Constant Isothiocyanate-Release Potentials across Biofumigant Seeding Rates.

Biofumigation is an integrated pest-management method involving the mulching of a glucosinolate-containing cover crop into a field in order to generate toxic isothiocyanates (ITCs), which are effective soil-borne-pest-control compounds. Variation in biofumigation efficacy demonstrates a need to better understand the factors affecting pest-control outcomes and develop best practices for choosing biofumigants, growth conditions, and mulching methods that allow the greatest potential isothiocyanate release. We measured the glucosinolate concentrations of six different commercial varieties of three biofumigant plant species: Brassica juncea (ISCI99, Vitasso, and Scala) Raphanus sativus (Diablo and Bento), and Sinapis alba (Ida Gold). The plants were grown in the range of commercially appropriate seeding rates and sampled at three growth stages (early development, mature, and 50% flowering). Within biofumigant species, the highest ITC-release potentials were achieved with B. juncea cv. ISCI99 and R. sativus cv. Bento. The highest ITC-release potential occurred at the 50% flowering growth stage across the species. The seeding rate had a minor impact on the ITC-release potential of R. sativus but had no significant effects on the ITC-release potentials of the B. juncea or S. alba cultivars.

Development of an efficient glucosinolate extraction method.

BACKGROUND: Glucosinolates, anionic sulfur rich secondary metabolites, have been extensively studied because of their occurrence in the agriculturally important brassicaceae and their impact on human and animal health. There is also increasing interest in the biofumigant properties of toxic glucosinolate hydrolysis products as a method to control agricultural pests. Evaluating biofumigation potential requires rapid and accurate quantification of glucosinolates, but current commonly used methods of extraction prior to analysis involve a number of time consuming and hazardous steps; this study aimed to develop an improved method for glucosinolate extraction. RESULTS: Three methods previously used to extract glucosinolates from brassicaceae tissues, namely extraction in cold methanol, extraction in boiling methanol, and extraction in boiling water were compared across tissue type (root, stem leaf) and four brassicaceae species (B. juncea, S. alba, R. sativus, and E. sativa). Cold methanol extraction was shown to perform as well or better than all other tested methods for extraction of glucosinolates with the exception of glucoraphasatin in R. sativus shoots. It was also demonstrated that lyophilisation methods, routinely used during extraction to allow tissue disruption, can reduce final glucosinolate concentrations and that extracting from frozen wet tissue samples in cold 80% methanol is more effective. CONCLUSIONS: We present a simplified method for extracting glucosinolates from plant tissues which does not require the use of a freeze drier or boiling methanol, and is therefore less hazardous, and more time and cost effective. The presented method has been shown to have comparable or improved glucosinolate extraction efficiency relative to the commonly used ISO method for major glucosinolates in the Brassicaceae species studied: sinigrin and gluconasturtiin in B. juncea; sinalbin, glucotropaeolin, and gluconasturtiin in S. alba; glucoraphenin and glucoraphasatin in R. sativus; and glucosatavin, glucoerucin and glucoraphanin in E. sativa.

Collaborative goal setting with adults attending physiotherapy at a specialist neuromuscular centre: is it always appropriate? A cross-sectional survey.

OBJECTIVES: Collaborative goal setting is an integral component of treatment planning for adults with neuromuscular disorders (NMD). However, due to the unique challenges for these individuals, identifying a process for goal setting that is advantageous for all can be problematic. This study aimed to evaluate collaborative goal setting at a specialist NMD centre, as reported by service users attending physiotherapy. It also aimed to generate discussion about collaborative goal setting and the practice of goal setting in adults with NMD in order to inform future practice. SETTING: Specialist NMD community-based centre in the UK. PARTICIPANTS: One hundred and four adults with NMD who attended the centre. DESIGN: Cross-sectional survey. Thematic and content analyses of goals set were performed alongside demographic data collection. RESULTS: One hundred and four patients (34 females) with a range of neuromuscular conditions - including Becker, facioscapularhumeral, limb girdle, Duchenne and myotonic muscular dystrophies - completed the survey. Thirty-six respondents (37%) stated that they had set goals with the physiotherapist, whilst 62 (63%) stated that they had not set goals with the physiotherapist. Respondents' goals were grouped into four themes: symptom management, maintenance, improving physical condition, and learning to live with the condition. CONCLUSIONS: Readiness to take part in collaborative goal setting is unique to each individual. Physiotherapists need to be skilful in supporting adults with NMD through the goal-setting process until they are capable of sharing responsibility. Setting personal goals to improve emotional well-being may help to develop confidence to take more control of their situation, hence facilitating skills in self-management.

Hemiparasitic plant impacts animal and plant communities across four trophic levels.

Understanding the impact of species on community structure is a fundamental question in ecology. There is a growing body of evidence that suggests that both subdominant species and parasites can have disproportionately large effects on other organisms. Here we report those impacts for a species that is both subdominant and parasitic, the hemiparasite Rhinanthus minor. While the impact of parasitic angiosperms on their hosts and, to a lesser degree, coexisting plant species, has been well characterized, much less is known about their effects on higher trophic levels: We experimentally manipulated field densities of the hemiparasite Rhinanthus minor in a species-rich grassland, comparing the plant and invertebrate communities in plots where it was removed, present at natural densities, or present at enhanced densities. Plots with natural and enhanced densities of R. minor had lower plant biomass than plots without the hemiparasite, but enhanced densities almost doubled the abundance of invertebrates within the plots across all trophic levels, with effects evident in herbivores, predators, and detritivores. The hemiparasite R. minor, despite being a subdominant and transient component within plant communities that it inhabits, has profound effects on four different trophic levels. These effects persist beyond the life of the hemiparasite, emphasizing its role as a keystone species in grassland communities.

Investigating preference-performance relationships in aboveground-belowground life cycles: a laboratory and field study with the vine weevil (Otiorhynchus sulcatus).

The preference-performance hypothesis has principally considered insect herbivores with aboveground lifecycles, although the hypothesis could be equally relevant to insects with life stages occurring both aboveground and belowground. Moreover, most studies have focussed on either laboratory or field experiments, with little attempt to relate the two. In this study, the preference-performance hypothesis was examined in an aboveground-belowground context in the laboratory using the vine weevil (Otiorhynchus sulcatus (F.)) (Coleoptera: Curculionidae) and two cultivars of red raspberry (Rubus idaeus), Glen Rosa and Glen Ample. A two-year field study (2008-2009) was also undertaken to characterise the population dynamics of adult weevils on the two raspberry cultivars. Larval performance (abundance and mass) differed significantly between Glen Rosa and Glen Ample, with Glen Rosa resulting in 26% larger but 56% fewer larvae compared to Glen Ample. Larval abundances were significantly and positively correlated with root nitrogen and magnesium concentrations, but negatively correlated with root iron. However, concentrations of these minerals were not significantly different in the two cultivars. Adult weevils did not preferentially select either of the two cultivars for egg laying (laying 3.08 and 2.80 eggs per day on Glen Ample and Glen Rosa, respectively), suggesting that there was no strong preference-performance relationship between adult vine weevils and their belowground offspring. Field populations of adult vine weevils were significantly higher on Glen Ample than Glen Rosa, which may reflect the higher larval survival on Glen Ample observed in laboratory experiments.

Are silica defences in grasses driving vole population cycles?

Understanding the factors that drive species population dynamics is fundamental to biology. Cyclic populations of microtine rodents have been the most intensively studied to date, yet there remains great uncertainty over the mechanisms determining the dynamics of most of these populations. For one such population, we present preliminary evidence for a novel mechanism by which herbivore-induced reductions in plant quality alter herbivore life-history parameters and subsequent population growth. We tested the effect of high silica levels on the population growth and individual performance of voles (Microtus agrestis) reared on their winter food plant (Deschampsia caespitosa). In sites where the vole population density was high, silica levels in D. caespitosa leaves collected several months later were also high and vole populations subsequently declined; in sites where the vole densities were low, levels of silica were low and population density increased. High silica levels in their food reduced vole body mass by 0.5% a day. We argue that silica-based defences in grasses may play a key role in driving vole population cycles.

Food-plant effects on larval performance do not translate into differences in fitness between populations of Panolis flammea (Lepidoptera: Noctuidae).

In the UK, Panolis flammea (Denis & Schiffermüller) is a pest of monocultures of non-native lodgepole pine Pinus contorta Douglas, but not of the indigenous host Scots pine P. sylvestrisL. This difference in population dynamics may be due to the adaptation of P. flammea populations to the phenology, chemical composition and natural enemy complement of lodgepole pine. To ascertain if there was local adaptation of P. flammea populations to lodgepole pine, this study tested for improved performance of both larvae and adults on the host plant species from which they were sourced, compared with their performance on the alternative host plant species. No difference was found in the relative mean performance of populations sourced from Scots pine or lodgepole pine plantations, when fed on Scots or lodgepole pine foliage. Larvae grew faster on Scots pine but this difference did not translate into differences in pupal weight, female body weight or fecundity. Indeed, those insects that had fed on lodgepole pine had a longer lifespan than those that had fed on Scots pine, which, if translated into greater probability of mating or higher fecundity, could contribute to the observed outbreak dynamics in the field. The prediction that the observed outbreak dynamics of P. flammea can be explained by the existence of populations locally adapted to lodgepole pine was not supported. These results cast doubt on the use of larval growth parameters as surrogates of fitness in Lepidoptera.

Exclusion of grass roots from soil organic layers by Calluna: the role of ericoid mycorrhizas.

The role of ericoid mycorrhizal colonization in competition between the dwarf shrub Calluna vulgaris and coarse grass Nardus stricta was investigated. Nardus was grown alone, or in competition with Calluna, in a layered organic/sand substrate with and without inoculation with the ericoid mycorrhizal endophyte Hymenoscyphus ericae, and with and without the addition of nitrogen. Root length and allocation between different substrate layers was assessed along with plant biomass, nutrient uptake and mycorrhizal colonization. Calluna was the superior competitor for nutrients, probably because of its ability to concentrate root growth in the upper organic layer. In the presence of Calluna both the absolute amount and proportion of Nardus root length in the organic layer were reduced, and this reduction was greatest when Calluna was mycorrhizal. The presence of ericoid mycorrhizal colonization did not reduce Nardus shoot nutrient content or concentration, suggesting that ericoid mycorrhizal suppression of Nardus growth was not due to nutrient competition: alternative mechanisms of interference are discussed.

Disarmed by domestication? Induced responses to browsing in wild and cultivated olive.

Some theories of plant allocation to defence predict that chemical or structural defences against herbivores should be maximised when browsing is most likely to occur. However, plants are constrained by a trade-off between growth and defence such that slow-growing plants usually have higher levels of secondary compounds, such as phenolics and tannins, than faster-growing ones. Thus, it is possible that the selection for increased yield and growth rate that occurs when plants are domesticated, may cause a reduction in allocation to these compounds. We tested this hypothesis using wild (Olea europaea L. var. sylvestris Brot.) and cultivated (O. europaea L. var. europaea) olive growing in an area with high densities of ungulates. In our study, olives outside fences excluding ungulates were heavily browsed. However, browsing induced an increase in the phenolic content of olives of both varieties in winter but not in spring. In spring, new leaves of both varieties had generally higher levels of phenolics and nitrogen than old leaves, but new leaves in both varieties exposed to browsing had a lower nitrogen content compared to controls. Browsing in both olive varieties caused leaf and shoot density to increase and leaf and shoot length to decrease, but in wild olives browsed shoots lost their leaves and became similar to spines. Structural responses to browsing occurred in spring during regrowth, whilst chemical changes were more obvious in winter, in both varieties. We suggest that olive may exhibit both morphological and chemical responses to browsing, depending on the different resource allocation priorities at different times of year. In spring, independently of browsing, cultivated olive had generally longer shoots and lower levels of phenolics than wild olive. We speculate that domestication may have selected for faster growth, at the expense of allocation to secondary compounds.

The chemical composition of plant galls: are levels of nutrients and secondary compounds controlled by the gall-former?

The chemical composition of galled and ungalled plant tissue was compared in a series of experiments. Gall and adjacent plant tissue was analysed for 20 species of gall-former on 11 different plant species. There were clear differences between galled and ungalled tissue in levels of nutrients and secondary compounds. Gall tissue generally contained lower levels of nitrogen and higher levels of phenolic compounds than ungalled plant tissue. The gall tissue produced by the same plant in response to different species of gall-former differed in chemical composition, as did the gall-tissue from young and mature galls of the same species. The chemical differences between gall and plant tissues were studied in more detail in two field manipulations. Firstly, the seasonal changes in phenolic biosynthesis in Pontania proxima and P. pedunculi (Hymenoptera: Tenthredinidae) gall tissue were compared to those of their host plants, Salix alba and S. caprea. In both types of gall tissue, phenolic levels declined as the season progressed, but levels in the surrounding plant tissue increased. When the gall insects were killed with insecticide, phenolic levels in the galled tissue dropped to the same level as those in adjacent plant tissue. Secondly, the density of Cynips divisa (Hymenoptera: Cynipidae) galls on Quercus robur leaves was reduced by removing half the galls present, either those from the central region of the leaf or those from the edge. Decreasing gall density increased the size of the remaining galls and the weight of the insects, but these effects were most marked when the galls remaining were growing centrally on the leaf, i.e. when the galls from the edge had been removed. Decreasing gall density increased the nitrogen content of the remaining galls, again to a greater extent in galls growing centrally on the leaf. The results of these studies suggest that the levels of nutrients and secondary compounds in gall tissue are usually markedly different to those of surrounding plant tissue, and that gall-formers may produce species-specific and temporally variable changes in the chemical composition of gall tissue.

C, Q, and restriction enzyme banding of the chromosomes in brook trout (Salvelinus fontinalis) and Arctic charr (Salvelinus alpinus).

The brook trout (Salvelinus fontinalis) and the Arctic charr (Salvelinus alpinus) represent different phylogenetic lines of the salmonid fish genus Salvelinus. Chromosome banding studies utilizing C, Q, and restriction enzymes reveal differences between the two species for the amount and sequence composition of their heterochromatic DNA. Arctic charr, the more recently evolved of the two species, possesses more C and Q bands than the brook trout. With the exception of Alu I, the banding patterns produced by restriction enzymes bear a close resemblance to the C band pattern. Alu I eliminates staining from large pericentromeric regions, including the centromeric heterochromatin, in the chromosomes of both species and from some telomeric regions in Arctic charr. These findings show that the evolutionary divergence of the Arctic charr from the brook trout has been accompanied by accumulation of heterochromatic DNA and subsequent sequence divergence.

Phenolic biosynthesis, leaf damage, and insect herbivory in birch (Betula pendula).

The effect of both caterpillar herbivory and artificial damage on phenylalanine ammonia lysase (PAL) activity of birch foliage was measured, using an intact cell assay. After artificial damage there was a small increase in PAL activity in damaged leaves but no change in adjacent undamaged ones. Insect grazing produced a larger increase in PAL activity, and the enzyme activity was also increased in adjacent undamaged leaves. Artificial damage increased the phenolic levels of the damaged leaves. Insect grazing caused a larger, longer-lasting increase in phenolic levels and also elevated phenolic levels in undamaged leaves. The possible role of these wound-induced biochemical changes in birch is discussed.

The inhibition of phenolic biosynthesis in damaged and undamaged birch foliage and its effect on insect herbivores.

1. The leaves of Betula pendula Roth trees were damaged artificially, or by insect-grazing. Both induced an increase in phenolic levels in damaged leaves, larger in the case of insect attack.-2. Some of the damaged trees were sprayed with an inhibitor of phenolic biosynthesis, (aminoxy) acetic acid, which led to a reduction in phenolic levels in both undamaged and damaged leaves. Hence both the effects of damage per se and damage-induced changes in foliage phenolic levels on insect feeding preference could be examined using this technique.-3. Herbivore feeding preferences were assessed in the laboratory by comparing damaged and undamaged leaves, with or without phenolic inhibition, using caterpillars of a natural birch feeder, Apocheima pilosaria D. & S. (Lepidoptera: Geometridae) and a non-birch feeder, Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae). Neither species showed any significant preferences and appeared indifferent to damage, irrespective of whether the trees had their damage-induced phenolic synthesis blocked.-4. The implications of these results for "induced defense" theory are discussed.

Effects of different types of damage on the chemistry of birch foliage, and the responses of birch feeding insects.

1. We collected insect-grazed, mined, and holepunched leaves of Betula pendula Roth, and assessed their palatability to four species of birch-feeding lepidopteran caterpillars (Apocheima pilosaria D. & S., Erranis defolaria Clerck, Epirrita dilutata D. & S., and Euproctis similis Fuessly) in laboratory preference tests. The palatability of hole-punched leaves of different ages was also determined, using Apocheima pilosaria only. 2. The total phenolic content and protein-precipitating ability of undamaged and all three types of damaged leaves was measured, together with the water content of mined, insect-grazed and undamaged leaves. 3. Only the mined leaves were consistently avoided in the feeding trials; the other sorts of damage were often preferred by the caterpillars, even though phenolic levels increased in all the damaged leaves. The insects appeared either to be indifferent to changes in the protein-precipitating ability of leaves, or actually preferred leaves showing the largest increase. 4. The results show clear qualitative as well as quantitative differences in birch's response to different types of damage. They also show that herbivore preferences depend upon both the damage type and the species of insect being tested. Preferences are difficult or impossible to relate to changes in phenolic levels, or to the protein-precipitating ability of leaves. The possible consequences of these results for 'induced defense' theory are discussed.

Chromosome relationships in the genus Salmo.

Chromosome numbers and polymorphisms in rainbow trout, Atlantic salmon, and brown trout are described. The karyotypes of these three species are compared with each other and with those of other salmonid fish from the genera Salmo, Salvelinus, and Oncorhynchus. Karyotype evolution from a postulated ancestral tetraploid is discussed.

Chromosome polymorphism in the rainbow trout (Salmo gairdneri Richardson).

Chromosome preparations from lymphocyte cultures of 50 rainbow trout were studied. Diploid chromosome numbers of 59, 60, 61, 62 and 63 were found in different individuals in which the arm number (NF) was 104. Intraindividual polymorphism was found at a low level in 25 of the fish. The results suggest that numerous chromosome polymorphisms exist in rainbow trout.

Cytogenetic follow-up in chronic myeloid leukemia.

Twenty-six patients with Philadelphia chromosome (Ph1)-positive chronic myeloid leukaemia have been followed-up cytogenetically. Twelve patients were found to have chromosome abnormalities in addition to the Ph1, either in the chronic phase or during progression of disease. The most common abnormality observed was an additional chromosome No. 19 although trisomy 8, a second Ph1 and isochromosome 17 were also observed.

The 5q - chromosome in a case of erythroid hypoplasia.

A case of erythroid hypoplasia with refractory anemia and an interstitial deletion of the long arm of one chromosome No. 5 is described. This 5q- anomaly has been previously described in cases of refractory anemia with erythroid hypoplasia or hyperplasia, and acute myelogenous leukemia. The relationship between the 5q- chromosome and associated clinical features is discussed together with evidence against a geographical localization.

Eosinophilic leukaemia in association with a double Philadelphia chromosome.

A case of eosinophilic leukaemia in association with chromosomal abnormalities including a double Philadelphia chromosome is reported. Comment is also made on the cardiological problems which arise in this condition.