Parentage of endemic Sorbus L. (Rosaceae) species in the British Isles: evidence from plastid DNA

The parentage of polyploid Sorbus species in the British Isles was investigated using plastid DNA microsatellites. Four hundred and fifty-three samples from 30 taxa were screened using six microsatellite fragments, which gave 28 haplotypes. The haplotypes formed groups clearly related to the ancestral diploids Sorbus aria , Sorbus aucuparia , and Sorbus torminalis . Species in the Sorbus aria group all had Aria haplotypes (with the exception of one English S. aria ), species in the Sorbus anglica group had an Aucuparia haplotype, and species in the Sorbus latifolia group had a Torminalis haplotype. Sorbus intermedia had an Aucuparia haplotype. This indicated that the hybridization events that led to the formation of species in the S. anglica and S. latifolia groups usually did so with S. aria s.l . as the pollen-donating (paternal) parent. The polyploids S. anglica , Sorbus bristoliensis , Sorbus croceocarpa , Sorbus decipiens , Sorbus devoniensis , Sorbus hibernica , Sorbus lancastriensis , Sorbus leptophylla , Sorbus leyana , Sorbus minima , Sorbus rupicola , Sorbus subcuneata , Sorbus vexans , Sorbus whiteana , Sorbus wilmottiana , and three unnamed taxa may each be derived from a single maternal lineage. The polyploids Sorbus eminens , Sorbus porrigentiformis , and S. latifolia have multiple maternal lineages. The two primary diploid hybrids S . ×  thuringiaca and S . ×  vagensis have arisen many times independently.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 291–304.     

Gut content and stable isotope analyses provide complementary understanding of ontogenetic dietary shifts and trophic relationships among fishes in a tropical river

1. Despite widespread recognition of the role of body size in fish trophic ecology, little attention has been focused on this issue in isotopic studies, particularly in tropical systems. 2. We used analyses of stomach contents and stable isotopes to examine size‐related shifts in diet in a terapontid fish assemblage in the Australian wet–dry tropics. Stomach content analysis identified substantial ontogenetic dietary shifts in all species, corresponding to changes in body size–isotope trajectories for two species. Shifts away from relatively specialised diets of heavily ¹³C‐depleted insect larvae to consumption of a range of items across multiple basal carbon sources appeared to be the proximate cause of observed isotopic changes. 3. Allochthonous organic matter in the form of C3 riparian vegetation was particularly important to smaller terapontids before larger fish shifted to a broad range of dietary items and similarly broad range of basal carbon sources. 4. While there was general agreement between δ¹³C and stomach content analysis, there was minimal concurrence between the latter and δ¹⁵N isotopic derivation of estimates of trophic position. Due to factors such as omnivory, isotopically overlapping basal sources and uncertainties about rates of isotopic fractionation in both predator and prey species, stomach content analysis provides an essential complement to isotopic methodologies in tropical systems. 5. Given that basal sources supporting any individual species can change markedly with ontogeny, consideration of intraspecific, size‐related variation is necessary in isotopic studies of food web structure.     

Isolation and cross‐familial amplification of 41 microsatellites for the brook charr (Salvelinus fontinalis)

The brook charr (Salvelinus fontinalis; Osteichthyes: Salmonidae) is a phenotypically diverse fish species inhabiting much of North America. But relatively few genetic diagnostic resources are available for this fish species. We isolated 41 microsatellites from S. fontinalis polymorphic in one or more species of salmonid fish. Thirty‐seven were polymorphic in brook charr, 15 in the congener Arctic charr (Salvelinus alpinus) and 14 in the lake charr (Salvelinus namaycush). Polymorphism was also relatively high in Oncorhynchus, where 21 loci were polymorphic in rainbow trout (Oncorhynchus mykiss) and 16 in cutthroat trout (Oncorhynchus clarkii) but only seven and four microsatellite loci were polymorphic in the more distantly related lake whitefish (Coregonus clupeaformis) and Atlantic salmon (Salmo salar), respectively. One duplicated locus (Sfo228Lav) was polymorphic at both duplicates in S. fontinalis.     

Trends and temperature response in the phenology of crops in Germany

The phenology of 78 agricultural and horticultural events from a national survey in Germany spanning the years 1951–2004 is examined. The majority of events are significantly earlier now than 53 years ago, with a mean advance of 1.1–1.3 days per decade. The mean trends for 'true phases', such as emergence and flowering, of annual and perennial crops are not significantly different, although more trends (78% vs. 46%) are significant for annual crops. We attempt to remove the influence of technological advance or altered farming practices on phenology by detrending the respective time series by linear regression of date (day number) on year. Subsequently, we estimate responses to mean monthly and seasonal temperature by correlation and regression in two ways; with and without removing the year trend first. Nearly all (97%) correlation coefficients are negative, suggesting earlier events in warmer years. Between 82% and 94% of the coefficients with seasonal spring and summer temperatures are significant. The conservative estimate (detrended) of mean temperature response against mean March–May temperature (−3.73 days °C⁻¹) is significantly less than the full estimate (−4.31 days °C⁻¹), the 'true' size of phenological temperature response may lie in between. Perennial crops exhibited a significantly higher temperature response to mean spring temperature than the annual crops.     

Floristic changes in vascular plants in the British Isles: geographical and temporal variation in botanical activity 1836–1988

The temporal and geographical variation in the history of botanical recording in the British Isles between 1836 and 1988 has been reconstructed from literature, herbarium, and field records, and related to the number and distribution of botanists. The number of botanists increased steadily to the 1930s and then five‐fold after the Second World War, and is a consistent proportion of the local population. The amount of variation in the literature, assessed from the number of pages published, number of publications, and number of floras, has changed from a low rate between 1836 and 1880, to twice that between 1890 and 1940, and increased steadily to 1988. The number of herbarium specimens collected was also low up to the 1870s and then increased three‐fold between 1870 and 1914, decreased between the World Wars, increased in the 1950s, and then decreased as conservation concerns came into play. The number of field records, now on computer, has risen dramatically since the 1930s, especially associated with major recording projects. The Botanical Society of the British Isles (BSBI) Monitoring Scheme data show a strong relationship between the number of hours spent recording at a site and the number of species recorded. The production of literature, collection of herbarium specimens, and field records also vary geographically, being concentrated in the areas in which botanists live. General patterns of recording activity are presented from a combination of the data that follow the general trends shown by the sources. There has been an increase in recording activity, with a low level between 1836 and 1870, followed by a large increase, peaking between 1890 and 1910, followed by decreases during the World Wars, with a recovery between, and a sustained increase since 1950. There is a clear trend from a high recording activity in south‐east England to low levels in Scotland and, especially, Ireland, high levels being associated with the main population areas. Temporal and geographical variations in recording activity need to be taken into account when assessing floristic change. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 152 , 303–330.     

Evidence for the mechanisms of zinc uptake by rice using isotope fractionation

In an earlier study, we found that rice (Oryza sativa) grown in nutrient solution well‐supplied with Zn preferentially took up light ⁶⁴Zn over ⁶⁶Zn, probably as a result of kinetic fractionation in membrane transport processes. Here, we measure isotope fractionation by rice in a submerged Zn‐deficient soil with and without Zn fertilizer. We grew the same genotype as in the nutrient solution study plus low‐Zn tolerant and intolerant lines from a recombinant inbred population. In contrast to the nutrient solution, in soil with Zn fertilizer we found little or heavy isotopic enrichment in the plants relative to plant‐available Zn in the soil, and in soil without Zn fertilizer we found consistently heavy enrichment, particularly in the low‐Zn tolerant line. These observations are only explicable by complexation of Zn by a complexing agent released from the roots and uptake of the complexed Zn by specific root transporters. We show with a mathematical model that, for realistic rates of secretion of the phytosiderophore deoxymugineic acid (DMA) by rice, and realistic parameters for the Zn‐solubilizing effect of DMA in soil, solubilization and uptake by this mechanism is necessary and sufficient to account for the measured Zn uptake and the differences between genotypes.     

The Galton–Darwin–Wedgwood Pedigree of H. H. Laughlin

A pedigree of the Galton–Darwin–Wedgwood families that was exhibited as a poster at the Third International Congress of Eugenics in 1932 at the American Museum of Natural History has been located in the archives of Truman State University in Kirksville, Missouri. This pedigree was prepared by Harry Hamilton Laughlin, Director of the Eugenics Record Office of the Carnegie Institute. The pedigree shows consanguineous marriages within the three families. A special collection of rare Darwin family photographs assembled by Leonard Darwin has also been found in the Truman State University archives. These photographs were exhibited as a poster alongside the pedigree at the 1932 Eugenics Congress. The poster of the Galton–Darwin–Wedgwood pedigree is published here, together with a tabular version providing ready access to the information contained in the pedigree. Also included are the Darwin family photographs and a biographical sketch of Laughlin. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 228–241.