Variations in carbon and nitrogen ratios and their effects on seed germination in Cupressus sempervirens populations

This study investigated the variations in the carbon (C), nitrogen (N), and C/N ratios in the seeds of the Mediterranean Cypress (Cupressus sempervirens L.), a typical forest tree of the Mediterranean Region. The data were gathered from populations distributed across Turkey. We also evaluated the relationship between these variations and germination parameters such as the germination percentage (GP) and mean germination time (MGT). All of the evaluated characteristics demonstrated statistically significant variations among the populations. The GPs were generally low and varied between 14% in Datça and 51% in the Köprülü Kanyon. The MGTs ranged from 14.9 in the Köprülü Kanyon to 18.9 in Marmaris. In addition, the C ratios varied between 46% in Marmaris and 52% in the Köprülü Kanyon, while the N ratios ranged from 1.1% in Beycik and Göksu to 1.8% in the Köprülü Kanyon. Furthermore, we observed a positive correlation between the GP and the C and N contents (R² = 0.51 and R² = 0.49, respectively) but found a negative correlation between the MGT and the C and N contents (R² = 0.56 and R² = 0.32, respectively). Moreover, with regard to the combined C and N seed ratios of the regression models, R² = 0.95 for the GP and R² = 0.87 for the MGT, and the populations with higher quantities of C and N in their seeds had shorter MGTs and higher GPs.     

Determination of Oestrous Cycle of the Rats by Direct Examination: How Reliable?

For determination of the oestrous cycle in rats classical Papanicolaou technique has long been used successfully. Instead of using many stains in Papanicolaou, staining the vaginal secretions with only methylene blue has also been defined. Recently a new technique in which vaginal samples are directly examined under light microscope has been introduced. The aim of this study was to assess the reliability of this new technique by comparing it with the classical staining techniques. From 20 Wistar rats 60 vaginal samples were collected with a micropipette, three from each. Briefly, the vagina was flushed two to three times then the fluid was placed onto a glass slide. The fluid was equally distributed onto three glass slides. The glass slides were coded. Two samples were stained with Papanicolaou and methylene blue while the other one was examined directly. Determination of the phases of the oestrous cycle was made by the same histologist who was blinded to the groups and coding system. After determination of the oestrous phase in all samples, the results were compared and it was found that the results were matching. In conclusion, the same results can be obtained with the direct examination technique and this technique is reliable, so there is no need to use relatively time-consuming, less practical and more expensive techniques such as Papanicolaou or methylene blue.     

Effect of pellet food size and polyphosphates in preventing calculus accumulation in dogs

Forty female Beagle dogs, aged 12 to 24-months were divided into four groups of ten dogs each. Results showed that increasing kibble diameter by 50.0% was associated with a 42.0% calculus reduction. Coating the kibbles with sodium tripolyphosphate, an anti-calculus agent, further induced a 55.0% calculus reduction. Sodium tripolyphosphate was shown to be at least as effective as sodium hexametaphosphate. The calculus reduction effect on teeth differed based on tooth location with the most pronounced effect being observed on caudally-located crushing teeth compared with incisor and canine teeth. The relevance of scoring non-crushing teeth when testing a product with mechanical effect on plaque and calculus needs to be questioned.     

The effects of nitrogen and iron fertilization on growth,yield and fertilizer use efficiency of soybean in a Mediterranean-type soil

Poor seed yield of soybean in Mediterranean-type environments may result from insufficient iron (Fe) uptake and poor biological nitrogen (N) fixation due to high bicarbonate and pH in soils. This study was conducted to evaluate the effects of N and Fe fertilization on growth and yield of double cropped soybean (cv. SA 88, MG III) in a Mediterranean-type environment in Turkey during 2003 and 2004. The soil of the experimental plots was a Vertisol with 176 g CaCO₃ kg⁻¹ and pH 7.7 and 17 g organic matter kg⁻¹ soil. Soybean seeds were inoculated prior to planting with commercial peat inoculants. N fertilizer rates were 0, 40, 80, and 120 kg N ha⁻¹ of which half was applied before planting and the other half at full blooming stage (R2). Fe fertilizer rates were 0, 200 and 400 g Fe EDTA (5.5% Fe and 2% EDTA) ha⁻¹. It was sprayed as two equal portions at two trifoliate (V2) and at five trifoliate stages (V5). Plants were sampled at flower initiation (R1), at full pod (R4) and at full seed (R6) stages. Application of starter N increased biomass and leaf area index at R1 stage whereas Fe fertilization did not affect early growth parameters. N application continued to have a positive effect on growth parameters at later stages and on seed yield. Fe fertilization increased growth parameters at R4 and R6 stages, and final seed yield in both years. This study demonstrated an interactive effect of N and Fe fertilization on growth and yield of soybean in the soil having high bicarbonate and pH. There was a positive interaction between N and Fe at the N rates up to 80 kg N ha⁻¹. However, further increase in N rate produced a negative interaction. Fertilization of soybean with 80 kg N ha⁻¹ and 400 g Fe ha⁻¹ resulted in the highest seed yield in both years. We concluded that application of starter and top dressed N in combination with two split FeEDTA fertilization can be beneficial to improve early growth and final yield of inoculated soybean in Mediterranean-type soils.     

Invertase activity as affected by cytokinin-like compounds during potato tuberizationin vitro

Acid invertase plays an important role in plants by hydrolyzing sucrose. Compounds exhibiting cytokinin activity were examined for their effects on acid invertase activity at three tuberization stages of potato,Solanum tuberosum L. Single nodal segments from the cultivar Atlantic were cultured on Murashige and Skoog (MS) medium with 6% sucrose and maintained under a 16-hr photoperiod. Media were supplemented with either 2 mg kinetin/1, 0.1 mg thidiazuron/1,1.0 mg AC243, 654/1 (a benzyl nitroguanidine), or 0.1 mg AC239, 604/1 (a phenyl nitroguanidine). Basal acid invertase activity was measured in stolon segments at three morphologically distinct tuberization stages: (1) “hook,” (2) “swelling,” and (3) “initiation.” The onset of tuber initiation was significantly advanced by kinetin and thidiazuron compared to controls. Stolons elongated during the hook and swelling stages until tubers were initiated. Basal acid invertase activity in stolons cultured on control medium significantly increased from hook stage to swelling stage and then decreased slightly when tubers were initiated. At the hook stage, highest basal acid invertase activity occurred when the segments were treated with kinetin and thidiazuron. Kinetin and thidiazuron induced basal acid invertase activity significantly decreased following the hook stage to tuber initiation. Basal acid invertase activity were significantly lower in stolons treated with nitroguanidines than the control activity following the hook stage of development. During the swelling and tuber initiation stages, nitroguanidines-treated segments showed reduction in basal acid invertase activity similar to segments treated with kinetin and thidiazuron treatments. Tuber initiation was preceded by a stimulation of basal acid invertase activity followed by a decrease prior to tuber initiation. Kinetin and thidiazuron stimulated enzyme activity early in the growth of stolons which may have resulted in faster stolon growth and in earlier tuber initiation. The two nitroguanidines, although able to mimic many cytokinin effects in bioassays, did not seem to act in the same way as kinetin.     

Effectiveness of an oral hygiene chew to reduce dental deposits in small breed dogs

Over a period of 4-months, feeding small breed dogs with a regular dry diet supplemented with a daily oral hygiene chew resulted in a significant reduction in plaque deposition (17.3%) and calculus accumulation (45.8%) compared with dogs fed the dry diet alone. Daily feeding of a specifically designed oral hygiene chew that reduces plaque and calculus accumulation may play a role in the severity of canine periodontal disease.     

Determination of the prevalence of whole blood taurine in Irish wolfhound dogs with and without echocardiographic evidence of dilated cardiomyopathy

ObjectivesTaurine plays an important role in maintaining myocardial function. Irish wolfhound dogs (IW) are at risk for dilated cardiomyopathy (DCM), but a relationship between whole blood taurine (WBT) deficiency and DCM has not been established. Our aim was to determine prevalence of WBT deficiency in IW with and without DCM and assess its association with diet.Animals115 privately owned IW.MethodsWhole blood taurine was measured in IW that received cardiovascular examination. Dietary history was recorded; crude protein and energy intake were estimated.ResultsForty-nine (42.6%) had DCM; 66 (57.4%) had no DCM. Dogs with DCM were older ([median; inter-quartile range or IQR] 5.3; 4.3, 6.2 years) than dogs without heart disease (3; 2, 4 years; P < 0.001). There was no significant relationship between WBT concentration and age (P = 0.64). Whole blood taurine was severely reduced (<130 nmol/mL) in 8 dogs (4 with and 4 without DCM) and moderately reduced (130–179.9 nmol/mL) in 32 dogs (12 with DCM and 20 without DCM). Follow up of dogs without DCM revealed that a higher proportion of dogs with any degree of WBT deficiency developed DCM later compared to dogs with normal WBT (P < 0.001).ConclusionsWhole blood taurine deficiency occurred in IW with and without DCM. Based on taurine measurement on a single occasion, there was no clear relationship between low WBT and presence of DCM in this population. Regardless of WBT, DCM affected predominantly older dogs, suggesting a relatively late onset disease in the IW.     

Tooth resorption and vitamin D3 status in cats fed premium dry diets

It has been suggested that tooth resorption (TR) in cats is associated with vitamin D3 status. The purpose of this study was to evaluate any correlation between serum 25-OH-D concentrations and the prevalence of TR. The healthy adult domestic cats (n=64) of this study had been fed similar premium dry-expanded foods throughout their lives. Serum 25-OH-D was measured, and cats received a single, complete periodontal examination, with periodontal probing of each tooth and exploration of the tooth surface using a dental explorer A complete set of 10 dental radiographs was taken for each cat. There were 168 TRs diagnosed in 40 of 64 cats (85 were Type 1 TR and 83 were Type 2). The mean serum 25-OH-D concentration was 187.7 +/- 87.3 nmol/L. The mean serum 25-OH-D in cats with one or more TR was 164.2 +/- 78.8 nmol/L, compared with 226.8 +/- 88.2 nmol/L for those without TR (p = 0.14). The mean serum 25-OH-D in the 13 cats with >5 TR was 131.2 +/- 49.5 nmol/L, which was significantly less than in cats with no TR (p < 0.05). There was no relationship between TR type and serum 25-OH-D. There was no effect of age or sex on serum 25-OH-D. On the contrary, variations in serum 25-OH-D were observed according to the studied breeds. There was no relationship between TR type and serum 25-OH-D. TR prevalence was greater in cats with lower serum 25-OH-D concentrations. In conclusion, the hypothesis that higher serum 25-OH-D concentrations are associated with a higher prevalence of TR is not supported by this study.