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The influence of isoosmotic Lutrol- and salt solutions upon the chlorophyll-concentration and chlorophyll a/b ratio of Phaseolus vulgaris The behaviour of the chlorophyll status of Phaseolus vulgaris was studied under the influence of different isoosmotic Lutrol and salt solutions in the root medium. Phaseolus seedlings, 12 days old, were raised in a nutrient solution containing isoosmotic concentrations of 0.54 (control); 1.26; 2.82 and 4.68 atm. created by either Lutrol or salts (40% chlorine, 60% sulfate). An increase in the osmotic pressure of the primary and normal leaves generally paralleled the increase in the osmotic pressure of the media with a more pronounced effect in the case of salts than in Lutrol. Mean values of osmotic pressure of both primary and normal leaves during the sampling period were 6.19; 10.35 and 12.98 atm. for control, Lutrol III and salt III respectively. Increasing the osmotic pressure of the media due to salts resulted in a significant decrease of the chlorophyll content of primary leaves (mean value during the sampling period: Cont.: 19.8 μg/cm2; salt II: 12.7 μ/cm2; salt III: 6.3 μg/cm2), accompanied with a decreasing tendency in the chlorophyll a/b ratio. Such effect was only detectable in the case of the highest Lutrol concentration at the end of the experiment. However, the mean values of the sampling period did not show any significant variation from those of controls (Lutrol II: 18.9 μg/cm2; Lutrol III: 16.1 μg/cm2). Both types of osmoticum decreased remarkably the total chlorophyll amount of normal leaves. This behaviour resulted more clearly from a reduction in the leaf area than from the decrease in the chlorophyll concentration. The mechanism of plant response to changes in the osmotic pressure of the medium seemed to depend mainly on the type of osmoticum affecting such variations. In general the changes in the osmotic pressure created by salts affected both mature and developing leaves i.e. primary and normal leaves respectively, whereas such changes in the case of Lutrol affected mainly the latter organs. 相似文献
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Reduction of stalk length in winter and summer rye by Ethrel (2-chloroethylphosphonic acid) . In pot experiments with winter and summer rye Ethrel (2-chloroethylphosphonic acid) considerably reduced stalk length so that a favourable effect on lodging can be expected. The shortening effect strongly depends on the time of application. Grain yield is scarcely affected. The experiments give indication for the optimal concentration and the amount of active substance required. 相似文献
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Mohamed M. A. Abumandour Raafat M. A. El-Bakary 《Veterinary research communications》2013,37(3):229-238
This study was carried out on the tongues of 12 adult normal healthy Egyptian fruit bats of both sexes. The tongue is protrusible, elongated flat with a rounded apex and its wide and thickness increase gradually toward the lingual root. There are four types of lingual papillae; two mechanical and two gustatory. The tongue divided into three parts (anterior, middle and posterior), each part subdivides into three regions; two lateral regions and median region, in addition to the lingual apex to the anterior region. The lingual papillae close to the median region of the tongue were posteriorly directed toward the pharynx, while theses present on the lateral regions of the tongue are directed medioposteriorly. There are sex subtypes of the filiform papillae; three on the anterior part (small, conical and giant), two on the middle part (cornflower and leaf-like papillae) while the posterior part contain rosette shape filiform papillae, in addition to transitional papillae and conical papillae. Two gustatory papillae represented by; small number of fungiform papillae which scattered among the filiform papillae on lingual apex and two lateral regions of the anterior and middle part of tongue, while the three circumvallate papillae on the posterior part were arranged in a triangle form. 相似文献
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Yin Yin Moe Shunsuke Koshio Manabu Ishikawa Shin-ichi Teshima Arthur Panganiban Jr Moe Thu Fady Raafat Michael & Torgjun Ren 《Aquaculture Research》2005,36(8):739-745
l ‐ascorbyl‐2‐monophosphate‐Na/Ca (AMP‐Na/Ca) was used as a vitamin C source to investigate the ascorbic acid (AsA) requirements on growth performance and stress resistance of the post‐larval kuruma shrimp, Marsupenaeus japonicus. Purified carrageenan‐microbound diets with six levels of AMP‐Na/Ca, AsA equivalent to 0, 20, 56, 87, 759 and 1697 mg kg?1 diet were fed to triplicate groups of M. japonicus (mean initial weight 16±0.3 mg) for 30 days. The diets with AsA 0, 20 and 56 mg kg?1 showed high cumulative mortality after 10 days of feeding. After the 30‐day trial, the shrimp fed these diets had significantly lower survival and weight gain (WG, %) than those fed the 87, 759 and 1697 mg AsA kg?1 diets. Specific growth rate and individual dry weight showed the same pattern as WG (%). There were no significant differences in growth performance among the groups fed the AsA levels at 87, 759 and 1697 mg kg?1 at the termination of feeding trial. Broken‐line regression analysis indicated that 91.8 mg AsA kg?1 in the diet was the optimum for post‐larval shrimp. On the other hand, dietary level of more than 800 mg AsA kg?1 was needed to ensure high resistance to stressful conditions such as osmotic and formalin stressors. 相似文献
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Fady Raafat Michael Shin-Ichi Teshima Shunsuke Koshio Manabu Ishikawa Orhan Uyan & Md. Shah Alam 《Aquaculture Research》2005,36(16):1563-1571
The present study was undertaken to clarify the effect and interaction of choline chloride (CC) and phosphatidylcholine (PC), the water‐ and fat‐soluble sources of choline, on the performances of kuruma shrimp, Marsupenaeus japonicus juveniles using as response variables such as percent weight gain (%WG), specific growth rate (SGR), survival (SR%), feed efficiency ratio (FER), protein efficiency ratio (PER), proximate composition, fatty acids profile and free choline and PC contents in the whole body of kuruma shrimp. A 40‐day feeding trial was conducted as a 2 × 3 factorial experiment with six test diets containing three levels of CC (0.3, 0.6 and 1.2 g kg?1) and two levels of soybean PC (SPC; 2 and 4 g kg?1). Both of the choline sources (CC and SPC) showed a significant interaction (P<0.05) regarding all the evaluated response variables except for the proximate and fatty acid contents. Interestingly, there was a positive effect (P<0.05) of CC observed with increasing its level at the low level of SPC and vice versa. However, the magnitudes of the beneficial effect of CC in terms of the evaluated parameters were changed with the different dietary levels of SPC. Also, the inclusion of higher levels of SPC (4 g kg?1) or CC (0.6 and 1.2 g kg?1) diminished the effect of the other source. 相似文献
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Raafat H ABD EL-WAHAB 《干旱区科学》2016,8(5):787-798
Knowledge about plant diversity along disturbance gradients is essential for conservation and management of fragmented coastal habitats.This study examined the effects of human disturbance intensity in coastal habitats of Kuwait on diversity,composition,identity and assemblage of vascular plant species.Plant survey data from 113 plots (5m×5m each) were randomly selected in 51 sites at coastal fragmented habitats at three levels of disturbance intensities (high,moderate and low) and were statistically analyzed.The results revealed that about 76% of the recorded species are considered threatened species in Kuwait,most of which are being lost in high disturbed habitats.Disturbance led to the dominance of Zygophyllum qatarense,Cornulaca aucheri and Salsola imbricata,which are species of disturbance indicators.Richness,total plant cover and species diversity were higher in moderate and low disturbed habitats than in high disturbed habitats.Beta diversity between high and low disturbed habitats was higher than either between high and moderate,or between moderate and low disturbed habitats.Cluster analyses showed statistically significant differences in composition of plant assemblages,which indicate high beta diversity between the habitat types.Intensive urbanization and industrialization are among the most serious threats that contribute to declines in biological diversity and rapid fragmentation of coastal habitats in Kuwait.Establishing protective enclosures in the disturbed habitats,planting endangered and vulnerable species,and establishing a natural reserve at Nuwaiseeb are recommended conservation actions to avoid loss of the fragmented coastal habitats and to facilitate restoration of native plants. 相似文献
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For 79 isolates from the tonsils of healthy cattle identified as Erysipelothrix by cultivation, biochemical and serological tests, genotypic identification was performed by polymerase chain reaction (PCR) using four species-specific sets of oligonucleotide primers (ER1F-ER1R, ER2F-ER2R, ER3F-ER3R and ER4F-ER4R). The results of PCR for 79 bovine isolates were compared with those of serological typing. For 19 isolates, serotyping and genotyping results were the same. PCR allowed for the identification of 36 untypable isolates as Erysipelothrix species, strain 1. Serotyping and genotyping results of the remaining 24 isolates were different. Supplemental tests are frequently needed for Erysipelothrix identification. 相似文献