不同光温条件对烟株叶片活性氧代谢的影响研究

设置4个处理(T1,25℃+遮光;T2,25℃+强光;T3,35℃+遮光;T4,35℃+强光),探讨了高温强光对成熟期烟叶活性氧代谢的影响.结果 表明:高温和强光均造成烟株叶片细胞膜透性增加,其中以T4处理下的烟叶相对电导度、MDA和H2O2含量均最高,分别达20.5％、4.774 μmol/g和23.139 mmol/mg;T3处理下烟株叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)活性均最高,分别达1.263和1.674 U/(mg·min);在T2处理下过氧化氢酶(CAT)的活性最高,达1.289 mg/(mg·min);在强光处理下烟株叶片的生长素(IAA)、脱落酸(ABA)含量均高于遮光处理,而在高温处理下烟株水杨酸(SA)含量均显著高于低温处理;在T4处理下烟株叶片的茉莉酸(JA)含量最低,只有7.435 ng/g.因此,高温、强光胁迫会破坏烟株叶片的生理代谢,但也会通过促使保护酶活性升高和内源生长激素含量增加来抵抗逆境胁迫.     

中国天然橡胶价格影响因素的灰色关联分析

天然橡胶价格的波动对我国经济发展以及橡胶产业安全有较大影响。采用灰色关联模型分析我国天然橡胶价格波动的影响因素,结果表明:各因素与天然橡胶市场价格的关联程度大小依次为:合成橡胶进口数量人均国民生产总值橡胶产量天然橡胶进口数量合成橡胶产量橡胶轮胎外胎产量。据此提出相关政策建议,以期为我国橡胶产业的长足发展提供参考。     

化学试剂对翅荚决明种子萌发和幼苗早期生长的影响

为探讨不同化学试剂对翅荚决明(SennaalataL.)种子发芽率和幼苗生长的影响,用4种不同浓度的化学试剂(KNO3、GA3、KMnO4和NaOH)分别处理种子。结果表明:0.5~4.0g/LKMnO4和0.05~0.4g/LGA3浸种显著促进种子萌发,加快幼苗生长速度,其中以0.1g/LGA3和4g/LKMnO4浸种24h效果最佳,是解除翅荚决明种子休眠、促进幼苗生长的有效措施;1~8g/LKNO3浸种显著促进了种子萌发,但对幼苗生长影响不明显;而5~40g/LNaOH浸种明显抑制种子萌发和幼苗生长,且随着浓度增加,抑制作用明显增大。。     

江淮丘陵和黄河故道不同施肥处理葡萄园葡萄十星叶甲Oides decempunctata与其天敌的关系

在运用葡萄丰产栽培措施的同时,为合理保护和利用自然天敌进行葡萄十星叶甲的综合防治,对安徽省萧县和肥东县喷施钕肥、镧肥、醋肥和清水的葡萄园葡萄十星叶甲及其主要天敌进行系统调查,并用灰色系统分析法和生态位分析法对两者之间在数量、时间和空间格局等方面的关系进行分析。经综合排序,萧县十星叶甲主要天敌喷水处理区为龟纹瓢虫、草间小黑蛛和拟环纹狼蛛,喷醋处理区为拟环纹狼蛛、龟纹瓢虫和异色瓢虫,喷钕处理区为草间小黑蛛、异色瓢虫和龟纹瓢虫,喷镧处理区为龟纹瓢虫、异色瓢虫和草间小黑蛛。肥东县十星叶甲主要天敌喷水处理区为草间小黑蛛、八斑球腹蛛和拟环纹狼蛛,喷醋处理区为拟环纹狼蛛、草间小黑蛛和龟纹瓢虫,喷钕处理区为草间小黑蛛、拟环纹狼蛛和八斑球腹蛛,喷镧处理区为八斑球腹蛛、草间小黑蛛和拟环纹狼蛛。萧县和肥东县两地间各处理的十星叶甲主要天敌的种类和位次差异明显。喷水区两地相同的两种主要天敌是草间小黑蛛和拟环纹狼蛛,喷醋区两地相同的两种主要天敌是拟环纹狼蛛和龟纹瓢虫,喷钕区和喷镧区两地相同的主要天敌都是草间小黑蛛。     

不同的遮光率对文心兰切花生长及品质的影响

比较了不同遮光率对文心兰切花品质的影响.结果表明:文心兰在不同的生长发育阶段对遮光率的要求不同,75％遮光率的环境有利于文心兰中小苗的生长发育,当文心兰花芽长度为10～20 cm时,则必须将遮光率调整为60％.60％的遮光率可以大幅度提高花穗的直立性,大大降低花穗的倒伏,明显缩短文心兰切花节间长度,降低花穗上第1个分叉...     

Evaluation of a point-of-care immunodot assay for predicting results of allergen-specific intradermal and immunoglobulin E serological tests

Immunotherapy to prevent recurrence of clinical signs of atopic dermatitis (AD) is based on intradermal or serological tests that assist in identifying allergen-specific immunoglobulin E hypersensitivities. Unfortunately, the results of such tests can be negatively influenced by several factors, which include the age of the patients, the season of testing and the administration of anti-allergic drugs. Screening to predict when these expensive tests will be useful would benefit owners of dogs with AD. The objectives of this study were to determine whether a point-of-care allergen-specific immunodot assay (Allercept E-Screen, Heska Corp., Ft Collins, CO, USA) could predict results of either intradermal or Allercept full panel serological tests in atopic dogs. Thirty dogs living in the south-eastern USA were diagnosed with AD in accordance with current standards. Allergen-specific intradermal, serological and E-Screen tests were performed in all subjects. For flea, house dust mite and pollen allergens altogether, results of the E-Screen assay agreed with those of intradermal and serological tests in 26/30 dogs (87%) and 25/30 dogs (83%), respectively. In this group of dogs, the probabilities of obtaining intradermal or serological tests positive for these allergens were 70 and 67%, respectively. If either skin or serum tests were performed only in dogs with positive E-Screen tests, the probability of obtaining positive results would be increased from 70 to 95% and from 67 to 90%, respectively. In this population of dogs with AD, results of the E-Screen point-of-care immunodot assay was found to often agree with those of allergen-specific intradermal or Allercept tests for selected allergen groups.     

The effect of four different pasture species compositions on nitrate leaching losses under high N loading

Nitrate () leaching can cause elevated concentrations of ‐N in water, which can have adverse impacts on water quality and human health. In grazed pasture systems, most of the ‐N leaching occurs beneath animal urine‐N deposits. The objective of this study was to investigate the effect of four different pasture species compositions [perennial ryegrass/white clover (P. ryegrass WC), tall fescue/white clover (T. fescue WC), Italian ryegrass/white clover (It. ryegrass WC) and perennial ryegrass/Italian ryegrass/white clover/red clover/chicory/plantain (Diverse)] on ‐N leaching losses from animal urine patches, and to examine the relative importance of root system architecture and seasonal activity to reduce ‐N leaching losses. The results show that ‐N leaching losses were 24–54% lower beneath It. ryegrass WC than other pasture species. Total dry matter (DM) yield in the season following establishment was 11–58% greater in the It. ryegrass WC pasture, while average winter daily N uptake rate of It. ryegrass WC over the two seasons was on average 58% greater than P. ryegrass WC and T. fescue WC. In the second season, the P. ryegrass WC and T. fescue WC pastures had up to 140 and 82% more roots between 0 and 40 cm depth, respectively, than the other pasture species compositions. These results suggest that in grazed pasture systems, high plant winter activity (plant growth/root metabolic activity) is more important than specific root architecture (e.g. deep roots) to reduce ‐N leaching losses.     

陆生植物菜用于有机废水的生态治理研究

试验研究了陆生植物蕹菜对有机废水的治理效果,结果表明:蕹菜在水体中可有效降解COD、有机氨氮;在曝气、进料COD浓度为1300mg/L条件下,COD降解率达90%以上,而进料COD浓度为2600mg/L时,COD最大处理能力达10.56g/L.d;蕹菜对无机氨氮降解率达94%,有机氨氮降解率达73%以上。与水葫芦废水处理过程相比,蕹菜具有较广泛的水体环境适应性,对猪场废水具有一定处理效果。     

Arsenate Displacement from Fly Ash in Amended Soils

Arsenic (As) is the biggest environment contaminant in most of the soils where fly ash is applied. Usually, it is not mobile and strongly adsorbed on to soil particles. However, in gypsum and phosphorus amended soils As may be much more mobile. A study in repacked columns was conducted to determine whether or not As becomes mobile when Ca(H₂PO₄)₂and CaSO₄are used as leaching solutions, and to compare the competitive interactions between PO₄-AsO₄and SO₄-AsO₄. Arsenic concentration in leachate was found to be approximately ten times greater when Ca(H₂PO₄)₂was used to leach the columns as compared to CaSO₄. A maximum concentration of 800 μg As L^-1was found in the leachate in this case, which is much higher than the groundwater limit of 50 μg L^-1for drinking water established by the United States Environmental Protection Agency. In fly ash, the portion of arsenate non-specifically adsorbed is believed to be much lower than that of specifically adsorbed. Sulfate anions were able to displace only non-specifically adsorbed arsenate. In this case the concentration of As in leachate was found to be within acceptable limits. On the other hand, phosphate can compete with arsenate for all available adsorption sites, non-specific and specific. Phosphate displacement of both forms of arsenates increases As mobility in both control and fly ash treatments.     

不同成熟度玉米种子活力的差异性研究

以玉米自交系48-2和杂交种正红311为材料,应用标准发芽试验法和电导率法研究了不同成熟度玉米种子的活力差异。结果表明,随着种子成熟度的提高,种子活力指数显著提高,电导率则呈降低的趋势。繁殖自交系48-2亲本时,以授粉后50 d采收为佳;而生产正红311杂交种子,则授粉后45d收获即可。