Five new species of Pythium (Peronosporomycetidae)

Five new species of Pythium are described, following ecological studies of the genus in the Reading (U.K.) area. Two of the new species were found abundantly, three were rarely isolated. Neither of the abundant species produces sporangia and both have very small oospores. Of the rarer species, two have filamentous sporangia and all three have rather large oospores.     

COMPARISON OF FLOWISE AND SIPWISE METHODS OF TASTING

Sipwise and flowise presentation of taste stimuli were compared and better taste discrimination was noted for flowise presentation. Using a model system, discrimination between NaCl solutions and purified water, analysis with atomic absorption spectrophotometry indicated that the superiority of flowise presentation was due to reduction in stimulus variance. Flowise presentation was also superior for discrimination between commercially available natural spring waters.     

Morphometric and population genetic analyses elucidate the origin,evolutionary significance and conservation implications of Orchis × angusticruris (O. purpurea × O. simia), a hybrid orchid new to Britain

We report the first confirmed occurrence in Britain of Orchis × angusticruris Franch. ex Rouy, a hybrid between two closely related orchid species of anthropomorphic Orchis (O. purpurea Huds. × O. simia Lam.) that hybridize frequently in Continental Europe. Seven individual hybrids, most likely F1 plants representing a single interspecific pollination event, first flowered with both parents in May 2006 at a nature reserve in the Chiltern Hills near Goring, Oxfordshire. Univariate and multivariate morphometric analyses (43 characters plus 12 indices), internal transcribed spacer sequencing, plastid microsatellites and amplified fragment length polymorphism (AFLP) analyses together readily separate the parents and confirm that O. purpurea was the ovule parent and O. simia the pollen parent, presumably reflecting the greater frequency and/or later flowering period of the latter at the site. This study reinforces a more general observation that, in most orchids, the ovule parent contributes substantially more to the hybrid phenotype than does the pollen parent, perhaps reflecting cytoplasmic inheritance. In contrast, the hybrids are placed closer to O. simia than to O. purpurea in the AFLP tree. Apparently recent arrivals, the few O. purpurea plants at Goring contrast genetically with the two other small populations of this species known in the Chilterns, but rather are consistent with relatively uncommon Continental populations. This suggests that the plants may have been deliberately introduced at Goring by man, although transport from the Continent in high‐level air currents cannot be ruled out. The Goring population of O. simia is likely to have become genetically impoverished through (1) preferential removal of many relatively fit plants to herbaria in the 19^th century and/or (2) a catastrophic population crash in the first half of the 20^th century. However, both our re‐examination of herbarium specimens and our population genetic data indicate past hybridization among anthropomorphic Orchis species occurring naturally in the Chilterns. Thus, we tentatively recommend retention of the hybrid plants at Goring, despite their likely anthropogenic origin from Continental material and the partial viability of their pollen and seeds, which offers opportunities for future introgression. Although the Goring hybrids broadly resemble morphologically O. militaris, another anthropomorphic Orchis still found at two Chiltern localities, sufficient morphological and molecular differences were observed to strongly refute our initial hypothesis that O. militaris could have originated through hybridization between ancestors that resembled O. purpurea and O. simia. The comparatively complex genetic properties evident in both O. simia and O. purpurea merit further study. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 687–711.     

Millipede assassins and allies (Heteroptera: Reduviidae: Ectrichodiinae,Tribelocephalinae): total evidence phylogeny,revised classification and evolution of sexual dimorphism

Evolution of sexual dimorphism in animals has long been of interest to scientists, but relatively few studies have reconstructed evolutionary patterns of extreme sexual dimorphism at a phylogenetic scale, especially in insects. Millipede assassin bugs (Heteroptera: Reduviidae: Ectrichodiinae; 736 spp.) and their sister taxon, Tribelocephalinae (150 spp.), exhibit sexual dimorphism that ranges from limited to extreme, a phenomenon apparently modulated by female morphology. Here, we reconstruct the first phylogeny for the subfamilies Ectrichodiinae and Tribelocephalinae with comprehensive generic representation (152 taxa in 72 genera) using morphological and molecular data (six gene regions). The combined phylogenetic results indicate that Tribelocephalinae are paraphyletic with respect to Ectrichodiinae, and that Ectrichodiinae themselves are polyphyletic. Based on these results, we synonymize Tribelocephalinae with Ectrichodiinae syn.n. , describe three new tribes (Ectrichodiini trib.n. , Tribelocodiini trib.n. , and Abelocephalini trib.n. ) and two new subtribes (Opistoplatyina subtrib.n. and Tribelocephalina subtrib.n. ), and revise Tribelocephalini sensu n. Ancestral state reconstruction of sexual dimorphism reconstructed limited sexual dimorphism in the ancestor of Ectrichodiinae sensu n. with at least seven evolutionary transitions to extreme sexual dimorphism within the clade. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:C810E20F‐D66A‐461F‐A0E6‐AB1073EA3E3C .     

Promotion of Flowering in the Pinaceae by Gibberellins

Gibberellins (GAs) were effective in promoting flowering in sexually mature (45-year-old scions) grafts of loblolly pine (Pinus taeda L.). Seed-cone production was increased 12-fold in field-grown, grafted ramets by bi-weekly, May-September applications of 500 μg per branch of GA_4/7. Gibberellin A₃ was equally effective at 500 μg but not at 100 μg per branch, while GA₅ was ineffective at either concentration. A second study using potted, less-sexually mature (8-to 10-year-old scions) grafts gave a reduced level of seed cones in response to GAs. However, even on these younger grafts GA_4/7 was a significant promotive treatment, GA₃ being considerably less effective. Branch girdling, tested as an adjunct treatment, was ineffective. It is now apparent that exogenous applications of GA_4/7 are effective on a number of Pinaceae species, and their use to promote earlier and more abundant flowering in breeding orchards of grafted ramets for at least two species, loblolly pine and Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] is practical.