Genotype × environment interactions in symptom development and yield of cassava genotypes with artificial and natural cassava bacterial blight infections

Thirty-seven cassava genotypes from Benin, including advanced breeding lines, were tested for their reaction to bacterial blight in the forest–savanna transition, wet savanna and dry savanna zones of Benin. Sixteen genotypes were repeated in 12 environments. In year 1998, genotypes RB92164, RB92022, TMS30572, BEN86004, RB92033 and Dangbo2, and in year 2000, genotypes RB92202, RB92151, RB92132 and TMS30572 were resistant in one ecozone. Among the more resistant genotypes, CAP94030, BEN86040, RB89509, RB92132 and TMS30572 showed low interaction across environments and were most stable in disease reaction. Ten genotypes were classified as high yielding across environments. Among the more resistant group of genotypes, only TMS30572 and RB89509 were high yielding, with RB89509 being unstable in yield across environments. Selection of genotypes proved reliable only after artificial inoculation. Comparing environments, artificially inoculated treatments in the wet savanna zone and in the forest–savanna transition zone with stable high symptom severity proved most suitable for screening of genotypes, while the wet savanna zone with low natural infection in year 1998 was suitable for production of propagation material, and the site in the dry savanna zone with natural infection in year 1998 was the best environment for cassava production. The correlation between disease severity and root yield was significant only for the non-inoculated treatment in the dry savanna zone in year 2000 (R = –0.58), but not in any other environment. Among the 37 genotypes tested, several genotypes can be recommended to farmers in specific ecozones, and genotype TMS30572 revealed as relatively stable in disease resistance and in high yield across ecozones.     

Enhancement of bromophenol levels in aquacultured silver seabream (Sparus sarba)

The effect of the addition of marine algae in fish feed on the levels of bromophenols in fish flesh was studied. These bromophenols include 2-bromophenol, 4-bromophenol, 2,4-dibromophenol, 2,6-dibromophenol, and 2,4,6-tribromophenol. Two types of algae-containing fish feeds with 30% Padina arborescens and 30% Sargassum siliquastrum were developed. The total bromophenol contents of these feeds were 132 and 340 ng/g respectively, which were significantly higher than that of the control feed (8.9 ng/g) (ANOVA, p < 0.05). Silver seabream was used as the model fish for the feeding experiment. Bromophenol contents of both fish gut and flesh were monitored at 2-week intervals throughout the 8-week period. Two-way ANOVA showed that only the 30% S. siliquastrum-containing feed significantly (p < 0.05) increased the total bromophenol content in the fish flesh with time. This also produced sensorial differences in the fish flesh.     

Angular leaf spot of phaseolus beans: relationships between disease, healthy leaf area, and yield

ABSTRACT Five field experiments were conducted to investigate the relationship between the severity of visible disease (X), area under the disease progress curve (AUDPC), healthy leaf area index on any given day (HLAI), radiation intercepted by healthy leaf area on any given day (HRI), healthy leaf area duration (HAD), total healthy leaf area absorption (HAA), and yield of Phaseolus beans, cultivars Rosinha and Carioca, inoculated with Phaeoisariopsis griseola at several doses. In general, yield was not related to disease severity (X) or AUDPC. In contrast, the highest yields were always related to the highest values of HAD and HAA. The relationship between yield and HAD was linear in each of five trials (29.9 < R(2) < 70.2%, P < 0.001). The relationship between yield and HAA was linear in four of the trials (52.3 < R(2) < 70.3%, P < 0.001) and exponential in one of them (in which the plant canopy was the largest). Singlepoint models using HRI to estimate yield at various times during the crop season were developed. The slope of the yield-HRI relationship proved to be stable (26.8 +/-2.4 g MJ(-1)), regardless of cultivar, locale, planting date, and bean growth stage (from R5 to R8). The yield-HLAI relationship proved to be less consistent. HRI is proposed as a key explanatory variable for a transportable system of disease management; it may be useful in producing precise recommendations at the farm level.     

Management of equine skull fractures using fixation with polydioxanone sutures

Ten horses presented with severe distortion of the facial contour, crepitus on palpation and mild to moderate epistaxis. Individual horses also showed ocular damage, ptosis, severe dyspnoea and movement of the facial bones concurrent with respiration. The fracture fragments were exposed using a large curvilinear incision and elevated using a retractor, periosteal elevator, chisel or Steinmann pin. The fracture fragments were unstable following reduction and fixation was necessary. Stabilisation was achieved with polydioxanone sutures placed through holes drilled in opposing sides of the fracture lines. Polydioxanone sutures provided good stability and had better handling properties than wire. There was good apposition of fracture edges and minimal complications. Use of polydioxanone sutures can also avoid the expense and complexity of plate fixation in selected cases, and should be considered as an alternative to fixation with stainless steel wire in any facial fracture that adjoins stable bone.     

Effect of Dimethyl Sulfoxide on Cell Cycle Synchronization of Goldfish Caudal Fin Derived Fibroblasts Cells

Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin‐derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.     

高温烘干测定土壤水分的时间规范研究

通过对4种质地(即沙壤、轻壤、中壤和重壤)土壤,在4种温度下的恒温烘干试验(105℃、125℃、140℃、150℃)和有机质含量测定。结果表明:它们的失水规律一般是沙壤和轻壤采用125℃恒温2h;中壤和重壤恒温2h20min,可代替常规烘干土样方法,从而缩短了烘土时间。而高温烘干土样有机质含量与风干土有机质含量比较,绝对误差小于0.05%,故有机质含量不影响高温烘干法。     

In-depth mechanistic study on the formation of acrylamide and other vinylogous compounds by the maillard reaction

The formation of acrylamide was studied in low-moisture Maillard model systems (180 degrees C, 5 min) based on asparagine, reducing sugars, Maillard intermediates, and sugar degradation products. We show evidence that certain glycoconjugates play a major role in acrylamide formation. The N-glycosyl of asparagine generated about 2.4 mmol/mol acrylamide, compared to 0.1-0.2 mmol/mol obtained with alpha-dicarbonyls and the Amadori compound of asparagine. 3-Hydroxypropanamide, the Strecker alcohol of asparagine, generated only low amounts of acrylamide ( approximately 0.23 mmol/mol), while hydroxyacetone increased the acrylamide yields to more than 4 mmol/mol, indicating that alpha-hydroxy carbonyls are much more efficient than alpha-dicarbonyls in converting asparagine into acrylamide. The experimental results are consistent with the reaction mechanism based on (i) a Strecker type degradation of the Schiff base leading to azomethine ylides, followed by (ii) a beta-elimination reaction of the decarboxylated Amadori compound to afford acrylamide. The beta-position on both sides of the nitrogen atom is crucial. Rearrangement of the azomethine ylide to the decarboxylated Amadori compound is the key step, which is favored if the carbonyl moiety contains a hydroxyl group in beta-position to the nitrogen atom. The beta-elimination step in the amino acid moiety was demonstrated by reacting under low moisture conditions decarboxylated model Amadori compounds obtained by synthesis. The corresponding vinylogous compounds were only generated if a beta-proton was available, for example, styrene from the decarboxylated Amadori compound of phenylalanine. Therefore, it is suggested that this thermal pathway may be common to other amino acids, resulting under certain conditions in their respective vinylogous reaction products.     

Serum concentrations of buprenorphine after oral and parenteral administration in male mice

Buprenorphine is the most commonly used drug for peri-operative pain relief in laboratory rodents. The systemic concentrations of buprenorphine were measured in mice following administration intravenously (IV), subcutaneously (SC), orally by gavage and by voluntary ingestion, to determine the post-administration serum concentration of buprenorphine. Voluntarily ingested buprenorphine resulted in long-lasting high serum concentrations, as did oral gavage administration (24 h serum concentration: 110 ng h/mL for both routes of administration). In contrast, buprenorphine administered parenterally remained in the circulation for a substantially shorter time (24 h serum concentration for IV and SC were 40 ng h/mL and 30 ng h/mL, respectively). This marked difference was probably due to the higher dose used for oral administration, which is regarded necessary for sufficient analgesic effect, and to the slower absorption of the oral boli, as well as saturation of the hepatic buprenorphine metabolising pathways. Voluntary ingestion of buprenorphine was found to constitute a practical way to provide laboratory mice with efficient pain relief.     

Effect of testicular tissue lysate on developmental competence of porcine oocytes matured and fertilized in vitro

The objective of the present study was to investigate the effect of testicular tissue lysate (TTL) on developmental competence of germinal vesicle (GV) stage porcine oocytes. Two types of TTL were prepared through repeated freeze–thaw in liquid nitrogen, one from whole testicular tissue (wTTL) and other from either of four different sections of testes, namely just beneath the tunica albuginea (TA), from the transitional area between the seminiferous cord/tubules and the mediastinum testis (TR) and from the intermediate area (parenchymal tissue origin) and CE (cauda epididymis origin). The whole or section‐wise TTL treatments were given for 44 hr during in vitro maturation (IVM). Oocyte maturation was done in either of the two media, namely defined (high‐performance basic medium for porcine oocyte maturation, commercially available) and serum containing (TCM199). After maturation, oocytes were co‐incubated with fresh spermatozoa for 6 hr and then transferred to embryo culture media. Treatment of GV stage oocytes with wTTL (1 mg/ml) increased the cleavage and morula percentage rate (69.23 ± 6.23 and 48.15 ± 6.77, respectively) than that of their control (58.33 ± 8.08 and 32.54 ± 5.53, respectively) in defined media, and in serum‐containing media, cleavage and morula percentage rate were almost equal in both treatment (54.56 ± 7.79 and 34.70 ± 6.78, respectively) and control (59.52 ± 8.21 and 38.52 ± 6.54, respectively). However, effect of wTTL was not significant. In case of section‐wise TTL supplements, TR section significantly (p < .01) improved cleavage and morula rate (58.43 ± 7.98 and 36.14 ± 6.89, respectively) followed by TA. In conclusion, present study indicates that IVM, in vitro fertilization and in vitro culture of embryo are improved in the presence of TTL, particularly its TR section. Further study is expected to reveal the principal components of TTL which may prove useful for IVM.