Use of near-isogenic wheat lines to determine the glutenin composition and functionality requirements for flour tortillas

In wheat ( Triticum aestivum L), the synthesis of high molecular weight (HMW) glutenins (GS) is controlled by three heterologous genetic loci present on the long arms of group 1 wheat chromosomes. The loci Glu-A1, Glu-B1, and Glu-D1 and their allelic variants play important roles in the functional properties of wheat flour. This study focused on understanding the functionality of these protein subunits on tortilla quality. Near-isogenic wheat lines in which one or more of these loci were absent or deleted were used. Tortillas were prepared from each deletion line and the parent lines. The elimination of certain HMW-GS alleles alter distinct but critical aspects of tortilla quality such as diameter, shelf stability, and overall quality. Two deletion lines possessing HMW-GS 17 + 18 at Glu-B1 and deletions in Glu-A1 and Glu-D1 had significantly larger tortilla diameters, yet tortilla shelf life was compromised or unchanged from the parent lines used to develop the deletion lines or the commercial tortilla flour used as a control. Alternatively, a deletion line possessing Glu-A1 and Glu-D1 (HMW-GS 1, 5 + 10) and a deletion in Glu-B1 also significantly improved tortilla diameters. Whereas the increase in diameter was less than the line possessing only HMW-GS 17 + 18 at Glu-B1, the stability of the tortillas were, however, maintained and improved as compared to the parent lines containing a full compliment of HMW-GS. Thus, the presence of subunits 5 + 10 at Glu-D1 alone or in combination with subunit 1 at Glu-A1 appears to provide a compromise of improvement in dough extensibility for improved tortilla diameters while also providing sufficient gluten strength to maintain ideal shelf stability.     

Impact of grain morphology and the genotype by environment interactions on test weight of spring and winter wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Wheat (Triticum aestivum L.) market grades and prices are determined in part by test weight (TW). Millers value high TW because it is typically associated with higher flour extraction rates and better end-use quality. Test weight is expected to be influenced by other directly quantifiable grain attributes such as grain length (GL), grain width (GW), shape, single-grain-density (SGD), thousand-grain-weight (TGW), and packing efficiency (PE). The objectives of this study were to: (1) determine the primary morphological grain attributes that comprise TW measurements for winter and spring wheat classes; and (2) determine TW stability and genotype and genotype × environment interactions (GEIs) of the attributes that comprise TW. A market class representative group of 32 hard spring and 24 hard winter wheat cultivars was grown at several locations in South Dakota in 2011 and 2012. A regularized multiple regression algorithm was used to develop a TW model and determine what grain attribute reliably predicts TW. A GGE biplot was used for stability and GEI analyses whereas a linear mixed model was used for variance analyses. Data were collected on eight grain traits: TW, SGD, TGW, protein concentration, GW, GL, shape, size, and PE. Observations showed that in both spring and winter wheat, SGD accounted for over 90% of the phenotypic variation of TW. Cultivars with stable and high TW were identified in both wheat classes. Apart from TW; significant (p?<?0.0001) genotype, environment, and GEI variances were observed for GW and SGD, a more direct measure of which could help improve genetic gain for TW.     

Prevalence of gastrointestinal bacterial pathogens in a population of zoo animals

Faecal prevalence of gastrointestinal bacterial pathogens, including Campylobacter, Escherichia coli O157:H7, Salmonella, Shigella, Yersinia, as well as Arcobacter, were examined in 317 faecal specimens from 44 animal species in Belfast Zoological Gardens, during July-September 2006. Thermophilic campylobacters including Campylobacter jejuni, Campylobacter coli and Campylobacter lari, were the most frequently isolated pathogens, where members of this genus were isolated from 11 animal species (11 of 44; 25%). Yersinia spp. were isolated from seven animal species (seven of 44; 15.9%) and included, Yersinia enterocolitica (five of seven isolates; 71.4%) and one isolate each of Yersinia frederiksenii and Yersinia kristensenii. Only one isolate of Salmonella was obtained throughout the entire study, which was an isolate of Salmonella dublin (O 1,9,12: H g, p), originating from tiger faeces after enrichment. None of the animal species found in public contact areas of the zoo were positive for any gastrointestinal bacterial pathogens. Also, water from the lake in the centre of the grounds, was examined for the same bacterial pathogens and was found to contain C. jejuni. This study is the first report on the isolation of a number of important bacterial pathogens from a variety of novel host species, C. jejuni from the red kangaroo (Macropus rufus), C. lari from a maned wolf (Chrysocyon brachyurus), Y. kristensenii from a vicugna (Vicugna vicugna) and Y. enterocolitica from a maned wolf and red panda (Ailurus fulgens). In conclusion, this study demonstrated that the faeces of animals in public contact areas of the zoo were not positive for the bacterial gastrointestinal pathogens examined. This is reassuring for the public health of visitors, particularly children, who enjoy this educational and recreational resource.     

Comparison of shifted multiplicative model,rank correlation,and biplot analysis for clustering winter wheat production environments

Categorization of locations with similar environments helps breeders to efficiently utilize resources and effectively target germplasm. This study was conducted to determine the relationship among winter wheat (Triticum aestivum L.) yield testing locations in South Dakota. Yield trial data containing 14 locations and 38 genotypes from 8 year were analyzed for crossover genotype (G) × environment (E) interactions according to the Azzalini-Cox test. G × E was significant (P < 0.05) and contributed a small proportion of variation over the total phenotypic variation. This suggested that for efficient resource utilization, locations should be clustered. The data were further analyzed using the Shifted Multiplicative Model (SHMM), Spearman’s rank correlation and GGE biplot to group testing locations based on yield. SHMM analysis revealed four major cluster groups in which the first and third had three locations, with four locations in each of the second and fourth groups. Spearman rank correlations between locations within groups were significant and positive. GGE biplot analysis revealed two major mega-environments of winter wheat testing locations in South Dakota. Oelrichs was the best testing location and XH1888 was the highest yielding genotype. SHMM, rank correlation and GGE biplot analyses showed that the locations of Martin and Winner in the second group and Highmore, Oelrichs and Wall in the third group were similar. This indicated that the number of testing locations could be reduced without much loss of grain yield information. GGE biplot provided additional information on the performance of entries and locations. SHMM clustered locations with reduced cross-over interaction of genotype × location. The combined methods used in this study provided valuable information on categorization of locations with similar environments for efficient resource allocation. This information should facilitate efficient targeting of breeding and testing efforts, especially in large breeding programs.     

A simplified approach for estimating age‐0 gizzard shad prey supply and predator demand

Gizzard shad, Dorosoma cepedianum (Lesueur), often compose a majority of the prey biomass in southern US reservoirs. Previous studies suggest prey limitation frequently occurs in these systems, suggesting that fisheries managers need tools to evaluate the production potential of the populations they manage. Bioenergetics modelling was used to quantify the abundance of age‐0 gizzard shad necessary to sustain multiple piscivore species with diverse growth rates, population sizes, mortality rates and diets. Gizzard shad biomass at the 50th percentile of published values was insufficient to support seven piscivore species in 69% of the simulations, suggesting that above‐average prey biomass is required to support multiple piscivore populations at high abundance and growth rates. To help guide management, estimates of the gizzard shad biomass needed to sustain piscivore communities are provided for management situations in which coarse‐scale (low, medium or high) growth, population size and percent of shad in diet data are available.     

Effects of natriuretic peptides on the gill vasculature of a hagfish, Eptatretus cirrhatus

An isolated, perfused gill pouch preparation and myography were used to determine responses of the branchial vasculature of a hagfish to the mammalian natriuretic peptides, rANP and CNP. In the isolated gill pouch preparation afferent perfusion pressures increased in the first 5 min of exposure to low concentrations (10^–14 to 10^–10M) of ANP and CNP and then decreased below starting values by 15 min. At higher concentrations the depressor response prevailed and natriuretic peptides switched the flow away from the efferent artery to the venous route, which would fill the peribranchial sinus in vivo. At low concentrations ANP increased circumferential tensions in afferent branchial arterial rings. At higher concentrations afferent and efferent branchial arteries relaxed in response to ANP and CNP.     

Functional resilience of microbial communities from perturbed upland grassland soils to further persistent or transient stresses

The microbial functioning of soils following perturbation was assessed at a temperate upland grassland site, maintained by the Soil Biodiversity and Ecosystem Function Programme at Sourhope Research Station, Scotland. Published results indicated that the soil microbial communities were resilient to these initial perturbations; in this paper we tested whether they were equally resilient to a subsequent perturbation. Soil samples were taken from field plots receiving treatments that represented different forms of perturbation, viz. reseeding, application of sewage-sludge, biocide or nitrogen plus lime, and a non-perturbed control. Functional resilience following further perturbation comprising a transient heat or persistent copper perturbation was assessed over 28 days, by monitoring the short-term decomposition of added plant residues. Bacterial community structure was assessed by DGGE separation of eubacterial 16S rDNA PCR products. PCR-DGGE did not distinguish any significant difference (P>0.05) between the bacterial communities of soils under different treatments, showing differences only between treated soils and the untreated, control soils.Two days after the application of stresses, functional capability differed in soils under different treatments. Soil samples from all the treated plots were less resilient to heat stress than soil from control plots. The initial reduction in decomposition following the addition of copper differed between treatments, but function had not recovered in any of the Cu-amended soils within 28 days. Soil resilience varied according to the type and duration of stress applied, microbial activity, soil characteristics and treatment regimes. The initial resistance of function to stress was not predictive of recovery of function over time.     

A new ornithological record,Pechora Pipit Anthus gustavi Swinhoe,1863,from Xinjiang

On 15 September,2010,a Pechora Pipit Anthus gustavi Swinhoe was found in the Hami prefecture(41°13’N and 93°29’E,1,143 m a.s.l.),Xinjiang,during the period of a comprehensive scientific survey in Lop Nur region.The bird,which was photographed,is a new avian record for Xinjiang.The pipit reproduces in northern Eurasia,mainly in wide meadows and low hills,and can be found in open forests and nearby residential areas in the process of on migration.The species is an insectivore and is a rare migrant or vagrant in Xinjiang.The geographical distribution,character,habitat,ecological habit and subspecies of the Pechora Pipit were discussed in this paper.