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11.
Conventionally flooded rice (CFR) requires enormous water and labor inputs. Water scarcity aspires for cultivation of water-saving rice. Growth response and physiology of basmati rice genotypes under the water-saving production systems has not been reported yet. Studies were conducted for 2 years to compare the growth and physiology of three rice cultivars (Super Basmati, Basmati-2000 and Shaheen Basmati), under high (CFR), medium (alternate wetting and drying [AWD]) and low water input (aerobic rice [AR]) systems. Leaf area index, crop growth rate, leaf area duration and dry matter accumulation were higher for AR followed by AWD and CFR, respectively. Shaheen Basmati had a lower growth and relative water contents than Super Basmati and Basmati-2000, probably due to its shorter stature and shorter life cycle. Photosynthetic rate and stomatal conductance of rice cultivars in the different production were affected only at reproductive stage. Basmati-2000 grown as AR had the highest photosynthetic rate followed by the same cultivar under AWD. The results of this study provide us an idea that basmati cultivars can attain a high growth and development with low water input. This would be helpful to grow rice successfully under water-short rice-growing environments.  相似文献   
12.

Background

The primary aims of this study were to determine the incidence of Giardia infections in dairy herds on farms in the New York City Watershed region and to evaluate risk factors associated with infections. Because co-infections of Giardia and Cryptosporidium spp. are common in this population, we also evaluated the effect of herd infection status on Giardia infections.

Methods

Farms were grouped into three cohorts based on their prior infection status with Giardia and/or Cryptosporidium spp. The sampling plan included collecting fecal samples from all calves below 30 days of age and proportional sampling of calves, young stock, and adults. A total of 10,672 fecal samples were collected and analyzed for the presence of Giardia cysts using zinc sulfate flotation. Herds enrolled in the study were sampled seasonally for a study period of two years. The probability of shedding cysts past a certain age and the factors that influenced the likelihood of shedding were evaluated using survival analysis. Linear regression was used to evaluate factors that were associated with the intensity of shedding.

Results

The majority of Giardia infections occurred in calves within their first 180 days of age, with the most number of calves shedding Giardia cysts between 11 and 20 days of age. The incidence of shedding of Giardia cysts ranged from 0.0004 per animal day for cattle in the low risk cohort to 0.0011 per animal day for cattle in the high risk cohort. The likelihood of shedding was influenced by the prior infection status of the herd and the season of collection. Infected animals shed on average 9,658 cysts/gram and the intensity of shedding Giardia cysts varied significantly with the age (p < 0.0001) and the season of collection (p = 0.0151 for Spring).

Conclusion

Giardia infections are common in dairy herds in the New York City watershed, particularly in calves less than 6 months of age. Seasonality may be an important factor in the perpetuation of infections based on changes in management practices corresponding to weather patterns of a particular season. A dairy herd''s prior infection status with Cryptosporidium influences the likelihood of infection with Giardia.  相似文献   
13.
A local isolate of Metarhizium anisopliae (Hypocreales: Clavicipitaceae), Bacillus thuringiensis subsp. kurstaki and chlorantraniliprole were assessed against six field populations of tomato fruitworm Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) in a series of laboratory bioassays. Two dose rates of B. thuringiensis (0.5, 1 μg g?1), one of both M. anisopliae (1.3?×?106 conidia ml?1) and chlorantraniliprole (0.01 ppm) were applied alone and in combination with each other against 2nd, 3rd, 4th and 5th larval instars. The mortality was observed every 24 h until pupation. The bioassays were carried out at 25°C and 75% r.h. The highest mortality was observed in Rawalpindi with the lowest pupation rate by applying the combined concentrations of B. thuringiensis and chlorantraniliprole. The lowest mortality was observed in population from Gujranwala among all the tested populations. The antagonistic interaction was noted where the high dose rate of B. thuringiensis was combined with M. anisopliae; however, the remaining interactions enhanced the mortality and reduced the percent pupation. The overall results demonstrated that all the treatments gave significant control of the larval instars of H. armigera. The population from Gujranwala proved least susceptible whereas the one from Rawalpindi was highly susceptible.  相似文献   
14.
This study was carried out to reveal the formation of the sacral plexus in the Eurasian Eagle Owls (Bubo bubo) and the nerves originating from this plexus. Five EEOs, three of them were male and two were female, were provided from Wildlife Rescue and Rehabilitation Center of Kafkas University and used as materials. Following the euthanizing of the animals, abdominal cavity was opened. The nerves of plexus sacrales were dissected and photographed. It was detected that the sacral plexus was formed by the ventral ramus of five synsacral nerves. Moreover, it was determined that the roots of the sacral plexus formed three trunks: the truncus cranialis, the truncus medius and the truncus caudalis in fossa renalis. The availability of the n. ischiofemoralis and the availability of n. parafibularis were detected in the EEOs. Five branches were specified as having segregated from the sacral plexus: the n. cutaneus femoralis caudalis, the mutual root of n. fibularis with n. tibialis (n. ischiadicus), the rami musculares, the n. coxalis caudalis and the ramus muscularis. It was observed that the sacral plexus was linked to the lumbar plexus by the n. furcalis, to the pudendus plexus via the n. bigeminus. Consequently, the anatomic structure of the EEO's sacral plexus, the participating synsacral nerves to plexus and the innervation areas of these nerves were revealed.  相似文献   
15.
In the present study, the influence of two different PGRs, indoleacetic acid (IAA) and kinetin (Kn) on immune potential enzymes, adenosine deaminase (ADA) and myeloperoxidase (MPO), and antioxidant defense enzymes such as glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD) in various tissues of rats were investigated during the treatment as a drinking water model. 100 ppm of IAA and Kn as drinking water were administered orally to rats (Sprague-Dawley albino) ad libitum for 21 days continuously. The PGRs treatments caused different effects on the immune potential and antioxidant defense enzymes of experimented rats compared to controls. Results show that IAA caused a significant decrease in GR activity in the lungs and liver and an increase in the spleen. Also, IAA caused a significant decline in GPx activity in the lungs and an increase in the heart. SOD was significantly reduced in the heart, while increased in the lungs. Furthermore, IAA caused a significant decrease in ADA activity in the heart and blood whereas an increase in the kidney and spleen. MPO activity was also significantly increased in the heart by IAA treatment. The activity of enzymes were also seriously affected by Kn; GR activity decreased in the lungs, brain, and blood while GPx activity decreased in the spleen, brain, and heart. ADA activity was also significantly reduced in the blood whereas MPO activity rose in the spleen. In addition, SOD activity lowered in all tissues except for lungs where a significant increment was determined. As a conclusion, the results indicate that PGRs might affect on antioxidant and immune potential enzymes. These data, along with the determined changes suggest that PGRs produced substantial systemic organ toxicity in the erythrocyte, liver, brain, heart, lungs, spleen, and kidney during the period of a 21-day subacute exposure.  相似文献   
16.
Vibrio harveyi causes vibriosis in various marine aquaculture fish species, especially when they are young. The infection subsequently leads to significant economic losses for aquaculture farms. Vaccination is recommended to control this disease. This study describes the efficacy of a live attenuated V. harveyi strain MVh_vhs (LAVh) as a vaccine candidate in controlling infection by wild‐type V. harveyi (WTVh) in Lates calcarifer. A total of 240 fingerlings were divided into four groups. Group 1 was not vaccinated and was not challenged, Group 2 was vaccinated with a formalin‐killed V. harveyi (FKVh), Group 3 was vaccinated with the LAVh before challenge and Group 4 was not vaccinated and was challenged. Bath vaccination was employed for one hour before the LAVh distribution was determined in the fish mucus, gill, liver, gut, kidney and spleen. The gills, livers, kidneys and skins were also sampled for gene expression analysis. To challenge the fish, skin abrasion was conducted before the fish were challenged by immersion with WTVh. The results revealed an extensive distribution of the LAVh in the liver and kidneys of the fish in Group 3 for the first 12 hr, resulting in mild lesions compared with Group 1. Similarly, there were significantly (p < .05) higher expressions of the Chemokine ligand 4 and major histocompatibility complex I genes in the skin and liver of the fish in Group 3 in comparison with other groups. Vaccination with LAVh resulted in a significantly high rate of survival (68%) of the fingerlings after being challenged with WTVh.  相似文献   
17.
Tetraploid induction has been conducted on temperate oysters but not on tropical oysters. In this study, different heat shocks (32, 35 and 38°C) and cold shocks (1, 4 and 7°C) were used to induce tetraploidy in two tropical oyster species, Crassostrea belcheri and Crassostrea iredalei, through meiosis I inhibition. Temperature shocks were applied on the newly fertilized eggs at 8–10 min post fertilization and terminated when second polar bodies began to form in the control eggs. The ploidy of the larvae and spat was determined via direct chromosome count. The percentage of larval survival until Day 20 was low (between 0.4% and 42.9%) for both temperature shocks and oyster species. No surviving larva was recorded for induction at 1, 4 and 38°C. Tetraploid spat was only recorded in C. iredalei but the percentage is low through heat shock induction of 32 and 35°C. This study shows that the tetraploid induction success rate was slightly higher in C. iredalei compared to C. belcheri. No surviving tetraploid spat were recorded for both oyster species through the cold shock method. This study shows that heat shock can be used to inhibit meiosis for the production of tetraploids but more experiments need to be conducted to determine the optimum temperature when dealing with tropical oysters.  相似文献   
18.
The aim of the present study is to reveal the anatomical structure of lumbosacral plexus of barn owl. Six barn owls were included in the study. Nerves originating from plexus were dissected individually, and findings of innervation areas of nerves were determined. Lumbosacral plexus of barn owl was observed to be formed by ventral rami of ten synsacral spinal nerves. It was found that while the r. cutaneus femoris lateralis, the n. obturatorius, the n. coxalis cranialis, the r. cutaneus femoris medialis, the n. cutaneus femoris cranialis and the n. femoralis originated from the lumbar plexus, the n. isciofemoralis, the n. cutaneus femoris caudalis, the n. coxalis caudalis and the n. ischiadicus originated from the sacral plexus. Consequently, when the results of the study were compared with information of different avian species, it was observed that differences focused on the formation of the lumbar and sacral plexuses and innervation level of digits.  相似文献   
19.
Erdogan  Cem  Ozdem  Ayse  Alpkent  Yasin Nazim  Demiroz  Duygu 《Phytoparasitica》2023,51(2):323-335
Phytoparasitica - The Green apple aphid, Aphis pomi de Geer (Hemiptera: Aphididae), is one of the most common and serious insect pests of apple orchards in Turkey. This species feeds on succulent...  相似文献   
20.
We studied the suitability of empirical crop water stress index (CWSI) averaged over daylight hours (CWSId) for continuous monitoring of water status in apple trees. The relationships between a midday CWSI (CWSIm) and the CWSId and stem water potential (ψ stem), and soil water deficit (SWD) were investigated. The treatments were: (1) non-stressed where the soil water was close to field capacity and (2) mildly stressed where SWD fluctuated between 0 and a maximum allowable depletion (MAD of 50 %). The linear relationship between canopy and air temperature difference (ΔT) and air vapor pressure deficit (VPD) averaged over daylight hours resulted in a non-water-stressed baseline (NWSBL) with higher correlation (?T = ?0.97 VPD – 0.46, R 2 = 0.78, p < 0.001) compared with the conventional midday approach (?T = ?0.59 VPD – 0.67, R 2 = 0.51, p < 0.001). Wind speed and solar radiation showed no significant effect on the daylight NWSBL. There was no statistically meaningful relationship between midday ψ stem and CWSIm. The CWSId agreed well with SWD (R 2 = 0.70, p < 0.001), while the correlation between SWD and CWSIm was substantially weaker (R 2 = 0.38, p = 0.033). The CWSId exhibited high sensitivity to mild variations in the soil water content, suggesting it as a promising indicator of water availability in the root zone. The CWSId is stable under transitional weather conditions as it reflects the daily activity of an apple crop.  相似文献   
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