CO2 enrichment of strawberry and cucumber plants grown in unheated greenhouses in Israel

Strawberries and cucumber plants were grown in ambient atmospheric CO₂ concentrations of 300 v.p.m. and at elevated levels of 900, 1500 and 3000 v.p.m. during winter and early spring in 10 unheated greenhouses in the coastal plain of Israel. Co₂ enrichment averaged 7 hours per day between the end of November and the second half of April.Strawberry plants of cultivar ‘Tioga’ yielded 31, 43 and 51 % more than the control when subjected to a 3-, 5- and 10-fold increase in CO₂ concentration, respectively.Cucumber plants of cultivar ‘Elem’ grown at 3000 v.p.m. CO₂ yielded 26 % more over the whole picking season than those grown at 300 v.p.m. Yield during the first month of picking was doubled by both a 3- and a 10-fold increase in aerial CO₂ concentration.     

Die Bienenzucht,auch ein Glied der angewandten Entomologie

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Über Chloropiden-Schwärme in Erlangen

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Interval mapping of growth quantitative trait loci in Japanese Black beef cattle using microsatellite DNA markers and half-sib regression analysis

A confirmatory scan for the regions of bovine chromosome 1 segregating the quantitative trait loci (QTL) influencing birthweight, weaning weight, yearling weight, and preweaning and postweaning average daily gains was performed by genotyping half‐sib progeny of four Japanese Black sires using microsatellite DNA markers. Data were analyzed by generating an F‐statistic every 1 cM on a linkage map by the regression of phenotype on the probabilities of inheriting an allele from the sire after adjusting for the fixed effects of sire, sex, parity and season of birth as well as age as a covariate. Permutation tests at chromosome‐wide significance thresholds were carried out over 10 000 iterations. A significant QTL for birthweight at 114 cM was detected in the sire 2 family. This identification of a birthweight QTL in Japanese Black cattle may be useful for the implementation of marker‐assisted selection.     

Structural Modification of Gluten Proteins in Strong and Weak Wheat Dough as Affected by Mixing Temperature

The effects of temperature (≥25°C) on dough rheological properties and gluten functionality have been investigated for decades, but no study has addressed the effect of low temperature (<30°C) on gluten network attributes in flours with strong and weak dough characteristics. This study monitored changes in protein extractability in the presence and absence of reducing agents, the contents of readily accessible and SDS‐accessible thiols, and the secondary structural features of proteins in doughs from commercial hard wheat flour (HWF) and soft wheat flour (SWF) mixed at 4, 15, and 30°C. SWF mixed at 4 and 15°C showed similar mixing properties as HWF mixed at 30°C (which is the standard temperature). The effect of mixing temperature is different at the molecular level between the two flours studied. Protein features of HWF did not change as mixing temperature decreased, with the only exception being an increase in SDS‐accessible thiols. Decreasing mixing temperature for SWF caused an increase in SDS protein solubility and SDS‐accessible thiols as well as an increase in β‐turn structures at the expense of β‐sheet structures. Thus, noncovalent interactions appear to drive protein network at low temperatures (4 and 15°C), whereas covalent interactions dominate at standard mixing temperature (30°C) in doughs from both flours.     

Bienenzucht und Schädlingsbekämpfung

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Scrotal circumference, bodyweight and serum testosterone concentration of Red Sokoto weaner bucks as influenced by dry season crop-residue supplementation

The effect of dry season supplementation with crop‐residue‐based rations on bodyweight, scrotal circumference and serum testosterone concentrations in Red Sokoto weaner bucks at 5, 6 and 7 months of age was investigated in the present study. There were 7 treatment groups which were fed a positive control ration (conventional concentrate) fed at 1 and 2% of the bucks’ bodyweights (Rations 1A and 2A), two crop‐residue‐based test rations each fed at 1 and 2% of bodyweight (1B, 2B, 1C and 2C), and a negative control that was unsupplemented (Ration D). All treatment groups had ad libitum access to natural pastures and Digitaria smutsii hay as a basal diet. Bodyweight and scrotal circumference of the bucks significantly increased (P < 0.05) with age from 5.9 kg to 10.2 kg, and 4.40 cm to 6.95 cm, at 5 and 7 months of age, respectively. Bucks on Ration D (unsupplemented group) had the lowest bodyweight and scrotal circumference. Bucks on Ration 2A showed a significant increase in basal testosterone concentration from 0.32 ng/mL at 5 months of age to 0.65 ng/mL at 7 months of age. Peak testosterone concentration also increased from 1.0 ng/mL at 5 months to 2.8 ng/mL at 7 months of age. Bucks on test Ration 2C had higher bodyweights (6.75, 8.00 and 10.00 kg at 5, 6 and 7 months of age, respectively) than bucks on the other test Ration B (6.20, 7.20 and 8.50 kg, respectively). There were no significant differences between the two test rations with regard to scrotal circumferences of the bucks at all ages. However, at 7 months of age, bucks on test Ration 2C had significantly higher peak testosterone concentration (1.80 ng/mL) than their counterparts on test Ration 2B (1.30 ng/mL). The secretory patterns of testosterone were episodic and pulsatile in nature. It was concluded that crop‐residue supplementation in prepubertal Red Sokoto bucks has a significant influence on their bodyweight, scrotal circumference and testosterone production. Test Ration C was a cheap, affordable and better crop‐residue‐based ration for optimal reproductive performance than test Ration B.