A cladistic analysis of Nassauvia Comm. ex Juss. (Asteraceae, Mutisieae) and related genera

FREIRE, S. E., CRISCI, J. V. & KATINAS, L., 1993. A cladistic analysis of Nassauvia Comm. ex Juss. (Asteraceae, Mutisieae) and related genera. Nassauvia and the most closely related genera Calopappus and Triptilion from the southern Andes and Patagonia of South America, form a monophyletic group diagnosed by the following synapomorphies: cypsela trichomes single two-celled, cypsela testa with strengthened cells, pollen grains spheroidal to spheroidal-oblate, colpi membrane with sexine processes, pappus bristles two to six, and pappus deciduous. Furthermore, Nassauvia, Triptilion, and Calopappus form a group with two other Andean genera, Moscharia and Polyachyrus, diagnosed by occurrence of pseudocephalia and a reduction in the number of flowers to five, three or one. A cladistic analysis of the group was undertaken using 35 characters from morphology, anatomy, and palynology. The monophyletic terminal taxa were the 38 species of Nassauvia, the genus Triptilion, the monotypic genus Calopappus, the genus Polyachyrus, and the genus Moscharia. Character polarity was based on outgroup comparison using Cephalopappus. The analysis resulted in 223 equally parsimonious cladograms, each with 70 steps and a consistency index of 0.57. A successive weighting procedure was applied, resulting in 15 cladograms with a consistency index of 0.82. Results of the cladistic analysis support most of the current systematic classification of Nassauvia, with three exceptions: (1) Nassauvia (excluding Calopappus) is paraphyletic; (2) section Masligophorus appears to be a polyphyletic group (N. pygmaea does not cluster with the remaining species of the section); (3) section Panargyrum (without N. lagascae= section Caloptilium) appears to be a paraphyletic group. The capitula arranged in cymose conflorescences in Triptilion are regarded as a primitive condition which gave rise to all stages present in Nassauvia (conflorescence spicate, pseudocephalium, capitula solitary). The capitula arranged in pseudocephalia in Moscharia and Polyachyrus are regarded as a parallel development to the pseudocephalium found in Nassauvia. Nassauvia, subgenus Strongyloma appears as the most primitive taxon, with its spicate conflorescence, whereas section Masligophorus with its solitary capitulum is thought-derived. These results correspond well with cytological data where species of the subgenus Strongyloma have n= 11 and the species of section Masligophorus are tetraploids (n = 22).     

Permeability of Whole Dunaliella Cells to Glucose

Ginzburg, M. and Richman, L. 1985. Permeability of whole Dunaliellacells to glucose.—J. exp. Bot. 36: 1959–1968.Whenglucose was dissolved in medium in which Dunaliella cells weresuspended, the amount recovered from pellets of centrifugedcells was greater than that expected if the glucose had beenrestricted to intercellular space, as measured with Blue Dextran.Glucose is not metabolized by whole Dunaliella cells. The glucoseadditional to that in the intercellular space must be eitheradsorbed in the coating outside the cells or must penetratethe cell through the cell membrane. Grounds are given for suggestingthat the latter hypothesis is correct and that the glucose comesto equilibrium with a space within the cell (the glucose–space)equivalent to 20–40% of the cell–water. It is suggestedthat most of the cell Na⁺ is restricted to the glucose-space. Key words: Dunaliella, glucose, permeability     

Preservation of Solanum pimpinellifolium genomic fragments in recombinant genotypes improved the fruit quality of tomato

Five recombinant inbred lines obtained from the F₂ generation of an interspecific cross between cultivar, Caimanta (Cai, Solanum lycopersicum) and wild accession, LA722 (P, S. pimpinellifolium) were crossed to obtain the second cycle hybrids (SCH). Eleven fruit quality traits were assessed in evaluating phenotypic variability among genotypes P, Cai, F₁ (Cai × P), five RILs, and 10 SCH. One of the five recombinant inbred lines and three SCH had higher values than P, as the best genotype for shelf life. Sequence-related amplified polymorphism was used as the molecular method for detecting polymorphism among these 18 genotypes. The percentage of polymorphism in RILs and SCH was 61% and 66% respectively. Moreover, some bands detected in P were present in SCH. Several multivariate analyses were performed to find agreement between the phenotypic variability observed for fruit quality traits and the polymorphism obtained from sequence-related amplified polymorphism markers. A general Procrustes analysis estimated that there was a consensus proportion of 75% between phenotypic and molecular data. There was considerable preservation of some bands from the wild genotype, which could increase the variability in fruit quality traits in populations where the genetic diversity is limited.     

Advances in laying date and increasing population size suggest positive responses to climate change in Common Eiders Somateria mollissima in Iceland

Models of climate change predict that its effects on animal populations will not always be negative, but most studies indicate negative associations between changes in climate and the phenology of animal migration and reproduction. For some populations, however, climate change may render particular environments more favourable, with positive effects on population growth. We used a 30-year population dataset on over 2000 Common Eiders Somateria mollissima at a colony in southwest Iceland to examine the response of this species to climate fluctuations. Eiders are strongly dependent on suitable climatic conditions for successful reproduction and survival. Temperatures in southwest Iceland, in both winter and summer, have generally increased over the past 30 years but have shown considerable fluctuation. We show that females laid earlier following mild winters and that year-to-year variation in the number of nests was related to the temperature during the breeding season 2 years previously. Milder summers could have positive effects on breeding success and offspring survival, producing an increase in nest numbers 2 years later when most Eiders recruit into the breeding population. In this part of their range, Eiders could benefit from a general warming of the climate.     

Evolutionary implications of hierarchical impacts of nonlethal injury on reproduction, including maternal effects

Nonlethal injury is pervasive in metazoans, but surprisingly little is known about its impact upon reproductive allocation. The impact of injury on reproduction has been explored in some detail in lizards and salamanders, which have tails that are adapted for fat storage but are also injured or lost during predatory and social encounters. We synthesize diverse insights from these studies and propose new hypotheses using graphical models which highlight three distinct, hierarchical effects of injury on reproduction: reproductive inhibition, reduction in propagule number and diminished per‐propagule investment (PPI), a maternal effect. Previous studies, which involved experimentally amputating the whole tail, have provided evidence of the first two effects, although there is little evidence of reduced PPI. We assayed these effects in free‐ranging Desmognathus salamanders exhibiting naturally occurring injury. Whereas earlier studies found that tail injury prohibits reproduction (precipitating functional conflict), we found that females missing 80% of their tails, including the smallest mature individuals, still reproduce. We also detected a negative correlation between magnitude of injury and PPI, a continuous maternal effect. Continuous (graded) effects of injury on PPI have not been reported previously; neither discrete nor continuous maternal effects due to injury have been previously demonstrated in free‐ranging vertebrates. The dearth of evidence for such effects may be due to the design of experimental manipulations that use all‐or‐nothing treatments. Future studies employing quantitative field data, or more realistic experimental treatments that mimic the continuous distribution of injury are likely to detect maternal effects arising from nonlethal injury. Although our comparative and empirical findings derive from studies of lizards and salamanders, we discuss how they apply in principle to all metazoans. Studies of these effects in nonvertebrate model systems are sorely needed. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 86 , 309–331.     

Do inefficient selfing and inbreeding depression challenge the persistence of the rare Dianthus guliae Janka (Caryophyllaceae)? Influence of reproductive traits on a plant's proneness to extinction

The yellow carnation Dianthus guliae Janka is a rare endemic of the Italian peninsula. As numerous extinctions have occurred in the past, very few populations are still present. Two years of field surveys revealed high mortality and an absence of recruitment in the southernmost populations of this species. Work in a botanical garden, under semi-natural conditions, revealed the occurrence of proterandrous hermaphroditism and self-compatibility. The durable flower lifespan, the competitive effects among flowers and the different outcomes from spontaneous and hand-performed pollinations (with both self- and cross-pollen) suggested low pollination rates in the experimental stand. Pollinator exclusion experiments revealed a low frequency of delayed autonomous selfing, suggesting that self-fertilization in D. guliae relies mainly on facilitated selfing and geitonogamy. Studies of inbreeding depression during the early life-history stages revealed significant differences between selfed and crossed progenies in terms of seed mass, germination rates, developmental vigour and mortality rates. Therefore, when pollen delivery is scarce, the plant may fail reproductive assurance via autonomous selfing. The influence of inbreeding depression contributes to a further reduction in recruitment chances in very small D. guliae populations. Experimental reintroductions are urgent to avoid local extinction at the southern periphery of its range.     

Taxon‐biased diet preference in the ‘generalist’ beetle‐hunting wasp Cerceris rubida provides insights on the evolution of prey specialization in apoid wasps

Opportunism and specialization appear to be widespread in apoid wasps, although the factors affecting the diet preference (and thus explaining the degree of specialization) are still largely unknown. Four hypotheses that stressed the importance of the size, sex, habitat, and taxonomic identity of prey of the beetle‐hunting digger wasp, Cerceris rubida, were formulated and tested. The wasp population hunted for phytophagous beetles belonging to abundant families around the wasp nesting site. In practice, the prey appeared to be hunted only in two cultivated fields, thus habitat accounted for a majority of the observed diet. The size of wasps was furthermore correlated with the size of their prey, and thus this also accounted for the frequencies of hunted prey and the strong individual specialization for both taxa and size. However, in the exploited habitat, some species were significantly over‐hunted than expected and some other significantly avoided by the wasps, causing an unexpected major role of prey taxon on the probability of being hunted, over the other explanatory variables (body size, body shape, sex, availability). This contrasts to that found in other wasp species, which appear to select prey basing essentially on their ecology and size or their relative abundance (opportunism). The results obtained in the present study show that even an apparent ‘generalist’ predator may turn out to be taxonomically specialized. Together with a re‐evaluation of previous studies, our results further suggest that the effect of size constraints and the developmental plan of prey (holometaboulous versus hemimetabolous) may have promoted either taxonomic opportunism or specialization in different lineages of apoid wasps. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 544–558.     

Insect immune priming: ecology and experimental evidences

1. Immune priming refers to improved protection of the host after a second encounter with the same parasite or pathogen. This phenomenon is similar to that of adaptive immunity in vertebrates. 2. There is evidence to suggest that this improved protection can be species/strain‐specific and can protect organisms for a lifetime. These two attributes, along with a biphasic immune response, are essential characteristics of immune priming and form the basis for the effectiveness of resistance to parasites and pathogens. 3. This paper considers the effect of immune priming within and across generations, the influence of a heterologous challenge during immune priming and the importance of testing the immune response with natural pathogens. 4. The analysis presented takes into account the multifaceted nature of the invertebrate immune response. The lack of evidence suggesting that the bacterial microbiome plays a complementary role in the immune priming outcome is discussed. 5. Finally, the cost of immune priming is explored. This is a poorly investigated issue, which could help to explain why there is a paucity of evidence in support of immune priming.