Quality of Hard Red Winter Wheat Grown Under High Temperature Conditions During Maturation and Ripening

High temperature during grain filling has been identified as a major factor in the end-use properties of bread wheat (Triticum aestivum L.). Our objectives were to assess the effect of high temperature during maturation on the grain characteristics, milling quality, and flour quality of hard red winter wheat. In three separate experiments, plants of wheat cultivar Karl 92 were subjected to regimes (day-night) of 20–20, 25–20, 30–20, and 35–20°C from 10 and 15 days after anthesis (DAA) until ripeness, and 25–20, 30–20, and 35–20°C from 20 DAA until ripeness. In other experiments, plants of wheat cultivars Karl 92 and TAM 107 were dried at 20 and 40°C, and spikes of Karl 92 were dried at different temperature and humidity conditions to asses the effects on quality of high temperature and drying rates during grain ripening. Flour yield correlated positively with kernel weight and diameter, test weight, and proportion of large kernels. Flour yield decreased as temperature increased and correlated negatively with hardness index and proportion of small grains. High growth temperatures and rapid grain desiccation decreased mixing time and tolerance of the flours. The greatest damage occurred when high temperature was maintained continuously from early grain filling until ripeness. Weakening of dough properties by rapid desiccation during ripening suggest that temperature, humidity, and possibly soil moisture all contribute to the final quality of bread wheat.     

Assessment of QoI resistance in Plasmopara viticola oospores

QoI fungicides, inhibitors of mitochondrial respiration at the Qo site of cytochrome b in the mitochondrial bc(1) enzyme complex, are commonly applied in vineyards against Plasmopara viticola (Berk. & MA Curtis) Berl. & De Toni. Numerous treatments per year with QoI fungicides can lead to the selection of resistant strains in the pathogen population owing to the very specific and efficient mode of action. In order to evaluate the resistance risk and its development, two different methods, biological and molecular, were applied to measure the sensitivity of oospores differentiated in vineyards, both treated and untreated with azoxystrobin, from 2000 to 2004. Assays using oospores have the advantage of analysing the sensitivity of bulked samples randomly collected in vineyards, describing accurately the status of resistance at the end of the grapevine growing season. Both methods correlated well in describing the resistance situation in vineyards. QoI resistance was not observed in one vineyard never treated with QoI fungicides. In the vineyard where azoxystrobin had been used in mixture with folpet, the selection of QoI-resistant strains was lower, compared with using solely QoI. In vineyards where QoI treatments have been stopped, a decrease in resistance was generally observed.     

The Genomic Sequence of Pseudomonas fluorescens Pf-5: Insights Into Biological Control

ABSTRACT The complete sequence of the 7.07 Mb genome of the biological control agent Pseudomonas fluorescens Pf-5 is now available, providing a new opportunity to advance knowledge of biological control through genomics. P. fluorescens Pf-5 is a rhizosphere bacterium that suppresses seedling emergence diseases and produces a spectrum of antibiotics toxic to plant-pathogenic fungi and oomycetes. In addition to six known secondary metabolites produced by Pf-5, three novel secondary metabolite biosynthesis gene clusters identified in the genome could also contribute to biological control. The genomic sequence provides numerous clues as to mechanisms used by the bacterium to survive in the spermosphere and rhizosphere. These features include broad catabolic and transport capabilities for utilizing seed and root exudates, an expanded collection of efflux systems for defense against environmental stress and microbial competition, and the presence of 45 outer membrane receptors that should allow for the uptake of iron from a wide array of siderophores produced by soil microorganisms. As expected for a bacterium with a large genome that lives in a rapidly changing environment, Pf-5 has an extensive collection of regulatory genes, only some of which have been characterized for their roles in regulation of secondary metabolite production or biological control. Consistent with its commensal lifestyle, Pf-5 appears to lack a number of virulence and pathogenicity factors found in plant pathogens.     

A NEW DEVICE FOR STEREOTACTIC CT-GUIDED BIOPSY OF THE CANINE BRAIN: DESIGN, CONSTRUCTION, AND NEEDLE PLACEMENT ACCURACY

An inexpensive device was created for computed tomographic (CT)-guided stereotactic biopsy of the canine brain. The accuracy of the device was tested using 16, formalin-perfused, canine head specimens. For each dog, a 6-inch biopsy needle was guided into pituitary gland and caudate nucleus targets. Needle tracks were measured using the CT computer and infused with tissue staining solution. Hit success and actual needle track lengths were determined from sliced brain specimens. The device enabled accurate orientation and placement of the canine head in the slice plane, such that progressive penetration of the biopsy needle could be monitored. The caudate nucleus was hit 12/16 times (75% accuracy) and the pituitary gland 15.5/16 times (98.6% accuracy). Hit proportions for the two targets did not differ (P < 0.05). A significant difference was found between CT and actual track length for both targets (P < 0.01). This was attributed to incomplete staining of the bevel portion of the needle track.     

Sugar metabolism by Brucellae

The metabolic capabilities of the species of Brucella were originally of interest as a means of distinguishing them from each other and from other genera. Certain unusual characteristics, especially erythritol utilization, were studied in the hopes they would shed light on the pathogenicity. With the advent of modern genetic methods and genomic sequencing, it is now possible to get a good idea of the total capabilities of the organism and to do tests to confirm these deductions. Brucella appears to be a fairly normal member of the -proteobacteria, but with some differences. A few questions remain, such as whether Brucella uses the Entner–Doudoroff pathway. Some of the genes in carbohydrate utilization have been shown to be important in virulence.     

Development of hard white winter wheats for a hard red winter wheat region

Summary Hard white winter wheat (HWWW) occupies a very limited area of the USA, but its purported advantages suggest that its production in the major hard red winter wheat (HRWW) region may be feasible. Objectives of our investigations were to develop experimental HWWW lines that combined desirable attributes-grain yield, functional grain quality, and resistance to preharvest sprouting-in single genotypes for comparison with popular cultivars in the major US RHWW region. Forty-four lines from seven parental combinations were tested in randomized complete block designs at three Kansas locations during the 1981–82 and 1982–83 seasons. Agronomic traits, grain yield, grain quality, and preharvest sprouting were measured. Plant characteristics and grain yield were similar in the HWWW experimental lines and the HRWW check cultivar, Newton. Mean grain SDS-sedimentation value and grain protein content of most experimental lines equaled or exceeded that of the check. Dough mixing times frequently were shorter for the experimental lines than for the check cultivar, whereas loaf volumes were greater. Falling number usually was similar in all geneotypes, but -amylase was higher in field-harvested grain of white lines than the check; both measures were more favorable than grain trade standards. We concluded that production of high yielding, high quality hard white winter wheat genotypes is feasible in the US breakbasket.Contribution no. 84-349-J, Department of Agronomy, Kansas State University, Manhattan, KS 66506 USA.     

Maize Starch Yield Calibrations with Near Infrared Reflectance

Maize starch yield is affected by variety, environmental growing conditions, and drying conditions. One-hundred gram starch yield tests that predict actual wet milling starch yield were used as a reference method for developing an extractable starch calibration on a NIRSystems Model 6500 spectrophotometer. A maize starch yield calibration was developed from 940 samples and used to predict a validation set of 304 samples. It had a standard error of prediction (SEP) of 1·06, a coefficient of determination r² of 0·77 and a ratio of performance to deviations (rpd) of 2·1. This indicates about 95% of similar samples could have starch yield predicted by near-infrared reflectance within about±2·1%. The calibration should be successful in segregating maize lots for high and low starch yield percentages.     

The germination problem of oat seed lots affected by Fusarium head blight

Mycotoxin contamination and reduced germination capacity (GC) of oats affected by Fusarium head blight (FHB) have become serious concerns in Norway. Spawn- and spray-inoculated field trials were conducted from 2007 to 2010 to screen for resistant genotypes and to study the relationship between GC and deoxynivalenol (DON) contamination. Correlation coefficients between GC and DON level varied from ?0.412 to ?0.711 (P?<?0.001). The strongest and the weakest correlations were recorded for the spray- and spawn-inoculated experiments of 2009, respectively. High DON levels were associated with low GCs but low DON levels did not guarantee higher GCs. DON did not inhibit initiation of germination, but did retard seedling growth in a germination assay conducted on DON-amended water agar. Most of the seedlings grown on the modified WA containing even as little as 2?ppm DON had abnormal morphology and would not be considered as ??germinated?? in official tests. A greenhouse experiment studying the effect of time of inoculation on GC, DON level, and seed infection (SI) showed a rapid reduction in DON levels resulting from later inoculations. Increments in GC were observed although they were not as strong as the decrements in DON level. Seed infection remained consistently high (> 60?%) for all inoculations. Seed dressing and dehulling individually were not effective in improving GC, but when combined increased GC to the percentage of kernels having viable germ. We hypothesize that in addition to the level of DON, SI influences the GC of Fusarium-damaged oats, especially in wet years that may facilitate late-initiated infections.