A potential early clinical phenotype of necrotizing meningoencephalitis in genetically at‐risk pug dogs

BackgroundNecrotizing meningoencephalitis (NME) in the pug dogs is a fatal neuroinflammatory disease associated with rapid progression and poor response to conventional immunosuppressive therapy. Diagnosis is typically made after severe neurological abnormalities have manifested.Hypothesis/ObjectivePug dogs at genetic risk for NME might manifest neurological abnormalities before developing pathognomonic clinical signs of NME.AnimalsThirty‐six pug dogs less than 4 years of age asymptomatic for NME.MethodsProspective observational cohort study with germline genome‐wide genotyping. Neurological examinations were performed 4 weeks apart to document reproducible findings of central nervous system disease. Magnetic resonance imaging, cerebrospinal fluid analysis, and testing for infectious diseases were performed in all pugs with reproducible abnormalities detected on neurological examination.ResultsThe overall risk allele frequency in this cohort was 40%; 5 (14%) dogs were high risk, 19 (53%) dogs were medium risk, and 12 (33%) dogs were low genetic risk for NME. Reproducible abnormalities detected on neurological examination were identified in 8/24 (33%) genetically at‐risk dogs and 0/12 (0%) low risk dogs. Clinical abnormalities included multifocal spinal pain in 8/8, reduced menace response in 5/8, and lateralizing postural reaction deficits in 5/8 pugs. There was a strong association between genotype risk and the presence of this clinical phenotype (P = .03).Conclusions and Clinical ImportanceOur findings suggest the presence of a novel early clinical phenotype of NME in apparently asymptomatic genetically at‐risk pugs which might be used to plan early diagnostic and therapeutic clinical trials.     

Variability in response to toosendanin in a laboratory colony of<Emphasis Type="Italic">Trichoplusia ni</Emphasis>

Laboratory rearing of insects for scientific research ensures a constant supply of insects. However, laboratory colonies may diverge genetically and/or phenotypically from wild populations due to selection pressures in their artificial environment. This study examined how variation in a colony ofTrichoplusia ni influenced reproducibility over time of bioassays of toosendanin (a limonoid extracted from the bark ofMelia azedarach). In four of five experiments insect growth was reduced significantly (P=0.05) by the presence of toosendanin in the diet. The fifth experiment showed the same trend, but the effect was not significant. Mean larval mass of both control and treated insects also varied greatly among experiments. The considerable variability observed in this population highlights the importance of replicating experiments in time, and not just space, to confirm reproducibility of treatment effects. http://www.phytoparasitica.org posting Jan. 23, 2007.     

Effect of conservation agriculture on soil organic and inorganic carbon sequestration and lability: A study from a rice–wheat cropping system on a calcareous soil of the eastern Indo-Gangetic Plains

Increasing soil carbon (C) in arable soils is an important strategy to achieve sustainable yields and mitigate climate change. We investigated changes in soil organic and inorganic carbon (SOC and SIC) under conservation agriculture (CA) in a calcareous soil of the eastern Indo-Gangetic Plains of India. The treatments were as follows: conventional-till rice and wheat (CT-CT), CT rice and zero-till wheat (CT-ZT), ZT direct seeded rice (DSR) and CT wheat (ZT-CT), ZTDSR and ZT wheat without crop residue retention (ZT-ZT), ZT-ZT with residue (ZT-ZT+R), and DSR and wheat both on permanent beds with residue (PB-PB+R). The ZT-ZT+R had the highest total SOC in both 0–15 and 15–30 cm soil layers (20% and 40% higher (p < .05) than CT-CT, respectively), whereas total SIC decreased by 11% and 15% in the respective layers under ZT-ZT+R compared with CT-CT. Non-labile SOC was the largest pool, followed by very labile, labile and less labile SOC. The benefits of ZT and residue retention were greatest for very labile SOC, which showed a significant (p < .05) increase (~50%) under ZT-ZT+R compared with CT-CT. The ZT-ZT+R sequestered ~2 Mg ha⁻¹ total SOC in the 0–15 cm soil layer in 6 years, where CT registered significant losses. Thus, the adoption of CA should be recommended in calcareous soils, for C sequestration, and also as a reclamation technique.     

Effect of management of a Himalayan Alfisol on water conservation for rainfed crops

Field experiments were conducted during 1989 and 1990 to study the effect of various soil management practices on water conservation during the two prime planting periods in the lower Himalayan region. Treatments studied were: zero tillage with weed control (ZT+W), zero tillage (ZT), fine tilth (FT), coarse tilth (CT), zero tillage with surface-applied lantana (Lantana camara L.) mulch at 10 t ha⁻¹ (ZT+M), fine tilth with surface-applied lantana mulch at 10 t ha⁻¹ (FT+M), fine tilth with surface-applied farmyard manure mulch at 10 t ha⁻¹ (FT+FYM) and fine tilth with FYM incorporated at 10 t ha⁻¹ (FYM). The soils were Typic Hapludalfs with pH 5.8, organic carbon 6.6 g kg⁻¹ and cation exchange capacity 12 cmol (P⁺) (100 g)⁻¹. The lantana mulch application to fine tilth (FT+M) or zero tillage (ZT+M) maintained higher seed-zone water content and profile water storage as compared with all the other treatments. Highest water depletion was observed under ZT+W treatment. Seed germination is likely to occur only under FT+M and ZT+M during the two prime planting periods, if field capacity water content is considered to be limiting for seed germination. However, for the other treatments rainfall would invariably be required to increase the surface water content, to allow germination and early seedling establishment.     

Isolation,purification, and biochemical characterization of a novel water soluble protein from Inca peanut (Plukenetia volubilis L.)

A water soluble storage albumin from Inca peanut (IPA) accounted for approximately 25% (w/w) of defatted seed flour weight, representing 31% of the total seed protein. IPA is a 3S storage protein composed of two glycosylated polypeptides, with estimated molecular weights (MW) of 32800 and 34800 Da, respectively. IPA has an estimated sugar content of 4.8% +/- 0.92% (n = 6). IPA is a basic protein (pI of approximately 9.4) and contains all of the essential amino acids in adequate amounts when compared to the FAO/WHO recommended pattern for a human adult. The tryptophan content of IPA is unusually high (44 mg/g of protein), whereas the phenylalanine content is low (9 mg/g of protein). IPA is a highly digestible protein in vitro.     

Role of Aeciospores in Outbreaks of Pea (Pisum sativum) Rust (Uromyces fabae)

Aeciospores in Uromyces fabae were found to be repeating spores and play an important role in pea rust outbreaks in the North Eastern Plain Zone (NEPZ) of India. Experiments conducted on pea rust from 2001 to 2004 revealed the dominance of aeciospores at all growth stages of pea in this region. Urediospore production was erratic and was only observed in a few samples of stems and tendrils (5–10%). Inoculation of pea plants either by aeciospores or urediospores resulted in the production of aeciospores. Production of aeciospores was observed at a temperature range of 10–25 °C, with a maximum at 25 ± 2 °C. Among the different growth stages of pea, the pod formation stage was highly susceptible and produced the maximum number (744) of aecidia/leaf at 20–25 °C. Significant effects of growth stages and temperature were also noticed for pustule number. Urediospore production mainly coincided with the senescence of the pea plants. Maximum germination (2%) of aeciospores was observed at 25 °C, whereas maximum urediospore germination (3.5%) was at 15 °C. Temperatures > 15 °C decreased urediospore germination. A relative humidity (RH) of 100% was favourable for aeciospore germination while 98% RH favoured urediospore germination. Typical histo-pathological behaviour of the aeciospores was observed.     

Breeding crops for reduced-tillage management in the intensive, rice–wheat systems of South Asia

The importance of reduced tillage in sustainable agriculture is well recognized. Reduced-tillage practices (which may or may not involve retention of crop residues) and their effects differ from those of conventional tillage in several ways: soil physical properties; shifts in host–weed competition; soil moisture availability (especially when sowing deeply or under stubble); and the emergence of pathogen populations that survive on crop residues. There may be a need for genotypes suited to special forms of mechanization (e.g. direct seeding into residues) and to agronomic conditions such as allelopathy, as well as specific issues relating to problem soils. This article examines issues and breeding targets for researchers who seek to improve crops for reduced-tillage systems. Most of the examples used pertain to wheat, but we also refer to other crops. Our primary claim is that new breeding initiatives are needed to introgress favourable traits into wheat and other crops in areas where reduced or zero-tillage is being adopted. Key traits include faster emergence, faster decomposition, and the ability to germinate when deep seeded (so that crops compete with weeds and use available moisture more efficiently). Enhancement of resistance to new pathogens and insect pests surviving on crop residues must also be given attention. In addition to focusing on new traits, breeders need to assess germplasm and breeding populations under reduced tillage. Farmer participatory approaches can also enhance the effectiveness of cultivar development and selection in environments where farmers’ links with technology providers are weak. Finally, modern breeding tools may also play a substantial role in future efforts to develop adapted crop genotypes for reduced tillage.