Distribution pattern and ecological determinants of an invasive plant Parthenium hysterophorus L., in Malakand division of Pakistan

After habitat loss,drastic effects of biological invasion caused by alien invasive species to the native biodiversity have been acknowledged worldwide by the agriculturists,ecologists,and governments as it is more overwhelming than pollution,harvest and disease combined.One such example of biological invasion is P.hysterophorus which is considered to be one of the topmost noxious weeds threatening ecosystems diversity in the world,particularly in Pakistan due to its invasive success and generalist nature.Yet no studies have explored the pattern and determinants of plant biodiversity in the Parthenium dominated landscapes.Here we explored the current distribution pattern of this species with relation to environmental variables in the Malakand division of northern Pakistan.Twenty-three sites dominated by P.hysterophorus were identified through a participatory mapping process combined with traditional ecological knowledge and quantitative inventories were made.In total,we found 62 plant species in 55 genera and 32 families,predominately from Asteraceae,Poaceae,and Solanaceae.Ward’s agglomerative clustering procedure showed three well-differentiated,and ecologically meaningful but overlapping vegetation communities.P.hysterophorus was found to be the leading species with an average Importance value ranging from 33.28%to 65.59%.Based on our criteria,surprisingly we found significantly less to be fully(30%)or partially invaded(21%)than the less invaded(47%)plots,indicating the gradual invasive success of the species across the landscape.Canonical Correspondence Analysis(CCA-ordination)has explained 36.9%of the cumulative variance by the first three axes and identified elevation(r=-0.526),slope(r=0.438)and percent sand(r=-0.474)to be the major environmental factors affecting the distribution of P.hysterophorus and associated vegetation.These results suggested that elevation and percent sand negatively affect Parthenium distribution whereas slope has a positive relationship thereby promoting its populations in the region.The generalist nature of this invasive species is likely to have an overall adverse negative effect on the ecosystem functioning and cannot be ignored.Therefore,quick actions should be taken for the management of this noxious weed to avoid economic consequences and potential threats to fragile ecosystems such as that in Malakand division.

Phenolic Acids from <i>Parthenium hysterophorus</i>: Evaluation of Bioconversion Potential as Free Radical Scavengers and Anticancer Agents

Parthenium hysterophorus is a globally recognized invasive alien weed that prominently colonizes grazing areas and cultivated lands causing adverse effect on crop production. Major allelochemicals released from parthenium include sesqueterpene lactones and phenolic acids. Among these the presence of caffeic, vanillic and ferulic acids is of industrial significance as they possess potent free radical scavenging and anticancer activities. This study reports for the first time, high total phenolic acid content (20.82 ± 0.82 mg GAE/g dry sample) in parthenium. The GC-MS analysis indicated the presence of ferulic, p-coumaric, vanillic and gallic acid as major phenolic components. Free radical scavenging activity of the phenolic acids extract gave an EC50 value 130.4 μg/ml when measured using DPPH assay. Anticancer activity of parthenium phenolic extract against A-498 (IC50 0.5237 μg/ml) and MDA-MB231 (IC50 and 0.2685 μg/ml) cancerous cell lines indicated its potential to be used as anticancer agent.

Distribution and Abundance of <i>Parthenium hysterophorus</i>L. in Metekel Zone, Northwest Ethiopia

Parthenium hysterophorus L. is a harmful invasive weed to plant biodiversity and human health. It is native to American tropics and first introduced to Ethiopia in the 1970s. Today, it is widely distributed across the country and severely affecting the biodiversity, crop, and animal production in the country. In the Metekel Zone, there was no report on its distribution and impacts so far. Therefore, this study was aimed to assess the distribution and abundance of the plant in the zone. The distribution and abundance data of the weed were recorded at five km intervals following all accessible roads of the zone. The result reveals that P. hysterophorus L. was less distributed in the area with a 4.95% frequency. However, it was found abundantly growing at roadsides, wastelands, around habitation, market place, and around Zeghibridge where it can rapidly spread to most economical lands like the arable and grazing lands. Moreover, it has aggressively invaded a nursery site, which enables the weed to enter agricultural fields directly. This suggests that the weed is on a fast move to agricultural lands in the zone. The regular active development activities such as agricultural investment, construction of roads, and factories are presumed to promote its spread. Therefore, a decisive and timely decision is needed to mitigate the weed when it is still sparse and small.

Comparative Efficacy of Common Broad Leaf Herbicides against an Invasive Weed: <i>Parthenium</i><i>hysterophorus</i>L.

Parthenium hysterophorus L. (parthenium weed) is an annual weed that grows rapidly in disturbed land. It is considered as one of the most hazardous weeds in Pakistan as it poses serious health problems to livestock as well as severe allergenic reactions in humans. It has invaded the Punjab and Khyber Pakhtunkhwa provinces and also been spreading in other parts of the country where it poses a risk for the grazing lands, roadsides, forests, wet lands, waste lands and of all types of cropped and non-cropped areas in Pakistan. The present studies were carried out to determine the impact of four locally available broad leaf herbicides viz;Stomp 455 CS (pendimethalin), Buctril Super 60 EC (bromoxynil + MCPA), Vantage 48 SL (glyphosate) and Logran Extra 750 WG (triasulfuron + terbutryn) (@ recommended and ½ of recommended dose) against P. hysterophorus grown in pots at research field of CABI CWA, Rawalpindi. All herbicides were applied at three growth stages (rosette, bolted and flowering). The observations for the mortality of P. hysterophorus were made 2 and 4 weeks after spray. The glyphosate was the most effective and reported 100% mortality of P. hysterophorus plants at flowering stage followed by bromoxynil + MCPA (89%), pendimethalin (80%) and triasulfuron + terbutryn (61%) at recommended dose after 4 weeks of spray. All tested herbicides achieved a mortality between 38% - 86% at rosette while 54% - 96% mortality at bolted stage after 4 weeks. Initially, 2 weeks after spray at flowering stage glyphosate caused 53% wilting followed by 49% (bromoxynil + MCPA), 33% (pendimethalin) and 9% (triasulfuron + terbutryn) at their recommended doses. The results indicated that P. hysterophorus is the most susceptible to glyphosate and bromoxynil + MCPA, both these herbicides are very promising for the wilting and management of parthenium weed.

银胶菊(Parthenium hysterophorus)中抗TMV活性成分的分离及活性测定

采用活性跟踪法从银胶菊中分离获得抗病毒活性物质,经质谱和核磁共振分析,确定该物质为小白菊内酯。采用半叶枯斑法和叶圆盘法测定了其对烟草花叶病毒(Tobacco mosaic virus,TMV)的抑制效果,结果表明:0.2 mg/mL的小白菊内酯在混合接种和药液浸泡两种处理中均表现出较好的体外抑制TMV活性,其抑制率分别为69.0%和72.1%;在离体条件下对烟草叶圆盘中的烟草花叶病毒复制也具有良好的抑制效果,抑制率为72.3%。

Proximate analysis: Relative feed values of various forage plants for ruminants investigated in a semi-arid region of Punjab, Pakistan

The experimental site “Sial Morr Sugar mill, District Sargodha” Punjab, Pakistan was selected to carry out present investigation. The forage samples of Eragrostis pilosa, Dactyloctenium aegyptium, Parthenium hysterophorus and Calotropis procera were collected from the three sites held in this area. The forage samples were cleaned with distilled water to rinse dust particles and other impurities. These forage samples were air dried, oven dried and ground for the assessment of proximate analysis. Proximate analysis procedures including the percentage of moisture content, crude protein, ash contents and crude fiber in the sample were determined by the Association of Official Analytical Chemists methods. The CP contents among different plant species ranged from 8.1% to 26.2% at all sites. The lowest CP value was found in Eragrostis pilosa at site III while the highest CP contents in Dactyloctenium aegyptium at site II. The CP content showed significant (p < 0.05) result among all species at all sites. There was consistence pattern of increase and decrease found during all plant species at all sites. Generally, CP concentration averaged high at site II. Our CP contents are above the critical value. Considering the overall percentage of moisture composition, it was highest at site II. However, the moisture was found more in Calotropis procera at site II. The Dactyloctenium aegyptium had the least moisture content of 3.9% while the highest water content of 7%. Ash contents varied from 7.2% to 17.9% among various plant species at all sampling sites. The lowest ash contents were recorded in Dactyloctenium aegyptium at site III. At site II, ash contents were highest in Eragrostis pilosa. The differences between ash contents of various plant species were significant (p < 0.05) at all sampling site. Generally, the ash contents were higher at site II. Crude fiber contents differed significantly (p Parthenium hysterophorus had greater crude fiber contents at site II while the lowest value of CF found in Dactyloctenium aegyptium at site I. The differences were significant between all plant species other than the Specie I at all sites. The values ranged from 1.2% to 4.1%. It was highest in Parthenium hysterophorus (4.1%) at site I and least in Dactyloctenium aegyptium (1.2%) at site III. Maximum ether extract value was achieved at site I.

外来入侵植物银胶菊水提物对三叶鬼针草和茶条木种子萌发的化感作用

以伴生草本植物三叶鬼针草和能源木本植物茶条木为受试植物,初步研究了外来入侵植物银胶菊根、茎、花水浸提液对二者种子萌发的化感效应。根据发芽率、化感效应敏感指数、发芽速率可以看出,银胶菊不同部位的浸提液在不同浓度下对三叶鬼针草的种子萌发的影响力不同;而对茶条木种子萌发无明显的作用。为选择适宜植物,生物替代防治银胶菊提供依据。

入侵植物银胶菊在不同生境下表型可塑性和构件生物量

研究了入侵植物银胶菊在4种不同小生境间花果期形态特征变化和构件生物量特征。结果显示:在植株密度小但土壤肥沃的小生境中,植株各形态指标如茎长、茎直径和花序直径等都明显高于其它小生境,在生物量结构特征上则表现为总生物量和花果生物量所占比例的升高。随着植株密度的增加以及土壤肥力下降,上述各形态指标都发生了较明显的变化,生物量投资也进行了优化配置,银胶菊表现出了较高的形态可塑性。银胶菊与觅光和竞争相关的几个指标如叶和根的比例都增加,但用于生殖构件的比例却减少了。相关分析显示,银胶菊花果期各构件生物量与高度成正相关,与密度为负相关,并受环境因素的制约。表明,较高的形态可塑性和较强的生殖配置策略可能是银胶菊成功入侵我国的重要特征。

外来入侵植物银胶菊在广西的分布与危害

银胶菊为一种菊科植物,原产中、南美洲。尽管在广西出现的时间不长,但分布范围较广,由路旁向荒地、耕地发展,引起了很大的危害,包括入侵道路旁,阻碍交通、破坏道路环境;入侵放牧地,减少放牧地产草量;入侵耕地,引起农作物减产;且有毒,能引起人的皮炎、鼻炎及哮喘,危害人类健康。在广西发展成为一种重要的外来入侵植物,已引起科学家的注意。该文介绍了银胶菊的生物学特性和在广西的入侵、扩散等情况,提出了防治措施。

几种菊科入侵植物和非入侵植物的化感作用比较

以萝卜为受体,采用培养皿法比较研究了几种菊科入侵种和非入侵种的化感潜力。结果表明:入侵种和非入侵种都具有化感作用,且入侵种在高浓度下的化感抑制作用强度不一定都大于非入侵种。在0.2 g.mL-1浓度时,艾蒿和黄鹌菜的综合化感作用强度分别是小飞蓬的2.5和3.1倍;而紫茎泽兰和银胶菊则是小飞蓬的3.8和3.5倍。而不同植物浸提液对萝卜的不同检测指标影响不同。其中,紫茎泽兰对萝卜种子发芽和幼苗生长的影响主要表现为化感抑制作用。银胶菊和除0.025 g.mL-1外的黄鹌菜各浸提液都使萝卜种子萌发受较强的抑制,且抑制强度随浸提液浓度的升高而增大,而对幼苗生长则表现为"低促高抑"的规律。小飞蓬和苦荬菜对萝卜种子萌发和幼苗根长为抑制作用,但对其苗高和鲜质量为促进作用。除0.025 g.mL-1外,艾蒿对萝卜种子萌发和幼苗根长有较强的抵制,对其苗高和鲜质量则呈"低促高抑"的规律。

银胶菊叶和花提取物对南方根结线虫的毒杀活性比较

为进一步明确银胶菊(Parthenium hysterophorus L.)的杀线虫活性,对银胶菊叶和花的不同溶剂提取物、甲醇提取物的不同萃取物以及甲醇提取物碱水层的不同极性组分对南方根结线虫(Meloidogyne incognita Chitwood)的杀虫活性进行了检测,并对不同提取物、萃取物和萃取组分进行了生物碱的定性分析。结果表明:银胶菊叶和花的蒸馏水、甲醇、乙酸乙酯和石油醚提取物的得率分别为24.5%和20.3%、19.6%和10.9%、6.8%和7.7%、2.0%和2.7%,其中,叶和花的蒸馏水和甲醇提取物的杀线虫活性均较强,而石油醚提取物的杀线虫活性最弱。用质量体积分数1.0%和0.5%的叶和花蒸馏水提取物分别处理24和48 h后试虫的校正死亡率均达到100.00%;用质量体积分数1.0%和0.5%的叶和花甲醇提取物处理48 h,试虫的校正死亡率均大于90%。叶和花甲醇提取物的碱水层、三氯甲烷Ⅰ层和Ⅱ层萃取物均具有一定的杀线虫活性,其中,用质量体积分数1.0%的花和叶碱水层萃取物以及花的三氯甲烷Ⅰ层萃取物分别处理48 h,试虫的校正死亡率均为100.00%,而三氯甲烷Ⅱ层萃取物的杀线虫活性最弱。银胶菊叶和花甲醇提取物碱水层的11个不同极性组分(A1～A11)也表现出不同程度的杀线虫活性,其中,用质量体积分数0.2%和0.1%花的A2〔溶剂为V(三氯甲烷)∶V(甲醇)=10∶1〕和A7〔溶剂为V(三氯甲烷)∶V(甲醇)=1∶1〕组分以及叶的A2和A6〔溶剂为V(三氯甲烷)∶V(甲醇)=2∶1〕组分处理48 h后,试虫的校正死亡率均达100.00%,显著高于其他组分。定性实验结果表明:银胶菊叶和花中具有杀线虫活性的提取物、萃取物和萃取组分中均含有生物碱。研究结果说明:银胶菊花的杀线虫活性高于叶片,其毒杀活性不仅与提取部位及溶剂的种类和极性有关,还与提取物浓度及作用时间等因素有关。

入侵植物银胶菊对不同氮、磷水平的繁殖适应性

通过模拟野外生境,研究了入侵植物银胶菊(Parthenium hysterophorus L.)在不同氮、磷养分水平下的繁殖特征,探讨其对土壤养分增加的繁殖适应性及繁殖能力。结果表明:在一定范围内,随氮水平的增加,银胶菊分枝数、头状花序数、繁殖器官的生物量及其比例、结实率等显著增加;对于磷养分来说,仅株高和种子千粒重明显增加,其余参数未见明显增加。银胶菊主要通过提高种子产量适应氮养分丰富的生境,而通过提高种子质量才能适应磷养分丰富的生境。土壤氮、磷养分的增加,提高了其繁殖能力,使其具有根据环境养分调节繁殖特性的能力,实现对不同养分资源生境的入侵。

入侵植物银胶菊对氮、磷营养的响应

研究入侵植物银胶菊在不同氮、磷营养水平下的形态、生长和生物量分配。结果表明:1在一定氮水平范围内,根生物量比(RMR)随氮的增加而降低,总生物量、叶生物量比(LMR)、相对生长速率(RGR)、叶面积指数(LAI)、总叶面积(TLA)、叶面积比(LAR)等随氮养分水平的增加而增加,与对照相比,有显著差异。2在磷养分处理下,吸收器官的生物量分配不随磷水平的升高而变化;但LMR、LAR、TLA随磷水平的增加而升高;适量的磷水平使GRG增加;总生物量、LAI等在各磷水平下无明显变化。3银胶菊对氮的可塑性反应高于对磷的可塑性反应。

银胶菊不同组织部位对黄瓜化感作用初步研究

运用室内培养皿生物测定法,对银胶菊化感作用研究,发现茎、叶、花水浸提液对黄瓜根长、芽长有抑制作用,抑制强度随处理浓度的增大而加强,在浓度为200 g/L时,叶、花水浸提液的根长抑制率和芽长抑制率均达到100.0%,芽长抑制强度随根水浸提液处理浓度的增大而减弱。根、茎、叶、花水浸提液能降低黄瓜的根系活力,提高丙二醛含量,表明不同组织部位水浸提液对黄瓜造成了伤害。

外来入侵植物银胶菊的生物学特性

采用田间观察和室内盆栽试验相结合的方法，对银胶菊（Parthenium hysterophorus L.）的物候期、生育习性、不同条件下种子萌发情况等主要生物学特性进行观察研究。结果表明：银胶菊为一年生有害杂草，以种子进行有性繁殖，其生长历期约为170d；3月中旬至9月下旬均有出苗，出苗高峰期为4月上旬和8月下旬，其出苗率分别为21．65％和11．9％；植株分枝期在5月中旬至7月初，5月下旬至8月上旬为开花期，7月中旬至8月下旬为结果盛期；单株瘦果量为7500～10000粒，千粒重为0．74～0．76g。瘦果在成熟后约有3个月的休眠期，种子萌发的适宜温度为15～30℃。种子出苗率与瘦果土埋深度有密切关系，瘦果处于土表时，种子出苗率最高，瘦果土埋深度超过1．5m时，种子不能出苗。

外来入侵杂草银胶菊种子萌发特性及无性繁殖能力研究

银胶菊Parthenium hysterophorus L.是一种危害性很强的外来入侵杂草,在我国南方多省均有分布,在山东省莒南县也大面积分布,目前已对发生地生态环境造成巨大影响。文章于2011年采用人工气候箱培养皿法和温室土壤盆栽相结合的方法,研究银胶菊的种子在不同pH、盐浓度、湿度、营养条件、不同埋藏深度等条件下种子萌发特性及其无性繁殖能力,以期为明确其入侵机制和适生环境提供依据。结果表明,银胶菊种子适宜的萌发环境为酸性,pH=6.0时发芽率最好,到pH=8.0时,种子不能萌发;盐对银胶菊种子的萌发影响很大,随着盐浓度的提高,发芽率下降明显,当盐浓度达到0.12 mol·Lˉ1时,种子不再萌发;但不同的营养条件和不同P水平对种子的萌发无显著影响;干旱或水涝均能降低种子发芽率;种子埋藏土层越深,其发芽率越低,土层深度达3.0 cm以上,银胶菊种子几乎无发芽率。银胶菊有较强的无性繁殖能力,根部、基部茎和上部茎等不同部位埋入土壤后均能发芽,基部茎的发芽率最高(为66.7%-88.9%),根部和上部茎发芽率较低(为22.2%-44.4%)。另外,从发芽后的生长来看,茎部(包括基部茎和上部茎)发芽后均能正常生长,但根部发出新芽后逐渐黄化死亡。由此可以看出,银胶菊种子适应力、耐贫瘠能力强,一般的农田、荒地环境均能萌发生长,但盐碱地的环境下不能萌发生长;散落在土壤表层的银胶菊种子萌发率最高,因此,没有人类扰动的荒地、沟渠更适宜其萌发和生长;由于其很强的无性繁殖能力,人工砍伐的防除措施不能将其彻底防除。这些都是银胶菊入侵后,能够在短时间内暴发成灾,且不易彻底防除的原因。

豚草卷蛾的生态适应性及其风险评价

豚草卷蛾是害草豚草和银胶菊的重要天敌 .本文就该虫生态适应性、对目标杂草的控制效能、引进与释放的安全性评价作了综述 .豚草卷蛾具有严格的寄主专一性 ,所有田间选择性寄主均局限于豚草亚族 ,而对向日葵和菊花仅表现为随机风险 (风险值 <0 .0 1 )或 0风险 ;生态适应性强 ,适宜发育的温度为 1 5～ 35℃ ,越冬虫态的低温下限为 - 8～ - 1 2℃ ;种群增长快 ,能在豚草和苍耳上分别以 2 3和 4倍的速度增长 ;控制能力强 ,大量感染时田间寄主的平均虫瘿达到每株 2 0～ 30头 ,营养生长前期 5 .2虫瘿可使植株死亡 ,营养生长后期 2 6个虫瘿可使植株致死 ,释放后 1 2个月内扩散区域超过 1 0 0km ;对释放地天敌苍耳螟不构成竞争 ,是控制豚草和银胶菊的有效天敌 ,可以安全应用 .

银胶菊在不同入侵生境中的繁殖特征

对银胶菊Parthenium hysterophorus L.在耕地、草地、疏林及公路旁4个入侵生境中的种群密度、花序数量特征、种子产量、种子千粒质量等进行了调查分析。结果表明:不同生境中银胶菊的密度、头状花序数、结实率、种子产量和种子千粒质量存在不同程度的差异;密度变化范围为(10±2)^(80±24)株/m2;头状花序变异范围为(2 618±843)^(14 539±3 296)个/m2;平均结实率为(43.8±5.6)%^(82.5±2.2)%;平均种子产量的变异范围为(10 308±1 036)^(60 361±14 661)粒/m2;种子千粒质量为(0.34±0.06)^(0.46±0.01)g。其中,生于公路旁生境的种群,密度最大,但结实率和种子千粒质量最小;生于耕地和疏林下的种群,密度较小,但结实率和种子千粒质量却最大。根据繁殖特征,探讨了银胶菊在不同生境中的入侵能力与适应性。

银胶菊水浸液对蔬菜种子萌发和幼苗生长的影响

[目的]研究银胶菊不同部位水浸液对蔬菜种子和幼苗的化感作用。[方法]以上海青和油麦2种蔬菜作物为受体,通过室内培养法,研究银胶菊不同部位水浸液对上海青和油麦种子萌发和幼苗生长的影响。[结果]银胶菊不同部位水浸液对上海青和油麦种子的萌发具有不同程度的抑制作用,且抑制作用大部分随处理浓度的增加而增强;对幼苗根长均具有抑制作用,而对苗高均表现出促进作用;对2种植物幼苗的鲜重也有一定的化感效应,有的表现为促进作用,有的表现为抑制作用。[结论]研究结果为银胶菊对植物的化感作用机理研究、银胶菊抑制植物生长的化感物质分离研究奠定了基础。

重庆恶性外来入侵植物1新纪录属:银胶菊属

银胶菊为菊科(Asteraceae)银胶菊属(Parthenium L.)1年生草本植物,原产于美国德克萨斯州及墨西哥北部,现广泛分布世界热带地区。银胶菊是世界上著名的恶性杂草,属《中国入侵植物名录》中1级恶性入侵类。2015年9月调查首次发现银胶菊入侵重庆地区。为给银胶菊入侵地区的治理提供技术参考,介绍了该物种的危害性,并提出相应的防治措施。