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The EndoRings device is a distal attachment consisting of two layers of circular flexible rings that evert mucosal folds. The aim of this study was to investigate whether EndoRing assisted colonoscopy (ER) improves polyp and adenoma detection compared to standard colonoscopy (SC).Multicenter, parallel group, randomized controlled trial.Total of 556 patients randomized to ER (n = 275) or SC (n = 281). Colonoscopy completed in 532/556 (96%) cases. EndoRings removed in 74/275 (27%) patients. Total number of polyps in ER limb 582 vs. 515 in SC limb, P = 0.04. Total number of adenomas in ER limb 361 vs. 343 for SC limb, P = 0.49. A statistically significant difference in the mean number of polyps per patient in both the intention to treat (1.84 SC vs. 2.10 ER, P = 0.027) and per protocol (PP) (1.84 SC vs. 2.25 ER, P = 0.004).Our study shows promise for the EndoRings device to improve polyp detection.

Background Few data exist describing laboratory related failure rates in prenatal diagnosis. The aim of this study is to assess the laboratory associated failure rate for karyotype, QF-PCR and CGH-array following amniocentesis in relation to gestation. Methods Retrospective database study of amniocenteses performed 2004-2014 comparing laboratory failure rate for karyotype, QF-PCR and CGH-array between 16 + 0 and 40 + 0 weeks' gestation. Results A total of 10 484 amniotic fluid test results were collected in three databases. Karyotype failed in 41/1797 (2.3%) tests; failure rate was significantly greater with advancing gestation reaching 43% at 36-40 weeks. QF-PCR failed in 132/5715 tests (2.3%) and was significantly greater with advancing gestation reaching 7% at 36-40 weeks. For CGH-array, 10/298 tests (3.4%) failed analysis. In one case, no result was obtainable by any technique. Conclusions These data provide gestation specific laboratory failure rates for amniocentesis enabling informed decisions about the timing and laboratory technique most applicable to the clinical situation. Before 20 weeks, karyotype is least likely to fail of the three techniques. However, in the late third trimester, QF-PCR and, in particular, karyotyping are more likely to fail than CGH-array. Although there is some overlap between the three different tests, they may be preferentially offered in different clinical scenarios. © 2016 John Wiley & Sons, Ltd.

Resilience of rice cropping systems to potential global climate change will partly depend on the temperature tolerance of pollen germination (PG) and tube growth (PTG). Pollen germination of high temperature-susceptible Oryza glaberrima Steud. (cv. CG14) and Oryza sativa L. ssp. indica (cv. IR64) and high temperature-tolerant O. sativa ssp. aus (cv. N22), was assessed on a 5.6–45.4 °C temperature gradient system. Mean maximum PG was 85% at 27 °C with 1488 μm PTG at 25 °C. The hypothesis that in each pollen grain, the minimum temperature requirements (Tn) and maximum temperature limits (Tx) for germination operate independently was accepted by comparing multiplicative and subtractive probability models. The maximum temperature limit for PG in 50% of grains (Tx(50)) was the lowest (29.8 °C) in IR64 compared with CG14 (34.3 °C) and N22 (35.6 °C). Standard deviation (sx) of Tx was also low in IR64 (2.3 °C) suggesting that the mechanism of IR64's susceptibility to high temperatures may relate to PG. Optimum germination temperatures and thermal times for 1 mm PTG were not linked to tolerating high temperatures at anthesis. However, the parameters Tx(50) and sx in the germination model define new pragmatic criteria for successful and resilient PG, preferable to the more traditional cardinal (maximum and minimum) temperatures.

Extreme temperature during reproductive development affects rice (Oryza sativa L.) yield and seed quality. A controlled-environment reciprocal-transfer experiment was designed where plants from two japonica cultivars were grown at 28/24 ⁰C and moved to 18/14 ⁰C and vice versa, or from 28/24 to 38/34 ⁰C and vice versa, for 7-d periods to determine the respective temporal pattern of sensitivity of spikelet fertility, yield, and seed viability to each temperature extreme. Spikelet fertility and seed yield per panicle were severely reduced by extreme temperature in the 14 d period prior to anthesis; and both cultivars were affected at 38/34 ⁰C while only cv. Gleva was affected at 18/14 oC. The damage was greater the earlier the panicles were stressed within this period. Later-exserted panicles compensated only partly for yield loss. Seed viability was significantly reduced by 7-d exposure to 38/34 ⁰C or 18/14 ⁰C at 1 to 7 and 1 to 14 d after anthesis, respectively, in cv. Gleva. Cultivar Taipei 309 was not affected by 7 d exposure at 18/14 ⁰C; and no consistent temporal pattern of sensitivity was evident at 38/34 ⁰C. Hence, brief exposure to low or high temperature was most damaging to spikelet fertility and yield 14 to 7 d before anthesis, coinciding with microsporogenesis; and it was almost as damaging around anthesis. Seed viability was most vulnerable to low or high temperature in the 7 or 14 d after anthesis, when histodifferentiation occurs.

Adult degree programs have been seen as a win-win solution for private colleges and adult learners, but their innovative and often-entrepreneurial postures are not a natural fit with governance structures in more traditional institutions. Through narrative and illustrative vignettes, this chapter presents an overview of efforts employed by some institutions to strike a balance between their historic missions and these nontraditional programs.

Two cases of unusual transmissible spongiform encephalopathy (TSE) were diagnosed on the same farm in ARQ/ARQ PrP sheep showing attributes of both bovine spongiform encephalopathy (BSE) and scrapie. These cases, UK-1 and UK-2, were investigated further by transmissions to wild-type and ovine transgenic mice. Lesion profiles (LP) on primary isolation and subpassage, incubation period (IP) of disease, PrP(Sc) immunohistochemical (IHC) deposition pattern and Western blot profiles were used to characterize the prions causing disease in these sheep. Results showed that both cases were compatible with scrapie. The presence of BSE was contraindicated by the following: LP on primary isolation in RIII and/or MR (modified RIII) mice; IP and LP after serial passage in wild-type mice; PrP(Sc) deposition pattern in wild-type mice; and IP and Western blot data in transgenic mice. Furthermore, immunohistochemistry (IHC) revealed that each case generated two distinct PrP(Sc) deposition patterns in both wild-type and transgenic mice, suggesting that two scrapie strains coexisted in the ovine hosts. Critically, these data confirmed the original differential IHC categorization that these UK-1 and UK-2 cases were not compatible with BSE.

In general, agricultural management has focused on differences between fields or on the gross differences within them. Recent developments in agricultural technology, yield mapping, Global Positioning Systems and variable rate applications, have made it possible to consider managing the considerable variation in soil and other properties within fields. This system is known as precision agriculture. More precise management of fields depends on a better understanding of the factors that affect crop input decisions. This paper examines the spatial variation in crop yield, soil nutrient status and soil pH within two agricultural fields using geostatistics. The observed properties vary considerably within each field. The relation between yield and the measured soil properties appears to be weak in general. However, the range of spatial correlation for yield, shown by the variogram, is similar to that of the soil chemical properties. In addition the latter changed little over two years. This suggests that information on the scale of variation of soil chemical properties can be derived from yield maps, which can also be used as a guide to a suitable sampling interval for soil properties.

Enteroviruses such as coxsackievirus B4 (CVB4) are proposed as possible environmental triggers or accelerants of the autoimmune process that leads to type 1 diabetes mellitus. One putative mechanism to account for this association is mimicry between virus components and islet autoantigens. Particular interest has focused on the CVB4 non-structural protein P2C, which we previously showed to be a major target of the effector memory anti-CVB4 CD4 T-cell response, and which harbours a region of sequence similarity with the islet autoantigen, glutamic acid decarboxylase (GAD65). Since several distinct human leucocyte antigen (HLA) Class II molecules are associated with development of type 1 diabetes, we hypothesized that for functional mimicry to be important, any potential region(s) of mimicry in P2C should bind to each of these susceptibility molecules. In the present study therefore we examined the affinity of 20-mer overlapping P2C peptides for soluble HLA-DR4, -DR3, -DQ2 and -DQ8. We identified one discrete region of P2C with high binding affinities for all of these HLA Class II molecules. Moreover, the binding affinity of P2C peptides was significantly correlated between HLA molecules present on the same susceptibility haplotype (e.g. DR4 and DQ8, P =0.0076; DR3 and DQ2 P = 0.002). We conclude that possession of these haplotypes favours restricted presentation of viral epitopes, and speculate that this could promote the potential for mimicry between microbial proteins and islet autoantigens.

Field experiments were carried out to assess the effects of nitrogen fertilization and seed rate on the Hagberg falling number (HFN) of commercial wheat hybrids and their parents. Applying nitrogen (200 kg N ha(-1)) increased HFN in two successive years. The HFN of the hybrid Hyno Esta was lower than either of its parents (Estica and Audace), particularly when nitrogen was not applied. Treatment effects on HFN were negatively associated with a-amylase activity. Phadebas grain blotting suggested two populations of grains with different types of a-amylase activity: Estica appeared to have a high proportion of grains with low levels of late maturity endosperm a-amylase activity (LMEA); Audace had a few grains showing high levels of germination amylase; and the hybrid, Hyno Esta, combined the sources from both parents to show heterosis for a-amylase activity. Applying nitrogen reduced both apparent LMEA and germination amylase. The effects on LMEA were associated with the size and disruption of the grain cavity, which was greater in Hyno Esta and Estica and in zero-nitrogen treatments. External grain morphology failed to explain much of the variation in LMEA and cavity size, but there was a close negative correlation between cavity size and protein content. Applying nitrogen increased post-harvest dormancy of the grain. Dormancy was greatest in Estica and least in Audace. It is proposed that effects of seed rate, genotype and nitrogen fertilizer on HFN are mediated through factors affecting the size and disruption of the grain cavity and therefore LMEA, and through factors affecting dormancy and therefore germination amylase. (c) 2004 Society of Chemical Industry.

Onion (Allium cepa) was grown in the field within temperature gradient tunnels (providing about -2.5 degrees C to +2.5 degrees C from outside temperatures) maintained at either 374 or 532 mumol mol (-1) CO2. Plant leaf area was determined non-destructively at 7 day intervals until the time of bulbing in 12 combinations of temperature and CO2 concentration. Gas exchange was measured in each plot at the time of bulbing, and the carbohydrate content of the leaf (source) and bulb (sink) was determined. Maximum rate of leaf area expansion increased with mean temperature. Leaf area duration and maximum rate of leaf area expansion were not significantly affected by CO2. The light-saturated rates of leaf photosynthesis (A(sat)) were greater in plants grown at normal than at elevated CO2 concentrations at the same measurement CO2 concentration. Acclimation of photosynthesis decreased with an increase in growth temperature, and with an increase in leaf nitrogen content at elevated CO2. The ratio of intercellular to atmospheric CO2 (C-i/C-a ratio) was 7.4% less for plants grown at elevated compared with normal CO2. A(sat) in plants grown at elevated CO2 was less than in plants grown at normal CO2 when compared at the same C-i Hence, acclimation of photosynthesis was due both to stomatal acclimation and to limitations to biochemical CO2 fixation. Carbohydrate content of the onion bulbs was greater at elevated than at normal CO2. In contrast, carbohydrate content was less at elevated compared with normal CO2 in the leaf sections in which CO2 exchange was measured at the same developmental stage. Therefore, acclimation of photosynthesis in fully expanded onion leaves was detected despite the absence of localised carbohydrate accumulation in these field-grown crops.

Domestication and subsequent genetic enhancement in lentil (Lens culinaris Medik.) have involved changes in plant structure and DM distribution. These changes were examined using a genetic gradient comprising three representatives each of Lens orientalis (Boiss.) progenitors, landraces, pre-1980 cultivars, and modern germplasm. All 12 genotypes were sown at Pullman, WA, in 1996 and 1997, and at Reading, UK, in 1997. The biomass (all genotypes) and N concentration (four genotypes) of above-ground tissues were measured at 50% flowering (leaf and stem) and at reproductive maturity (leaf, stem, pod wall and seed). The progenitors produced meager biomass (averaging 0.72 Mg ha -1 ) and poor HI (0.19), and consequently small seed yields (0.11 Mg ha -1 ). Productive landraces had substantially higher biomass (3.52 Mg ha -1 ), improved HI (0.34), and larger seed yields (1.13 Mg ha -1 ). Biomass and seed yield were increased further by the selection of cultivars (5.11 and 1.32 Mg ha -1 , respectively). The development of modern germplasm by hybridization further increased seed yields (1.95 Mg ha -1 ). Consistent seed yield improvements have not been associated with consistent increases in HI. Instead a strong, positive correlation between seed yield and biomass has persisted. NHI increased more rapidly than HI and is unlikely to increase further in the future. Future seed yield improvement will therefore depend on increased N accumulation. Reliance on N 2 fixation must be supported by increased photosynthetic capacity and therefore by vegetative biomass. An advantageous correlation between seed yield and residue production seems likely to persist as crop improvement continues.

Episodes of high temperature and drought are predicted to occur more frequently under conditions of future climate change. This study investigated whether an episode of high air temperature (HT, +15°C), water deficit (WD), or both (HTWD), for 8 d, had the same effects on the yield of soybean [Glycine max (L.) Merrill, cv. Fiskeby V] grown under either ambient (aCO 2 ; 360 μmol mol -1 CO 2 ) or elevated (eCO 2 ; 700 μmol mol -1 CO 2 ) CO 2 concentrations. Plants were grown in a glasshouse at either aCO 2 or at eCO 2 until 52 d after sowing (DAS). The 8-d stress treatments were then imposed before the plants were returned to their original environments. Across harvests, total biomass was 41% greater under eCO 2 than under aCO 2 but reduced by HT, WD, and HTWD under both CO 2 concentrations. The relative response of total biomass to HT, WD, and HTWD episodes was the same for plants grown under either aCO 2 or eCO 2 . At maturity, seed dry weight and number per plant under eCO 2 were increased by an average of 32 and 22%, respectively, compared with aCO 2 . The same parameters were reduced after HTWD by 29 and 30%, respectively, in aCO 2 and eCO 2 . Seed filling was earlier under HT and HTWD. The rate of change in harvest index was unaltered by CO 2 while under HTWD, it decreased. Seed number explained 85% of the variation in yield, but yield was also related linearly to photosynthesis during seed filling, suggesting both are important determinants of yields under stress.

The use of Mucuna spp. in cover crop and green manure technologies is proving to be successful in the tropics and subtropics following intensive efforts in technology transfer to farmers by NGOs (Non-Governmental Organizations). This includes the transfer of seeds of Mucuna spp. for which the range of adaptation and the effect of environment on crop phenology are poorly understood. A selection of Mucuna spp. germplasm was evaluated over a range of contrasting photothermal conditions in controlled-environment glasshouses. Dates of emergence and first flowering were recorded. Where possible, triple-plane rate of development models were fitted to the first flowering data to quantify the relative sensitivity of each species to photoperiod and temperature. All accessions showed short-day responses but there were substantial differences in the sensitivity of rate of progress to first flowering to environment, particularly to photoperiod. This results in differences in maturity period between accessions which, with appropriate understanding, could be functionally exploited by NGOs and NARS. However, if ignored, it could result in the promotion and use of accessions ill adapted to the environment in which they are tested. In consequence there might be unnecessary resistance from farmers to the adoption of green manure and cover crops technologies which are vital to the design and maintenance of sustainable farming svstems in low-income countries in the tropics.

Carbon isotope discrimination (A) and specific leaf area (SLA) have been shown to be correlated with water-use efficiency (WUE) of peanut (Arachis hypogaea L.) and SLA has been proposed as an indirect selection criterion for Δ and WUE. The effect of high temperature and water deficit on WUE, A, and SLA, and relations between them, was investigated in controlled environments. Five Spanish (A. hypogaea ssp.fastigiata) and three Virginia (A. hypogaea ssp. hypogaea, botanical type) lines were grown at mean temperatures of 27 and 34°C and at 50 and 100% available soil water (ASW) from first flowering to maturity, and WUE, A and SLA measured at maturity. Virginia genotypes had higher total dry matter, water use and WUE (P < 0.01), but were more sensitive to high temperature (P < 0.01) than Spanish genotypes. Water defidt reduced water use and SLA, and increased WUE. The only water deficit × temperature interaction (P < 0.05) was for A, where water deficit reduced the value of Δ at 27° but not at 34°C. High temperature had no effect on water use, but decreased WUE and increased SLA. Across all water defidt and temperature treatments (n = 32), WUE was correlated with Δ (r = -0.78, P < 0.001) and SLA (r = - 0.70, P < 0.001), and SLA correlated with A (r = 0.75, P < 0.001) with no difference associated with botanical type. Temperature and water deficit had significant (P ≤ 0.05) effects on the intercept, but not the slope of these relations. The results support the view that SLA can be used as an indirect selection criterion for Δ and WUE in genotypic selection.

Elevated CO 2 (691 cf. 371 μmol CO 2 mol -1 air) and warmer temperatures (over the range 1.0°C below to 1.6°C above ambient) increased light interception by crops of two contrasting cultivars (Hereward and Soissons) of winter wheat (Triticum aestivum L.) during winter growth in the field. The fractional interception of light by the canopy increased more rapidly initially in Soissons than in Hereward, but Hereward showed a much greater response to CO 2 (35% increase in Hereward but only 7% in Soissons) at 500°Cd after sowing. By terminal spikelet formation, in contrast, fractional interception was greater in Hereward than in Soissons, while the effect of CO 2 was the same in both cultivars (9%). Thus, although differences in the relative response of canopy development to CO 2 were detected between cultivars initially, differences were negligible during later development. The greater interception of light by the canopy in elevated CO 2 , at any one temperature, resulted from increased tillering. The number of tillers plant -1 at terminal spikelet was a linear function of main stem dry mass at this developmental stage but with a greater response in elevated CO 2 , viz 2.3 and 3.8 tillers g -1 main stem dry mass at 371 and 691 μmol CO 2 mol -1 air, respectively; these relations were unaffected by cultivar.

Leaf-tip appearance and duration from planting to panicle initiation (PI) are important developmental processes in cereals. This study was conducted to determine the effect of air temperature on rates of leaf-tip appearance and 1/PI for sorghum [Sorghum bicolor (L.) Moench]. Nine genotypes were grown in pots at mean temperatures of 17 to 33°C and photoperiods of 11.0 to 123 h d -1 in glasshouses. Leaf-tip appearance was recorded every 3 to 5 d and PI determined by apical dissection. The optimum temperature (T o ) for 1/PI was between 26 and 27°C and supra-optimal temperatures delayed PI in all genotypes. The base temperature (T b ) ranged from 6 to 10°C but only one genotype had a T b significantly different from a common value of 8.5°C. Growing degree days (GDD) for PI among genotypes at sub-optimal temperatures varied from 411 to 592 (P 27°C) reduced the rate of leaf-tip appearance in five genotypes; in the remaining genotypes the rate of leaf appearance was effectively constant at mean temperatures between 23 and 33°C. There was no significant difference (P > 0.20) among genotypes in the phyllochron, which was 57 GDD above a T b of 8.5°C. The final number of leaf-tips was constant within genotypes at mean temperatures of 18 to 30°C, but varied among genotypes from 11.8 to 17.3. In conclusion, the T b and T o for 1/PI were approximately 8.5 and 27°C and there was variation in 1/PI but not in the rate of leaf-tip appearance among the genotypes studied.

Episodes of high temperature and water deficit may be more frequent under predicted future climates of warmer mean temperatures and elevated CO 2 . This study investigated whether the effects of an episode of high air temperature (HT, 43°C as a daily maximum), water deficit (WD), or both, had the same effect on the recovery of photosynthesis and on leaf water relations of soybean [Glycine max (L.) Merr., cv. Fiskeby V] grown at ambient CO 2 (aCO 2 ) or elevated CO 2 (eCO 2 ). An 8-d period of HT, WD, or both (HTWD) were imposed during early seed filling of soybean grown in glasshouses at either 362 or 685 μmol mol -1 CO 2 . Photosynthesis (Amax), stomatal conductance (g s ), and water relations were measured in fully expanded upper-canopy leaves. Immediately after the 8-d treatments at 60 d after sowing (DAS), Amax was reduced by 31, 48, and 64% in aCO 2 and by 28, 39, and 49% in eCO 2 under HT, WD, and HTWD, respectively, but no significant interactions were detected. At 60 DAS, g s was reduced by WD and HTWD in aCO 2 but not by HT while there was little change in g s by WD, HT, and HTWD under eCO 2 . Amar fully recovered under WD in eCO 2 by 66 DAS, while Amax remained reduced under WD in aCO 2 . Under each CO 2 concentration, almost full recovery of Amax occurred under HT by 75 DAS but under HTWD Amax never attained control values. At 60 DAS, early morning leaf water potential (Ψ) was lower after HT, WD, and HTWD and Amax was a negative function of Ψ, at each CO 2 concentration. The results suggest that full recovery of Amax from WD was only possible under eCO 2 , because at aCO 2 , immediately after the stress episode, Ψ was below the threshold for chloroplast damage.

The yield of groundnut (Arachis hypogaea L.) grown in West African environments is often limited by high temperatures. We tested whether or not differences in the tolerance of groundnut genotypes to high temperature episodes are due to genotypic differences in the rates of dry matter partitioning to yield. A high temperature tolerant (HIT) and a high temperature sensitive (HTS) genotype were grown in a polyethylene-covered greenhouse (polytunnel) at 30/25°C (day/ night) until after the start of pegging (49 d after planting, DAP). Then, cohorts of each genotype were exposed for 6 d to four different constant day temperatures between 30 and 50°C before returning to the common environment until harvest maturity (98 DAP). Total plant biomass and seed yield at 98 DAP were reduced by the hottest temperature episodes and were less in the HTS compared with the HIT genotype. Proportional reduction in biomass and seed yield due to high temperature stress was greater in the HTS than the HTT genotype. The root/total biomass ratio declined more rapidly after flowering in the HTS compared with the HTT genotype. The start of seed-filling was delayed by progressively hotter temperature episodes and was 11.7 d later in the HTS than the HTT genotype. However, the rate of increase in seed harvest index during seed filling was 0.0068 d -1 for both genotypes and was not affected by high temperature stress. We conclude that genotypic differences in the response of groundnut yield to episodes of high temperature stress were due to differences in the timing of seed filling rather than to genotypic differences in the rate of dry matter partitioning to fruits.

Models of the giant squid (Architeuthis spp.) are probably unique in natural history exhibition: they are representations of a giant living animal that has never been seen in a healthy state by a human being. Since its discovery in the mid-nineteenth century, the giant squid has remained one of the world's great zoological mysteries. In the attempt to introduce this fabulous creature, museums around the world have resorted to life-sized models. Yale teuthologist A.E. Verrill was responsible for the first such models in 1882; then Ward's Natural Science Establishment in Rochester, New York, manufactured and sold them. In this century, various museums (and one zoo) have made their own models of these ten-armed monsters of the deep. Their disparate attempts to re-create Architeuthis for the museum public represent one of the most intriguing case histories in the annals of museum exhibition.

A temperature gradient chamber (TGC) is described which enables elevated CO 2 concentrations and a dynamic temperature gradient to be imposed on field crops throughout their life cycle under standard husbandry. Air is circulated through two double-walled polyethylene-covered tunnels connected to a split heat pump system to give a near-linear temperature gradient along each tunnel. Solar energy gain along each tunnel and exchange with outer tunnel air flow contribute to the temperature gradient and also produce diurnal and seasonal temperature fluctuations corresponding to ambient conditions. Mean temperature gradients of between 3 and 5 °C have been recorded throughout the growing seasons of crops of lettuce, carrot, cauliflower and winter wheat. Elevated or present CO 2 concentrations are maintained in each of two pairs of tunnels throughout the cropping season using pure CO 2 injected through motorized needle valves. This system can realistically simulate aspects of the effects of projected future environmental change on crop growth, development and yield, and in particular the possible interaction of the effects of increased CO 2 and temperature.

Stands of carrot (Daucus carota L.) were grown in the field within polyethylene-covered tunnels at a range of soil temperatures (from a mean of 7·5°C to 10·9°C) at either 348 (SE = 4·7) or 551 (SE = 7·7) μmol mol−1 CO2. The effect of increased atmospheric CO2 concentration on root yield was greater than that on total biomass. At the last harvest (137d from sowing), total biomass was 16% (95% CI = 6%, 27%) greater at 551 than at 348 μmol mol−1 CO2, and 37% (95% CI = 30%, 44%) greater as a result of a 1°C rise in soil temperature. Enrichment with CO2 or a 1°C rise in soil temperature increased root yield by 31% (95% CI = 19%, 45%) and 34% (95% CI = 27%, 42%), respectively, at this harvest. No effect on total biomass or root yield of an interaction between temperature and atmospheric CO2 concentration at 137 DAS was detected. When compared at a given leaf number (seven leaves), CO2 enrichment increased total biomass by 25% and root yields by 80%, but no effect of differences in temperature on plant weights was found. Thus, increases in total biomass and root yield observed in the warmer crops were a result of the effects of temperature on the timing of crop growth and development. Partitioning to the storage roots during early root expansion was greater at 551 than at 348 μmol mol−1 CO2. The root to total weight ratio was unaffected by differences in temperature at 551 μmol mol−1CO2, but was reduced by cooler temperatures at 348 μmol mol−1 CO2. At a given thermal time from sowing, CO2 enrichment increased the leaf area per plant, particularly during early root growth, primarily as a result of an increase in the rate of leaf area expansion, and not an increase in leaf number.

Summary Changes in seed quality in pepper (Capsicum annuum L.) were monitored during seed development and maturation in two seasons. Seed quality was assessed by a number of different tests, but principally by determining seed storage longevity in laboratory tests and seedling growth in glasshouse tests. Mass maturity (defined as the end of the seed-filling phase) occurred 49–53 days after anthesis (DAA) in 1989 (varying among fruit layers) and 53 DAA in 1990 when seed moisture contents were 51–53%. The onset of both germinability and desiccation tolerance occurred either just before or at mass maturity. Maximum potential longevity (assessed by the value of the seed lot constant Ki) was achieved 63–65 DAA, i.e. not until 10–12 days after mass maturity (DAMM), in both years. Seedling dry weights in the glasshouse growth tests were maximal later still - for seeds harvested 17–21 DAMM in 1989 and 17 DAMM in 1990; the effects on seedling weight arose from differences in times from sowing to emergence (P 0.25). Seed priming reduced mean germination times for seeds harvested at all stages of development, but had little effect on germination capacity and potential longevity, and did not affect the pattern of changes in potential longevity during seed development and maturation. The results contradict the hypothesis that seed quality is maximal at the end of the seed-filling phase and that viability and vigour begin to decline immediately thereafter.

Summary The storage potential of seeds harvested at weekly intervals after controlled pollination was studied in three diverse cytoplasmic male sterile pearl millet (Pennisetum glaucum) lines. In the first experiment in 1989, a comparison of p50 (time for viability to decline to 50% during storage) among seeds of the line DSA 105A harvested 14, 21, 28, 35 and 42 days after pollination (DAP), and then stored at 35°C with 15% moisture content or 40°C with 13% moisture content, showed that those harvested 35 DAP had the greatest longevity. In the second experiment in 1990, a comparison of p50 within the lines 5141A and L 67A harvested 28, 35 and 42 DAP, and then stored at 40°C with 13% moisture content, showed that seeds of both lines harvested 42 DAP had the greatest longevity. In both the seasons, and in all three lines, maximum seed longevity (p50) was attained one week after physiological maturity (defined as the end of the grain filling period), which is therefore the optimum time of harvest to obtain good quality seeds for conservation.

SUMMARY Differences in maturation drying and desiccation tolerance during seed development were detected between the two contrasting Acer spp., Norway maple (Acer platanoides L.), which shows orthodox seed storage behaviour, and sycamore (A. pseudoplatanus L.), which shows recalcitrant seed storage behaviour. In both species, the onset of germinability (150 d tests at 5 °C) occurred after percentage seed moisture content had begun to decline, but before net loss in seed moisture. The onset of germinability in Norway maple occurred 4 wk before physiological maturity (i.e. 4 wk before the end of the increase in seed dry matter), whereas in sycamore it occurred some ten weeks before physiological maturity when the seeds were only 60 % filled. Seeds of Norway maple were able to tolerate enforced rapid desiccation to 10% moisture content (f. wt) at physiological maturity, when maturation-drying had reduced seed moisture content to 54 %. Between 2 and 4 wk later seed moisture content rapidly declined naturally to 25 %, at which value the fruits were shed. In contrast, a constant rate of maturation-drying was observed in sycamore. The seeds were shed at 58 % moisture content and, in almost all cases, the seeds were intolerant of rapid desiccation to c. 10 % moisture content throughout seed development. A very small proportion of sycamore seeds did survive rapid desiccation when harvested between 6 September and 4 October, but no seeds survived desiccation to 5 % moisture content or below. A comparison of the germination of sycamore seeds harvested on four dates and dried to various moisture contents showed that the seeds tolerated greater desiccation as they matured between 12 July and 20 September, but there was no further change thereafter. The results are therefore compatible with previous classifications of seed storage behaviour in each species, and with the view that the initial decline in seed moisture content stimulates the developmental switch which results in the onset of germinability in both orthodox and recalcitrant seeds.

SUMMARY The possibility that pellets of the molluscicide Draza (a.i. methiocarb) might reduce field emergence of seeds of winter oilseed rape (Brassica napus, cv. Jet Neuf) when sown admixed, laboratory germination when stored admixed, or field emergence when both stored and sown admixed was the subject of three separate investigations. Admixture at sowing did not influence the emergence of five seed lots (P > 0·05). Neither did admixture influence loss in germination or change in moisture content during 2 months' storage of one lot in four different regimes (P > 0·05). Field emergence following 2 months' storage in paper bags was not influenced by admixture (P > 0·05), whereas a 12% reduction in field emergence resulting from storage in admixture within polyethylene bags was detected (P < 0·05). Thus short-term storage within paper sacks of winter oilseed rape seeds in admixture with slug pellets containing methiocarb did not damage the seeds. The emergence of five seed lots differed considerably within and between field sowings. Tentative advice on the calculation of sowing rates for different seed lots of winter oilseed rape is provided to account for this variation.

Summary The germination response of seeds of Brnmus mollis L. and B. sterilis L. to white fluorescent light was studied over a wide range of photon flux densities and photoperiods. Photon doses below 3 × 10−3 mol m−8 d−1 had little effect on the percentage germination of either species, although in B. sterilis photon doses as low as 10−4 mol m−2 d−1 depressed the rate of germination. An increase in photon dose above 10−1 mol m−2 d−1 in B. mollis at 15 °CC, 3 × 10−3 mol m−2 d−1in B. sterilis at 15 °C, and 3 × 10−2 mol m−2 d−1 in B sterilis at 25 °C prevented the germination of an increasing number of seeds. The proportion of seeds which were inhibited showed a cumulative normal distribution with respect to the logarithm of photon dose. For a given photon dose, however, there was evidence that longer photoperiods were more inhibitory in both species: 24 h (continuous light) more than 8 h, and in fi sterilis 8 h more than 1 h. We conclude that the high irradiance reaction is the major cause of inhibition by white light in both species, but the sensitivity amongst the seeds within a population to photon dose varies by a factor of up to 105. Amendments to seed-testing procedures for B mollis are suggested.

Anhand von DTA/TGA-Analyse und IR-Untersuchungen des quadratischplanaren Komplexes (Ia) wird der Mechanismus der trans-cis-Umlagerung von (I) in (II) diskutiert.