Santiago Andrés-Sánchez

Systematic significance and evolutionary dynamics of the achene twin hairs in Filago (Asteraceae, Gnaphalieae) and related genera: further evidence of morphological homoplasy

The variation and evolutionary dynamics of the twin hairs covering the achenes of the external female florets in Filago and related genera are studied using scanning electron microscope (SEM) and a Bayesian reconstruction of ancestral character states. A molecular phylogenetic hypothesis based on sequences of ITS and ETS (nuclear ribosomal DNA) and plastid rpl32-trnL intergenic spacer regions was used as a framework to test the phylogenetic, evolutionary and taxonomic significance of this character in the study group. The phylogenetic position of three island-endemic species (F. petro-ianii, F. tyrrhenica and F. wagenitziana) is explored. Three types of twin hairs are described, which alone or combined define five different types of indumentum. The results suggest that glabrous achenes are the ancestral condition for “Filago group s.str.”, while the presence of long-clavate twin hairs on the achene represents the ancestral character state for the genus Filago. Several cases of parallelisms are detected. With regard to taxonomy, twin hairs provide additional support for the recognition of Bombycilaena and Logfia at the generic level and allow the taxonomic re-evaluation of F. lutescens subsp. atlantica and F. crocidion. Finally, the utility of a Bayesian Binary MCMC approach (using the software RASP) for evolutionary reconstruction of morphological characters is demonstrated.

Filago longilanata and F. prolifera (Gnaphalieae: Asteraceae): two neglected species from the Filago desertorum clade rediscovered

Abstract Filago longilanata was collected only once until now by Maire and Wilczek in 1934. On its side, Filago prolifera is a rare plant endemic to North Africa, and most of the available herbarium materials corresponding to this species were collected in the late 19th or early 20th centuries. In this work, respectively two and three new populations of Filago longilanata and F. prolifera from Morocco are reported. Additionally, the phylogenetic position of these taxa within the genus Filago is elucidated. Last, complete description, a nomenclatural treatment and iconographies are presented for both species.

Divide and conquer! Data-mining tools and sequential multivariate analysis to search for diagnostic morphological characters within a plant polyploid complex (Veronica subsect. Pentasepalae, Plantaginaceae)

This study exhaustively explores leaf features seeking diagnostic characters to aid the classification (assigning cases to groups, i.e. populations to taxa) in a polyploid plant-species complex. A challenging case study was selected: Veronica subsection Pentasepalae, a taxonomically intricate group. The “divide and conquer” approach was implemented—that is, a difficult primary dataset was split into more manageable subsets. Three techniques were explored: two data-mining tools (artificial neural networks and decision trees) and one unsupervised discriminant analysis. However, only the decision trees and discriminant analysis were finally used to select diagnostic traits. A previously established classification hypothesis based on other data sources was used as a starting point. A guided discriminant analysis (i.e. involving manual character selection) was used to produce a grouping scheme fitting this hypothesis so that it could be taken as a reference. Sequential unsupervised multivariate analysis enabled the recognition of all species and infraspecific taxa; however, a suboptimal classification rate was achieved. Decision trees resulted in better classification rates than unsupervised multivariate analysis, but three complete taxa were misidentified (not present in terminal nodes). The variable selection led to a different grouping scheme in the case of decision trees. The resulting groups displayed low misclassification rates when analyzed using artificial neural networks. The decision trees as well as the discriminant analysis are recommended in the search of diagnostic characters. Due to the high sensitivity that artificial neural networks have to the combination of input/output layers, they are proposed as evaluation tools for morphometric studies. The “divide and conquer” principle is a promising strategy, providing success in the present case study.

Advances in the systematics and evolution of western Mediterranean representative species of the Pentanema conyzae clade through genetic fingerprinting: Pentanema in the western Mediterranean area

Forty‐five populations of Pentanema corresponding to seven species included in the Pentanema conyzae clade have been studied using AFLP fingerprinting. The results show that allopolyploidization could have been involved in the diversification of this group, specifically in species P. langeanum and P. maletii. Molecular data confirm the presence of P. britannicum in the Iberian Peninsula and key steps are provided to identify the species that are morphologically the most challenging.

SSR markers for Filago subg. Filago (Gnaphalieae: Asteraceae) and cross-amplification in three other subgenera

Premise of the Study Microsatellite primers were developed for the first time in the genus Filago (Gnaphalieae: Asteraceae). These markers will facilitate low‐scale phylogenetic, phylogeographic, and population genetic studies within the genus Filago. Methods and Results Ten pairs of polymorphic microsatellite primers (as well as five pairs of monomorphic primers) were identified and optimized on two species of Filago (F. gaditana and F. carpetana) using a microsatellite‐enrichment library method and 454 GS‐FLX technique. The polymorphic primers amplified tri‐ to hexanucleotide repeats and showed one to six alleles per locus for both species. Transferability was performed in 29 samples corresponding to nine representative species of Filago. Conclusions The results indicate the utility of the newly developed markers, which will be useful to delve into the phylogenetic relationships among the taxa within Filago. These microsatellites will enable studies of phylogeographic, reproductive, and genetic variation.