花生植株和土壤水浸液自毒作用研究及土壤中自毒物质检测

通过盆栽试验及生物测试研究花生植株、土壤水浸液对其种子萌发和幼苗生长的自毒作用,利用单因子方差分析结合多重比较分析各处理组生物活性差异;采用液相色谱法(HPLC)对正茬、连作2、4 a和6 a的花生根际土壤中酚酸类物质进行定性和定量分析。结果表明:花生植株不同部位及根际土壤水浸液对花生种子萌发和幼苗生长均具有不同程度的抑制作用,且抑制作用具有浓度梯度效应,浓度越高抑制作用越强,16 g/10 mL水浸液的抑制作用最大。花生生长受自毒物质的影响,此影响作用强度因自毒物质的来源部位不同而存在差异。种子萌发以茎水浸液的自毒作用最为明显。但针对幼苗生长的不同测定指标其部位差异不一致,其中以茎水浸液对幼苗株高和叶面积的自毒作用最为明显,根际土壤水浸液对幼苗主根长、单株鲜重和单株干重的自毒作用最为明显。在根际土壤水浸液中鉴定到4种酚酸物质,分别为对羟基苯甲酸、香草酸、香豆酸和香豆素,其中香草酸和香豆素含量较高且变化规律性明显,在土壤中的含量随连作年限的增加而上升,连作6 a后土壤中的含量达到0.289μg/g和0.025μg/g干土。     

草莓连作土壤酚酸类物质积累对土壤线虫的影响

通过大田试验和盆栽试验相结合的方式,对不同连作年限草莓土壤酚酸类物质含量、土壤线虫数量和食细菌线虫数量以及外源酚酸类物质对土壤线虫数量和食细菌线虫数量的影响进行了研究。结果表明:随连作年限的增加,草莓连作土壤中酚酸类物质含量明显增加,土壤线虫总数和食细菌线虫总数整体呈现下降趋势,且连作5年的土壤线虫总数和食细菌线虫数量最低,酚酸类物质含量与土壤线虫总数和食细菌线虫数量呈负相关;对羟基苯甲酸和对香豆酸在浓度低于200μg·g-1时使土壤线虫总数和食细菌线虫数量增加,而高于200μg·g-1时起抑制作用;肉桂酸在浓度低于100μg·g-1时增加了土壤线虫总数和食细菌线虫数量,而高于100μg·g-1时起抑制作用;随阿魏酸浓度的增加,线虫数量变化规律不明显,当其浓度高于100μg·g-1时起抑制作用;混合酚酸随浓度增加对土壤线虫总数和食细菌线虫数量的抑制作用增强。     

外来植物火炬树水浸液对土壤微生态系统的化感作用

引种自北美的外来植物火炬树(Rhus typhina L.)是中国北方主要造林树种之一.然而,近年来分布区的不断扩大暗示着该树种的潜在入侵性.以火炬树为对象,研究火炬树不同浓度(0、0.005、0.025、0.1g/mL)的鲜枝叶水浸液对土壤微生物群落结构、酶活性、土壤养分含量及土壤矿化的影响.研究结果表明:随着水浸液浓度的提高,火炬树增加了细菌和真菌的数量;火炬树对所测土壤酶活性产生了不同程度的影响,脲酶和磷酸酶均有随着水浸液浓度的提高而增大的趋势,而蔗糖酶活性受影响不明显;随水浸液浓度升高,火炬树显著提高了土壤全碳、全钾、速效氮、有效磷、速效钾的含量,对土壤含水量、pH值、全氮与全磷没有显著影响;同时,火炬树通过促进微生物的矿化速率,提高了土壤无机氮的供给.以上结果表明,火炬树可以改变土壤的微生物组成和土壤酶活性并影响土壤相关营养元素循环,从而为自身的入侵创造有利条件.本研究揭示外来植物火炬树水浸液对土壤微生态系统的影响,从化感间接作用角度为火炬树的潜在入侵性提供进一步的数据支持.     

连作障碍与根际微生态研究Ⅲ.土壤酚酸物质及其生物学效应

以黑龙江省大豆重茬 5年与正茬土壤和根系为主要研究对象 ,采用高效液相色谱法 ,研究土壤和根系浸提液中的酚酸物质的含量及其生物学效应 .结果表明 ,重茬土壤中对羟基苯甲酸和香草酸的含量 (1mol·L-1NaOH提取 )大于正茬土壤 ,且差异达到极显著水平 ,香草醛含量差异不显著 ;重茬大豆根系水提液中对羟基苯甲酸、香草酸、阿魏酸、香草醛、香豆素含量均高于正茬 .大豆连作条件下土壤多酚氧化酶活性高于正茬土壤 .重茬大豆根系水提液及在水培条件下外加对羟基苯甲酸对大豆幼苗生长发育有一定的抑制作用 ;酚酸物质加入土壤 1周后 ,对羟基苯甲酸、香草酸、香草醛、阿魏酸、苯甲酸、香豆素残留率分别为 10 .4%、15 .3 %、4.1%、2 .3 %、5 .0 %、17.5 % ;且外加酚酸浓度与土壤中真菌数量呈极显著指数相关 .     

粗茎秦艽根茎品质与栽培土壤化学因子的相关性分析

对云南丽江鲁店乡18个样点粗茎秦艽（Gentiana crassicaulis Duth.ex Burk.）的根茎品质指标以及栽培土壤基本养分和矿质元素含量进行了测定;在此基础上,分析了根茎品质指标与土壤化学指标的相关性,并采用逐步回归分析方法筛选出影响粗茎秦艽根茎品质的主要土壤化学因子。测定结果表明：各样点间粗茎秦艽根茎的总灰分、酸不溶性灰分、水分、醇溶性浸出物、马钱苷酸和龙胆苦苷含量的差异较大,平均值分别为2.84%、0.28%、6.21%、28.57%、1.53%和4.70%,均符合相关的药材标准。土壤p H值为p H 4.67~p H 6.83,平均值为p H 5.51;土壤中有机质、速效N、速效P和速效K含量差异明显,平均值分别为7.38%、128.09μg·g-1、86.85μg·g-1和232.33μg·g-1;土壤中交换性Ca、交换性Mg、有效Zn、有效Mn、有效Fe和有效Cu含量也有较大差异,平均值分别为1 391.16、91.87、2.81、56.18、51.07和0.92μg·g-1。相关性分析结果表明：土壤速效P含量与粗茎秦艽根茎中醇溶性浸出物和龙胆苦苷含量分别呈极显著和显著正相关;土壤有效Fe含量与根茎中总灰分、酸不溶性灰分、醇溶性浸出物和龙胆苦苷含量呈极显著或显著正相关;土壤有效Cu含量与根茎中总灰分含量呈极显著正相关。逐步回归分析结果表明：影响粗茎秦艽根茎中总灰分含量的土壤化学因子是有效Zn、有效Fe和有效Cu含量,影响根茎中酸不溶性灰分和龙胆苦苷含量的土壤化学因子是有效Fe含量,影响根茎中醇溶性浸出物含量的土壤化学因子是速效P含量;而根茎中水分和马钱苷酸含量与各土壤化学因子均无明显的回归关系。综合分析结果显示：云南丽江粗茎秦艽种植区域的土壤均呈弱酸性,基本养分充足、矿质元素含量丰富,适宜于粗茎秦艽的生长;土壤有效Fe含量对粗茎秦艽根茎的品质指标影响最大,在实际生产中应适当喷施含Fe的微肥。     

不同间隔年限地黄土壤的自毒作用和酚酸类物质含量

分别取2、4、6、8年前种植过地黄的土壤进行大田再植生物测试,并采用HPLC检测再植地黄土壤中与化感现象密切相关的5种酚酸（阿魏酸、对羟基苯甲酸、香草酸、香豆酸和丁香酸）的含量。结果表明：随着土壤间隔年限的增加,大田再植地黄的块根干质量、体积和叶片干质量依次增加,且从地黄苗期就开始表现出这种变化趋势;地黄土壤中5种酚酸的含量也依次降低, 间隔2、4、6、8年的再植地黄土壤中5种一元酚酸总含量分别为1.503、1.323、0.700和0.340 μg·g^-1。间隔2、4、6、8年的再植地黄土壤水提液中阿魏酸、对羟基苯甲酸和香豆酸含量与地黄大田生物测试结果呈显著或极显著负相关。从整体看,地黄生育的前期和中期应当是地黄化感作用的重点时期。     

酚酸类物质对三七幼苗的化感影响

该文研究了不同浓度的阿魏酸、对香豆酸、丁香酸、对羟基苯甲酸、香草酸5种酚酸类物质对三七幼苗生长和生理的影响。结果表明:处理后,三七幼苗的苗高、根长、可溶性蛋白质含量、根系活力、CAT以及POD活性均有所降低。其中,阿魏酸各处理组幼苗的苗高及POD活性均显著降低,50、100 mg·L~(-1)的对香豆酸以及100 mg·L~(-1)的香草酸处理组幼苗苗高也分别比对照显著降低16.19%、16.67%和29.29%;对香豆酸、丁香酸以及对羟基苯甲酸各处理组幼苗根长均显著低于对照;香草酸处理组幼苗的根系活力也显著低于对照,且幼苗的CAT活性在10、50、100 mg·L~(-1)丁香酸、对羟基苯甲酸以及香草酸处理下也达到了显著降低水平。此外,1 mg·L~(-1)阿魏酸以及100 mg·L~(-1)香草酸处理组幼苗的叶绿素含量也均显著降低;中高浓度的阿魏酸、对香豆酸、丁香酸、对羟基苯甲酸增加了三七幼苗的MDA含量,而香草酸在0.1、1、10、100 mg·L~(-1)浓度下显著降低幼苗的MDA含量;丁香酸、香草酸、对羟基苯甲酸以及中高浓度的对香豆酸增加了三七幼苗的SOD活性,且香草酸各处理组均达到了显著性水平。综上结果表明,5种酚酸类物质对三七幼苗均具有一定的化感抑制作用,但各酚酸物质的作用方式及强度并不完全一致,阿魏酸的化感影响较大,这为进一步研究三七的化感自毒作用提供了一定的理论参考。     

花椒叶浸提液对土壤微生物数量和土壤酶活性的影响

通过用花椒叶浸提液浇灌盆栽花椒幼苗,研究浸提液对土壤酶和土壤微生物的影响.结果表明, 花椒叶浸提液使根际土中细菌、真菌和放线菌数量以及微生物总数均有不同程度的减少,根际土中真菌和放线菌的数量变化呈降-升-降-升的趋势.20、60和80 g·L^-1浓度的叶浸提液使非根际土中细菌的数量显著增加21.59%、107.55%和8.62%,而40 g·L-1浓度的叶浸提液则使非根际土中细菌数量显著降低22.56%.叶浸提液使根际土蛋白酶、蔗糖酶和酸性磷酸酶活性明显低于非根际土相应的酶活性,而过氧化氢酶和多酚氧化酶活性则显著升高.土壤的蛋白酶活性与蔗糖酶活性呈显著正相关,与土壤放线菌数量呈显著负相关;多酚氧化酶活性与蔗糖酶活性呈显著负相关,与细菌、真菌、放线菌以及微生物总数呈显著正相关;放线菌只与蛋白酶、多酚氧化酶、蔗糖酶3种酶活性及真菌呈显著相关,与过氧化氢酶、酸性磷酸酶以及细菌和微生物总数的相关性均不显著.     

黄瓜连作土壤酚酸类物质积累对土壤微生物和酶活性的影响

伴随连作年限的增加,日光温室黄瓜连作土壤中酚酸类物质(对羟基苯甲酸、阿魏酸、苯甲酸)明显积累,连作5～9年的土壤酚酸类物质含量显著高于连作1～3年的土壤.伴随外源酚酸类物质处理浓度的增加,黄瓜根区土壤中细菌、放线菌和微生物总量以及N生理群均呈先升后降趋势,在80 μg·g^-1处理浓度下细菌、放线菌数量最多,处理浓度在120μg·g^-1以下土壤真菌数量(包括尖孢镰刀菌、疫霉)急剧增长;多酚氧化酶、过氧化氢酶、蔗糖酶、脲酶和蛋白酶活性也同样呈先升后降趋势,但其峰值对应的浓度不同.     

辣椒茎、叶对酸化土壤交换性能及土壤酶活性的影响

采用辣椒秸秆废弃物与酸化土壤共培养的方法, 设计了不同添加量的辣椒茎、叶与酸化土壤充分混合、共培养, 测定了土壤交换性离子及土壤酶活性的变化, 探讨辣椒茎、叶对酸化土壤交换性能及土壤酶活性的影响。结果表明, 辣椒茎、叶可以改善酸化土壤pH, 降低酸化土壤交换性酸含量; 添加辣椒茎、叶可提高土壤NH4+-N含量, 影响土壤NO3--N转化; 添加辣椒茎、叶可提高土壤交换性盐基含量、CEC及盐基饱和度, 尤其以添加辣椒叶5%的效果最好; 辣椒茎、叶可以提高土壤脲酶活性, 但培养60 d后各处理土壤过氧化氢酶、蔗糖酶、酸性磷酸酶活性无显著性差异; 添加辣椒茎、叶能提高土壤酶的几何平均数, 改善酸化土壤质量, 其对酸化土壤质量的改变与辣椒茎、叶的添加量有关。研究结论可为开拓辣椒秸秆利用途径、改善土壤酸度, 提高土壤肥力等方面提供理论依据。     

栽植生姜对不同种植模式下紫色土微生物生物量及水解酶活性的影响

研究了岷江下游紫色丘陵区玉米+红薯间作、大豆单作、生姜连作、水稻-紫云英轮作等4个典型种植模式下栽植生姜后土壤微生物生物量碳、氮、磷含量和水解酶活性的变化特征.结果表明： 栽植生姜显著降低了4个种植模式下土壤微生物生物量碳、氮和磷含量,但各种植模式之间存在较大差异.其中,玉米+红薯间作和水稻-紫云英轮作模式下土壤微生物生物量碳、氮的下降幅度明显低于大豆单作与生姜连作模式,但土壤微生物生物量磷下降幅度明显较高.栽植生姜显著降低了土壤酸性磷酸酶活性,其下降幅度以玉米+红薯间作模式最大,水稻-紫云英轮作模式最小;土壤转化酶活性在生姜连作模式下显著降低;土壤脲酶活性在大豆单作、生姜连作和水稻-紫云英轮作模式下均显著降低.相对于其他模式,栽植生姜使玉米+红薯间作模式下的土壤维持了较高的转化酶和脲酶活性.     

Impact of mineral fertilizers on mineral nutrients in the ginger rhizome and on soil enzymes activities and soil properties

Ginger is used as one of the important ingredients in traditional as well as modern medicine besides as a spice. It boosts immunity and is a rich source of many biologically active substances and minerals. Although it is a medicinally important crop, its productivity is, however, affected due to poor nutrient management and therefore it requires an adequate supply of nutrients in the form of inorganic fertilizers or organic manuring, or a mixture of both. In this context, the present study was aimed to investigate the effect of mineral fertilizers on the content of mineral elements in the ginger rhizome, on soil enzyme activity, and soil properties. Lysimeter experiments were conducted at the Institute of Genetics and Plant Experimental Biology, Kibray, Tashkent region, Uzbekistan. The experiment comprised of four treatments T1 – Control, T2 - N₇₅P₅₀K₅₀ kg/ha, T3 - and T4 - N₁₀₀P₇₅K₇₅ + B₃Zn₆Fe₆ kg/ha. The results showed that the application of N₁₂₅P₁₀₀K₁₀₀ kg/ha increased rhizome K content by 49%, P content by 20%, and Na content by 58% as compared to control without fertilizer. While the application of N₁₀₀P₇₅K₇₅ + B₃Zn₆Fe₆ kg/ha showed a significant enhancement in rhizome K, Ca, P, Mg, Na, Fe, Mn, Zn, Cu, Cr, Mo, and Si contents over the control. This treatment also improved active P content by 29%, total P content by 80%, total K content 16%, and N content by 33% content, and the activities of urease, invertase, and catalase activities as compared to control of without mineral fertilizer and control respectively. Thus the application of NPK + BZnFe at the rate of 100:75:75:3:6:6 kg/ha helps in improving macroelements and microelements in the ginger rhizome and activities of soil enzymes that helps in mineral nutrition of the rhizome.     

葡萄根系浸提液的化感作用

以晚红(Red Globe)葡萄组培苗为材料,研究了葡萄根系浸提液对葡萄幼苗生长的影响,并采用LC-MS技术对其中的主要化感物质进行鉴定.结果表明:0.02g.ml-1(风干根质量/浸提液体积,下同)、0.1g.ml-1、0.2g.ml-1的葡萄根系浸提液显著抑制了葡萄幼苗的生长,且浓度越高,抑制作用越强.葡萄根系浸提液中含有对羟基苯甲酸、水杨酸、苯丙酸和香豆酸4种酚酸类物质.盆栽模拟试验表明,不同浓度的(0.1、1、10mmol.L-1)水杨酸和苯丙酸显著抑制了葡萄植株的生长,随着作用浓度的升高,葡萄的株高、茎粗、地上和地下鲜质量、叶片净光合速率和根系活力降低,叶片可溶性糖、MDA含量升高,淀粉含量降低,而叶片蛋白质含量无明显变化规律.     

土壤紧实度对生姜植株衰老的影响

通过测定不同容重土壤中生长的生姜植株的主要生理特性,研究了土壤紧实度与生姜植株衰老的关系.结果表明：随土壤紧实度增大,生姜根系活力降低,叶片硝酸还原酶活性及叶绿素含量下降,光合作用减弱,叶片的电解质渗漏率及MDA含量升高.在生长前期,叶片SOD、POD及CAT活性随土壤紧实度的增加而降低,后期则相反.生姜旺盛生长期,土壤容重为1.20和1.49 g·cm^-3的植株根系活力分别为37.3和28.5 μg·g^-1FM·h^-1,后者较前者降低30.9%,叶片叶绿素含量及光合速率分别降低19.0%和17.9%,而叶片电解质渗漏率及MDA含量则分别提高57.2%和26.3%,表明紧实土壤加速了生姜植株的衰老.     

腐植酸肥料对生姜土壤微生物量和酶活性的影响

设4个处理:空白对照、等量腐植酸、等量无机养分和腐植酸复合肥.通过小区试验,研究了腐植酸肥料在生姜不同生育时期对土壤微生物量和3种重要酶活性的影响.结果表明:与不施肥处理比较,施用腐植酸使前期的微生物量碳增加、脲酶活性降低,后期的微生物量碳减少、脲酶活性提高;施用腐植酸增加土壤活跃微生物量、提高酸性磷酸酶活性、降低蔗糖酶活性,全生育期平均土壤活跃微生物量和酸性磷酸酶活性分别提高17.34%和11.40%、蔗糖酶活性降低10.57%.与施用等量无机养分处理比较,施用腐植酸复合肥也使前期的微生物量碳增加、脲酶活性降低,后期的微生物量碳减少、脲酶活性提高;施用腐植酸复合肥增加土壤活跃微生物量、提高酸性磷酸酶和蔗糖酶活性,全生育期平均土壤活跃微生物量、酸性磷酸酶和蔗糖酶活性分别提高18.61%、10.07%和7.61%.     

Total phenolic and flavonoid contents and antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome,callus and callus treated with some elicitors

The present study was aimed at determining total phenolic and flavonoid contents and studying the antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome and callus, 6-gingerol and 6-shogaol and callus treated with elicitors. Petroleum ether (PE) and chloroform: methanol (1:1, v/v) (CM) extracts were prepared by maceration. Highest total phenolic content was obtained from the CM extract (60.34?±?0.43?mg gallic acid/g) of rhizome while callus showed lower content detected in the CM extract (33.6?±?0.07?mg gallic acid/g). Flavonoids were only detected in rhizome (CM extract 40.25?±?0.21?mg quercetin/g). Both rhizome extracts exhibited good antioxidant activity with higher activity recorded in PE extract (IC₅₀ value 8.29?±?1.73?μg/mL). Callus extracts revealed lower antioxidant activity (IC₅₀ value 1265.49?±?59.9?μg/mL obtained from CM extract). 6-gingerol and 6-shogaol displayed high antioxidant activity in both assays with IC₅₀ 4.85?+?0.58_DPPH and 5.35?±?0.33_ABTS μg/mL for the former and IC₅₀ 7.61?±?0.81_DPPH and IC₅₀ 7.05?±?0.23_ABTS μg/mL for the latter. Treatment of callus with elicitors showed significant (p?<?0.05) effects in enhancing phenolic content and related antioxidant activity. The highest significant increase in phenolic content (37% and 34%) and antioxidant activity in DPPH assay (34% and 30%) was observed in callus treated with 100?mg/L yeast extract and 50?mg/L salicylic acid respectively. Therefore, studying the effect of the elicitation of ginger cultured tissues in phenolic accumulation would be of immense importance for pharmacological, cosmetic and agronomic industries.     

Identification of difurocumenonol, a new antimicrobial compound from mango ginger (Curcuma amada Roxb.) rhizome

AIM: The aim of the present work was to purify and characterize potential natural antibacterial compound from mango ginger (Curcuma amada Roxb.) rhizome. METHODS AND RESULTS: The mango ginger rhizome powder was sequentially extracted and screened for antibacterial activity by agar well diffusion method and broth dilution method. Nonpolar extracts of mango ginger showed high antibacterial activity against gram-positive bacteria with low minimum inhibitory concentration (60-180 ppm). Among five extracts of mango ginger, the chloroform extract demonstrated highest antibacterial activity. Antibacterial activity-guided fractionation of the chloroform extract by repeated silica gel column chromatography yielded pure compound. The purified antibacterial compound was analysed by UV, IR, LC-MS and 2D-HMQCT NMR spectra and was identified as a difurocumenonol, a novel compound not reported previously. CONCLUSIONS: Mango ginger extracts and isolated difurocumenonol demonstrated high antibacterial activity against gram-negative and gram-positive bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: A novel and natural antibacterial compound as well as mango ginger extracts can be used as food preservative to control the growth of food-borne pathogens and as a source of mango flavour.     

Effect of hydroalcoholic extract of Zingiber officinalis rhizomes on LPS-induced rat airway hyperreactivity and lung inflammation

Ginger, the rhizome of Zingiber officinalis Roscoe (Zingiberaceae), is a common constituent of diets around the world and its extracts have been reported to exhibit several pharmacological activities. We investigated the effect of crude hydroalcoholic extract of ginger on the rat trachea hyperreactivity (RTHR) and lung inflammation induced by lipopolysaccharide (LPS). Our results demonstrate that ginger extract and celecoxib attenuated RTHR 90 min and 48 h after LPS. Ginger and celecoxib reduced the serum level of prostaglandin (PGE2) and thromboxane (TXA2) 90 min after LPS. Celecoxib and ginger also reduced myeloperoxidase activity and the number of cells in rat bronchoalveolar lavage 48 h post-LPS. On lung parenchyma, ginger and celecoxib reduced the release of PGE2 and TXA2 48 h post-LPS. These results suggest that ginger exerts an anti-inflammatory effect on lung attenuating RTHR and COX metabolites seem to be involved in these processes.     

Allelopathic hormesis and potent allelochemicals from multipurpose tree Moringa oleifera leaf extract

Abstract

The secondary metabolites produced by higher plants may act as allelochemicals to stimulate or inhibit growth of other plant species. Moringa oleifera is a multipurpose tree which have been reported, in separate studies, to promote growth of other plant species at low concentrations and inhibit the growth at high concentrations. However, allelopathic hormesis and allelochemicals from Moringa oleifera has not been reported. The present studies were conducted to evaluate hormesis, allelopathic potential and allelochemicals from Moringa oleifera leaf extract using Lepidium sativum as a test species. The results revealed that aqueous leaf extract of Moringa oleifera promoted the shoot growth of Lepidium sativum by 41% at lowest tested concentration of 2.5%, while the highest tested concentration (10%) of leaf extract inhibited shoot length and root length of Lepidium sativum by 38% and 85%, respectively, showing allelopathic hormesis. Twelve allelochemicals (p-coumaric acid, salicylic acid, p-hydroxybenzoic acid, m-coumaric acid, protocatechuic acid, ferulic acid, p-hydroxysalicylic acid, syringic acid, vanillic acid, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde and gallic acid) were identified from leaf extract of Moringa oleifera. The results suggest that Moringa oleifera exhibit allelopathic hormesis which may have critical impact on defence, survival and invasion of plants in natural as well as agroecosystems.