缺镁、铁、硼胁迫对4 个柑橘砧木生长及养分吸收的影响

 通过水培方式分别研究了缺镁、铁、硼处理对枳、香橙、红橘、崇义野橘4种柑橘砧木植株和根系生长及养分吸收的影响。结果表明：缺镁处理下,红橘在株高、叶片数、叶绿素含量、总根长、总根表面积及镁吸收速率等变化中表现出较强的抗缺镁特性,崇义野橘次之,枳、香橙较差;缺铁处理下,香橙在株高、叶片数、植株干样质量、总根体积、总根表面积和铁吸收速率等变化中表现出较强的抗缺铁特性,红橘次之,枳、崇义野橘较差;缺硼处理下,红橘在总根数、总根表面积、总根体积及硼吸收速率的变化中表现出较强的抗缺硼能力,而崇义野橘的地上部较耐缺硼,香橙、枳则表现出不耐缺硼。     

柑橘4种砧木幼苗对铜过量胁迫的生理响应与耐受性差异

为探究不同柑橘砧木的铜过量胁迫耐性差异,分析砧木铜过量胁迫的生理响应,试验选用4种常用的柑橘砧木枳、资阳香橙、红橘和沙田柚180 d实生苗为材料,用1.5（对照）、7.5、37.5、187.5和937.5 μmol • L-1的CuSO4溶液进行处理。结果显示,高浓度CuSO4处理导致叶绿素含量和光合能力下降,叶片细胞相对电导率和MDA含量值显著上升;SOD、POD酶活性上升;高浓度下,砧木对K、P、Ca、Mg、Fe、Mn和Zn营养元素的吸收和转运下降。高CuSO4处理导致砧木叶片黄化脱落,根系褐变短小,生长受阻,严重时死亡。不同砧木对CuSO4过量胁迫耐受性差异明显,枳最先出现新叶失绿、老叶落叶、生长量下降和光合等生理指标下降,随后依次为沙田柚、红橘和资阳香橙。主成分分析和隶属函数综合分析显示,资阳香橙对铜过量胁迫耐性最强,红橘其次,沙田柚再次,枳对铜过量胁迫最敏感。     

硅对复合碱式盐胁迫下黑麦草生长及光合作用的影响

以多年生黑麦草品种‘Ascend'为试材,采用基质培的方法,研究了硅对复合碱式盐NaHCO3∶NaCO3(1∶1)胁迫下黑麦草生长和光合作用的影响.结果表明:浓度为0.6％的NaHCO3∶Na2CO3(1∶1)复合碱式盐胁迫下,硅处理有效促进了黑麦草的生长,减缓了叶绿素a的降低幅度,提高了叶绿素b和总叶绿素的含量,缓解了碱式盐胁迫对黑麦草叶片净光合速率的抑制,减缓了气孔导度、蒸腾速率、气孔限制值和水分利用率的降低,缓解了碱式盐胁迫对叶片光合作用的影响,但是硅缓解复合碱式盐NaHCO3与Na2CO3对黑麦草的胁迫存在一定的浓度范围.     

锌胁迫下水培枳幼苗锌分布及矿质营养元素含量变化

为了解锌胁迫(缺乏或过量)下枳体内锌分布及其他矿质元素含量变化,以30d枳实生幼苗为试材,分别进行锌缺乏(0μmol·L-1)、对照(0.7μmol·L-1)和锌过量(70μmol·L-1)水培处理,70d后测定和分析。结果表明,枳幼苗根、茎和叶中锌含量随处理浓度升高而显著升高,不同器官锌含量为根茎叶,锌胁迫下植株地上部分含锌量比例增加。与对照相比,缺锌处理枳幼苗叶片K、Mn和Cu含量显著降低,叶片Fe含量显著升高,根系Mn含量显著上升,根系Cu含量显著下降。与对照相比,锌过量处理枳幼苗叶片P、Ca、Mg和Cu含量,茎P和K含量,根系Fe和Cu含量均显著升高;叶片K、Fe和Mn含量,茎Ca和Fe含量,根系K和Mn含量均显著降低。各器官不同处理间S含量差异无显著性。相关性分析显示,Zn和Cu含量在枳幼苗根、茎、叶中呈显著或极显著正相关;Zn和Fe含量在叶片和茎中呈极显著负相关,在根中呈极显著正相关。     

氮胁迫对枳和‘资阳香橙’砧木氮代谢及相关基因表达的影响

【目的】对枳[Poncirus trifoliata(L.)Raf.]与‘资阳香橙’(Citrus junos Sieb. ex Tanaka)在氮胁迫下的无机氮含量、氮同化酶活性与基因表达进行研究,为深入揭示柑橘氮高效利用机制奠定基础。【方法】以采用水培培养的枳与‘资阳香橙’幼苗为试材,进行正常氮水平(10 mmol·L~(-1),对照)、缺氮(0 mmol·L~(-1))和高氮(50 mmol·L~(-1))胁迫处理。【结果】(1)枳与‘资阳香橙’的氮累积量与对照相比,缺氮分别降低了46.6%和51.1%,高氮分别升高了50.4%和81.6%。(2)‘资阳香橙’各处理的硝态氮含量均显著大于枳,枳与‘资阳香橙’叶片中的硝态氮含量以及铵态氮含量各处理均呈高氮对照缺氮的趋势。(3)缺氮和高氮处理均显著降低了枳与‘资阳香橙’叶片和根的硝酸还原酶、亚硝酸还原酶、谷氨酰脱氢酶和谷氨酸合成酶活性,而高氮处理时枳叶片中的硝酸还原酶、亚硝酸还原酶、和谷氨酸合成酶的活性与‘资阳香橙’相比被抑制的程度更低。(4)枳和‘资阳香橙’在氮胁迫下叶片中基因NR、NiR、GDH2的相对表达量比对照有明显下降;根系中基因NR、NADH1、NADH3、NADP相对表达量也显著下降。【结论】氮胁迫显著抑制了枳与‘资阳香橙’的氮代谢相关酶活性和氮同化相关酶基因的相对表达量,枳在高氮处理下表现出更高的耐受性‘,资阳香橙’与枳相比有更高的氮吸收能力。     

苏打盐碱胁迫对香樟幼苗光合特性的影响

以2a生的香樟幼苗为试材,以蒸馏水为对照,用0、50、100、200 mmol/L NaHCO3和Na2 CO 1∶1的混合液处理.每7d施用1次,21 d后研究盐碱胁迫对香樟幼苗光合色素及光合特性的影响.结果表明:随盐碱胁迫程度的增加,植物体内叶绿素a的含量、叶绿素b的含量、总叶绿素的含量、类胡萝卜素的含量下降;植物叶片的光合速率、气孔导度、蒸腾速率、水分利用效率降低,胞间CO2浓度升高.     

土壤铅胁迫对紫穗槐幼苗叶片叶绿素的影响

采用盆栽的方法,在栽培基质中加入Pb(CH3COO)2·5H2O,研究紫穗槐在单一铅胁迫下的叶绿素变化。研究结果表明:随着土壤铅胁迫浓度的增加,紫穗槐幼苗叶片叶绿素a+b、叶绿素a、叶绿素b及叶绿素a/b值逐渐下降,与胁迫浓度存在明显的负相关性。     

不同pH营养液处理下3种柑橘砧木有机酸分泌的差异

以资阳香橙、枳和红橘幼苗为材料,在不同pH值的营养液中处理30 d,测定其生长指标、根系形态及生理指标,用液相色谱（LC）法分析根系分泌的有机酸含量,分析3种砧木根系分泌有机酸种类和对酸碱耐性的差异。通过比较3种砧木在不同pH营养液处理下的生长指标、根系形态及生理指标发现,枳比资阳香橙和红橘更耐酸,红橘和资阳香橙比枳更耐碱。在酸性（pH 4、pH 6）条件下,3种砧木根系分泌有机酸中只检测到草酸和奎宁酸,且草酸含量高于奎宁酸;红橘分泌的有机酸总量最高,其次是资阳香橙,最低为枳。在碱性（pH 8）条件下,除草酸和奎宁酸外,还检测到苹果酸;资阳香橙分泌的苹果酸含量最高,红橘次之,枳最低。以上结果表明资阳香橙和红橘比枳更耐碱,可能是因为资阳香橙和红橘分泌的有机酸高于枳,尤其是在碱性条件下分泌的苹果酸含量远高于枳;而枳比资阳香橙和红橘更耐酸的可能原因是枳在酸性条件下分泌的有机酸总体偏低。     

自然干旱胁迫对米槁幼苗叶片显微结构及叶绿素含量的影响

以一年生米槁为试材,在为期22d的自然失水胁迫处理下,研究了米槁生长形态、叶形态解剖结构以及光合色素在不同胁迫时间下的变化特点,以期探讨米槁幼苗对持续干旱胁迫的适应能力及对策。结果表明:随着胁迫时间的增加,其生长指标受显著抑制;叶绿素a、b含量呈先降低后升高再降低的趋势,但叶绿素a/b的趋势相反,类胡萝卜素含量先下降后上升;叶片厚度、上表皮细胞厚度、叶脉周长和面积呈先下降后上升趋势;海绵组织厚度呈上升的趋势,栅栏组织厚度和叶片组织结构紧密度(CTR)呈先下降后上升的趋势。表明米槁在干旱胁迫时可以通过改变叶片内组织结构来提高其抗旱性。     

铝胁迫对辣椒叶绿素及叶绿素荧光的影响

在不同浓度铝胁迫下,以‘红辣椒王ⅡF1’、‘卡其特长条辣906’、‘汴椒1号’和‘苏长红’4个品种为材料,研究辣椒叶片叶绿体含量、叶绿素荧光参数的动态变化,以期为研究辣椒铝胁迫提供理论依据。结果表明,铝处理抑制辣椒叶片叶绿素的合成,从而降低辣椒叶片叶绿素的含量。辣椒叶片叶绿体色素(叶绿素a、叶绿素b、叶绿素a+b、叶绿素a/b)含量在低铝浓度(50μmol/L)下呈升高趋势,高铝浓度(200μmol/L)下则均下降。荧光参数的研究表明,随着铝胁迫的增加,初始荧光(F_0)随之增大,最大荧光(F_m)、原初光能转化效率(F_v/F_m)下降,植株抵抗逆境的能力下降,光合电子传递随之减小,最终导致光合速率下降。     

Effect of salinity and water table on growth and tolerance of plum and peach

The effects of combinations of salinity (no salt, 2000 p.p.m. or 4000 p.p.m. of CaCl₂ and NaCl, 1:1) and water table (30 cm, 60 cm or 90 cm from the soil surface), on the vegetative growth and tolerance of ‘Golden Japanese’ plum and ‘Mit Ghamre’ and ‘Balady’ peaches were studied. The plants were grown in lysimeters. The growth of the trunk, total shoot length, the increase in shoot length per cm and the fresh weight of top, root and total plant were reduced with increasing salinity of the irrigation water. The effect was accentuated when the plants were maintained at high water table level. The salinity treatments resulted in the death of 43%, 73% and 76% of the plants in the plum, and the ‘Mit Ghamre’ and ‘Balady’ peaches, respectively, indicating that the plum is more tolerant to salinity than the peach. The plants of the salinity treatments showed various symptoms of salt injury, such as leaf burn, defoliation, shoot die-back and finally death. In the peaches, salt injury started to occur in the first growing-season, whereas the salt injury appeared in the plum in the second growing-season. The symptoms were more pronounced in the 4000 p.p.m. treatment than in the 2000 p.p.m. treatment and were more pronounced at the high water table level. The salinity level was the predominant factor and the effect of the water table on the vegetative growth diminished with increase in the salinity level of the irrigation water.     

洞庭1号无籽西瓜套种棉花高产高效模式的研究与应用

根据西瓜、棉花两者生长发育特点进行套种试验,研究其高产高效栽培模式。试验示范结果表明,以西瓜行株距4.5m×0.65m,棉花行株距1.5m×0.45m的种植密度,西瓜与棉花之间互颉作用最小,西瓜和棉花的产量和产值在3个套种模式中位居第1,在5个处理中经济效益最高。     

Primary culture and identification of mouse PASMCs and effects of hypoxia on proliferation and apoptosis of PASMCs

AIM：To establish a fast, accurate and economical technique for culturing mouse pulmonary arteriolar smooth muscle cells (PASMCs), and to explore the effects of hypoxia on the proliferation and apoptosis of the PASMCs. METHODS：In sterile condition, the pulmonary artery was isolated from the male BALB/c mice by digesting with collagenase I, and the cells were cultured in fetal bovine serum-coated flask. Centrifugal procedure was not used during the cell passage. The cell morphology was observed under an inverted phase-contrast microscope. α-Smooth muscle actin was identified by immunocytochemistry and immunofluorescence. The effects of hypoxia on the proliferation and apoptosis of the PASMCs were detected by CCK-8 assay and TUNEL assay. RESULTS：PASMCs were identified by the methods of immunocytochemistry, immunofluorescence staining and observation of morphology. Unlike the rat PASMCs with typical subcultured peak-vally pattern, the mouse PASMCs showed a lot different without a peak-vally pattern. The cells could be subcultured after 5 d to 7 d and there was 3 to 5 generations depending on the activity of the cells. CCK-8 assay demonstrated that the A values of PASMCs exposed to hypoxia increased after 24 h (P＜0.05) as compared with normoxia. TUNEL result showed that the apoptotic index of the PASMCs in hypoxia decreased after 24 h (P<0.05). CONCLUSION：This technique for obtaining cultured mouse PASMCs is simple, fast, accurate and economical. The digestion time is easy to control. Hypoxia promotes the proliferation and inhibits the apoptosis of PASMCs.     

小檗碱和壳聚糖抗蔬菜病原真菌活性测定及复合膜制备

研究了小檗碱和壳聚糖对几种常见蔬菜病原真菌的抑制活性,以及以小檗碱和壳聚糖为主料制备复合膜的方法,并测定了该膜的药物释放效果。试验表明:低浓度(0.234 mg/mL)小檗碱即可抑制辣椒炭疽病菌(Vermicularia capsici)等5种蔬菜病原真菌的生长。20 mg/mL浓度壳聚糖对番茄灰霉病菌(Botrytis cinerea)的抑制率高达65%,而对其余4种果蔬病原真菌也有一定的抑制作用。为了集成这2种天然化合物的优点,制备了小檗碱-壳聚糖复合膜,该膜具有缓释功能,在模拟外部环境(磷酸缓冲液,pH 6.8)条件下,20 d小檗碱累计释放率接近25%,提示其在果蔬贮藏抗菌中的应用价值。     

西瓜与粮油菜套种栽培试验

近年来,我省西瓜发展速度较快,到2004年全省西瓜栽培面积已达3万hm^2.由于我省耕地面积有限,大幅度扩大西瓜单种面积,不仅造成我省西瓜与粮油菜争地的矛盾,而且土地也未能得到充分有效的利用.为了解决这一生产中存在的实际问题,我们从2002年开始,进行了西瓜与粮油菜套种的栽培试验.历经4年的试验、示范,取得了显著的经济效益和社会效益.现将试验结果报告如下.     

世界及中国鳄梨产销概况与展望

依据联合国粮食及农业组织(FAO)数据库、联合国商品贸易统计数据库(UN Comtrade)中的数据,围绕鳄梨种植面积、产量、迚出口市场、主产国生产情况、主要迚出口国贸易情况等斱面,对世界及中国鳄梨的生产与贸易迚行回顾、分析与展望,幵在此基础上,对中国鳄梨产业的发展提出建议。     

Storability of onion seeds and effects of packaging and storage conditions on viability and vigour

Fresh onion seeds desiccated to 6.0% seed moisture content (SMC) were stored in various packaging materials under different storage conditions. Seeds packed in aluminum-laminated pouches beside those stored with silica gel at 25 °C maintained satisfactory germinability and vigour after 12 months. Desiccated seeds stored in moisture impervious containers produced more vigourous seedlings. Germination potential of onion seeds increased with reduced SMC besides storage in moisture impervious packets along with desiccants as physiological and biochemical attributes are regulated. Seed viability and vigour decreased with accelerated ageing due to increased lipid peroxidation, decreased activities of several free radical and peroxide scavenging enzymes. Electrical conductance of seed leachates also increased with ageing. Thus, adoption of appropriate storage temperature and moisture control techniques would significantly affect onion seed quality, which was due to minimum accumulation of free peroxide radicals and enhanced activity of free radical scavenging enzymes.     

热处理对果蔬采后品质及病虫害的影响

采后热处理是近年来快速发展的果蔬采后处理技术,广泛应用于改善果蔬贮藏期间的品质、增强抗逆性等 方面。从果蔬贮藏期间的生理生化、采后品质及防治病虫害等方面阐述了热处理的机理,讨论了热处理对果蔬衰老 方面的生理特征如色泽、风味、硬度(软化)、失重、呼吸、乙烯释放、酶活性等变化及与抗逆性有关的诱导蛋白质合成 及基因表达的影响,较全面阐述了热处理防治果蔬贮藏期间病虫害的机理如直接作用于病菌、害虫与提高果蔬的抗 病虫性等。     

陕西冬枣黑斑病和炭疽病病原菌的分离鉴定及特征比较

以大荔县冬枣种植区采集的发病枣果为试材,采用常规组织分离法进行病原菌的分离纯化,通过柯赫氏证病法则、形态学观察及分子生物学分析,研究鉴定了冬枣黑斑病和炭疽病的病原菌种类,并采用田间调查法对2种病害为害特征进行比较分析,以期为田间有效区分冬枣黑斑病和炭疽病为害症状,并快速判断其病原类型,及进一步深入开展精准防控提供参考和指导.结果表明:陕西大荔冬枣黑斑病的病原菌为细极链格孢(Alternaria tenuissima),炭疽病的病原菌为胶孢炭疽菌(Colletotrichum gloeosporioides).2种病害均主要为害枣果实,在枣果果腰或果肩上形成黑褐色病斑,可能同时存在且症状相近极易混淆,但在病斑表面、皮下及久置表型3个方面存在明显区别.     

钾肥在小白菜和萝卜上的施用效果

采用盆栽试验方法研究了施用钾肥对小白菜、萝卜生长发育、产量、品质及钾素含量的影响。结果表明 ,施用钾肥对小白菜和水萝卜的株高、叶片数无显著的影响 ,但可提高水萝卜块根的产量 ,提高幅度为 31.0 4 %～ 97.93%。施用钾肥可提高小白菜和萝卜的蛋白质和VC含量 ,降低硝酸盐含量 ,增加植株的钾素含量