations were observed (Q. eduardii ϕst=0.19, P < 0.002; Q. potosina ϕst=0.13, P < 0.002). Both species maintain high levels of clonal and genetic diversity, probably due to successful sexual reproduction, which allows gene flow among populations. Conservation and/or reforestation programs must include seed collections and germplasm banks. Due to the small genet size and the high clonal diversity of these species, seeds can be collected in any place in Sierra Fría, Aguascalientes.

Characterization of Scenedesmus obtusiusculus AT-UAM for high-energy molecules accumulation: deeper insight into biotechnological potential of strains of the same species

Highlights • S. obtusiusculus AT-UAM and CCAP 276/25 had different biochemical profiles.• ITS2 secondary structures confirmed S. obtusiusculus AT-UAM identity.• S. obtusiusculus AT-UAM has potential for biofuels production.• The maximum lipid content and productivity were obtained at 613 μmol m−2 s−1.• Lipids and carbohydrates accumulation indoors and outdoors were similar.

Vaucheria zapotecana (Xanthophyceae), a new species from Oaxaca, Mexico

Bonilla-Rodríguez M., Garduño-Solórzano G., Martínez-García M., Campos J.E., Monsalvo-Reyes A.C. and Quintanar-Zúñiga R.E. 2013. Vaucheria zapotecana (Xanthophyceae), a new species from Oaxaca, Mexico. Phycologia 52: 550–556. DOI: 10.2216/13-162.1 A new species of Vaucheria was isolated from the Santa Gertrudis River in Oaxaca, Mexico. This taxon was distinguished from the other six species in the Pseudogeminata group of section Racemosae by wider siphonous filaments and antheridia of a larger diameter, lack of septa in the gametophore, broader oogonial beak, erect oogonia and oospores that lacked yellowish spots. This species was named Vaucheria zapotecana sp. nov. The phylogenetic relationship of this species was investigated by analyzing a 2022-base-pair sequence that included the rbcL gene; results revealed a close relationship among this species, V. pseudogeminata and other species of the section Racemosae; although, the sequence for V. zaptecana is distinct.