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Showing 1553 articles

October, 2014  Volume (34 - 2)
Plant diversity, algicial effect, joint allelopathy, phytoplankton, ecological sustainability.
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Combined allelopathic potential of aquatic plants species to control Algae
  • Pages - 315-324
  • S. P. ZUO *, K. WAN and S. M MA and L. T. YE
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  • View Abstract  In field investigations, we discovered that in areas of high diversity of aquatic plants species, there was low density of harmful phytoplankton (Microcystis aeruginosa and Chlorella pyrenoidosa). The ß diversity and evenness of aquatic plants communities in all sites reduced the phytoplankton population(Microcystis aeruginosa and Chlorella pyrenoidosa]. Major reason for the algal inhibition, was combined effects of allelopathic potential from allmacrophytes. In greenhouse tests, the combinations of 2 or >2 plant species [Alternanthera philoxeroides, Ranunculus sceleratus, and Trapa incise], showed >50% suppressive capacity of two representative phytoplankton (Microcystis aeruginosa and Chlorella pyrenoidosa). The synergistic effects in the combined plants allelopathy depended on kinds of plants species, their ratios, test period and presumed allelochemicals, etc. The aquatic plant species diversity based on comprehensive allelopathy would play an important role in blocking harmful algae bloom. So it was feasible for macrophytes biodiversity to eliminate the cyanobacteria in some shallow lakes.


October, 2014  Volume (34 - 2)
Aspergillus niger,1,2-Benzenedicarboxylic acid, 2,4-Bis(1,1-dimethyl), bis(2-ethylhexyl) ester, Cinnamic acid,Coriandrum sativum, GCMS, Mentha Piperita, Ovidin A, Phenol, Pseudomonas aeruginosa, Spinacia oleracea,Trigonella foenum-graecum.
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Antifungal potential of fenugreek coriander, mint, spinach herbs extracts against Aspergillus niger and Pseudomonas aeruginosaphyto-pathogenic fungi
  • Pages - 324-334
  • YACHANA JHA *, R.B. SUBRAMANIAN 1and SUSMITA SAHOO
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  • View Abstract  We investigated the antimicrobial properties of leaf extracts of fenugreek (Trigonella foenum-graecum), coriander (Coriandrum sativum), mint (Mentha Piperita), and spinach (Spinacia oleracea) against the phytopathogenic fungi and bacteria i.e. Aspergillus niger and Pseudomonas aeruginosa respectively. The phytochemical analysis of these leaf extracts showed presence of total phenolics and flavonoids. GCMS analysis identified the antimicrobial molecules in leaf extracts as phenol, 2,4-Bis (1,1-dimethyl), phenol, gallic acid, cinnamic acid, kaempferol-3-orutinoside and other compounds. The main phenolics (Phenol, 2,4-Bis(1,1-dimethyl), Ovidin A, 1,2-Benzenedicarboxylic acid, bis(2-ethylhexyl) ester, Cinnamic acid etc) showed antifungal activity at two concentrations (10mg/ml & 50mg/ml) and MIC was determined. More research is required to develop these phenolics as ecofreindly fungicides to control plants disease


October, 2014  Volume (34 - 2)
Allelopathic mechanism, berberine, gene expression, Microcystis aeruginosa; photosynthesis.
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Inhibition of photosynthesis-related gene expression by berberine in Microcystis aeruginosa
  • Pages - 335-343
  • X. D. BI *, W. DAI, S. L. ZHANG *, Y. PANG, K.Z. XING. and D.J. ZHANG
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  • View Abstract  The effects of berberine on the expression of six key photosynthesis-related genes inM. aeruginosa was examined. Berberine induced the expression of psaAand psaBat 1 mg·L -1 , psbAat 2 mg·L -1 , but repressed at higher concentrations. It inhibited the transcription of psbD1, rbcLand rbcXsignificantly (p <0.05). This inhibition of transcription of key photosynthesis-related genes by berberine led to disturbed photosynthesis, specially by blocking the electron transport chain, affecting carbon assimilation and photo-respiratory carbon oxidation.


January, 2013  Volume (31 - 1)
Abundance, antibiosis, antixenosis, crop-germplasms, insects, pests, population tests, resistance mechanisms, screening, tolerance
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Screening of crop germplasms for insect-pests
  • Pages - Jan-32
  • BOGUMIL LESZCZYNSKI
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  • View Abstract 

    Common methods to screen crop germplasms for insect-pests in the fields require sampling techniques, observation of insect populations, evaluation of insect-pest development and evaluation of crop-germplasms resistance mechanisms to herbivorous insects. This paper describes the most used simple methods and tests for screening the crop-resistant germplasms for insect-pests, with special reference to aphids. This paper serves as manual for easy use in field by students and young researchers, while primary observations and experiments. It includes, the insect sampling techniques (counting on plants, trapping, extraction from plants), observations in the fields (abundance on plants and soil, eggs laying), evaluation of insect population (under natural and artificial infestation, population parameters) and evaluation of resistance mechanisms (antixenosis, antibiosis, tolerance).


January, 2013  Volume (31 - 1)
Diseases, pests, phytochemical resistance-trait, secondary metabolism
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Phytochemical resistance-traits in crops against pests and diseases
  • Pages - 33-50
  • D. A. SAMPIETRO*, M. A. SGARIGLIA, J. R. SOBERÓN and M. A. VATTUONE
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  • View Abstract  The phytochemical-resistance trait comprises of is one or more compounds produced by the crop for resistance against pests and diseases. Breeding for phytochemical resistance-traits may offer more stable crop resistance and less dependance on pesicides.. Nevertheless, incorporation of phytochemical resistancetraits in crop improvement faces several problems viz., monitoring during breeding process and their biological impact on agroecosystems. This Paper describes several methods for easy monitoring of phytochemical resistance-traits in crop species,including the rapid and often cheap assays to measure contents of glucosinolates,cyanogenic glycosides, phenylpropanoids, alkylresorcinols, resveratrol, salicylic acid and activity of phenylalanine ammonia-lyase. These methods should be used complementary to visual traits of resistance such as ratings of disease, or insect feeding. They can provide a better understanding of the underlying mechanisms involved in crop defense to pests and diseases


January, 2013  Volume (31 - 1)
Allelopathic microorganisms, bacteria, fungi, Fusarium spp., hydroponics bioassays, rhizobacteria, rhizosphere, seedling bioassays, soilborne phytopathogens
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Interactions between the plants and microorganisms
  • Pages - 51-70
  • ROBERT J. KREMER
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  • View Abstract 

    Allelopathic microorganisms comprise rhizobacteria and fungi that colonize the surfaces of plant roots and produce and release phytotoxic metabolites, similar to allelochemicals, that adversely affect the growth of their host plants. The allelopathic microorganisms are grouped separately from typical phytopathogens because they do not follow classical disease cycles involving aggressive infection and colonization of plant tissues. Allelopathic microorganisms passively suppress or inhibit the plant root growth through production of variety of phytotoxic compounds absorbed by the plant, or they compete for limited plant nutrients in the rhizosphere. Thus it is important to understand the effects of allelopathic microorganisms on plant growth and discern these from traditional phytopathogens so that appropriate management of plant growth problems can be implemented based on this knowledge. The purpose of this paper is to provide basic information on protocol development of bioassays to identify allelopathic microorganisms associated with plants. Guidance provided by the general procedures is presented as templates for devising custom protocols to aid in eventual development of standardized bioassays for consistent detection and characterization of allelopathic microorganisms, for which little information and reliable data currently exist. The use of improved bioassays that yield reproducible results will enhance comprehension of the effects of allelopathic microorganisms on plant growth and increase the overall perspective of functional biology and ecology of the rhizosphere microbial community beyond general descriptions of interactions between plants and soilborne phytopathogens.


January, 2013  Volume (31 - 1)
Allelopathic effect, antioxidant defence, cytotoxicity, hydrogen peroxide, micronuclei, oxidative stress, Lantana camara L, Lathyrus sativus L
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Allelopathic effects of Lantana camara L. on Lathyrus sativus L.: Oxidative imbalance and cytogenetic consequences
  • Pages - 71-90
  • DIBYENDU TALUKDAR
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  • View Abstract 

    Allelopathic effects of Lantana camara L. leaf aqueous extracts were determined on Lathyrus sativus L. in Petri plate bioassay and pot experiments by studying growth parameters, antioxidant defence responses and cytological anomalies observed in root-tip mitosis and flower bud (anther) meiosis. Germination and dry weight of the legume were reduced significantly in dose-dependent way. Activities of superoxide dismutase and catalase increased, but these of ascorbate peroxidase declined at higher doses (200-300 mg/mL). Significant loss of ascorbate redox pool and decrease in ascorbate peroxidase activity in treated plants seriously impeded the scavenging of hydrogen peroxide, leading to its over-accumulation and concomitant rise in lipid peroxidation and membrane damage. At cytogenetic level, decrease in mitotic activity was indicated by low mitotic index, abnormal transition of divisional phases and even, complete halt in division. The chromotoxic effect of leaf extracts was exhibited by diverse types of chromosomal abnormalities, (stickiness and micronuclei formation in both divisions), while some phenomena like c-mitosis, anomalous nucleolous, unequal/late separation were found stage specific. This study strongly indicated the allelopathic potential of Lantana leaf extracts, particularly at 200 mg/mL and 300 mg/mL doses, on induction of oxidative stress and cytotoxicity in L. sativus L.


January, 2013  Volume (31 - 1)
Allelopathy, arid land, Diplotaxis erucoides, Eruca sativa, extract, germination, leachate, plant interactions, seedling growth, weeds invasion
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Does allelopathy increase the invasion of Diplotaxis erucoides in disturbed arid land?
  • Pages - 91-104
  • M. H. ABU-DIEYEH*, H. AL-ABEID and E. Y. QNAIS
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  • View Abstract  Diplotaxis erucoides has invaded the arid land in Zarqa, Jordan. A field study indicated a gradual and significant increase in D. erucoides accompanied with significant decrease in E. sativa and other weed species. Aqueous and ethanolic extracts of D. erucoides caused significant decrease in seed germination of E. sativa,Sonchus oleraceus, Tragopogon coelesyriacus, Launea nudicaulis, Salsola baryosma and Taraxacum officinale. Laboratory experiments showed that foliage and root aqueous extracts of D. erucoides at 6 mg ml-1 and 5 mg ml-1 concentrations respectively decreased the seed germination of E. sativa. Similarly ethanolic extracts of D. erucoides reduced the germination of E. sativa seeds at lower concentrations of 3 mg ml-1 and 2 mg ml-1of foliage and roots, respectively. Reciprocal allelopathic effects of aqueous extracts of D. erucoides and E. sativa were significant. Autotoxicity of foliage aqueous extract was also significant on the germination of D.erucoides seeds. Soil amended with full strength or 1:1 diluted solutions of leaf leachates of D. erucoides decresed the shoot growth of E. sativa seedlings. The inhibitory effects were similar in autoclaved or not autoclaved soils. These field and laboratory results indicated that D. erucoides use its allelopathic activity to shift the balance of competition in its favour and consequently it dominated the dry land habitat.


January, 2013  Volume (31 - 1)
Aqueous leaf extract, Calotropis procera, Citrullus colosynthis, germination, maize, phytochemicals, nutrients, seedling growth, Vigour index, Zea mays
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Effects of Calotropis procera and Citrullus colosynthis on germination and seedling growth of maize
  • Pages - 105-116
  • RABIA NAZ and ASGHARI BANO*
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  • View Abstract  The allelopathic potential of leaf extracts (0.8, 0.1 and 1.2%) of Calotropis procera and Citrullus colosynthis, were studied in laboratory and pot in culture on germination and seedlings growth of maize. The aqueous leaf extracts of C. procera enhanced the germination, but all concentrations of C. colosynthis extracts were inhibitory. However all concentrations of C. procera and C. colosynthis extracts stimulated the seedling growth (root length, shoot length, fresh and dry weight of root and shoot) of maize. The highest concentration (1.2%) of both species C. procera and C. colosynthis increased the seedling growth of maize by stimulating their root length, shoot length, fresh and dry weight in both laboratory and pot study. Thus Zea mays can be planted in the vicinity of these naturally growing plant species due to their stimulatory effect on growth.


January, 2013  Volume (31 - 1)
Allelopathic effects, corn, Glycine max, maize, potato plantlet growth, root leachates, soybean, Solanum tuberosum, tuber sprout, Zea mays.
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Allelopathic effects of corn and soybean root leachates on tuber sprouting and plantlet growth of potato
  • Pages - 117-128
  • YUYAN WANG, ZHONGWEI WANG*, FENG WANG, GUICHUN YANG, LI WANG,SHENGAI ZHANG1 and XIAOHUA SHI
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  • View Abstract  We studied the allelopathic effects of corn and soybean root leachates on tuber germination and plantlet growth of potato. Root leachates were collected from seedlings in a specialized collection device and tested at three concentrations (100%,50%, and 25%). The results showed that root leachates from corn and soybean promoted the potato tuber sprouting and plantlet growth, but effects differed with concentration. In corn leachates, 100% solution significantly enhanced the tuber sprouting and sprouting potential. While the soybean root leachates at 25 and 100 % concentrations significantly enhanced the sprouting. Both corn and soybean root leachates significantly increased the bud dry weight and bud length, with the greatest increase at highest concentration. Both types of root leachates also significantly increased the potato plantlet growth. The corn leachates had a greater stimulatory effect than the soybean leachates, but concentration had no significant effect. Both corn and soybean leachates significantly increased the amylase vigour in tubers 5-days after plantlet emergence, with the highest concentrations of each having the greatest effect. Higher concentrations of corn and soybean root leachates proved beneficial to potato tuber sprouting and plantlet growth. These experiments used tissue culture to isolate the allelopathic effects and increase accuracy.


January, 2013  Volume (31 - 1)
Allelochemical, allelopathy, cambara, germination, leaf extract, lettuce, phenolic compounds, tomato, Vochysia divergens
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Leaf extract effects of Vochysia divergens on lettuce and tomato
  • Pages - 129-138
  • A. K. M. OLIVEIRA*, J. W. F. RIBEIRO, F. M. FONTOURA and R. MATIAS
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  • View Abstract  In laboratory bioassays, the phytochemical activity of leaf extracts (0, 2.5, 5,10 and 20%) of Vochysia divergens Cambará (Pohl) was investigated on germination and growth of lettuce and tomato. In all concentrations, the pH of extract was 4.3 ±0.3, electrical conductivity was 14.9 to 26.1 µScm-1 and soluble solids concentration (expressed in degrees Brix) was 0.8. The extract concentrations did not influence the lettuce seed germination but reduced the seedlings vigour. The development of primary roots and aerial part was inhibited. The tomato seeds germination was affected at 20% concentration. The vigour of germination was greatly reduced at all concentrations and the development of primary roots and aerial part was notably impeded. Chemical analysis of extract revealed presence of phenolic compounds (FC=4.16 to 9.32 µg/g), tannins, flavonoids (F= 2.44 to 4.17 µg/g), coumarins, steroids and free triterpenes.


January, 2013  Volume (31 - 1)
Allelopathy, Brassica rapa L. ssp. Chinensis L Eupatorium catarium, fluazifop-butyl, germination, glyphosate, herbicides, paraquat
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Effects of herbicides application on allelopathic potential of Eupatorium catarium
  • Pages - 139-146
  • QINFEN LI1,2, , GUANGYI LI1, 2*, ZHENDI LIU3, XIAO DENG1, 2 and YUKUN ZOU1, 2
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  • View Abstract  This study aimed to evaluate the effects of 3-herbicides (Paraquat,Glyphosate, Fluazifop-butyl) on the aqueous extract of Eupatorium catarium on seed germination of Brassica rapa L. ssp. Chinensis L. experiments. The E. catarium aqueous extract were prepared every 10-days after the herbicides application at various rates. The B. rapa L. ssp. Chinensis L. seeds were immersed in 4- concentrations (0.5,0.25, 0.125 and 0.0625 g/ml) of aqueous extract of E. catarium. The inhibitory effects of E. catarium aqueous extracts on germination were enhanced under herbicides stress.Compared to control, the 0.5g/mL aqueous extract treated with herbicides drastically reduced germination from 80-90% to 5-20%, while, aqueous extract <0.25 g/mL concentrations had no inhibit the germination. Furthermore, herbicides stress time influenced the allelopathic potential of E. catarium, the aqueous extracts at day 10 after application of paraquat (extract concentration: 0.25,0.5 g/mL) and fluazifop-butyl(extract concentration: 0.5 g/mL) caused maximum inhibition, while, for glyphosate (extract concentration: 0.25,0.5 g/mL), aqueous extracts at 30 days after application was most inhibitory. Thus, our results indicated that allelopathic activities of aqueous extracts from E. catarium varied with herbicides stress, which strongly inhibited the germination of B. rapa L. ssp. Chinensis..


January, 2013  Volume (31 - 1)
Amaranths retroflexus, Echinochloa crusgalli, extraction methods, organic solvents, Sorghum bicolor, weed control.
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Phenolic compounds in sorghum leaf extracts and their effects on weed control
  • Pages - 147-156
  • O.J. WON a, M.R. UDDIN a, K.W. PARK, J.Y. PYON 1and S.U. PARK
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  • View Abstract  The allelopathic potential of shoot extract of Sorghum bicolor(L.) Moench, was evaluated for sustainable weed management in organic farming. Its 2 to 15-days-old seedlings contained more total phenolic compounds than older plants. The ethyl acetate partitioned phenolic compounds from methanol extracts of sorghum leaf were better than other organic solvents test. Among the6- physical methods of extraction used, the extract from grinding plus boiling provided good weed control, however, methanol extract of sorghum leaf proved the best. The sorghum leaf extracts may provide effective and environmentally sustainable weed control.


January, 2013  Volume (31 - 1)
Amino acids, carbohydrates, HPLC, Ipomoea batata, polyphenol oxidase, Spodoptera litura. Tobacco cutworm.
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Insect herbivory induced foliar oxidative stress: Changes in primary compounds, secondary metabolites and reactive oxygen species in sweet potato Ipomoea batata L
  • Pages - 157-168
  • KURRA SANDHYARANI and PATHIPATI USHA RANI
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  • View Abstract  Herbivore damage induces several chemical changes in the infested plants which are normally considered as plant’s defense responses. We studied the effects of tobacco cutworm [Spodoptera litura(Fabricius)] feeding on primary, secondary metabolites and enzymatic constituents in leaves ofsweet potato (Ipomoea batata L) plants. Quantitative and qualitative changes in biochemical and enzymatic profile of infested plants were analyzed spectrophotometrically and compared with normal intact plants. The individual phenolic acids were identified using high performance liquid chromatography (HPLC) by comparing with standard phenolic compounds in accordance to retention times. The quantities of proteins, amino acids and total phenol content in infested plants were enhanced, whereas, carbohydrate concentration was decreased than normal plants. An increase in the activities of peroxidase (POD), phenyl alanine ammonia lyase (PAL), super oxide dismutase (SOD) and a decrease in the levels of polyphenol oxidase (PPO) with respectto healthy plants were recorded in pest damaged I. batataplants. An elevated levels of individual phenolicsacids such as chlorogenic, caffeic and cinnamic acids were observed in S. liturainfested plants compared to normal healthy sweet potato plant leaves


January, 2013  Volume (31 - 1)
Juglone, Juglans mandshurica Maxim. Manchurian walnut, phospholipid fatty acid analysis (PLFA), root exudates, soil microbial community
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Temporal variations in soil juglone and soil microbial community structure under Manchurian walnut (Juglans mandshurica Maxim.) plantations
  • Pages - 169-180
  • YUEZHI SUN, LIXUE YANG*, ZHENGQUAN WANG and JING FAN1
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  • View Abstract  The seasonal dynamics of juglone concentration and microbial community structure and the relationship between them is described. High Performance Liquid Chromatography (HPLC) and Phospholipid fatty acid (PLFA) patterns were used to measure the juglone concentration in soil and to describe the composition of soil microbial communities in 0-10 cm rhizosphere and bulk soil of Manchurian walnut plantations of 15, 23 and 51 years age. Our results indicated that Manchurian walnut trees release a large quantity of juglone into the rhizosphere, but very little juglone reaches the bulk soil. This resulted in various impacts on the structure of soil microbial communities. Juglone therefore plays a critical allelochemical role in altering the composition of soil microbial communities.


January, 2013  Volume (31 - 1)
Activated carbon, benzoic acid, carbonized corncob, cinnamic acid, degradation, phenolic acids, phthalic acid, soil.
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Degradation patterns of phenolic acids in soil
  • Pages - 181-188
  • LIANG-LIANG LI, TIAN-LAI LI, GUANG-CAI ZHANG, EN-PING ZHANG*,JIAN ZANG and ZHENG-CHAO WU
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  • View Abstract  We studied the degradation of 3- Phenolic Acids (phthalic acid, benzoic acid and cinnamic acid) in soil in laboratory incubation experiment to determine their residence time in soil. The correlations between the residual rates and some soil properties were statistically analyzed. The decomposintion rate of test phenolic acids was highest in first 5- days. The decomposition rate of benzoic acid and cinnamic acid in the soil was relatively slow. The total content of phenolic acid substance was not reduced by adding activated carbon or carbonized corncob to soil, but the content of water-soluble phenolic acid substances was reduced. Degradation of phthalic acid was primarily affected by soil pH and soil clay content, and benzoic acid was affected by soil pH, activated manganese and iron and that of cinnamic acid was influenced by soil pH, activated iron and organic matter.


January, 2013  Volume (31 - 1)
Algae, allelochemicals, lichens, Psudevernia furfuracea, secondary metabolites, toxicity, Trebouxia erici, Umbilicaria hirsuta, Xanthoria parietina
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Allelopathic effects of lichen secondary metabolites on lichen photobiont Trebouxia erici
  • Pages - 189-198
  • M. BACKOR*, V. IVANOVA1, H. LAATSCH2, V. LOKAJOVÁ and M. BACKOROVÁ
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  • View Abstract  Atranorin, gyrophoric acid and parietin were isolated from the lichens: Psudevernia furfuracea, Umbilicaria hirsuta and Xanthoria parietina to compare their phytotoxicity on cultures of aposymbiotically grown lichen photobiont Trebouxia erici. The cortical didepside atranorin had strong phytotoxic effects on the photobiont cells. Application of atranorin at the highest dose (0.1mg/disk) decreased the growth of photobiont cells and altered the composition of assimilation pigments (decreased chlorophyll a content, its fluorescence and increased its phaeophytinization).Atranorin also induced the formation of reactive oxygen species, hydrogen peroxide and superoxide. Atranorin as cortical lichen compound, may be in direct contact with the photobiont cells forming layer in lichens with a stratified thallus. Thus it appears that atranorin may be functioning as an allelochemical, controlling the cell division of algal partner inside the thallus and thereby regulating the balance between the symbionts. However, phytotoxicity of tridepside gyrophoric acid and anthraquinone parietin on the photobiont cells was not observed at the tested concentrations used in this study.


January, 2013  Volume (31 - 1)
Allelochemical, cell volume, chlorophyll afluorescence, esterase activity, flow cytometry, internal cell complexity, membrane integrity, phytoplankton.
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Toxicity of allelochemicals released by submerged macrophytes on phytoplankton
  • Pages - 199-210
  • J.WANG 1,2 , J.Y.ZHU 1, Y.N.GAO, B.Y.LIU *, S.P.LIU 3, F.HE and Z.B.WU *
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  • View Abstract  The allelopathic mechanism of submerged macrophyteswas investigated on the cyanobacterium Microcystis aeruginosa and the green alga Pseudokirchneriella subcapitata. The effect of the allelochemicals pyrogallic acid(PA), gallic acid (GA), (+)-catechin (CA), caffeic acid (CFA), protocatechuic acid (PCA), nonanoic acid (NA) and cis-9-octadecenoic acid (COA) was evaluated by flow cytometry on esterase activity, membrane integrity, chlorophyll afluorescence, cell volume and internal cell complexity. The highest sensitivity was observed for esterase activity in both test species. NA damaged the cell membrane and severely altered the internal cell complexity of both species. PA changed the esteraseactivity of both species and significantly decreased the fluorescence of chlorophyll a in M. aeruginosacells (P< 0.05). Both GA and PCA inhibited the fluorescence of chlorophyll aand caused morphological changes in M. aeruginosa(P< 0.05). CFA inhibited the esterase activity, fluorescence of chlorophyll aand cell volume inM. aeruginosaat 50 and 100 mg L -1 concentrations; In P. subcapitata, the fluorescence of chlorophyll aand cell volume was inhibited at 50 mg L -1 but was stimulated at 100 mg L -1 . COA changed the esterase activity. CA at 100 mg L -1 slightly inhibited the fluorescence of chlorophyll a in M. aeruginosaand stimulated the esterase activity in P. subcapitata. The responses observed for each parameter investigated were highly dependent on the specific inhibitory mechanism of each allelochemical. These allelochemicals act on multiple target sites.


January, 2013  Volume (31 - 1)
Acetone, algicidal activity, allelochemical, chloroform, ethanol, fractions, Macleaya microcarpa, 6-methoxy-dihydrochelerythrine, Microcystis aeruginosa, oxidative stress, sanguinarine, petroleum ether, water
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Growth inhibition and oxidative stress of cyanobacteria induced by sanguinarine and 6-methoxydihydrochelerythrine isolated from Macleaya microcarpa
  • Pages - 211-224
  • YANG-LEI YI1, YU-JUN KANG2, LEI XIA3 and GAO-XUE WANG 1,2*
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  • View Abstract  To investigate the algicidal allelochemicals from Macleaya microcarpa we used the activity-guided isolation. Five solvents (petroleum ether, chloroform, acetone, ethanol and water) were employed for the extraction of M. microcarpa. Among them,only the ethanol extract was active (7d-EC50 = 95.52 mg L-1) and hence, was subjected to further isolation and purification using various chromatographic techniques. Two benzophenanthridine alkaloids with potent algicidal activity, sanguinarine and 6-methoxy-dihydrochelerythrine were isolated. The algicidal effects of these compounds were species-specific, both sanguinarine and 6-methoxy-dihydrochelerythrine were active against Microcystis aeruginosa with 3 d-EC50 values of 0.47 and 3.43 mg L-1, and the 7 d-EC50 values of 0.36 and 2.87 mg L-1, respectively. However, sanguinarine showed low inhibition on Chlorella pyrenoidosa and Scenedesmus obliquus with 3 d-EC50 values of 5.32 and 9.70 mg L-1, respectively. 6-Methoxy-dihydrochelerythrine had little effect on C. pyrenoidosa and S. obliquus. The active compounds could cause oxidative damage in M. aeruginosa based on the observed malondialdehyde (MDA) content decrease in superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC). These results indicated that M. microcarpa extract and the isolatedallelochemicals may serve as new agents for controlling the growth of toxic M.aeruginosa in eutrophic water bodies.


January, 2013  Volume (31 - 1)
Ageratum conyzoides, Allelochemical, Novosphingobium capsulatum, Precocene II degradation.
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Bio-degradation of Precocene II by Novosphingobium capsulatum
  • Pages - 225-232
  • QINFEN LI1.2, YUKUN ZOU1, 2*, GUANGYI LI1, 2 and GUIHUA ZHANG
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  • View Abstract  Precocene II is a major allelochemical produced by the weed Ageratum conyzoides. Its degradation is important in the recovery of A.conyzoides invaded plant communities. Using a strain of N. capsulatum isolated from the A. conyzoides invaded/infested soil; we examined the effects of various factors viz., incubation time,temperature, initial pH, and carbon and nitrogen source on the degradation of precocene II. We found that under optimal conditions with supplementation with a carbon and nitrogen source, up to 79.8% precocene II is degraded by N. capsulatum.


April, 2013  Volume (31 - 2)
Allelopathic effects, forestry, plants, research methods, soil.
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Forestry Research Methods
  • Pages - 233-280
  • P. PAVLOVIC *, L. DJURDJEVIC, S. JARIC, O. KOSTIC, D. PAVLOVIC, M. PAVLOVICand M. MITROVIC
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  • View Abstract  Field studies to test the effects of natural levels of allelopathic compounds on coexisting native species are rare because allelopathic effects are difficult to quantify and evaluate under the field conditions. Field studies are conducted to demonstrate the effects of allelochemicals on ecosystem-level (through effects on litter decomposition, activity of decomposers, soil C and N cycling, soilhumus, soil nutrients availability, soil water relation and soil respiration, plant mycorrhizal fungi and plant pathogens) and also to test allelopathic potential of allelochemical compounds from fresh leaves, leaf litter and soil of donor species on individuals of the same species (autotoxicity) and on coexisting species (growth, photosynthesis, respiration, chlorophyll and water relations of target plants) in forest community, through simultaneous measurements of allelochemical content in fresh leaves, leaf litterand in soil in experimental and control plots. This paper describes some field research methods and techniques to screen and monitor the effects of allelochemicals in forest ecosystems.


April, 2013  Volume (31 - 2)
Allelochemicals, allelopathy, coumarin, cytological and biochemical, enzymes, genotype, morphological, Oryza sativaL., response.
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Differential morphological, cytological and biochemical responses of two rice cultivars to coumarin
  • Pages - 281-296
  • K. MAHMOOD 1, 2,3 , M. B.KHAN 1, 2,4 , Y. Y. SONG 1, 21 , MAO YE 1, 2 , S. R. BAERSON 5and R. S. ZENG 1, 2
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  • View Abstract  We investigated the differential responses of two contrasting rice cultivars (susceptible BS-2000 and less susceptible BR-41) tocoumarin at the cytological, biochemical and morphological levels. Both rice cultivars, showed similar trend in the relative sensitivities of specific root parameters to coumarin: total number of root hairs >total number of lateral roots > radical length. However, the light and electron microscopic observations of seedling root and leaf cells exhibited differential responses to coumarin exposure. BR-41 showed higherribosomal density (RD), more mitochondria in root cells, larger starch granules in leaves and more vacuoles (smaller size) than BS-2000. Coumarin also induced differentantioxidant responses in two cultivars. BR-41 showed 23% higher superoxide dismutase (SOD), 16% higher catalase (CAT) and 17% higher peroxide dismutase (POD) activities than BS-2000 when exposed to 400 µM coumarin. However, malondialdehyde (MDA) contents and electrolyte leakage were significantly higher in BS-2000, which exhibited 8 and 10 % higher MDA levels and 49 and 45% higher electrolyteleakage than BR-41, when exposed to 200 and 400 µM coumarin, respectively. Our results suggested that biochemical and cytological responses and root morphological characteristics jointly affect the rice resistance to coumarin stress.


April, 2013  Volume (31 - 2)
Allelopathy, Arachis hypogaea, autotoxicity, continuous cropping, coumarin, phenolic acids, peanut, vanillic acid.
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Autotoxicity of peanut and identification of phytotoxic substances in rhizosphere soil
  • Pages - 297-308
  • Y. Q. HUANG *, X. R. HAN *, J. F. YANG, C. H. LIANG 1* and X. M. ZHAN
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  • View Abstract  We evaluated the autotoxicity of peanut (Arachis hypogaea L.) leaf, stem and root extracts, and identified the phytotoxic substances accumulated in peanut rhizosphere soil during continuous cropping. We prepared aqueous extracts from peanut leaves, stems, and roots, and evaluated their effects on peanut germination and growth. Soil collected from areas in which peanut had been continuously cultivated for 1, 2, 3, or 4 years was analyzed by HPLC in 2009. Leaf extracts drastically inhibited the seed germination, followed by stem extracts and then root extracts. Root extracts severely inhibited the seedling growth, followed by stem extracts and then leaf extracts. We detected 4-types of phenolic acids (p-hydroxy benzoic acid, vanillic acid, coumaric acid, and coumarin) in peanut rhizosphere soil. After 4- years cropping), the vanillic acid and coumarin contents were 0.289 ug/g dry soil and 0.025 ug/g dry soil, respectively. The phenolic acids concentrations increased during the continuous cropping. After 4- year cropping, the vanillic acid concentration in soil was 12-times more than coumarin. The combined concentration of vanillic acid and coumarin increased during continuous cropping (from0.067 to 0.314 µg/g dry soil over 4-years). This may be one reason underlying problems with continuous cropping. Thus peanut is a potentially autotoxic specie.


April, 2013  Volume (31 - 2)
Allelopathy, bioassay, germination, growth inhibition, invasive plant species, juglone index, Sinapis alba
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Allelopathic potential of some invasive plant species occurring in Hungary
  • Pages - 309-318
  • Á. CSISZÁR *, M. KORDA, D. SCHMIDT, D. ŠPORCIC, P. SÜLE, B. TELEKI, V. TIBORCZ, G. ZAGYVAI and D. BARTHA
  • View 
  • View Abstract  This study aimed to determine the allelopathic potential of some invasive plant species occurring in Hungary. Juglone index of 14-alien woody- and 20-alien herbaceous plant species was determined to compare the effects of juglone and leachates of plant species on germination and seedling growth (shoot length, root length) of white mustard (Sinapis alba L.) used as receiver species. The leachates significantly inhibited the root length of test plant. The juglone index at higher concentration leachates of most species was near to1 or above 1 i.e. the effect of leachates was similar to or higher than juglone. Leachates of 21-plants [Acer negundo L., Ailanthus altissima(Mill.) Swingle, Ambrosia artemisiifolia L., Amorpha fruticosa L., Asclepias syriaca L., Celtis occidentalisL., Echinocystis lobata (Michx.) Torr. et Gray, Fallopia japonica (Houtt.) Ronse Decr., Fraxinus pennsylvanica Marsh. var. subintegerrima(Vahl) Fern., Helianthus tuberosus L., Heracleum mantegazzianum Somm. et Lev., Impatiens balfourii Hook. f., Impatiens glandulifera Royle, Impatiens parvifloraDC., Juglans nigra L.,Parthenocissus inserta (A. Kern) Fritsch, Phytolacca esculenta van Houtte, Prunus serotina Ehrh., Ptelea trifoliataL., Rudbeckia hirta L. andVitis ripariaMichx] reduced the germination and seedling growth (shoot and root length) of S. alba L. than control.


April, 2013  Volume (31 - 2)
Barley, germination, isoschaftoside, lucenin-2, palmitic acid, Passiflora incarnata,Passionflower, radish, saponarin, vitexin
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Phytotoxicity of Passiflora incarnata extracts on germination and growth of Hordeum vulgare and Raphanus sativus
  • Pages - 319-332
  • A. W. KEASLING 1,2* , R. R. OTTER 2, F. C. BAILEY 2
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  • View Abstract  Phytotoxic chemicals are of interest because they represent potentially novel pharmacophores possessing herbicidal activity that may target new molecular receptor sites. This study aimed to evaluate the phytotoxicactivity of Passiflora incarnata extracts against the monocotyledonous and dicotyledonous indicator test species barley and radish. Continuous exposure to total aqueous extracts of P. incarnata inhibited the barley germination at the lowest tested concentration (1.25% w/v), whereas 10% w/v concentration was required for radish. Aqueous fractions from sequential-solvent partitioning showed reduced seedgermination inhibitory activity in both test species relative to total aqueous extracts. A 14-day growth assay showed that 24 h pre-/post-germination exposure to total aqueous extracts had no effect on dry weights of either species. However, 47% leaf-bleaching was observed in the 24 h post-germination exposure in barley. GC-MS analysis of solvent extracts identified phytol and palmitic acid as the major components. LC-ESI-MS/MS analysis of aqueous fractions tentatively identified ten compounds: phenylalanine, leucine, and tryptophan, swertisin, vitexin, saponarin, isoschaftoside, orientin, lucenin-2, and eugenol.


April, 2013  Volume (31 - 2)
Allelopathy, Chemotype, Essential oil, Madagascar, Phytotoxic effect, Ravensara aromatica Sonnerat
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Allelopathic effects of volatile compounds of essential oil from Ravensara aromatica Sonnerat chemotypes
  • Pages - 333-344
  • S.N. ANDRIANJAFINANDRASANA1,2*, H.S. ANDRIANOELISOA2,3, M.L. JEANSON2,4,5, I. RATSIMIALA RAMONTA1,2 and P. DANTHU2,5
  • View 
  • View Abstract 

    The chemical compositions of three chemotypes of Ravensara aromatica Sonn. (Lauraceae) leaf essential oils (EOs) was determined by GC and GC/MS. One chemotype rich in aromatic components (methyl chavicol) and two chemotypes rich in terpenic components (limonene and sabinene as main compounds, respectively) were identified. The three chemotypes were inhibitory to germination and phytotoxic to seedlings of rice (Oryza sativa), garden cress (Lepidium sativum) and greengram (Vigna radiata). Germination inhibition and phytotoxicity varied significantly among the chemotypes. The limonene chemotype was least herbicidal and the sabinene chemotype was most toxic to rice and cress seedlings. The chemotype rich in methyl chavicol was most inhibitory to germination of greengram and rice. Rice proved most resistant to allelopathic effects of test essential oils than two dicotyledons (Green gram, garden cress). The potential use of essential oils of R. aromatica as a bioherbicide is discussed.


April, 2013  Volume (31 - 2)
Antioxidants, Avena fatuaL., Echinochloa colonaL., enzymes, jungle rice, organic fractions, oxidative stress, phytotoxicity, tricin, wild oat.
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Effects of tricin isolated from jungle rice (Echinochloa colonaL.) on amylase activity and oxidative stress in wild oat (Avena fatuaL.)
  • Pages - 345-354
  • M. M. HEGAB *, H. ABDELGAWAD, M. S. ABDELHAMED, O. HAMMOUDA, RENU PANDEY 1. V. KUMAR 2and G. ZINTA 3
  • View 
  • View Abstract  Bioactive compounds were isolated from the jungle rice (Echinochloa colona L.) and their phytotoxicity was evaluated against the weed wild oat (Avena fatuaL.). Tricin (flavonoid compound) purified from E. colonawas tested at 5, 25, 50 and 100 µM on wild oat growth. Tricin suppressed the germination and growth of target weed at higher concentrations (25, 50 and 100 µM). The inhibitory effects of tricin were due to the attenuation of amylase activity, which decreased the starch mobilization and also hampered the activities of antioxidant enzymes. The increase in the non-enzymatic antioxidant molecules (polyphenol, ascorbate and glutathione) was not sufficient to prevent the damage from tricin, because the level of H2O2 and lipid peroxidation was high. More studies are required toevaluate the use of tricin as bioherbicide to control the wild oat.


April, 2013  Volume (31 - 2)
Allelopathic stimulation, aqueous extract, exudates, genome, methonolic extract, Orobanche minor, ploidy level, Triticumspp., wheat
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Allelopathic stimulatory effects of wheat differingin ploidy levels on Orobanche minor germination
  • Pages - 355-366
  • S. Q. DONG, Y. Q. MA *1 , H. W. WU 2, J. F. SHUI 1, X. X. YE 3and Y. AN
  • View 
  • View Abstract  Orobanche minorseed germinates only when germination stimulants from host plants or some non-hosts become available. Wheat is trap crop to stimulate the O. minorgermination, hence, wheat of different ploidy levels were evaluated for their impacts on O. minorgermination. The wheat exudates collected hydroponically induced the O. minorgermination. Wheat of different ploidy levels differed in their allelopathic stimulation on O. minor germination, with the hexaploid wheat being the most stimulatory. Root exudate activity was concentration-dependent, with no activity at 1 mg/L concentration. Likewise, the stimulation of O. minorgermination also depended on wheat ploidy level, the growth stage and the concentrations of aqueous or methanolic extracts. The highest germination (41.6%) was achieved with aqueous extracts from the tillering stage with hexaploid T. aestivumvar. Shaan No. 253, while the lowest rate (4.2%) was from maturity stage withdiploid T. boeoticum L. Plant methanolic extracts resulted in higher O. minorgermination than aqueous extracts. Thus wheat accessions of differed ploidy levels differed in their allelopathic stimulation of O. minorgermination and the stimulation increased from diploid to hexaploid. The wheat allelopathic activity could beused as a non-chemical option for O. minorcontrol.


April, 2013  Volume (31 - 2)
Amaranthus palmeri, biocontrol agent, bioherbicide, biological weed control, glyphosate-resistance, Myrothecium verrucaria, Palmer amaranth, pigweed.
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Bioherbicidal effects of Myrothecium verrucariaon glyphosate-resistant and-susceptible Palmer amaranth biotypes
  • Pages - 367-376
  • R.E. HOAGLAND *, N.D. TEASTER and C.D. BOYETTE 1
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  • View Abstract  Bioherbicidal effects of the fungus Myrothecium verrucaria(MV) on glyphosate-resistant and -susceptible Palmer amaranth were examined on whole plants and in leaf bioassays of young and mature plants. Leaf bioassays using mycelia from the fermentation product of MV indicated that excised leaves of young greenhouse-grown (glyphosate resistant and -susceptible) and mature field-grown (glyphosate-resistant) plants were injured by the bioherbicide.Generally, injury was directly proportional to the MV mycelial concentration applied, and glyphosate-susceptible and -resistant plant leaves were equally sensitive to the MV phytotoxic effects as measured by reduction of chlorophyll content. Similar effects occurred on whole plants challenged by MV spray applications to foliage, as substantiated by plant growth reduction (fresh and dry weight accumulation) at termination of the time course. MV disease progression over a 7-d period in young (2-week-old) plants increased with time, and at 48 to 72 h after treatment, disease was severe with nearly 100% mortality occurring and there were no significant response differences in the glyphosate-susceptible and -resistant plants. As expected, disease progression in 4-week-old plants was slower, indicating more tolerance to the bioherbicide, but injury was moderately severe at the endpoint (168 h) aftertreatment. Results demonstrate that under greenhouse and laboratory conditions, MVcan control both glyphosate-resistant and susceptible Palmer amaranth seedlingswhich could make this bioherbicide a possible candidate for use against this economically important weed.


April, 2013  Volume (31 - 2)
Alfalfa, glutamine synthase (GS), glutamate dehydrogenase (GDH), net nitrate uptake, nitrate reductase (NR), plant growth.
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Effects of coumarin on net nitrate uptake and nitrogen metabolism in roots of alfalfa (Medicago sativa)
  • Pages - 377-386
  • XIANRONG ZHOU, HE SONG 1and JINCHUANG WANG 2*
  • View 
  • View Abstract  We investigated the effects of coumarin applicationon growth, net nitrate uptake, concentration of nitrate (NO3 -), ammonium (NH4 +), soluble proteins and enzymes [nitrate reductase (NR), glutamine synthase(GS) and glutamate dehydrogenase (GDH)] activities in roots of alfalfa(Medicago sativa). Five-d-old alfalfa seedlings were exposed to 0, 0.025, 0.05, 0.1 and 1 mM concentrations of coumarin. High concentration of coumarin (=0.1 mM) decreased fresh weight (FW) production in the shoots and roots and the root to shoot (R/S) FW ratio. In addition, there were no statistically significant effects on the soluble protein in roots among all treatments. In seedlings exposed to 0.025 and 0.05 mM coumarin, the net nitrate uptake was significantly stimulated but reduced at 0.1 and 1 mM. Moreover, 0.05 mM coumarin treatments markedly increased the NO3 -content, whereas, coumarin in the range of 0.1 to 1 mM, decreased it. Endogenous ammonium (NH4 +) level was reduced at 0.025 to 0.1 mM, whereas, it was elevated at 1 mM. The activities of NR were repressed at the high coumarin concentration. GS levels were enhanced at 0.05 mM, whereas they were reduced by 1 mM. At the highest coumarin concentration, the activities of GDH were inhibited in roots. Therefore, low concentration of coumarin stimulated net nitrate uptake and N metabolism in roots, but higher concentration adversely affected the plant growth and the key enzymes of nitrogen metabolism in alfalfa.


April, 2013  Volume (31 - 2)
Chinese onion, root exudates, allelopathy, ISSR,F. oxysporum f.sp lycopersici
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Allelopathic effects of root exudates of Chinese onion on tomato growth and the pathogen Fusarium oxysporum(Sch1) f.sp. lycopersici
  • Pages - 387-404
  • SHUQIN LIU 1, FENGZHI WU *and XIANGYING WEN 1
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  • View Abstract  Fusarium wilt [caused by Fusarium oxysporum(Sch1) f.sp.lycopersici (Sacc.) Snyder et Hansen] is a serious soil-borne disease of tomato worldwide, especially in continuous monocropping. Rotations with Chinese onion [Allium. cepaL. var. aggregatumG. Don (syn. var. multipilcansBailey)] improved the tomato growth and reduced the occurrence of Fusarium wilt. We investigated the mechanism underlying this phenomenon. Root exudates of 47 accessions of Chinese onion were assayed for effects on germination and seedling growth of tomatoes in the laboratory and field. Genetic similarity of accessions was determined using ISSR-PCR technique. Allelopathic potential of root exudates of onion different accessions were also assayed on F. oxysporumf.sp lycopersici. The root exudates of most Chinese onion accessions stimulated the seedling growth of tomato. The allelopathic potential was accession dependent, and not correlated to DNA-fingerprinting. Two pairs of accessions, ‘Sui Hua-Ning An Hongcheng’ and ‘Wu Chang Hongqishe-Qi Tai He II’ with similar DNA-fingerprints but with different allelopathic potential were screened. Their root exudates inhibited the spore germination, mycelial growth, biomass and sporulation of F. oxysporum f.sp lycopersici. Sui Hua and Wu Chang Hongqishe was more inhibitory to pathogen than Qi Tai He II and Ning An Hongcheng(except biomass) (p < 0.05). Our results suggested that in crop rotations, the root exudates of Chinese onion accessions promoted the tomato growth and decreasedthe incidence of Fusarium wilt. The accession Sui Hua and Wu Chang Hongqishe decreased the incidence of pathogen and thereby improve the tomato yield.


April, 2013  Volume (31 - 2)
Antibacterial activity, antifungal activities, fractions, pathogenic fungi, Potentilla fruticosa, triterpenoids
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Antifungal activities of Potentilla fruticosa on 12 fungi spp.
  • Pages - 405-414
  • Y. X. KANG, C. C. ZHANG , D. M. WANG *, W. J. PU and R. ZHOU
  • View 
  • View Abstract  The antimicrobial activity of ethanol extracts of Potentilla fructicosawas examined on 12 phytopathogenic fungi. Among the 12 fungi, Rhizoctonia cerealis, Botrytis cinerea, Alternaria alternata and Bipolaris sorokinianawere strongly inhibited. The ethanol extracts was sequentially fractionated with petroleum ether, ethyl acetate, n-butanol and water and the fractions were tested for their antifungal activity against 4-pathogenic fungi (strongly inhibited by ethanol extract). It was found that the ethyl acetate (EAF) and n-butanol (BF) fractions inhibited the 4-fungi (Rhizoctonia cerealis, Botrytis cinerea, Alternaria alternata and Bipolaris sorokiniana) more than the other two. The EAF was further fractionated on a silica column using a petroleum ether /acetone gradient systems to obtaintwo compounds with strong inhibitory activity. These were identified as betulinic acid and olenolic acid by physical and spectral analysis. Furthermore, both compounds were obtained from P. fruticosafor the first time. While both these triterpenoidsinhibited the B. cinereaonly, while the olenolic acid inhibited the B.sorokiianaThese two chemicals were also active against Eschericia coli, while Bacillussubliitswas inhibited only by Betulinic acid. These results suggested that the two triterpenoids present in P. fructicosawere antifungal and had the potential for use in plant disease control.


April, 2013  Volume (31 - 2)
Allelochemicals, axolotl (Ambystoma mexicanum), Cladocera, fish (Poeciliopsis occidentalis), frog tadpole (Hyla eximia) kairomone, life history, Moina macrocopa, Predation.
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Effects of allelochemicals released by vertebrates (fish, salamander and tadpole) on Moina macrocopa(Cladocera)
  • Pages - 415-425
  • JOSÉ LUIS GAMA-FLORES *, MARÍA ELENA HUIDOBRO-SALAS, S.S.S. SARMA 1and S. NANDINI 1
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  • View Abstract  We studied the survivorship (average lifespan, lifeexpectancy at birth and generation time) and reproduction (gross and net reproductive rates, and the rate of population increase) of Moina macrocopa, a common cladoceran found in many freshwater bodies of Mexico. We used 3-conditioned-media obtained from (a) fish (Poeciliopsis occidentalis), (b) axolotl (Ambystoma mexicanum) and (c) frog tadpole (Hyla eximia). Standard life table demography experiments were done at laboratory temperature (22°C) on neonates from a single parthenogenetic female of M. macrocopaand fed Chlorella at 1.0x10 6cells ml -1 . Compared with survivorship variables, the age-specific reproduction of M. macrocopawas more dramatically influenced by the predator conditioned-medium. Compared with controls, there was a significant increase in the offspring production inall three treatments involving the vertebrate conditioned medium; the highest was observed in the tadpole conditioned medium while the lowest was with Ambystoma-conditioned medium. Average lifespan (ALS), gross (GRR) and net reproductive rates (NRR), generation time (GT) and the rate of population increase (r) were all significantly affected depending on the vertebrate-conditioned medium. For example, ALS wasadversely affected due to Ambystoma while, it was stimulated due to fish-conditioned medium. Gross and net reproductive rates were lowest in control than in conditioned media from fish, frog tadpoles and axolotl. Generation time was lowest (6days) in controls and in axolotl-conditioned medium but longer (9 days) in treatments containing fish or frog tadpole-conditioned medium. The three conditioned-media from the predators induced the differential changes in life traits of M. macrocopa. The effects of kairomones in Ambystoma-conditioned medium, however, than other two on themeasured demographic variables of M. macrocopa.


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