Effect of titanium ascorbate on the lipoxygenase pathway of tomato and red pepper seedlings

The effect of titanium applied as titanium ascorbate (Titavit^®) on the lipoxygenase (LOX) pathway of tomato and red pepper seedlings was studied. Seeds were germinated in solutions containing titanium at 5 and 10 ppm. The uptake of titanium was significant and occurred at a similar amount for both tomato and red pepper. LOX and hydroperoxide decomposing (HPD) activities were determined in the crude extracts. The results showed that LOX activity in the extract of Titavit‐germinated seedlings was significantly higher than that of the control, whereas no effect was observed on the activity of HPD enzymes. It is suggested that activation of LOX by Titavit was due to a chemical interaction of titanium within the reaction mixture than to an induction of the biosyntheis of the enzyme.     

The Effect of Irrigation Management and Nitrogen Fertilizer On Grain Yield and Water-use Efficiency of Rice Cultivars in Northern Iran

Gesunde Pflanzen - Alternate wetting and drying irrigation (AWDI) is a water-conserving strategy in rice fields. An experiment, conducted as a split-split plot design and based on...     

Contribution of Small-Scale Agroforestry Systems to Carbon Pools and Fluxes: A Case Study from Middle Hills of Nepal

In view of the heavy people’s dependence (80 %) on various forms of land-based resources, carbon sequestration should not only be targeted in forests, but also on private land agroforestry. A survey was conducted in 2011 to investigate the gap in contribution of agroforestry carbon to the household economy in the middle hills region of Rasuwa district of Nepal. A total of 120 households were randomly selected and surveyed, of which eight were further examined for detailed tree carbon measurement. It is estimated that a total of 48.60 ton C per hectare has been stocked in agroforestry sites in the middle hills region. Assuming a carbon price of $US12/ton, the total potential income from carbon sequestration per household would amount to NPR 45,490/ha in 20 years of agroforestry if a payment scheme were introduced. The income from carbon sequestration is quite low compared with other agroforestry income. Policy implications are thus oriented towards farmers reaping multiple benefits from the existing international mechanisms by having negotiations based on contribution of all agroforestry components (farm trees, crops and animals) rather than limited to forest carbon stock. To benefit from these multiple functions of farms and forests, the policy framework to address the climate-related affects and risks (e.g., of landslides, burst of Himalayan lakes) should be broad enough to produce potential synergy between the negative effect of climate change and agroforestry income.     

Cryptogein and capsicein promote defence responses in Quercus suber against Phytophthora cinnamomi infection

The decline of cork oak (Quercus suber) stands in Iberian Peninsula is associated with infection by Phytophthora cinnamomi. Most Phytophthora species secrete elicitins, which can enhance defence reactions against some pathogens. Here cytological and physiological effects of the elicitins cryptogein and capsicein on cork oak root infection by P. cinnamomi were evaluated. The progression of the pathogen in root tissue and its effects on total fatty acid (TFA) composition of roots and leaves were analysed in seedlings. Net photosynthesis (P _n ), stomatal conductance (g _s ), chlorophyll a fluorescence measurements (quantum yield of linear electron transport ? _e , photochemical quenching q _P, non-photochemical quenching NPQ) and carotenoid determinations were carried out in well established (4?months) plants. In elicitin-treated roots, 2?days after inoculation, the pathogen which presented loss of viability and membrane degradation was mainly restricted to the intercellular spaces of the cortical parenchyma, and did not reach the vascular cylinder. Electron dense materials accumulated in the intercellular spaces of the cortex next to disorganized hyphae, suggested to be related with defence reactions. Cryptogein (or its interaction with P. cinnamomi) induced enhanced lipid synthesis in leaves, which may contribute to preserve membrane stability. P. cinnamomi decreased P _n , g _s , ? _e , and q _P, whereas elicitin-treated plants displayed values similar to controls. Overall, the results indicated a resistance response of cork oak against this oomycete, induced by the elicitins.     

Antimicrobial susceptibility of Staphylococcus pseudintermedius colonizing healthy dogs in Saskatoon,Canada

This study reports antimicrobial susceptibility of Staphylococcus pseudintermedius carried by healthy dogs in Saskatoon, and describes changes in antimicrobial resistance since a 2008 study. One hundred healthy dogs presenting to the wellness service at the Western College of Veterinary Medicine were screened for S. pseudintermedius by culturing rectal and pharyngeal swabs. Staphylococcus pseudintermedius was identified biochemically and antimicrobial minimum inhibitory concentrations were determined by broth microdilution. Methicillin resistance was confirmed by polymerase chain reaction (PCR) and sequencing of the mecA gene. Of 221 S. pseudintermedius isolates from 78 dogs, 7 were methicillin resistant. No resistance to the fluoroquinolones, nitrofurantoin, tigecycline, vancomycin, quinupristin-dalfopristin, linezolid, or daptomycin was identified. Of the 78 positive dogs, isolates resistant to penicillin were found in 78%, to ampicillin in 61% and to tetracycline in 26%; resistance to oxacillin, erythromycin, clindamycin, trimethoprim + sulfamethoxazole, chloramphenicol, and gentamicin was found in < 10% of dogs. Compared to the 2008 study, the frequency of resistance to all drugs increased, and the frequency of colonization with pan-susceptible isolates decreased from 46% to 30%.     

Effect of Drought Stress and Different Levels of Nitrogen and Potassium Fertilizers on the Accumulation of Osmolytes and Chlorophyll in Rice (Oryza sativa L.)

Gesunde Pflanzen - Management of plant nutrition using fertilizers is an approach to deal with drought and to increase water productivity in paddies. The aim of this study, therefore, was to...     

A single progenitor population switches behavior to maintain and repair esophageal epithelium

Diseases of the esophageal epithelium (EE), such as reflux esophagitis and cancer, are rising in incidence. Despite this, the cellular behaviors underlying EE homeostasis and repair remain controversial. Here, we show that in mice, EE is maintained by a single population of cells that divide stochastically to generate proliferating and differentiating daughters with equal probability. In response to challenge with all-trans retinoic acid (atRA), the balance of daughter cell fate is unaltered, but the rate of cell division increases. However, after wounding, cells reversibly switch to producing an excess of proliferating daughters until the wound has closed. Such fate-switching enables a single progenitor population to both maintain and repair tissue without the need for a "reserve" slow-cycling stem cell pool.     

Mapping of Lr56 translocation recombinants in wheat

In an attempt to transfer the Lr56/Yr38 resistance loci from Aegilops sharonensis to wheat, a 6A‐6S^sh chromosome translocation was produced. It involves essentially the entire chromosome 6S^sh with a small terminal segment of 6AL. Induced homoeologous recombination of the translocated chromosome with 6A produced numerous recombinants including three recombined chromosomes carrying Lr56 that could not be precisely mapped for lack of suitable markers. This study aimed to determine the chromosomal locations of the translocation breakpoints in these three recombinants using various DNA markers as well as physical and genetic mapping. The three recombinants Lr56‐39, ‐157 and ‐175 carry small segments of Ae. sharonensis chromatin distally to the Xgpw4329 and IWA5416 loci near the 6AS telomere. The Ae. sharonensis chromatin that remains in each line includes a homoeolocus of the wheat marker locus Xdupw217 (on 6BS) and its characteristic amplification product can be used as a dominant marker for the presence of Lr56. Of the three recombined chromosomes, Lr56‐157 retained the least alien chromatin and appears to be the best candidate for use in wheat breeding.     

Effects of pruning intensity on the biochemical status of shoot buds in three mango (Mangifera indica L.) cultivars planted at high density

Summary

Mango (Mangifera indica L.) trees grown at high density show a decline in flowering and fruiting after good fruiting years as a result of various factors. Annual pruning can restore production and productivity in such trees. Chlorophyll, total sugars (TS), total phenolics (TP), and proline contents as well as polyphenol oxidase (PPO) activities, were measured in the 2005–2006 and 2006–2007 seasons in shoot buds with a few leaves in three mango cultivars (‘Amrapali’, ‘Mallika’, and ‘Dashehari’). Trees were grown at high density in an orchard and the aforesaid parameters were measured 1 month after different degrees of pruning (Stage I) and after subsequent fruit bud differentiation (FBD; Stage II). Severely-pruned mango trees had the highest contents of chlorophyll a, while chlorophyll b and total chlorophyll contents were found to be highest in moderately-pruned trees. Lightly-pruned trees had the highest contents of reducing sugars (RS), whereas TS contents were highest in severely-pruned trees. The contents of RS and TS increased in shoot buds during the FBD stage. A moderate intensity of pruning significantly increased TP contents, while the lowest TP contents were recorded in non-pruned trees. ‘Off’-year shoots had higher TP contents than ‘on’-year shoots. Irrespective of pruning intensity, shoot buds of ‘Mallika’ trees had the highest PPO activities, with lower levels in ‘Amrapali’ and ‘Dashehari’ shoot buds. PPO activities were reduced at the FBD stage in ‘on’-year shoots. Severely-pruned trees had the highest PPO activities, while the lowest PPO activities were recorded in lightly-pruned trees. Shoot bud proline contents were found to be highest in non-pruned trees, and decreased with increasing pruning intensity. Thus moderate pruning can be adopted in high density orchards to obtain sustainable production with improved maintenance of canopy architecture.     

Intermediary spleen microvasculature in canis familiaris- morphological evidences of a closed and open type

Numerous studies have been made regarding circulation via the red pulp of the spleen, and intense controversy surrounds the question as to whether or not endothelial continuity exists between arterial and venous vessels. Aware of this intense controversy, and in order to perform investigation over the spleen of dogs infected with a parasitic disease (future reports shall be done), the authors studied the vascularization of the normal dog spleen in order to define its normal pattern and evaluate the eventual changes of the circulation pattern under the parasitic condition. These studies led us to report, unequivocally, using complementary vascular replective techniques, that the normal dog's intermediary circulation is morphologically closed and of the open kind also. These findings are contrary to the thesis that defends the existence of a physiologically closed and morphologically open circulation in the dog spleen. Lymphatic vessels in the spleen of the dog are also demonstrated.