Nematodes and Plant Health: Legislation and Sampling Strategies in Decision Making for Nematode Management

UK plant health measures are based principally on the Plant Health (Great Britain) Order 1993 and the similar Order covering forestry pests, both implementing EU Directive 77/93/EEC, as amended. Nematode species of quarantine status are Aphelenchoides besseyi, Bursaphelenchus xylophilus, Ditylenchus destructor, D. dipsaci, Globodera pallida, G. rostochiensis, Longidorus diadecturus, Nacobbus aberrans, Rhadopholus similis, Xiphinema americanum sensu lato (non-European populations), and X. californicum. Soils are tested for freedom from Globodera spp. and virus vector nematodes under certain certification schemes and where necessary, for export crops. EU Marketing schemes require visual freedom from quality-affecting nematodes. Soil samples normally comprise 500 g of soil from 100 cores per 4 ha (or less).     

Calibration and performance of moisture sensors in soilless substrates: ECH2O and Theta probes

Reliable and affordable moisture sensors for measuring the water content in soilless substrates are limited. In this study, we examined the efficacy of two moisture sensors (ECH₂O-10 and Theta probe ML2X) for measuring water content in soilless substrates. We developed calibration equations and analyzed the effect of increasing electrical conductivity (EC) and substrate temperature on the voltage output of probes. We found that a single equation (one for each probe) could be used to adequately measure water content in different custom-made substrates maintained at low EC and a substrate temperature of ∼23 °C. The calibration equation developed for the Theta probe from substrates maintained at low EC could also be used in two commercial substrates with high EC (2.0–5.0 dS m⁻¹). Further measurements in substrates maintained at different water contents and EC levels indicated that the output of the ECH₂O-10 probe, but not the Theta probe, was significantly affected by substrate EC. The lack of a substrate EC effect on the Theta probe readings was surprising, because the probe was sensitive to EC when fertilizer solutions with different ECs were measured. Increasing the temperature of the substrate from 10 to 40 °C increased the voltage output of ECH₂O-10 probes by 1.88 mV °C⁻¹, or on average 0.0022 m³ m⁻³ water content per °C. There was no effect of increasing substrate temperature on the Theta probe. It was concluded that ECH₂O-10 probes can be used in greenhouse operations requiring less measurement precision (like irrigation), however for accurate measurements of water content, the Theta probe is preferred.     

Role of catalase in the virulence of Brucella melitensis in pregnant goats

An isogenic katE mutant derived from virulent Brucella melitensis 16M displays hypersensitivity to hydrogen peroxide in disk sensitivity assays but retains the capacity to colonize pregnant goats and induce abortion. These experimental findings indicate that although the sole periplasmic catalase of Brucella melitensis functions as an antioxidant, this enzyme does not play a critical role in virulence in the natural host.     

Diagnosis of canine claw disease – a prospective study of 24 dogs

The aetiology of claw disease in 24 dogs exhibiting only claw disease was investigated with cytologic examination of claw exudate, complete blood count (CBC), serum biochemistry panel, urinalysis, total thyroxine (tT4) concentration, antinuclear antibody (ANA) titre, bacterial culture and sensitivity testing, fungal culture, histopathology of claw biopsy samples and elimination diet. Abnormalities on the CBC, serum biochemistry panel and urinalysis were minor and nonspecific. Total T4 concentrations were within the normal laboratory reference range. Fungal cultures and ANA titres were negative in all dogs. A bacterial infection was present in approximately half of the dogs. On histological examination of claw tissue, a cell-poor or cell-rich interface onychitis was seen in all but one dog. Evidence for an adverse reaction to food was present in four dogs. One dog responded completely to antibiotic therapy. Interface onychitis seems to be a histological reaction pattern of the claw matrix in the dog with various possible underlying aetiologies. In dogs with claw disease as the only clinical sign, the recommended initial diagnostic evaluation includes cytologic examination, bacterial culture and sensitivity, claw biopsy and an elimination diet.     

Anti-Neospora caninum antibody detection and vertical transmission rate in pregnant zebu beef cows (Bos indicus): Neospora caninum in pregnant beef cows (Bos indicus)

The aim of the present study was to evaluate anti-Neospora caninum antibodies and the vertical transmission rate in naturally infected pregnant zebu beef cows (Bos indicus) reared on pasture. The present study began with 200 cows from four farms (50 cows from each farm), and these animals were submitted to timed artificial insemination (TAI). After ultrasonography, 76 pregnant cows were selected, 22, 15, 22, and 17, respectively, from farms 1, 2, 3, and 4. Blood samples were taken from cows thrice during the first, second, and third trimester of gestation, and a blood sample was collected from 31 calves before colostrum milking. From 76 cows 23 (30.3%) had anti-N. caninum antibodies detected by indirect ELISA (Idexx), and 53 (69.7%) did not. Sixty-four cows that initiated the experiment were negative to N. caninum and 11 became positive either during the second or third trimester of gestation, this mean an infection incidence of 17.2% (11/64). OD for ELISA was higher (OD = 2.08) during the second and third (OD = 2.10) trimesters of pregnancy when compared with the first (OD = 1.81), however, there were no statistical differences (P = 0.45). The vertical transmission was calculated to be 29.0% (9/31), and the risk of vertical transmission of N. caninum in seropositive dams was 26.25 times higher than seronegative animals (OR = 26.25, 2.38 < OR < 289, P = 0.007). In conclusion, the rate of vertical transmission of N. caninum in pregnant zebu beef cows was 29%, and the risk was 26.25 higher in seropositive dams relative to than seronegative animals.     

试析省属农业高校的经费困难与对策

分析了省属农业高校经费困难的现状与原因，提出了克服困难的对策。     

水稻和菰远缘杂交后代抗旱性初探

以７个抗旱力不同的水稻和范远缘杂交后品系为试材，进行抗旱测定，对其种子、幼苗、成株进行水分胁迫及叶片气孔观察发现，寒九和远４４３７是真正的抗旱类型，而其余６个品系均同敏感抗旱类型。     

Comment on "A centrosome-independent role for gamma-TuRC proteins in the spindle assembly checkpoint"

Müller et al. (Reports, 27 October 2006, p. 654) proposed a role for microtubule nucleation in mitotic checkpoint signaling. However, their observations of spindle defects and mitotic delay after depletion of gamma-tubulin ring complex (gamma-TuRC) components are fully consistent with activation of the established pathway of checkpoint signaling in response to incomplete or unstable interactions between kinetochores of mitotic chromosomes and spindle microtubules.     

A family business: Women,children and smallholder sugar cane farming in Fiji

Abstract: This paper highlights the contribution of women and children to the sugar industry in Fiji by examining the importance of family labour in the historical development of the smallholder system and describing the present situation for the study participants. It is based on ethnographic fieldwork conducted during 1996–97, on the island of Vanua Levu in the northern region of Fiji. The twenty smallholder households in the study comprised both Fijian and Fiji Indian respondents who relied primarily on selling sugar cane for their cash income. How inequalities within the household in terms of allocation of labour and resources are legitimated is outlined. Resource distribution within the household in regards to two important issues for the sugar industry, land and trade liberalisation, are examined. In light of global trends in trade liberalisation and probable falls in sugar prices, future strategies for survival identified by Fijian and Fiji Indian smallholders are also discussed. The case study demonstrates that the sugar industry is still largely reliant on family labour and, particularly for low socio‐economic smallholders, the unremunerated labour of family members makes an essential contribution to the production of sugar cane.