Asplenium obovatum Viv. en la Península Ibérica

Se estudian los caracteres morfológicos de la fronde, epidermís y esporas de 48 muestras correspondientes a A. obovatum, A. bi/lotii, A. foreziense yA. fontanum, así como las dimensiones de las esporas y estomas. El análisis de estos caracteres, especialmente los cuantitativos y la morfología de los dientes de las pínnulas nos inducen a afirmar queA. obovatum forma parte de la flora pteridofítica peninsular. Se incluye una clave para la diferenciación de los cuatro táxones.Frond, epidermis and spore morphology from 48 samples of A. obovatum, A. billotii, Aforeziense andA.fontanum as well as size of spores and stomates are studied. The analysis of these characters, specially thecuantitative ones and teeth's shape, led us to confirm the presence ofA. obovatum in the Iberian Peninsula A diagnostic key of the four species is presented

Food intake and satiety response after medium-chain triglycerides ingested as solid or liquid

Consuming medium-chain triglycerides (MCT) may reduce subsequent energy intake and increase satiety compared to long-chain triglycerides (LCT), but may be dependent on the physical form in which MCT is ingested. Twenty-nine participants completed four trials where they consumed a breakfast containing either LCT or MCT in solid (Con-S and MCT-S, respectively) or liquid (Con-L and MCT-L, respectively) form. Appetite ratings and gastric emptying (GE) were taken at baseline and at 15 min intervals for 4 h. Energy intake was assessed at an ad libitum meal and via weighed food records for the remainder of the day. Ad libitum energy intake was highest in Con-L (4101 ± 1278 kJ vs Con-S, 3323 ± 1196; MCT-S, 3516 ± 1058; MCT-L, 3257 ± 1345; P = 0.001). Intake over the whole day was significantly lower in MCT-L (7904 ± 3244) compared to Con-L (9531 ± 3557; P = 0.001). There were significant differences in GE times (P < 0.05), with MCT breakfasts delaying GE to a greater extent than LCT, and MCT-L having the longest GE times. There were no differences in appetite sensations. MCT reduce subsequent intake without affecting subjective sensations of appetite when consumed in liquid form

Tipos esporales en Aspleniaceas ibéricas

Mediante microscopía óptica y electrónica de barrido se estudian las esporas de 22 taxones de la familia Aspleniaceae presentes en la Península Ibérica e Islas Baleares. El modelo básico es el flaviforme, pudiendo establecerse varios tipos esporales atendiendo a la ornamentación del perisporio y a las características de los pliegues. Se incluye un cuadro resumen de los principales caracteres palinológicos de cada taxón.Spores from 22 iberian and balearic taxa of Aspleniaceae were studied by light and scanning electron microscopy. The basic pattern is flaviform, and several types were recognized according to the perisporial ornamentation and fold features. A summary of the main palynological characters is presented

Fitness of an allopolyploid rupicolous fern compared with its diploid progenitors: from sporogenesis to sporophyte formation

PREMISE: When two populations of related cytotypes grow in sympatry, the rarer cytotype tends to be excluded due to a frequency‐dependent mating disadvantage. Evolutionary models predict that polyploids, which are typically the rarer cytotype upon first formation, should have higher relative fitness and/or higher selfing rates to establish and then coexist with diploid parents. METHODS: Performance during early recruitment was compared among three co‐occurring rupicolous fern species: the allotetraploid Cheilanthes tinaei and its diploid ancestors, C. hispanica and C. maderensis. In culture experiments, fresh spores and samples of soil spore banks were tested for variation among cytotypes in germination, survival, fecundity, and mating system of gametophytes. RESULTS: Compared with its diploid parents, C. tinaei fresh spores had higher abortion percentages, lower dispersal ability as a result of its larger spores, and similar vigor at germination. For gametophytes from soil spore banks, C. tinaei had high survival similar to C. maderensis, but its sex expression resembled that of C. hispanica, with a high proportion of males. Patterns of sporophyte formation by females and bisexuals indicate that the polyploid does not have an increased gametophytic selfing rate. Gametophytes were larger in C. tinaei, but its reproductive success (sporophyte formation) was intermediate relative to diploids. CONCLUSIONS: Our results show no evidence of higher selfing or fitness advantage of the allopolyploid over both diploid parents at any stage of early recruitment. These two unexpected findings suggest that further factors, such as niche differentiation, play a more important role in cytotype coexistence.Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEMinisterio de Ciencia e Innovación (MICINN)pu

Mixed mating system in the fern Asplenium scolopendrium: implications for colonization potential

Background and Aims Human-mediated environmental change is increasing selection pressure for the capacity in plants to colonize new areas. Habitat fragmentation combined with climate change, in general, forces species to colonize areas over longer distances. Mating systems and genetic load are important determinants of the establishment and long-term survival of new populations. Here, the mating system of Asplenium scolopendrium, a diploid homosporous fern species, is examined in relation to colonization processes. Methods A common environment experiment was conducted with 13 pairs of sporophytes, each from a different site. Together they constitute at least nine distinct genotypes, representing an estimated approx. 95 % of the non-private intraspecific genetic variation in Europe. Sporophyte production was recorded for gametophytes derived from each parent sporophyte. Gametophytes were grown in vitro in three different ways: (I) in isolation, (II) with a gametophyte from a different sporophyte within the same site or (III) with a partner from a different site. Key Results Sporophyte production was highest in among-site crosses (III), intermediate in within-site crosses (II) and was lowest in isolated gametophytes (I), strongly indicating inbreeding depression. However, intragametophytic selfing was observed in most of the genotypes tested (eight out of nine). Conclusions The results imply a mixed mating system in A. scolopendrium, with outcrossing when possible and occasional selfing when needed. Occasional intragametophytic selfing facilitates the successful colonization of new sites from a single spore. The resulting sporophyte, which will be completely homozygous, will shed large amounts of spores over time. Each year this creates a bed of gametophytes in the vicinity of the parent. Any unrelated spore which arrives is then selectively favoured to reproduce and contribute its genes to the new population. Thus, while selfing facilitates initial colonization success, inbreeding depression promotes genetically diverse populations through outcrossing. The results provide further evidence against the overly simple dichotomous distinction of fern species as either selfing or outcrossing