南方根结线虫不同接种密度对灯盏花抗氧化系统的影响

通过室内接种方法,测定了南方根结线虫2龄幼虫在不同接种时间(25、35d)和不同接种密度(0、500、700、1 000、1 200、1 500头/株)下对灯盏花生长和根系及叶片丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化物酶活性(POD)及过氧化氢酶活性(CAT)的影响。研究结果表明,南方根结线虫接种密度为1 000头/株时,接种后25d与35d的根结指数达到最大,分别为87.2及65.6;接种密度500头/株,对根结指数影响较大。接种后25d,接种量对灯盏花病根与病叶的过氧化物酶活性影响不大;接种后35d,灯盏花病根的过氧化物酶活性(POD)随接种密度的增加先降低后升高,病叶中的POD活性除了接种密度为1 000头/株时低于健康叶部外,其他均高于健康组;接种密度对灯盏花的过氧化氢酶(CAT)活性影响较大,在1 000头/株时,病根和病叶中的过氧化氢酶活性都明显高于对照。接种密度对于灯盏花叶片的丙二醛(MDA)含量影响不大,当密度为1 000头/株接种35d对根部丙二醛的影响最大,其含量明显高于对照;接种密度对于灯盏花病叶和病根中的超氧化物歧化酶(SOD)活性影响较大,病叶中的超氧化物歧化酶(SOD)普遍高于健康组,而病根中的SOD活性普遍低于健康组。综合研究结果,当南方根结线虫接种密度为500头/株时,对灯盏花有一定危害,随着接种密度的增加,危害逐渐加重,当接种密度为1 000头/株时,根结指数最大,几种酶活性都显著高于健康植株,接种密度大于1 000头/株时,酶活性逐渐下降。接种初期,南方根结线虫对灯盏花叶部危害较大,随着种植时间的推移,对根部危害逐渐加重。     

<Emphasis Type="Italic">Erigeron annuus</Emphasis> (L.) Pers., as a green manure for ameliorating soil exposed to acid rain in Southern China

Background, aims, and scope  Increasing soil acidification is a growing concern in southern China. The traditional green manures applied in the fields mostly comprise legumes that tend to accelerate soil acidification. Moreover, acid deposition can act as a source of nitrogen. Hence, we looked for new plant species that would enhance nutrient concentrations when used as green manure and would reduce soil acidity or at least not worsen it. Materials and methods  We studied the use of Erigeron annuus (L.) Pers. for ameliorating acid soil in a pot experiment with simulated acid rain (SAR) treatments (pH 5.8 to 3.0) in an open area in Guangzhou City. The pots were divided into two groups named A and B groups. On day 0, pots of A group were filled with soil and planted with Erigeron annuus seedlings. Pots of B group were only filled with soil as the control. On day 40, seedlings of E. annuus were harvested and buried in the corresponding pots. On day 54, two seeds of Phaseolus vulgaris L. were sown in each pot in both groups. The growth and bean yield of P. vulgaris seedlings were then used to evaluate the effects of E. annuus on acid soil. Plant and/or soil samples were collected on days 0, 40, 54, and 150; corresponding parameters were measured. Results  Results showed that E. annuus could maintain a good growth even on very acid soil. On day 40, the pH decreased significantly (P < 0.0001) in the B group pots without E. annuus compared with the A group. On day 54, after E. annuus was buried as a manure, the soil pH of all A group treatments except the pH 4.0 treatment showed a significant increase compared to day 40 (P < 0.01). At the same time, the application of E. annuus as a manure produced a significant increase of soil K and P (P < 0.001), Ca (P < 0.05), and Mg (P < 0.001) concentrations of all A group SAR treatments compared to their B group counterparts (except control pots for Ca). The soil exchangeable K and available P concentration doubled, and Ca and Mg increased by around 25% in the presence of the E. annuus manure application. Discussion  The higher soil pH in the A group than B group on the day 40 was due to a great absorption of NO₃ ⁻ by the roots of E. annuus. The soil pH increase after E. annuus was applied to the soil of A group was attributed to the release of high amount of K, the mineralization of organic N, and the oxidation of organic acid anions. Nutrient increase in the A group after E. annuus application was mostly the result of the nutrient release during the residue decomposition. The amelioration of the soil was effective as demonstrated by the enhanced growth and bean yield of P. vulgaris seedlings on the manured soil compared to the seedlings grown on a control that was not manured. Conclusions   E. annuus could maintain a good growth in the acid lateritic field soil. Cultivating this plant and applying it to the soil with a rate of 1.6 ton ha⁻¹ doubled the soil K and P concentrations and increased soil exchangeable Ca and Mg concentrations by around 25%. This species would be a good green manure candidate for growing in the acid soils of southern China. Application of E. annuus also has beneficial effects on crop growth through reduced Al toxicity and cation leaching. Recommendations and perspectives  Since E. annuus would improve soil pH and nutrient concentrations with minimum care, it is recommended for treating acid soils with poor yield whenever a low-cost solution is required.     

Effect of erigeron on intercellular adhesion molecule-1 and its mRNA expression during cerebral ischemia and reperfusion in rats

AIM: To investigate the effect of erigeron on intercellular adhesion molecule-1 (ICAM-1) and mRNA expression during cerebral ischemia/reperfusion. METHODS: The rat models of middle cerebral artery (MCA) focal cerebral ischemic reperfusion were established with the suture method in the study. The ICAM-1 mRNA and protein expression were measured by RT-PCR and immunohistochemistry techniques, respectively. RESULTS: By down-regulating the expression of ICAM-1 protein and mRNA and alleviating inflammation in cerebral ischemic region, erigeron exerted a protective effect in cerebral ischemia and reperfusion. CONCLUSION: The results suggest that erigeron protects the brain against cerebral ischemia and reperfusion injury via inhibiting ICAM-1 expressino.     

灯盏花根际土壤3种垫刃线虫的鉴定

 灯盏花[Erigeron breviscapus (Vaniot) Hand.-Mazz.],又名灯盏细辛、短葶飞蓬,是一种多年生野生草本植物,属菊科(Compositae) 飞蓬属(Erigeron),产于湖南、广西、贵州、四川、云南、西藏等省区,常见于海拔1 200~3 500 m的中山和亚高山开阔山坡、草地、林缘^[1],具有重要的药用价值,被列为国家重点发展的中草药品种和中医治疗心脑血管疾病临床必备急救药品。     

入侵种加拿大蓬对玉米的化感潜力及机制研究

采用盆栽法研究了入侵杂草加拿大蓬Erigeron canadensis L.对玉米Zea mays L.成熟植株的化感作用,并对其作用机制进行了探讨.结果发现,经加拿大蓬水提液处理后,玉米植株有矮化、弱化的趋势,生物量积累受阻,单株减产可达27.46％.分析玉米叶片的结构参数和气体交换参数发现,受试玉米叶面积减小12....     

不同居群灯盏细辛生长势比较研究

为探明不同灯盏细辛居群生长势差异,以云南及其周边地区的22个灯盏细辛居群为材料,在昆明地区栽培后进行生长势的对比研究。结果表明:成苗至营养生长末期,不同灯盏细辛居群株高增长趋势相同,而基生叶高度、冠幅、叶片数、丛芽数、花数则显示出多样的增长趋势;文山广南及曲靖沾益居群具有明显的生长优势,可作为优良种源筛选材料;昭通靖安、楚雄永仁、大理苍山居群则生长势较弱,不适于在昆明地区推广种植。     

短葶飞蓬种子活力测定方法的初步研究

[目的]研究短葶飞蓬种子活力的测定方法。[方法]比较种子数目、培养温度对种子发芽的影响,并采用TTC染色测定种子活力。[结果]测得种子出苗率为15.37%,与培养第6天的种子发芽数目比例接近;100和700粒种子发芽试验的重复间发芽率差异较大,300和500粒种子发芽试验的发芽率差异较小;经TTC染色后,短葶飞蓬种子呈现不同类型,可将全部着色和下部着色的种子认定为具有活力的种子,其比例为15.00%,该数值与发芽势和出苗率接近,试验误差较小。[结论]该方法准确可靠,可用于初步测定短葶飞蓬的种子活力。     

Molluscicidal and antifungal activity of Erigeron speciosus steam distillate

The steam-distilled fraction of the aerial parts of Erigeron speciosus (Lindl) DC was tested for activity against strawberry plant pathogenic fungi Botrytis cinerea Pers ex Fr, Colletotrichum acutatum Simmonds, C fragariae Brooks, C gloeosporioides (Penz) Penz & Sacc, and the intermediate host snail Planobdella trivolvis that harbors the trematode, Bolbophorus confusus, that infests and causes severe infections in pond-raised catfish in the Mississippi Delta region of the USA. Bioautography on silica TLC plates demonstrated antifungal activity in the steam distillate. Preliminary bioassays of the steam distillate indicated the presence of phytochemicals toxic to P trivolvis. The bioactive compounds methyl 2Z, 8Z-deca-2,8-diene-4,6-diynoate and its 2E, 8E isomer were isolated by bioassay-guided fractionation and chromatographic techniques and identified by 1H NMR spectroscopy.     

灯盏细辛栽培密度与产量关系研究

目的：通过试验,找出最佳栽培密度,进一步降低成本,提高单位面积产量和经济效益。方法：采用随机区组试验。结果：增加株行距有利于单株或单丛的生长发育;密度越大,单位面积产量越高;在构成产量的三因素中,株距贡献率最大,行距次之,双株略低于行距。栽培管理及育苗成本是株距>双株>行距。结论：最佳密度组合为（20cm×10cm）+双株。     

外来种一年蓬化感作用的初步研究

为探讨外来种一年蓬的入侵机理,本文采用滤纸培养皿法研究了一年蓬水浸提液对莴苣、黄瓜、油菜、萝卜4种不同植物的化感作用.研究结果发现,一年蓬地下和地上部分浸提液对供试种子的萌发表现显著的抑制作用,并随着浸提液浓度的增加,抑制作用增强;一年蓬浸提液对供试植物主根的生长产生抑制作用,而对幼苗的生长,低浓度一年蓬的水浸提溶液对受试植物幼苗苗长则表现促进作用,高浓度才能抑制幼苗的生长.这说明一年蓬的化感作用主要表现在抑制植物种子的萌发和主根的伸长生长.