Physiological and Biochemical Responses of Hexaploid and Tetraploid Wheat to Drought Stress

An experiment was conducted to investigate the physiological and biochemical responses of two hexaploids viz., C 306 (water stress tolerant) and Hira (water stress susceptible), and two tetraploids, HW 24 (Triticum dicoccum) and A 9‐30‐1 (Triticum durum) wheat genotypes to water stress under pot culture condition. Water stress was imposed for a uniform period of 10 days at 50, 60 and 70 days after sowing (DAS) and observations were recorded at 60, 70 and 80 DAS. Total dry matter and plant height were recorded at harvest. Water stress caused a decline in relative water content (RWC), chlorophyll and carotenoid content, membrane stability and nitrate reductase activity and increased accumulation of proline at all stages and abscisic acid (ABA) at 80 DAS in all the genotypes. Both the tetraploids showed a lower reduction in RWC and highest ABA accumulation under water stress. Among the hexaploids Hira showed the most decline in RWC and the lowest ABA accumulation. The tetraploids also showed comparatively higher carotenoid content and membrane stability, closely followed by C 306, while Hira showed the minimum response under water stress. Nitrate reductase activity and chlorophyll content under irrigated conditions were highest in Hira but under water stress the lowest per cent decline was observed in C 306, followed by HW 24, A 9‐30‐1, and Hira. Proline accumulation under water stress conditions was highest in hexaploids C 306 and Hira and lowest in tetraploids HW 24 and A 9‐30‐1. Tetraploids HW 24, followed by A 9‐30‐1 maintained higher plant height and total dry matter (TDM) under water stress and also showed a lower per cent decline under stress than hexaploids C 306 and Hira. From the results it is clear that proline accumulation did not contribute to better drought tolerance of tetraploids than hexaploids. It is also apparent that water stress tolerance is the result of the cumulative action of various physiological processes, and all the parameters/processes may not be positively associated with the drought tolerance of a particular tolerant genotype.     

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.     

Production and biological properties of M-protein of Streptococcus equi

The production of M-protein antigen of Streptococcus equi was studied during in vitro growth in equine blood and in various media. Of 11 S equi strains studied, seven which had initially possessed 0.04 mg or less M-protein per 10 mg of streptococcal cell extract showed an increase in M-protein content after successive culture in heparinised horse blood. Maximum proliferation occurred in Todd-Hewitt (TH) medium with added 0.2 per cent w/v glucose when compared with TH medium alone or TH medium with 2 per cent w/v sucrose, starch, neopeptone or normal horse serum. The M-protein of these strains did not change after the addition of either neopeptone or normal horse serum to TH medium but declined with the addition of sugars. In experiments involving phagocytosis of S equi by equine polymorphs, the percentage of polymorphs which engulfed cocci was higher with a capsule-deficient strain (69.0 +/- 11.6 per cent) than with five typical encapsulated strains (21.1 +/- 7.0 per cent to 30.9 +/- 13.3 per cent). Phagocytosis of five typical strains was greater after growth in a trypsin-containing medium than in medium devoid of trypsin. Trypsin-grown cells took longer to kill mice than did normal cells. It was concluded that M-protein was one of the factors involved in the virulence of S equi.     

A note on adenosine triphosphatase activity in foetal goat liver, testis, allantoic and amniotic fluids

The activity of the enzyme adenosine triphosphatase was measured in liver, testis and foetal fluids. The activity was maximum in the foetal liver and minimum in adult liver. On the other hand the activity in adult goat testis was higher than foetal goat testis.     

Disposition and dosage regimen of cephaloridine in calves

The disposition and dosage regimen of cephaloridine were investigated in healthy calves following a single intramuscular administration of 10 mg/kg. The absorption halflife, climination halflife, apparent volume of distribution and total body clearance were 0.107±0.025 h, 2.08±0.14 h, 0.70±0.07L kg^-1 and 235.8±21.9 ml kg^-1 h^-1, respectively. Therapeutic plasma levels (1 g/ml) were maintained for up to 7 h. A satisfactory intramuscular dosage regimen for cephaloridine in calves would be 10 mg/kg repeated at 8 h intervals.     

Genetic diversity for mineral accumulation in the foliage of Chenopodium spp.

Chenopodium spp. is being used as a leafy vegetable and subsidiary grain crop in different parts of the world due to its rich nutritional quality and its ability to grow in stress conditions. A field experiment was conducted in Lucknow (India) to assess the genetic diversity in 40 accessions of Chenopodium spp. based on mineral composition of the leaves. Principal Component Analysis (PCA) showed that the first 4 PCs (Principal Component) accounted for 74.70% of the total variance among the accessions. The first PC (PC1) accounted for 41.96% of the total qualitative variation and had nickel, zinc and chromium with high positive and copper with high negative coefficients. The most important loadings for PC2 were calcium and potassium. Cluster analysis grouped the accessions into 4 major clusters. The first cluster, which showed maximum diversity, had 17 accessions, all of C. quinoa having high content of most of the heavy metals viz. zinc, chromium, nickel and cadmium. Cluster II was the largest consisting of 18 accessions which had low content of nickel, cadmium and chromium. Cluster III contained 3 accessions that had lowest amount of calcium, iron, magnesium and zinc, while accessions in cluster IV were characterized by high levels of calcium, sodium, magnesium, nickel, chromium and cadmium. Significant genotypic differences existed in the heavy metal uptake by plants. Mineral uptake and concentration in Chenopodium spp. corresponds to the taxonomic categorization in the genus and could also be utilized as a supplementary taxonomic tool for grouping together of closely related taxa. Conclusively the diversity can be exploited in plant breeding programs for increasing nutritional value and for bioremediation purposes.     

Amelioration of Sodic Soil for Wheat Cultivation Using Bioaugmented Organic Soil Amendment

A novel bioaugmented organic amendment (SF_OA) [consisted of vermicompost (pre‐enriched with plant growth promoting fungi) mixed with pressmud and Azadirachta indica (A. Juss.) seed cake] was developed to reclaim sodic soil and support wheat production. A field trial of the SF_OA application with/without chemical fertilizers conducted in completely randomized design with four replications to compare growth, yield and seed protein contents of wheat (Triticum aestivum L.) on sodic soil. The favourable changes occurred in different properties of amended soils were studied. A combined application of chemical fertilizer and SF_OA significantly (p < 0·05) increased the number of spikelet per plant (63%) and weight of grains per ear (65%) in the amended soil compared with the control. Likewise, the grain yield, weight of 1000 grains and seed protein contents of wheat were significantly (p < 0·05) increased in the combined application compared with other treatments. The expression of protein bands with molecular weights of 36, 52 and 66 kDa were higher in seeds of wheat under the combined treatment. The improvement in wheat production was attributed to significant favourable changes in different soil characteristics such as bulk density, total organic C, alkaline phosphatase, β‐glucosidase, dehydrogenase and cellulase activities that were increased by 234%, 181%, 234%, 176%, 189% and 150%, respectively, in case of amended soil under the combined treatment compared with the control. The tested SF_OA may be recommended as soil amendment for reclaiming sodic soil and supporting wheat cultivation with better crop growth and yield in combination with chemical fertilizers on sodic soil. Copyright © 2014 John Wiley & Sons, Ltd.