水分胁迫下玉米叶片中一氧化氮与钙和钙调素的相互作用

以玉米(Zea mays L.)为材料,研究水分胁迫下玉米叶片中NO与Ca2+和钙调素(CaM)含量之间的关系。结果显示:Ca2+鳌合剂、Ca2+通道阻塞剂和CaM拮抗剂预处理均抑制了水分胁迫诱导的NO产生和一氧化氮合酶(nitric ox-idesynthase,NOS)活性的提高,同时也能抑制水分胁迫诱导的叶片线粒体NO产生,而对叶绿体NO产生并没有影响;NO清除剂羟基2苯基4,4,5,5四咪唑1羟基3氧化物(2-4-carboxypheny l-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide,c-PTIO)能抑制水分胁迫条件下Ca2+和CaM的产生以及CaM1基因表达,但对水分胁迫最初诱导的玉米叶片叶肉细胞原生质体Ca2+和玉米叶片中CaM1基因表达以及CaM含量增加没有影响。上述结果表明:水分胁迫下NO和Ca2+/CaM之间存在相互作用。     

Improved management of mango fruit though orchard and packinghouse treatments to reduce lenticel discoloration and prevent decay

Mango fruit are exposed to complex postharvest handling management, intended to improve postharvest quality retention during export shipment. Susceptibility to lenticel discoloration and to Alternaria side rots and Phomopsis stem-end rot under current handling conditions led us to re-evaluate and modify the chain of postharvest treatments, from the orchard to the packinghouse. The previously developed hot-water brushing (HWB) treatment was found effective in reducing incidence of Alternaria and stem-end rots, but it significantly induced development of red lenticels. Two factors were key to improving fruit quality, by simultaneously reducing lenticel discoloration and decay development: (a) postharvest water and/or NaOH washes in the orchard, and (b) hot-water spray (HWS) applied over rollers without brushes in the packinghouse. The present results indicate that optimal management involves combinations of water washes in the orchard with packinghouse HWS treatment; this significantly reduced the severity of lenticel discoloration by 50–60%, and the incidence and extent of postharvest side rots caused by Alternaria by 60% or more. These results indicate that appropriate handling of fruit can appreciably improve their quality during prolonged storage and shipment.     

大花萱草对水分胁迫的光合响应

对黄色(T1)、金黄色(T2)和红色(T3)3个不同大花萱草的品系进行水分胁迫,利用CI- 340便携式光合仪测定了其水分胁迫下叶片的光合特性.结果表明:3种大花萱草的光合速率日变化呈双峰曲线,在中午有明显的“午休”现象,干旱处理下的3种大花萱草光合速率明显低于对照;随胁迫程度的增大,各品系的光合速率均呈缓慢增加然后迅速降低的变化趋势,T1黄色品系表现出较强的光合能力,T3红色品系其次,T2金黄色品系的光合能力表现最弱.     

单生育期水分胁迫对温室葡萄根际土壤酶活性及微生物群落的影响

为明确单生育期水分胁迫对土壤酶活性和微生物群落结构的影响,选取5a生'红地球'鲜食葡萄为试验材料,采用单因素完全随机试验设计,以全生育期充分供水为对照(CK),依次在葡萄5个生育期分别设置轻度(M)和重度(S)两个水分胁迫水平进行大田试验,利用Illumina高通量测序技术分析土壤微生物的群落构成和多样性.结果表明:葡...     

Ecological impacts of small hydropower plants on headwater stream fish: from individual to community effects

Hydroelectricity is increasingly used worldwide as a source of renewable energy, and many mountain ranges have dozens or hundreds of hydropower plants, with many more being under construction or planned. Although the ecological impacts of large dams are relatively well known, the effects of small hydropower plants and their weirs have been much less investigated. We studied the effects of water diversion of small hydropower plants on fish assemblages in the upper Ter river basin (Catalonia, NE Spain), which has headwater reaches with good water quality and no large dams but many of such plants. We studied fish populations and habitat features on control and impacted reaches for water diversion of 16 hydropower plants. In the impacted reaches, there was a significantly lower presence of refuges for fish, poorer habitat quality, more pools and less riffles and macrophytes, and shallower water levels. We also observed higher fish abundance, larger mean fish size and better fish condition in the control than in impacted reaches, although the results were species‐specific. Accordingly, species composition was also affected, with lower relative abundance of brown trout (Salmo trutta) and Pyrenean minnow (Phoxinus bigerri) in the impacted reaches and higher presence of stone loach (Barbatula quignardi) and Mediterranean barbel (Barbus meridionalis). Our study highlights the effects of water diversion of small hydropower plants from the individual to the population and community levels but probably underestimates them, urging for further assessment and mitigation of these ecological impacts.     

不同灌水处理对小桐子生长及耐盐性的影响

为研究不同灌水处理对小桐子生长及耐盐性的影响,取1 a生小桐子幼苗为试验材料,设置19.80,19.80和39.60(交替灌溉),39.60 mm 3个水平的灌水处理;3个水平的施盐处理:每50 g风干土中NaCl分析纯为0,0.15,0.30 g,并监测小桐子的形态,根区Na⁺环境以及植物体Na⁺累积的情况.结果表明:小桐子有一定的耐盐性,受到每50 g风干土中含有0.30 g NaCl分析纯盐胁迫时,交替灌溉处理更有利于小桐子的生长;随着盐浓度的增大,小桐子根区土壤电导率增大的幅度逐渐减小,同时,盐浓度的增大使土层中Na⁺含量增大的幅度也逐渐减小,小桐子干样中各器官Na⁺含量从大到小依次为叶片、根部、茎;19.80 和39.60 mm交替的灌溉方式比39.60 mm灌溉方式节水25%,但小桐子的生长并未受到影响,且各器官钠离子含量差异不具有统计学意义.本试验条件下,受到不同程度盐胁迫的小桐子,19.80和39.60 mm交替的灌溉方式更有利于小桐子生长,提高其耐盐性.     

Research on a dynamic tracking model for reservoir water flooding of separated zone water injection

Waterflood is one of the main oil reservoir development ways. Premature flooding of production wells during water flooding process will reduce oil recovery. Therefore,it is particularly important to establish a dynamic tracking model for reservoir water flooding of separated zone water injection. Based on the basic principles of heat and mass transfer,according to well temperature curve to determine the water profile,Poisson process analysis and stochastic process methods are adopted to calculate water saturation,water breakthrough time and water cut of each layer in water flooded reservoir at any one time. When oil reservoir gradually become water flooded,the calculated water cut of model considering micro-pore distribution of the reservoir tends to the measured water cut,and the calculation error is less than 5%. Case study shows that the layer of the higher injection rate,with high flow channel such as micro fracture,where there is the faster increase in water saturation,the shorter water breakthrough time and faster increase in water cut,and vice versa. Research result provides time guarantee to take measures for inhibiting or delaying water breakthrough of production wells.     

The effect of omeprazole paste on intragastric pH in clinically ill neonatal foals

REASON FOR PERFORMING STUDY: Administration of omeprazole paste per os to healthy neonatal foals has been shown to effectively increase intragastric pH, but has not been evaluated in sick neonatal foals. OBJECTIVES: To determine the effect of orally administered omeprazole paste on intragastric pH in clinically ill neonatal foals requiring nasogastric intubation. METHODS: Intragastric pH was measured continuously for 24 h using an indwelling electrode and continuous data recording system in hospitalised neonatal foals age < or =2 days. Intragastric pH was measured for 12 h prior to (pretreatment period) and 12 h following (post treatment period) treatment with omeprazole paste (4 mg/kg bwt per os). All foals displayed periods of acidity (pH <4) prior to treatment. Statistical analysis compared pre- and post treatment mean and median intragastric pH, and percentage of time below pH 4. RESULTS: Eight foals were evaluated age 1-3 days, a gestational age of at least 320 days or reported to be full term. The mean (3.19 +/- 1.50 vs. 6.20 +/- 0.93) and median (4.6 +/- 1.7 vs. 6.86 +/- 0.89) pH were significantly higher and the percentage of time below pH 4 (32.25 vs. 1.1%) was significantly lower in the post treatment compared to the pretreatment period. CONCLUSION: Omeprazole paste effectively increases intragastric pH in clinically ill neonatal foals after one dose at 4 mg/kg bwt orally.     

化学预处理对稻草硅化程度的影响及其对瘤胃降解率的改善效果

本试验结合化学分析与电镜技术,探讨了氨化与碱化处理对稻草硅化程度的影响,分析了稻草硅化程度与降解率的相关性。化学分析显示,碱化或氨化处理稻草的总硅含量随氢氧化钠或碳酸氢铵处理剂量的增加而线性下降(P<0.01);可溶性硅含量随碳酸氢铵处理剂量的增加变化不显著(P>0.05),但随氢氧化钠处理剂量增加线性下降(P<0.01);总硅与稻草干物质降解率间存在极显著负相关(r=-0.560,P<0.01)。电镜观察发现,氢氧化钠处理的稻草茎表皮根毛皱缩、乳突和瘤状结构部分溶解,碳酸氢铵处理的稻草茎外表皮层部分脱落;氢氧化钠处理的稻草茎表皮有明显的降解优势,碳酸氢铵处理的稻草茎表皮瘤胃降解72h后仍保持完整的乳突和瘤状结构。上述结果表明,氨化和碱化处理可以在一定程度上降低稻草的硅化程度,借此提高稻草的降解率,但两者降低稻草硅化的程度与方式不同。氨化处理通过使稻草表皮层部分脱落,降低稻草总硅含量,但借此提高稻草降解率的作用较弱;碱化处理可使稻草表皮硅酸盐部分溶解,从而使稻草总硅含量、可溶性硅含量下降,加速稻草降解。     

奶牛乳腺炎防治方法的研究进展

综述了传统及现代防治乳腺炎的方法,如注射、激光、中草药疗法等。同时,概述了国内外新型制剂和乳房炎的预防措施。