Variation patterns in the Phlomis x composita (Lamiaceae) hybrid complex in the Iberian Peninsula (original) (raw)
Related papers
2007
Aims The historical influence of gene flow and genetic drift after the last glacial phase of the Quaternary Period is reflected in current levels of genetic diversity and population structure of plant species. Moreover, hybridization after secondary contact might also affect population genetic diversity and structure. An assessment was made of the genetic variation and hybrid zone structure in Iberian populations of the Mediterranean Phlomis lychnitis and P. crinita, for which phylogenetic relationships are controversial, and hybridization and introgression are common. † Methods Allozyme variation at 13 loci was analysed in 1723 individual plants sampled from 35 natural locations of P. lychnitis, P. crinita subsp. malacitana and P. crinita subsp. crinita in southern and eastern Spain. Standard genetic diversity parameters were calculated and patterns of genetic structure in each taxon were tested to fit the equilibrium between gene flow and genetic drift. Individual multilocus genotypes were subjected to Bayesian clustering analysis to estimate hybridization and introgression rates for both geographic regions. † Key Results Contrasting patterns in the distribution of genetic variation among the three taxa were found. Phlomis lychnitis showed no significant inbreeding, low genetic differentiation among populations and no evidence of isolation by distance. Phlomis crinita subsp. malacitana and P. crinita subsp. crinita showed high levels of genetic structure consistent with a pattern of gene flow-drift equilibrium. Higher instances of hybridization and introgression were detected in locations from southern Spain compared with locations from eastern Spain, matching unimodal and bimodal hybrid zones, respectively. † Conclusions High instances of historical gene flow, range expansion and altitudinal movement during the Quaternary Period, and lineage sorting can explain the diversity of patterns observed. The results suggest that P. lychnitis is the most differentiated lineage in the group; however, the relationship between the three taxa remains unclear.
Ecological characteristics of the flora of the Northwest Iberian Peninsula
Plant Ecology, 1998
An analysis of the ecological characteristics (life form, seed-dispersal mode, pollination mode, and reproductive mode) of about 1800 species of the flora of northwest Spain indicates that the most frequent characteristics are hemicryptophyte or therophyte life form, semachorous or barochorous seed dispersal, entomophilous pollination, and hermaphroditism. Following binary classification of the above characteristics (herbaceous versus woody life form, animal-assisted versus abiotic seed dispersal, animal-assisted versus abiotic pollination, dioecous versus hermaphrodite reproductive mode), statistically significant associations were found for all pairs of characteristics except pollination mode and reproductive mode (in disagreement with the results of previous studies which have detected significant associations between dioecy and abiotic pollination) and pollination mode and life form. To investigate the evolutionary plasticity of the different characters, we used nested analysis of variance with (in the case of life form, for example) percentage of species in genus with herbaceous life form as response variable, and with genus, family, order and subclass as nested factors and class as crossed factor. The results of this analysis indicated that higher-level grouping (class or subclass) accounted for the majority of total variance only in the case of pollination mode, suggesting either that pollination mode was typically determined early in evolutionary history and that there is currently little plasticity in this characteristic (i.e., phylogenetic constraints), or that this characteristic has been subject to stabilizing selection (i.e., phylogenetic niche conservatism). The other ecological characters, by contrast, showed high variability at lower levels in the taxonomic hierarchy.
2000
Phlomisimargaritae is a rare and sterile hybrid taxon found in a single endangered population in southern Spain. It was previously described as a morphologically intermediate hybrid, putatively between Phlomis purpurea and P. composita. The present study used allozymes as molecular markers to assess the hybrid identity of P.imargaritae. Ten putative loci from seven enzyme systems were resolved : five were monomorphic and fixed across all taxa studied and the rest (Aat-1, Aat-2, 6-Pgdh-2, Pgi and Pgm) were polymorphic in at least one taxon. The two parental taxa are fixed for different alleles at 6-Pgdh-2 and show distinct allelic frequency differences for four other loci. Phlomisimargaritae displays fixed heterozygous phenotypes for four of the five polymorphic loci, these being composed of combinations of the alleles found in the parental taxa. No unique alleles were detected in P.imargaritae. We conclude that this taxon is of hybrid origin and confirm the identity of the parental taxa involved.
Fitness components of the hybrid Phlomis x margaritae Aparicio & Silvestre (Lamiaceae)
Botanical Journal of the Linnean Society, 1997
Studies of microsporogenesis, pollen gcrrnination. pollen stainaljility, fruit and sccd set and ovary predation have hren undcrtakrn t o rvaluate the fitness of the hyhrid gcno1)pr of P/z/oiiii.~ x m a p d t l r relative to its parciits (P /iriipurea and P x r.omnpo.h) and allied tam (P x corr$osita nothom. composita, P x coiii/jo.sito not horn. trullenquei, and f! A~chnilir). Ptilmi\ x inqaaritar shows irre<pIar meiosis uith vrry low pollen germination rate and v e n high pollen sterility, no seed set, and very high ovary ptedation. It thus has very low rcproclucti\.r success and fitness. PhlomiJ x composita nothom. /iul/mquei also shows low pollen gcrniiiiation and seed set, hut these follow rcgular m i c~o s~~~~r o g r n e s i s. 'l'he existence of cryTitic structural strrility is suggested for this taxon. 'The rcs(of the studied taxa (P pwpztrun, P ! y h i f t \ and P x I.omposita nothom. com$osita) werc Ibrlilc and can support the specific or subspecific taxonomic status of P x comn,/mita. i \ liscd i~\~u l c ahortion pattern in the taxa with)ellow fiowrrs was found, since 'brood size' consistcd just of one seed per fruit. O n the contrary, P /mi)una was found to produce from onr t o lbur seeds per fknit. Sonic coiiseii-ittioii implications are suggested. 0 1997 '1111~ l. i r i r i r m Socictv of I.ond~iii I'DDITIONAL KEY \YORDS:-hrootl s i x ~ (.onsenration ~ fruit srt iriicrosporogr~rr~ii ovary predation ~ pollen germination pollen viability ~ seed setS Spain.
Fitness components of the hybrid Phlomis × margaritae Aparicio & Silvestre (Lamiaceae)
1997
Studies of microsporogenesis, pollen germination, pollen stainability, fruit and seed set and ovary predation have been undertaken to evaluate the fitness of the hybrid genotype of Phlomis × margaritae relative to its parents (P. purpurea and P. × composita) and allied taxa (P. × composita nothom. composita, P. × composita nothom. trullenquei, and P. lychnitis). Phlomis × margaritae shows irregular meiosis with very low pollen germination rate and very high pollen sterility, no seed set, and very high ovary predation. It thus has very low reproductive success and fitness. Phlomis × composita nothom. trullenquei also shows low pollen germination and seed set, but these follow regular microsporogenesis. The existence of cryptic structural sterility is suggested for this taxon. The rest of the studied taxa (P. purpurea, P. lychnitis and P. × composita nothom. composita) were fertile and can support the specific or subspecific taxonomic status of P. × composita. A fixed ovule abortion p...
Contribution to the Knowledge of Rocky Plant Communities of the Southwest Iberian Peninsula
Plants, 2021
The rocky habitats of southern Portugal are ecosystems with extreme xericity conditions, associated with special abiotic strains. In these unstable ecological conditions, a considerable diversity of plant communities occurs. The objective of this study, carried out in the Algarve and Monchique, and the Mariánica Range biogeographical sectors, is to compare chasmo-chomophytic communities of the southwestern Iberian Peninsula, using a phytosociological approach (Braun–Blanquet methodology) and numerical analysis (hierarchical cluster analysis). From these results, two new communities were identified, Sanguisorbo rupicolae-Dianthetum crassipedis and Antirrhinetum onubensis, as a result of floristic and biogeographical differences from other associations already described within the alliances Rumici indurati-Dianthion lusitani and Calendulo lusitanicae-Antirrhinion linkiani, both included in the Phagnalo saxatilis-Rumicetea indurate class.
Pteridophyte richness in the NE Iberian Peninsula: biogeographic patterns
Plant ecology, 2000
The richness and coexistence of pteridophyte species were studied at the mesoscale level in the NE Iberian Peninsula (Catalonia and Andorra) using a grid system with 10× 10 km cell-size. The number of pteridophytes, the number of monolete and trilete ferns (two spore patterns), and the number of polyploid and diploid ferns were studied in 371 of such units. The results suggest:(a) a significant relationship of pteridophyte species richness with higher-taxon richness (genera, family, order, class);(b) a significant relationship between ...