青蒿种子品质检验及质量标准的研究

目的:研究青蒿种子品质检验方法和质量分级标准,为青蒿种子检验规程及质量标准的制定提供依据。方法:对不同产地的青蒿种子的品质进行测定。结果与结论:测定了不同产地青蒿种子净度、千粒重、含水率、生活力、发芽率等,并初步制定了青蒿种子的质量分级标准。     

中药青蒿提取液对水稻种子和幼苗的生理效应

用中药青蒿提取液处理水稻种子 ,研究其对水稻幼苗生长和若干生理生化特性的影响。结果表明 :在适当浓度范围内 ,青蒿素提取液能明显提高水稻种子生长率、活力和活力比 ,增加植株干物重 ,根系活力及淀粉酶活性 ,提高水稻幼苗的叶绿素、可溶性糖和蛋白质含量 ,增强 SOD,CAT和 POD等几种保护酶活性 ,对水稻种子萌发和幼苗生长有明显促进作用。     

正交设计优化青蒿SRAP-PCR反应体系及引物筛选

为了建立青蒿的SRAP最佳扩增体系,并筛选出SRAP多态性引物,本研究以青蒿叶片DNA为模板,采用正交试验设计,以Mg^2+、dNTP Mix、Taq DNA聚合酶、引物和DNA模板5种因素5个水平,对青蒿SRAP反应体系进行研究。结果表明,青蒿SRAP-PCR最佳反应体系为:引物0.6μmol/L、Mg^2+2.0 mmol/L、模板DNA 5.1 ng、Taq DNA聚合酶2.0 U、dNTPs 0.25 mmol/L,总体积为25μL。各因素对扩增反应均有不同影响,其中引物浓度的影响最大,dNTPs的影响最小。运用该体系对不同种质资源的青蒿进行验证,证明该体系稳定可靠,并在30个引物组合中筛选出了25对扩增条带清晰,多态性丰富的引物组合。这一结论为今后利用SRAP标记技术进行青蒿分子遗传学研究提供了科学依据。     

黄花蒿对绿豆种子萌发及幼苗生长的化感效应

以绿豆种子为受体,采用室内生测法,探讨黄花蒿不同部位水浸提液对绿豆种子的萌发率、幼苗生长及叶绿素含量的影响。结果表明:黄花蒿各部位(根、茎、叶)水浸提液随处理浓度增加,对绿豆的化感效应增强,对种子萌发的抑制强弱为:叶>茎>根,且随处理浓度升高,发芽率降低;对幼苗的根系生长表现为低浓度(20mg/mL根、茎水浸提液)促进,当浓度高达40mg/mL均有明显抑制作用;幼苗高度总体降低,最高降幅分别为46.29%,47.67%和56.48%;叶绿素a和叶绿素b的含量也不同程度减少。可见黄花蒿影响绿豆种子萌发及幼苗生长,因此大面积栽培黄花蒿或绿豆种植应考虑黄花蒿的化感效应。     

NaCl胁迫对胡卢巴幼苗抗氧化酶活性和丙二醛含量的影响

以胡卢巴幼苗为试验材料,研究NaCl胁迫下胡卢巴幼苗叶和根中抗氧化酶SOD、POD、CAT活性及丙二醛(MDA)含量的变化。结果表明:随着NaCl处理浓度的升高,SOD、POD、CAT活性总体呈现先上升后下降的趋势,MDA含量则呈上升趋势。叶片中抗氧化酶活性在NaCl浓度为1.0%时达到峰值,根中抗氧化酶活性在NaCl浓度为0.5%时达到峰值。在0.5%的NaCl浓度处理下,随着处理时间的延长,3种抗氧化酶协同作用,使MDA含量减少并控制在较稳定的阶段。可见,盐胁迫下胡卢幼苗可通过提高抗氧化酶活性,降低膜质过氧化水平,减缓盐胁迫对植株的伤害,从而增强其耐盐性。     

黄花蒿杀螨活性物质的提取分离及活性评价

采用石油醚(30￣60℃)、石油醚(60￣90℃)、乙醇、丙酮和水等5种溶剂对采自6月份的黄花蒿的根、茎、叶分别进行活性成分的初步提取,然后用柱层析进行分离检查,并进一步用分离得到的组份对朱砂叶螨进行生物测定。结果表明,在黄花蒿根、茎、叶的不同溶剂提取物中,丙酮提取物对朱砂叶螨普遍具有较高的触杀活性。其中叶的丙酮提取物杀螨活性最高,在48h内(5mg/ml)的杀螨校正死亡率达到98.95%。在分离的13个大的组分中,第11和12组分活性较高,48h,5mg/ml对朱砂叶螨的校正死亡率分别为99.30%,和99.29%。用这两组份对朱砂叶螨进行毒力回归分析,得到它们的LC50分别为0.3683、0.1586mg/ml。     

Copper‐Induced Oxidative Stress and Responses of the Antioxidant System in Roots of Medicago sativa

The effects of various copper (Cu) concentrations on the antioxidative system in the roots of Medicago sativa were explored. The results indicated that the Cu content of the roots reached a value of 854 μg g^?1 DW at 10 μm Cu and a value of 4415 μg g^?1 DW at 100 μm Cu, suggesting that M. sativa has better ability to tolerate and accumulate Cu than other Cu‐bioaccumulators, and is a potential plant for phytoremediation. Treatment with Cu resulted in a significant increment in the levels of H₂O₂, O₂˙^? and OH˙. The reduced form of ascorbate and glutathione reached a peak at 30 μm Cu, and was followed by a sharp depletion to a lower level than that of the control. In contrast, the levels of the oxidised forms of ascorbate and glutathione showed a progressive increment with increasing Cu concentrations, suggesting that the antioxidant system was unable to cope with Cu stress at higher Cu levels. Under the Cu concentrations tested, the activity of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) increased at lower Cu concentrations, and then decreased, reaching a maximum at 30 μm of Cu for APX and GR, at 10 μm for CAT, whereas the activities of guaiacol peroxidase (POD, EC 1.11.1.7) were gradually increased with increasing Cu concentrations. PAGE analysis of superoxide dismutase (SOD, EC 1.1.5.1.1) revealed that one band is a Mn‐SOD and five bands are identified as Cu, Zn‐SOD, whereas Fe‐SOD isoforms were not found in the roots of alfalfa. Cu at 10–100 μm increased the intensity of constitutive isozymes of CAT, APX and POD, whereas it decreased the intensity of isozymes of glucose‐6‐phosphate dehydrogenase (G6PDH, EC 1.1.1.49) significantly. The activities of lipoxygenases (LOX, EC 1.13.11.12) were gradually augmented with increasing Cu concentrations, demonstrating that LOXs are probably involved in production of lipid hydroperoxides and superoxide anion. There was a continuous and pronounced enhancement in the activity of esterase (EST, EC 3.1.1.1) in roots treated with 10–30 Cu μm , whereas EST activity in roots exposed to above 30 μm Cu declined, suggesting that EST plays a protective role under lower Cu concentrations stress.     

外源锌对氮胁迫下薏苡幼苗生长及抗氧化系统的影响

为缓解薏苡氮胁迫伤害,为缺氮地区薏苡栽培提供参考依据。以贵州省黔西南薏苡种子为试验材料,采用盆栽试验方法,测定分析外源锌与氮胁迫对薏苡幼苗形态生长、叶绿素含量、生物量积累与分配、过氧化氢酶(CAT)、过氧化物酶(POD)活性及丙二醛(MDA)积累的影响。结果表明,（1）缺氮时薏苡幼苗株高、根长、主根数、总叶片数及各部分生物量显著下降（P<0.05,下同）,致使总生物量较对照显著降低80.65%,CAT、POD活性受到显著抑制,MDA含量显著增加26.29%。（2）施锌显著增加了薏苡株高、叶面积及茎生物量,叶绿素含量整体呈上升趋势,CAT、POD活性显著提高;同时,根系对外源锌表现较为敏感,其根长显著降低28.09%,而主根数显著增加16.86%;（3）缺氮施锌显著提高缺氮薏苡幼苗株高和根长,增幅分别为20.30%、17.72%,抗氧化酶CAT活性显著提高171.01%,而对POD活性及MDA积累影响不大。研究认为,氮胁迫下施锌能促进薏苡幼苗生长和抗氧化系统的平衡,提高薏苡幼苗的适应能力,在一定程度上缓解了氮胁迫所导致的不良影响。     

Alleviation of Water Deficit Stress Effects by Foliar Application of Ascorbic Acid on Zea mays L.

The effects of water-deficit stress and foliar application of ascorbic acid were studied in leaves of Zea mays L. (single cross 704). The activity of antioxidant enzymes, superoxide dismutase, peroxidase, catalase and polyphenol oxidase was clearly increased by water-deficit stress. Foliar application of ascorbic acid reduced stress-induced and antioxidative enzymes activities. Proline and malondialdehyde levels were decreased in water-deficit stressed plants by ascorbic acid application. It seems that, ascorbic acid application helps the plants for better resistance under the stress by inactivation and scavenging of free radicals. Chlorophyll content was also decreased by water-deficit stress. The significant decrease of chlorophyll content was obtained in stressed plant than control. Ascorbate was oxidized to dehydroascorbate whereupon total ascorbate was decreased and dehydroascorbate was increased in leaves. The results of the present study indicated that ascorbic acid reduced the harmful effects of reactive oxygen species and improved plant resistance to water stress. In brief, ascorbic acid treatment reduced the damaging action of drought and decreased enzyme activity due to scavenging of reactive oxygen species; thereupon it may be effective for the improvement of stressed plants in arid and semi-arid regions.     

铜胁迫对油麦菜生长和土壤酶活性的影响

在室内进行土培盆栽实验,通过对油麦菜幼苗植株生长、生物量和土壤酶活测定,研究了不同浓度铜胁迫（50,300,500,800,1200,2000 mg/kg干土）对油麦菜幼苗生长和土壤酶 (脲酶、转化酶、酸性磷酸酶、过氧化氢酶) 活性的影响。结果表明：与对照相比,随着铜浓度的增加,油麦菜的叶片受伤率增加,成活率下降,油麦菜鲜重、株高、平均根长亦随 Cu 浓度升高而递减;土壤酶活性随着铜胁迫程度的增加而显著降低,其中脲酶、酸性磷酸酶活性降低最明显。相关分析结果表明,脲酶、转化酶、酸性磷酸酶、过氧化氢酶活性,油麦菜的平均根长、鲜重、株高与土壤铜含量存在着显著或极显著的负相关关系,酶活性与油麦菜的生理指标呈显著或极显著的正相关。可见土壤酶活性可作为检测土壤中重金属污染程度的参考指标之一。     

藏北野生驯化早熟禾的生产性能和品质评价

基于藏北地区饲草缺乏和草地植被退化等问题,开展野生牧草资源的开发利用研究,驯化筛选适宜藏北高寒区种植的优质乡土早熟禾。选取西藏野生的中亚早熟禾（Poa litwinowiana）、渐尖早熟禾（P. attenuata）和冷地早熟禾（P. crymophila）为材料,以国审栽培品种青海冷地早熟禾（P. crymophila cv. Qinghai）为对照,在海拔4 512m环境条件下完成田间种植,分析比较不同早熟禾的生长特性和营养品质。结果显示,随生育期推进,供试材料地上生物量、株高、中性洗涤纤维和酸性洗涤纤维含量呈现逐渐增加的现象,粗蛋白质和粗脂肪含量下降。乳熟期3种材料的地上生物量均显著（P<0.05）高于对照品种,其根系生物量大小排序为渐尖早熟禾>中亚早熟禾>冷地早熟禾>对照;冷地早熟禾的粗蛋白含量显著（P<0.05）高于渐尖早熟禾,渐尖早熟禾的酸性洗涤纤维和中性洗涤纤维含量最低。采用熵权赋值法的灰色系统理论对乳熟期不同早熟禾生产性能及营养品质指标进行综合评价,优劣顺序为渐尖早熟禾>冷地早熟禾（野生种）>中亚早熟禾>青海冷地早熟禾（栽培种）。     

The Effects of Foliar Application of Ascorbic Acid (Vitamin C) on Antioxidant Enzymes Activities, Lipid Peroxidation and Proline Accumulation of Canola (Brassica napus L.) under Conditions of Salt Stress

The effects of salt stress on protein (PROT) content, lipid peroxidation, proline accumulation, chlorophyll (Chl) content, and superoxide dismutase (SOD; EC 1.15.1.1), catalase (EC 1.11.1.6) and peroxidase (EC 1.11.1.7) activity were studied in the leaves and roots of canola (Brassica napus L. cv. Okapi). Four weeks after sowing (at the V₄ stage), plants were exposed to salt stress by the application of NaCl solution (200 mm ) for 6 days daily, After 6 days followed by foliar application of ascorbic acid (AsA) solution (25 mm ). The activity of all the antioxidant enzymes assayed (except SOD in the roots) was increased significantly in the plants under conditions of salt stress. The application of AsA decreased enzyme activity in the leaves, but it had no effect on enzyme activity in the roots. The total PROT content of the leaves and roots decreased under the conditions of high salinity. AsA treatment of plants under salt stress increased the total PROT content significantly in both leaves and roots. Measurement of the malondialdehyde content of leaves and roots showed that lipid peroxidation was increased by interaction with damaging reactive oxygen species during salt stress, and that application of AsA reduced lipid peroxidation only in the leaves. The Chl content was also affected by salt stress. There was significant difference between the controls and salt‐stress treatments in Chl content. The results of the present study indicate that usage of AsA reduces the harmful effects of salinity and increases resistance to salinity in canola plant.     

Effect of Chemical and Physical Stress Conditions on the Concentration and Composition of Essential Oil Components in Leaves of Full‐Grown Artemisia annua L.

Full‐grown Artemisia annua plants were subjected to chemical and physical stress conditions, and the effect of these on the concentration and chemical composition of essential oil components (EOC) in the leaves was studied. The chemical stress treatments were performed by foliar application of NaCl, H₂O₂, salicylic acid and chitosan oligosaccharide (COS). The EOC of the leaves were extracted with n‐hexane and identified and quantified by GC–MS and GC–FID, respectively. Approximately 96 % of EOC in the extracts were identified and quantified of which β‐pinene, camphene, germacrene D, camphor, coumarin and dihydro‐epi‐deoxyarteannuin B were the major EOC accounting for about 75 % of the total content of EOC in the extracts. The physical stress treatment, sandblasting of the plants resulted in a significant enhancement in the content of α‐pinene, camphene, coumarin and dihydro‐epi‐deoxyarteannuin B. The total yield of identified EOC in non‐treated plants (control) was 86.2 ± 13.8 μg g^?1 fresh weight (FW) compared with 104.0 ± 9.1 μg g^?1 FW in sandblasted plants. The chemical stress treatments did not affect the composition of EOC significantly. The results indicate that chemical stress treatments do not affect the concentration and composition of EOC in full‐grown A. annua plants to the same extent as physical stress treatment by sandblasting.     

Growth, Oxidative Damage and Antioxidant Responses in Greengram (Vigna radiata L.) under Short-term Salinity Stress and its Recovery

Spatio-temporal differences under short-term NaCl-salinity (0, 50, 100, 150 m m l⁻¹) stress for 24 h and post-NaCl recovery after 24 h on the growth, water relations, ionic composition, proline and antioxidants of 12-day-old roots, stem and leaves of Vigna radiata were observed. Fresh and dry weight, relative water content and K⁺ ion decreased, whereas, Na⁺ ion and Na⁺/K⁺ ratio increased significantly in roots, stem and leaves. Post-NaCl recovered roots, stem and leaves showed similar results with lower values. Chlorophyll and carotenoid pigments decreased significantly in the leaves. Peroxide and lipid peroxidation level increased significantly with higher ratio in stressed compared to recovered leaves. Ascorbate and proline content increased significantly with no significant change in glutathione content in stressed roots, stem and leaves. Significant decrease in protein content, SOD, CAT, POX, APX and GR activities was observed in roots with no significant change in stem and leaves. The recovered parts showed similar results except increased POX and GR activities showing a tissue-specific response to NaCl-salinity stress. Improved tolerance to salt stress may be accomplished by increased capacity of antioxidative defence system and by lower level of lipid peroxidation and improvement in the plant water status, activities of some of the antioxidants in the recovered parts suggest that significant tissue differences in response to salt stress in V. radiata is closely related to differences in the activities of antioxidants, ion and proline content.     

Methyl Jasmonate‐Induced Alteration in Lipid Peroxidation,Antioxidative Defence System and Yield in Soybean Under Drought

Methyl jasmonate (MeJA), a plant‐signalling molecule, is involved in an array of plant development and the defence responses. This study was conducted to explore the role of exogenous MeJA application in alleviating the adversities of drought stress in soybean (Glycine max L. Merrill.). Soybean plants were grown under normal conditions until blooming and were then subjected to drought by withholding irrigation followed by foliar application of (50 μm ) MeJA. Drought stress substantially suppressed the yield and yield‐related traits, whereas it accelerated the membrane lipid peroxidation. Nonetheless, substantial increase in activities of enzymatic antioxidants (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), proline, relative water contents (RWC) with simultaneous decrease in membrane lipid peroxidation was observed in MeJA‐treated plants under drought. These beneficial effects led to improvement in biological and grain yield, and harvest index under drought. Interestingly, MeJA application was also useful under well‐watered conditions. These results suggest the involvement of MeJA in improving the drought tolerance of soybean by modulating the membrane lipid peroxidation and antioxidant activities.     

刺槐在盐胁迫下的生理响应及耐盐性综合评价

为了研究四个刺槐品种(豫刺1号、豫引1号、豫引2号、3-I)在不同浓度NaCl胁迫处理下的生理响应并对其耐盐性进行评价排序。本研究采用不同浓度(0nmol/L、200nmol/L、400nmol/L)NaCl胁迫处理,研究四个一年生刺槐品种的生理响应水平变化情况,并根据十项生理指标的统计结果,利用隶属函数法对刺槐的耐盐性进行综合评价。结果表明,不同刺槐品种在不同浓度NaCl胁迫下的生理指标响应水平各不相同。四个刺槐品种的耐盐性依次为豫引1号>豫刺1号>豫引2号>3-I。     

Role of Arbuscular Mycorrhizae in the Alleviation of Ionic, Osmotic and Oxidative Stresses Induced by Salinity in Cajanus cajan (L.) Millsp. (pigeonpea)

Salinity stress causes ion toxicity and osmotic imbalances, leading to oxidative stress in plants. Arbuscular mycorrhizae (AM) are considered bio‐ameliorators of saline soils and could develop salinity tolerance in crop plants. Pigeonpea exhibits strong mycorrhizal development and has a high mycorrhizal dependency. The role of AM in enhancing salt tolerance of pigeonpea in terms of shoot and root dry weights, phosphorus and nitrogen contents, K⁺ : Na⁺, Ca²⁺ : Na⁺ ratios, lipid peroxidation, compatible solutes (proline and glycine betaine) and antioxidant enzyme activities was examined. Plants were grown and maintained at three levels of salt (4, 6 and 8 dSm^?1). Stress impeded the growth of plants, led to weight gain reductions in shoots as well as roots and hindered phosphorus and nitrogen uptake. However, salt‐stressed mycorrhizal plants produced greater root and shoot biomass, had higher phosphorus and nitrogen content than the corresponding uninoculated stressed plants. Salt stress resulted in higher lipid peroxidation and membrane stability was reduced in non‐AM plants. The presence of fungal endophyte significantly reduced lipid peroxidation and membrane damage caused by salt stress. AM plants maintained higher K⁺ : Na⁺ and Ca²⁺ : Na⁺ ratios than non‐AM plants under stressed and unstressed conditions. Salinity induced the accumulation of both proline and glycine betaine in AM and non‐AM plants. The quantum of increase in synthesis and accumulation of osmolytes was higher in mycorrhizal plants. Antioxidant enzyme activities increased significantly with salinity in both mycorrhizal and non‐mycorrhizal plants. In conclusion, pigeonpea plants responded to an increased ion influx in their cells by increasing the osmolyte synthesis and accumulation under salt stress, which further increased with AM inoculation and helped in maintaining the osmotic balance. Increase in the antioxidant enzyme activities in AM plants under salt stress could be involved in the beneficial effects of mycorrhizal colonization.     

外源硼酸对铀胁迫下四季豆生理以及铀富集的影响

为了研究外源硼酸对铀胁迫下四季豆生理生化以及铀富集能力的影响,笔者以四季豆(Phaseolus vulgaris L.)为材料,通过盆栽控制试验,在含有铀污染的土壤中分别施加0、10、20、30、40、50 mg/kg的硼酸,在温室中种植培养四季豆,待四季豆开花前取样测定其生理指标和铀富集含量。结果表明:(1)随着硼酸浓度的升高,最大光化学效率(FV/Fm)和光合性能指数PIABS以及单位反应中心吸收的光能(ABS/RC)、单位反应中心捕获的能力(TRo/RC)、单位反应中心捕获的用于电子传递的能量(ETo/RC)和单位反应中心耗散的能量(DIo/RC)均呈现先升高后下降的趋势;叶绿素、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性、可溶性蛋白、可溶性糖、游离脯氨酸也呈现先上升后下降的趋势;丙二醛(MDA)呈现先下降后升高的趋势;(2)随着外源硼酸浓度的升高,四季豆地上部和地下部铀含量以及植物铀含量都升高。说明了外源施加适宜浓度的硼酸可以提高四季豆对重金属铀的抗性,增加四季豆对铀的富集能力和转移能力。     

油莎豆对自然盐碱胁迫的生长及生理响应

探究油莎豆在不同浓度自然盐碱胁迫下的生长及生理响应,揭示油莎豆在盐碱胁迫的耐盐碱机制与能力。本试验以‘中油莎1号’品种为供试材料,通过采集自然盐碱土和农田土,分别按0%、25%、50%、75%、100%的盐碱土比例进行胁迫,观测油莎豆的生长发育、渗透调节物质、丙二醛及保护酶活性等生理代谢指标。结果表明：随着盐碱胁迫强度的增大,油莎豆叶绿素合成受阻,其株高、分蘖数、结豆数、总粒重及生物量均显著下降;脯氨酸、可溶性糖、可溶性蛋白及丙二醛含量均呈上升趋势,且在75%盐碱土比例下均显著上升;SOD活性呈先上升,在50%盐碱土处理下达到最大后下降。油莎豆在自然盐碱胁迫下生长受到抑制,出苗和分蘖期均显著延后,随盐碱胁迫程度的升高细胞膜脂过氧化逐渐加重,而油莎豆可通过提高体内SOD活性来缓解盐害,同时盐碱胁迫下油莎豆可通过调节脯氨酸与可溶性糖的积累,从而增强植株从环境中的保水能力,以提高植株对盐碱胁迫的适应能力。     

水浸胁迫对超表达Sub1A油菜(Brassica napus)抗氧化能力的影响

环境中水分含量变化对于生长期油菜的产量和品质影响极大。国内外研究表明,异源表达Sub1A基因具有提高水涝条件下植物的抗逆性和恢复生长的潜能。本研究以组成型表达Sub1A基因的甘蓝型油菜作为实验材料,测试了其在水浸胁迫30 d内的生长速度和抗氧化水平。结果表明,超表达株系在地上部分和地下部分的生物量积累速率均显著高于野生型油菜,在胁迫早期尤为明显,表现出响应水浸胁迫的优良表型。同时,抗氧化酶(SOD,POD,CAT和GPX)活性和胁迫响应基因的表达变化也基本一致,呈现出胁迫早期强,随着处理时间增加呈逐渐降低的趋势。以上结果说明超表达Sub1A基因可能通过提高细胞的抗氧化酶活性、提高胁迫响应基因的表达水平提升抗水浸胁迫能力。本研究将为深入研究外源表达Sub1A基因提高油菜抗水浸胁迫提供依据,并为抗涝油菜新品种的开发提供前期基础。