西安南郊不同深度土壤CO_2浓度变化研究   总被引：2，自引：0，他引：2  

李艳花  赵景波 《干旱区资源与环境》2006,20(2):124-128

利用红外CO2监测仪对西安南郊不同深度条件下的土壤CO2浓度进行了多次昼夜观测。观测结果表明:在一昼夜内土壤CO2浓度具有从低到高再到低的变化规律,这种变化特点与昼夜温度变化基本一致;土壤CO2浓度从总体来看具有白天高,夜间低,夏季高,秋季低的特点;浅层土壤CO2浓度昼夜变化幅度明显大于深层土壤CO2浓度变化幅度;在厚层黄土的150cm深度范围内,土壤CO2浓度随着深度的增加而增加,在150~600cm深度范围内CO2浓度基本恒定,显示出与薄层土CO2浓度变化明显不同。  相似文献   

Correlation of phytoplasma concentration in Hydrangea macrophylla with green-flowering stability     

Elly Kesumawati  Takushi Kimata  Tatsuya Uemachi  Munetaka Hosokawa  Susumu Yazawa 《Scientia Horticulturae》2006

The interaction between phytoplasma concentration and green-flowering stability was studied in hydrangea cultivars. Three green and 18 nongreen cultivars were subjected to polymerase chain reaction (PCR) analysis to determine Japanese hydrangea phyllody (JHP) phytoplasma infection. The results showed that JHP-phytoplasma was detected only in ‘Midori’ plants, which have green sepals. ‘Midori’ plants were propagated, and from 29 rooted cutting plants, they were grouped into three types on the basis of sepal color, that is, green (75.9%), blue-green (13.8%) and blue (10.3%) sepals. To clarify the variability in the sepal color of ‘Midori’ plants, JHP-phytoplasma concentration in the sepals and leaves of green-, blue-green- and blue-flowering plants was determined by PCR analysis. The semiquantitative PCR comparisons of 370 bp DNA fragments showed that the JHP-phytoplasma concentrations in green sepals were 16 times higher than that in blue-green sepals. JHP-phytoplasma could not be identified by PCR analysis in blue sepals and leaves. These results showed that JHP-phytoplasma concentration correlated with green sepal stability in ‘Midori’ plants. A histological observation of sepals showed that epidermal cells of blue and blue-green sepals had a dome shape. Otherwise, green sepals were leaflike with flat epidermal cells, and palisade parenchyma cells with numerous chloroplasts.  相似文献   

Factors affecting the incubation period of dark leaf and pod spot (Alternaria brassicae) on oilseed rape (Brassica napus)     

C. X. Hong  B. D. L. Fitt 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(6):545-553

Experiments to investigate the factors affecting the incubation period of dark leaf and pod spot (Alternaria brassicae) on leaves and pods of oilseed rape (Brassica napus) were done in controlled environment (constant temperatures) and glasshouse conditions (fluctuating temperatures). The length of the incubation period of dark leaf and pod spot decreased as infection and incubation temperatures increased from 6 to 20 °C. The incubation period decreased as wetness period increased from 2 to 12 h, as inoculum concentration increased from 80 to 2 × 10³ spores ml^–1 and as leaf age increased from 4 to 10 days. Asymptotes of leaf age and inoculum concentration, above which the length of the incubation period did not decrease, were 10 days and 2 × 10³ spores ml^–1, respectively. The shortest and longest incubation periods were 1 and 11 days. The mechanism by which the infection conditions influenced the incubation period of dark leaf and pod spot on oilseed rape seemed to be linked to lesion density. Usually, the length of the incubation period decreased greatly with increasing lesion density.  相似文献   

锰源和锰水平对南美白对虾生长性能和组织锰含量的影响     

董晓慧  周歧存  郑石轩  张志华 《中国饲料》2005,(9):29-31

南美白对虾配合饲料中添加10、20、30mg/kg的硫酸锰和甘氨酸锰。饲养8周,于试验第4、8周末称重,并在第8周末测定对虾肝胰脏和肌肉中的锰含量。试验结果表明:甘氨酸锰各水平组和20、30mg/kg硫酸锰组显著提高了对虾第4周末的体重,锰源和锰水平对第8周末的体重无显著影响。肌肉中的锰含量不受锰源和锰添加量的影响,但肝胰脏中的锰含量表现为随锰添加量的增加而呈升高的趋势。综合生长和锰含量指标,饲料中添加10mg/kg的甘氨酸锰或30mg/kg硫酸锰为好。  相似文献   

Plasma ammonia concentration in dogs using ion-exchange method of analysis     

Zenoble RD  Prasse KW 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1978,7(2):6-9

Laboratory methods for measuring plasma ammonia concentration were reviewed. The ion-exchange method of analysis was evaluated using canine plasma from 15 clinically normal dogs and five dogs with portosystemic shunts. Mean and standard deviation was 40.3 +/- 8.1 microgram NH(3)/dl in normal dogs, and values ranged from 125 to 200 microgram NH(3)/dl in dogs with portosystemic shunts. Handling of blood samples properly for accurate results was found to require pre-chilled collection tubes, chilling the samples in an ice bath, immediate separation of plasma from red blood cells and immediate analysis for ammonia concentration. The ion exchange method was determined to be sufficiently accurate for clinical use and is suggested for any veterinary clinical pathology laboratory.  相似文献   

培养基对胡萝卜悬浮系茄红素合成代谢活性的影响   总被引：3，自引：0，他引：3  

梁燕  陈大明  王鸣  陈杭 《园艺学报》2003,30(5):545-548

 以胡萝卜品种‘新透心红’稳定的细胞悬浮系为材料, 研究了基本培养基、蔗糖浓度和PO₄^3-浓度对其茄红素合成代谢活性的影响。结果表明, 在B₅ 、MG₅ 、ER 和White 培养基中, MG₅ 培养基最适宜于茄红素合成代谢, 细胞中茄红素含量显著高于其它培养基。以MG₅ 为基本培养基, 在7 个蔗糖浓度处理中, 100.0～120.0 g·L^-1范围内, 细胞中茄红素含量极显著高于其它处理, 茄红素合成代谢活性最高; 在13个PO₄^3-浓度处理中, 30.0～50.0 mmol·L^-1范围内, 细胞中茄红素含量极显著高于其它处理, 茄红素合成效果最佳。  相似文献   

SPF鸡屏障系统净化技术研究   总被引：1，自引：0，他引：1  

李新华  秦卓明  张世栋  宋敏训  王莉莉  李峰  金维江  王春玲 《中国家禽》2008,30(1):12-17

本文从理论上较为系统地对SPF鸡实验动物房的净化管理技术进行研究,对净化原理,洁净度、压力梯度以及该动物房各个部位、洁净室的风量风速、压力损失和静压差进行了分析和计算,使读者对SPF鸡屏障系统有了较清晰的认识。希望对相关净化管理人员有一定的参考价值。  相似文献   

云南省肉羊产业发展现状及比较优势分析     

王雪娇  李隆伟  杜春燕 《中国农学通报》2022,38(2):141-149

本研究分别从生产、消费、价格波动以及贸易等角度对云南省肉羊产业的发展现状进行分析.在此基础上,采用定性与定量相结合的方法分别从产业基础优势、区位商、产业集中度及专业化系数等多方面对2008-2019年云南省肉羊产业发展的比较优势进行较为深入的研究.结果 表明,云南省肉羊产业区位商得分均在1以上,且表现为逐年增强的趋势;...  相似文献   

2015—2021年亚洲玉米螟对Cry1Ie杀虫蛋白的敏感性监测     

王月琴  静大鹏  刘凯强  王振营  何康来 《植物保护学报》2024,51(2):405-412

为明确亚洲玉米螟Ostrinia furnacalis田间种群对Cry1Ie杀虫蛋白的敏感性,于2015—2021年连续7年从黄淮海夏玉米区和北方春玉米区7省14地采集亚洲玉米螟田间种群,采用人工饲料混合法评价其对Cry1Ie杀虫蛋白的敏感性。结果表明,Cry1Ie杀虫蛋白对54个亚洲玉米螟田间种群的抑制中浓度LC₅₀介于0.65~6.28 μg/g之间,其中对2016年齐齐哈尔种群的LC₅₀最低,对2017年肇东种群的LC₅₀最高;LC₉₅介于4.99~70.29 μg/g之间,其中对2015年合肥种群的LC₉₅最低,对2017年松原种群的LC₅₀最高。在LC₅₀水平上,相较于室内对照种群,最敏感种群和最不敏感种群分别为2018年铁岭种群和2017年肇东种群,抗性倍数分别为0.26和1.17。虽然各地理种群对Cry1Ie杀虫蛋白的敏感性存在差异,但均处于敏感水平,且是自然选择的结果,表明Cry1Ie杀虫蛋白可用于亚洲玉米螟田间种群的防治。  相似文献   

Studies on differential response of wheat cultivars to boron toxicity   总被引：1，自引：0，他引：1  

M. Kalayci  A. Alkan  I. Çakmak  O. Bayramoğlu  A. Yilmaz  M. Aydin  V. Ozbek  H. Ekiz  F. Ozberisoy 《Euphytica》1998,100(1-3):123-129

Experiments were carried out to study the differential responses of different wheat cultivars to boron toxicity in field, greenhouse and growth chamber conditions. In field trials carried out at two locations, both of which are known to contain toxic amounts of water-extractable B, significant correlations were obtained between toxicity symptoms and grain yields. The only durum cultivar included in this group of experiments (Kunduru 1149) was the most sensitive of the 21 cultivars trialed. The most tolerant cultivars were of local origin. Genotype-environment interaction was considerably large. Twenty-nine bread wheat and three durum wheat cultivars were compared in a greenhouse experiment with and without the application of 40 mg L^-1 B. Again, the durums were the most sensitive cultivars. The most tolerant cultivars were either selections from local populations or had at least one parent of local origin. The detrimental effect of B on root dry matter production was much higher than on shoot dry matter (45 and 26%, respectively), but genotypical variation was greater in shoot growth retardation. While this implies the possible role of reduced translocation, high concentrations of B in the shoots of tolerant cultivars (though lower than in the sensitive cultivars) indicated the existence of other contributing mechanisms, such as tissue tolerance. Also, greater genotypical variation in older leaves showed that reduced uptake might be more important than reduced translocation in some cases. Due to the lack of correlation between results from the field and the controlled-environment studies, it was concluded that screenings should be undertaken in both situations as a means of verification. Another conclusion drawn was that symptom scoring for B tolerance was more reliable than measuring plant B concentrations. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献