Facultative diazotrophy increases Cylindrospermopsis raciborskii competitiveness under fluctuating nitrogen availability

Relative fitness of three bloom-forming and potentially toxic cyanobacteria from the subtropical St. John's River, Florida was investigated under a range of nutrient conditions, during a bloom dominated by Cylindrospermopsis raciborskii. Nitrogen (N) was the primary nutrient limiting phytoplankton primary productivity and biomass. Phytoplankton biomass was also enhanced by phosphorus (P) added either alone or jointly with N, suggesting different components of the phytoplankton experienced distinct nutrient limitations. Based on quantitative PCR, the diazotrophic cyanobacteria Anabaena sp. and C.?raciborskii were responsible for the primary production response to P additions, while the nondiazotrophic Microcystis aeruginosa appeared to benefit from N released from the diazotrophs. Cylindrospermopsis raciborskii maintained high net growth rates under diazotrophic and nondiazotrophic conditions, while Anabaena sp. growth was significantly reduced under DIN enrichment. C.?raciborskii appears to be a generalist with regard to N source, a lifestyle traditionally not considered a viable ecological strategy among diazotrophs. Using facultative diazotrophy, C.?raciborskii gains a growth advantage under fluctuating DIN conditions, such as systems that are under the influence of anthropogenic N loading events. The described niche differentiation may be a key factor explaining the recent global expansion of C.?raciborskii.     

镇海水库拟柱孢藻的分离鉴定和氮磷对其生长的影响

以分离自广东省镇海水库的拟柱孢藻N8为对象, 探究其在不同磷浓度及氮磷浓度组合下的生长情况。结果表明, 拟柱孢藻N8对磷的适应范围很宽, 在0.025.12 mg/L磷浓度下均能生长, 最适生长磷浓度范围为0.165.12 mg/L, 磷浓度的升高能显著延长拟柱孢藻的对数生长期和提高生物量。动力学分析表明, 拟柱孢藻N8有较低的KSP值, 对磷元素的亲和性较高, 在磷营养贫乏的环境下更容易形成优势。在氮磷组合实验中, 低氮(0.5 mg/L)显著抑制拟柱孢藻的生长, 且这种生长抑制不受磷浓度的影响; 而在低磷(0.04 mg/L)条件下, 水体中氮浓度的增加会显著促进拟柱孢藻的生长, 拟柱孢藻在高氮中磷和高氮高磷下的生长显著优于其他氮磷组合条件。研究表明, 广东省水库拟柱孢藻的生长受磷的限制较弱, 氮是其生长的决定因子。       

Molecular characterization of the toxic cyanobacterium Cylindrospermopsis raciborskii and design of a species-specific PCR

Cylindrospermopsis raciborskii is a toxic-bloom-forming cyanobacterium that is commonly found in tropical to subtropical climatic regions worldwide, but it is also recognized as a common component of cyanobacterial communities in temperate climates. Genetic profiles of C. raciborskii were examined in 19 cultured isolates originating from geographically diverse regions of Australia and represented by two distinct morphotypes. A 609-bp region of rpoC1, a DNA-dependent RNA polymerase gene, was amplified by PCR from these isolates with cyanobacterium-specific primers. Sequence analysis revealed that all isolates belonged to the same species, including morphotypes with straight or coiled trichomes. Additional rpoC1 gene sequences obtained for a range of cyanobacteria highlighted clustering of C. raciborskii with other heterocyst-producing cyanobacteria (orders Nostocales and Stigonematales). In contrast, randomly amplified polymorphic DNA and short tandemly repeated repetitive sequence profiles revealed a greater level of genetic heterogeneity among C. raciborskii isolates than did rpoC1 gene analysis, and unique band profiles were also found among each of the cyanobacterial genera examined. A PCR test targeting a region of the rpoC1 gene unique to C. raciborskii was developed for the specific identification of C. raciborskii from both purified genomic DNA and environmental samples. The PCR was evaluated with a number of cyanobacterial isolates, but a PCR-positive result was only achieved with C. raciborskii. This method provides an accurate alternative to traditional morphological identification of C. raciborskii.     

What drives the distribution of the bloom-forming cyanobacteria Planktothrix agardhii and Cylindrospermopsis raciborskii?

The cyanobacteria Planktothrix agardhii and Cylindrospermopsis raciborskii are bloom-forming species common in eutrophic freshwaters. These filamentous species share certain physiological traits which imply that they might flourish under similar environmental conditions. We compared the distribution of the two species in a large database (940 samples) covering different climatic regions and the Northern and Southern hemispheres, and carried out laboratory experiments to compare their morphological and physiological responses. The environmental ranges of the two species overlapped with respect to temperature, light and total phosphorus (TP); however, they responded differently to environmental gradients; C.?raciborskii biovolume changed gradually while P. agardhii shifted sharply from being highly dominated to a rare component of the phytoplankton. As expected, P.?agardhii dominates the phytoplankton with high TP and low light availability conditions. Contrary to predictions, C.?raciborskii succeeded in all climates and at temperatures as low as 11?°C. Cylindrospermopsis raciborskii had higher phenotypic plasticity than P.?agardhii in terms of pigments, individual size and growth rates. We conclude that the phenotypic plasticity of C.?raciborskii could explain its ongoing expansion to temperate latitudes and suggest its future predominance under predicted climate-change scenarios.     

Growth strategy,phylogeny and stoichiometry determine the allelopathic potential of native and non‐native plants

Secondary compounds can contribute to the success of non‐native plant species if they reduce damage by native herbivores or inhibit the growth of native plant competitors. However, there is opposing evidence on whether the secondary compounds of non‐native plant species are stronger than those of natives. This may be explained by other factors, besides plant origin, that affect the potential of plant secondary compounds. We tested how plant origin, phylogeny, growth strategy and stoichiometry affected the allelopathic potential of 34 aquatic plants. The allelopathic potential was quantified using bioassays with the cyanobacterium Dolichospermum flos‐aquae. The allelopathic potential showed a strong phylogenetic signal, but was similar for native and non‐native species. Growth strategy was important, and emergent plants had twice the allelopathic potential as compared to submerged plants. Furthermore, the allelopathic potential was positively correlated to the foliar carbon‐to‐phosphorus (C:P) and total phenolic content. We conclude that eudicot plant species with an emergent growth strategy and high plant C:P ratio exhibit a high allelopathic potential. Unless non‐native plant species match this profile, they generally have a similar allelopathic potential as natives.     

Morphological characteristics of Cylindrospermopsis raciborskii (Wołoszyńska) Seenayya et Subba Raju in laboratory cultures

The freshwater cyanoprokaryote Cylindrospermopsis raciborskii has become increasingly prevalent in tropical and temperate water bodies worldwide. The morphological characteristics of this species were investigated under different growth rates in continuous cultures (at steady state) and in batch (phosphorus starved) cultures with different mineral nitrogen forms. The species displays an enormous morphological variability under controlled condition. The occurrence of extreme long twisted filaments was found near the maximum growth rate and under high ammonium concentration. Rarely the heterocytes of Cylindrospermopsis raciborskii arise intercalarly between two neighbouring cells(i.e. intercalary heterocytes were found). The morphological features are highly effected by environmental conditions and nutrient availability. Under P-starvation extreme morphology appeared. The specifications of C. africana and C. cuspis overlap with that of C. raciborskii accordingly this is not clear characteristic feature to distinguish species. A pure culture of a pro- or eukaryote alga growing in continuous cultures is a good method for giving a suitable overview on all morphological possibilities of a tested organism.     

Induction of polyunsaturated fatty-acid synthesis enhances tolerance of a cyanobacterium, Cylindrospermopsis raciborskii, to low-temperature photoinhibition

Acyl-lipid desaturation introduces double bonds (unsaturated bonds) at specifically defined positions of fatty acids that are esterified to the glycerol backbone of membrane glycerolipids. Desaturation pattern of the glycerolipids of Cylindrospermopsis raciborskii (C. raciborskii), a filamentous cyanobacterial strain, was determined in cells grown at 35 degrees C and 25 degrees C. The lowering of the growth temperature from 35 degrees C to 25 degrees C resulted in a considerable accumulation of polyunsaturated octadecanoic fatty acids in all lipid classes. Lipid unsaturation of C. raciborskii was also compared to Synechocystis PCC6803. In C. raciborskii cells, a shift in growth temperature induced a much more pronounced alteration in the desaturation pattern of all lipid classes than in Synechocystis PCC6803. The tolerance to low-temperature photoinhibition of the C. raciborskii cells grown at 25 degrees C and 35 degrees C was also compared to the tolerance of Synechocystis cells grown at the same temperatures. Lower growth temperature increased the tolerance of C. raciborskii cells but not that of Synechocystis cells. These results strengthen the importance of polyunsaturated glycerolipids in the tolerance to environmental stresses and may give a physiological explanation for the determinative role of C. raciborskii strain in algal blooming in the Lake Balaton (Hungary).     

The tolerance of cyanobacterium Cylindrospermopsis raciborskii to low-temperature photo-inhibition affected by the induction of polyunsaturated fatty acid synthesis

Acyl-lipid desaturation introduces double bonds (unsaturated bonds) at specifically defined positions of fatty acids that are esterified to the glycerol backbone of membrane glycerolipids. Desaturation patterns of the glycerolipids of Cylindrospermopsis raciborskii, a filamentous cyanobacterium, were determined in cells grown at 35 degrees C and 25 degrees C. The lowering of the growth temperature from 35 degrees C to 25 degrees C resulted in a considerable accumulation of polyunsaturated octadecanoic fatty acids in all lipid classes. The tolerance to low-temperature photo-inhibition of the C. raciborskii cells grown at 25 degrees C and 35 degrees C was also compared. The lower growth temperature increased the tolerance of C. raciborskii cells. These results strengthen the importance of polyunsaturated glycerolipids in the tolerance to environmental stresses and may give a physiological explanation for the determinative role of C. raciborskii in algal blooming in Lake Balaton (Hungary).     

N-苯基-2-萘胺对拟柱胞藻生长、抗氧化酶及光合系统Ⅱ的影响

为探究化感物质对入侵水华蓝藻-拟柱胞藻(Cylindrospermopsis raciborskii)的影响, 研究对不同浓度(0、0.05、0.10、0.50、1.00和2.00 mg/L)N-苯基-2-萘胺处理下拟柱胞藻的生长、抗氧化酶活性及叶绿素荧光诱导动力学进行了测定。结果表明, 藻叶绿素a含量随N-苯基-2-萘胺浓度升高而显著降低, 浓度大于0.50 mg/L时, 拟柱胞藻叶绿素a含量显著低于对照。72h, N-苯基-2-萘胺对拟柱胞藻的EC50为1.02 mg/L。叶绿素荧光诱导动力学参数表明, 浓度小于0.50 mg/L时, 拟柱胞藻的最大光化学效率(P0)、单位面积上有活性的反应中心(RC/CS0)、以吸收光能为基础的性能指数(PIABS)及以单位面积为基础的性能指数(PICS)均显著高于对照, 而反映2ms时有活性的反应中心的开放程度的0则显著低于对照组。当N-苯基-2-萘胺浓度大于0.50 mg/L时, 以上参数均呈现相反趋势。这表明低浓度N-苯基-2-萘胺能提高拟柱胞藻的光合效率, 而在高浓度时, 拟柱胞藻PSⅡ有活性的反应中心减少, 电子传递受到阻碍, 光合效率下降。与对照相比, 在浓度高于0.50 mg/L条件下, 拟柱胞藻的过氧化氢酶(CAT)、过氧化物酶(SOD)及谷胱甘肽过氧化物酶(GPX)的活性显著增加, 表明拟柱胞藻能产生大量的抗氧化酶来减少N-苯基-2-萘胺的损伤。这些结果表明N-苯基-2-萘胺可能通过抑制PSⅡ的电子传递和减少其有活性的反应中心来影响拟柱胞藻的生长, 也暗示了N-苯基-2-萘胺能作为潜在的抑藻物质来控制拟柱胞藻水华。       

几种高等水生植物的克藻效应研究

研究了五种高等水生植物(黑藻、金鱼藻、水花生、茭白、空心菜)对蛋白核小球藻、斜生栅藻生长的抑制作用。试验结果显示,各种受试植物均有不同程度的克藻效果,金鱼藻与黑藻的克藻作用最强,水花生的作用次之。克藻效果以受试植物与藻共培养最佳,其次为连续添加种植水,表明在植物的生长过程中其化感物质是连续释放且能迅速降解的,而黑藻干物质的浸提液所具有的克藻效应说明有些化感物质对一定温度和光照是较稳定的。     

Phylogeography of the invasive cyanobacterium Cylindrospermopsis raciborskii

Cylindrospermopsis raciborskii is a planktonic freshwater cyanobacterium that has become increasingly prevalent in tropical and temperate water bodies world-wide. This species is of concern from a water-quality perspective because of its known ability to produce toxins that can affect the health of humans and other animals. This study investigates genetic variation between strains of C. raciborskii isolated from freshwater rivers and reservoirs in Australia, Brazil, Germany, Hungary, Portugal and the USA. Strains were first characterized by analysis of their 16S rRNA gene nucleotide sequences and were found to have a sequence divergence of 99.1%. A phylogenetic tree, constructed using the 16S rRNA gene sequences showed that strains grouped into Australian, European and North/South American phylotypes. To investigate further the observed separation of strains into geographically distinct groups, we applied a cyanobacterium-specific short tandem repeat sequence technique, HIP1. An electrophoretic comparison of the HIP1 polymerase chain reaction products showed clear distinctions between the C. raciborskii strains. A phylogenetic tree, based on the repeat element banding patterns, also revealed three distinct groups of C. raciborskii strains. The first group consisted of strains from the USA and Brazil; the second comprised European strains from Germany, Hungary and Portugal; and the third were strains from Australia. In general, between-country variation was greater than within-country variation, indicating that this fingerprinting technique can successfully distinguish C. raciborskii strains taken from different global locations. The relationship between toxicity and the observed HIP1 polymerase chain reaction fingerprint profiles was less clear, although it is interesting to note that of the strains analysed in this study, only Australian strains are known to produce cylindrospermopsin and only Brazilian strains have been reported to produce paralytic shellfish poisoning toxins.     

Preponderance of Oxygenated Sesquiterpenes and Diterpenes in the Volatile Oil Constituents of Lactuca serriola L. Revealed Antioxidant and Allelopathic Activity

Using synthetic chemicals in industry and agriculture has led to several environmental problems. Thus, plant products derived from volatile oils (VOs) could be a potential green source for bioherbicides. Little is known about the VOs of Lactuca serriola. Hence, the present study aimed to characterize the VOs chemical composition from the aerial parts of L. serriola, assessment of antioxidant activity, and evaluate allelopathic potential against the noxious weed Bidens pilosa. The VOs were extracted by hydrodistillation and analyzed by GC/MS. The VOs from the Egyptian ecospecies of L. serriola were found to comprise 34 compounds mainly oxygenated sesquiterpenes and diterpenes. The major compounds were isoshyobunone (64.22 %), isocembrol (17.35 %), and alloaromadendrene oxide‐1 (7.32 %). So, L. serriola can be considered as a good source for isoshyobunone, considering that it has a much higher concentration than any other plants. Also, this plant has a high content of the oxygenated diterpene compound, isocembrol, which is rarely found in the VOs of most plants. The VOs expressed strong antioxidant activity. Also, for the first time, our results showed a strong allelopathic activity of VOs from L. serriola on germination and seedling growth of the noxious weed, B. pilosa. We suppose that the activity of the VOs from L. serriola could be attributed to these previously mentioned major compounds, as they represent about 89 % of the total identified oil constituents. Nevertheless, to evaluate these compounds as new allelochemicals, further study is needed to test the allelopathic activity of authenticated standard of these compounds either singular or in combination on several weeds as well as evaluate the safety, and improve the efficacy and stability at the field scale.     

Comparison of phenolic compounds and the effects of invasive and native species in East Asia: support for the novel weapons hypothesis

One prediction of the novel weapons hypothesis (NWH) for the dominance of exotic invasive plant species is that the allelopathic effects of successful invaders will, in general, be more biochemically inhibitory to native species and microbes in invaded regions than the native plants themselves. However, no study has compared biochemical concentrations, compositions, or effects of large numbers of native species to those of large numbers of invasive species. In this context we tested the allelopathic and antimicrobial potentials of nine native plant species and nine invasive species in East Asia by comparing their broad phenolic contents and the effects of extracts made from each of the species on target plants and soil fungi. Three of the invasive species, including Eupatorium rugosum, had higher concentrations of total phenolic compounds than any of the native species, and the mean concentration of total phenolics for invasive species was 2.6 times greater than the mean for native species. Only scopoletin was novel to the invasive species, being found in all of nine invasive species, but not in the native species. More importantly, the effects of the total suites of phenolic compounds produced by invasive species differed from the effects of phenolics produced by natives. Extracts of invasive species reduced radicle growth of the three test plant species by 60–80%, but extracts of native species reduced radicle growth by only 30–50%. Extracts of invasive species reduced shoot growth of the three test species by 20–40%, but the overall effect of native species’ extract was to stimulate shoot growth. The antimicrobial activity of invasive species was also significantly higher than that of native species. It should be noted that phenolics are just one component of a plant’s potential allelopathic arsenal and non-phenolic compounds are likely to play a role in the total extract effect. For example, extracts of P. americana contained the lowest levels of phenolic compounds, but exhibited the strongest inhibition effect. We could not determine whether the greater inhibitory effects of the extracts from invasive species were due to novel combinations of chemicals or higher concentrations of chemicals, but our results are consistent with the predictions of the NWH.     

Use of Chenopodium murale L. transgenic hairy root in vitro culture system as a new tool for allelopathic assays

We investigated Chenopodium murale transgenic hairy root in vitro culture system as a new tool for allelopathic assays. Transgenic hairy roots were induced by Agrobacterium rhizogenes A4M70GUS from roots, cotyledons, leaves, and internodes of C. murale seedlings. Roots were found to be the best target explants, providing transformation efficiency of up to 11.1%. Established hairy root clones differed in their morphology and growth potential. Molecular characterization of these clones was carried out by PCR, RT-PCR and histochemical GUS analyses. No differences in rol gene expression were observed. Liquid culture system of characterized hairy root clones was maintained for over 2 years. Six hairy root clones were selected for assaying the allelopathic effect of their growth medium against germination and seedling elongation of wheat and lettuce test plants. The inhibitory potential varied depending on the hairy root clone. Some transgenic clones showed significantly higher inhibition compared to wild-type roots. These results revealed that hairy roots as an independent system synthesize some bioactive substances with allelopathic activity and exude them into the growth medium. Concentrations of caffeic, ferulic and p-coumaric acids (0.07-2.85 μmol/L) identified by HPLC analysis in the growth media were at least 1000 times lower than the inhibitory active concentration (5 mmol/L) of pure grade phenolic acids, suggesting that they have a limited role in the allelopathic phenomena of C. murale. The presented hairy root system appears to be a suitable tool for further investigation of the potential and nature of root-mediated allelopathic interference of C. murale.     

The effect of growth temperature on the long-chain alkenes composition in the marine coccolithophorid Emiliania huxleyi

The hydrocarbon fraction of a pure culture of Emiliania huxleyi, composed of a mixture of C31, C33, C37 and C38 polyunsaturated n-alkenes, appeared strongly dependent on the growth temperature of the alga between 8 degrees C and 25 degrees C. The total hydrocarbon content increased linearly with decreasing temperatures. C37 and C38 alkenes (which accounted for more than 90% of the total hydrocarbons) showed distinct changes in distribution compared to C31 and C33 alkenes, suggesting different biological syntheses and/or functions for these two groups of compounds. C37 and C38 alkenes and C37 methyl ketones (alkenones) all showed a trend to lower proportions of the two diunsaturated isomers and to higher proportions of the corresponding trienes with decreasing temperature. Unlike the alkenone unsaturation ratio (U37k'), ratios based on the C37 and C38 alkadi- and trienes could be linearly related to the growth temperature of E. huxleyi only between 15 degrees C and 25 degrees C. The modifications in the distribution of alkenes induced by varying temperature appeared, however, to be twice as fast as the modifications undergone by the alkenones. Although structurally and biochemically related, the distinct evolutions of alkenes and alkenones in response to changes in growth temperature might indicate that these two classes of compounds play two distinct physiological functions. The non-systematic linearity of relationships to temperature of parameters based on alkenes distribution suggested that these compounds are of limited use as paleotemperature indicator in the marine environment in contrast with the alkenones.     

CO2浓度变化对拟柱胞藻生长与光合作用的影响

为了探讨大气CO₂浓度升高对水华藻类的影响,利用水华蓝藻-拟柱胞藻作为实验材料,研究了CO₂浓度升高对其生长生理和光合作用的影响,结果表明CO₂浓度升高,导致拟柱胞藻的生物量、最大光合放氧速率、光合效率显著增加。当CO₂浓度为700 mg/L以下,暗呼吸速率和光饱和点无明显影响,而CO₂浓度为1000 mg/L时,暗呼吸速率和光饱和点显著提高。随着CO₂浓度增加,藻细胞光合作用对无机碳的亲和力降低,同时胞外碳酸酐酶活性显著下降。这表明大气CO₂浓度的增加,有利于拟柱胞藻的生长和光合,进而增加了水华发生的风险。     

Allelopathic inhibition of primary producer growth and photosynthesis by aquatic fungi

Autochthonous primary production is generally much reduced in forested headwater streams. Several hypotheses have been proposed for explaining this observation, among them, the low light intensity, or the strong constraints exerted by stream current. Allelopathic inhibition of competitors is a common ecological process in aquatic environments. Aquatic hyphomycetes are known to chemically inhibit bacteria and other fungi (including other aquatic hyphomycetes) but a possible allelopathic effect of aquatic hyphomycetes on primary producers has never been tested. The inhibitory effect of twelve aquatic hyphomycete species was tested on three diatom species. Nine aquatic hyphomycete species exhibited anti-diatom activity. Up to 100% diatom growth inhibition was observed. Our study reveals that such allelopathic interactions might be common in streams and probably involve an array of fungal compounds. We propose that the generally reduced primary production observed in forested headwater streams is, among other factors, due to the inhibition of primary producers by allelopathic compounds released by aquatic hyphomycetes.     

Preliminary molecular identification of cylindrospermopsin-producing Cyanobacteria in two Polish lakes (Central Europe)

The presence of toxigenic cyanobacteria capable of biosynthesis of cylindrospermopsin (CYN) was measured in 24 water samples collected from the lakes Bytyńskie (BY) and Bnińskie (BN) in the Western Poland. The study also covered analysis of toxigenicity and production of CYN by the culture of Cylindrospermopsis raciborskii isolated from BY. The cyrJ gene associated with CYN production was identified in 22 water samples collected in the summer seasons of 2006 and 2007. The presence of CYN was confirmed in 16 samples. The homology searches revealed that amplified sequences of four water samples, which were selected from among all the samples, displayed a strong 99% homology to cyrJ gene of Aphanizomenon sp. 10E6. The culture of C.?raciborskii did not contain the cyrJ gene nor the CYN. The specificity of C.?raciborskii was confirmed by application of a fragment of the rpoC1. These first genetic analyses have shown that Aphanizomenon seems to be the main cyanobacterial genus responsible for the production of CYN in the Polish lakes. The lack of toxigenicity of the isolated C.?raciborskii suggests that it is possible that this invasive species does not demonstrate toxigenic activity in Polish water bodies.     

芦苇叶水提物的化感活性分析及潜在化感成分的筛选

采用不同溶剂对芦苇﹝Phragmites australis ( Cav.) Trin. ex Steud.﹞叶片水提物进行萃取,并以小麦( Triticum aestivum Linn.)和萝卜( Raphanus sativus Linn.)种子为实验材料对不同萃取物的化感效应进行检测;采用薄层层析和柱层析对抑制作用最强的正丁醇萃取物进行进一步分离,并采用GC-MS法对生物活性较高的组分进行组成成分分析;在此基础上,选择相对含量高并具有代表性的潜在化感成分进行生物活性检测,以期筛选出芦苇叶中的潜在化感成分。结果显示：随质量浓度(20、100和500 mg·L-1)提高,芦苇叶水提物的石油醚、二氯甲烷、乙酸乙酯、正丁醇和水萃取物对小麦和萝卜种子萌发的抑制作用均逐渐增强,其中正丁醇萃取物的抑制作用最强。在正丁醇萃取物的11个组分中,Fr.5、Fr.6、Fr.7、Fr.9和Fr.10组分均能显著抑制萝卜或小麦幼苗的生长,经质量浓度500 mg·L-1各组分处理液处理后萝卜或小麦幼苗的株高、根长及单株鲜质量均显著低于对照(P<0.05)。采用GC-MS法从Fr.5、Fr.6、Fr.7、Fr.9和Fr.10组分中分别鉴定出11、15、15、12和22种成分,分别占各组分总相对含量的83.02%、91.31%、87.36%、97.92%和94.34%,主要成分包括糖类、醇类、有机酸类、酮类、酰胺类和酯类。对14种潜在化感成分生物活性的检测结果显示这些成分对小麦幼苗生长有明显的抑制作用,其中,经质量浓度20 mg·L-1油酸酰胺、棕榈酸甲酯、亚油酸、2-苯乙胺、2-甲基烯丙醇和4-羟基-3-甲氧基苦杏仁酸处理后,小麦幼苗的株高、根长及单株鲜质量显著低于对照。综合分析结果显示：芦苇叶水提物具有较强的化感活性,其潜在的化感成分为油酸酰胺、棕榈酸甲酯、亚油酸、2-苯乙胺、2-甲基烯丙醇和4-羟基-3-甲氧基苦杏仁酸。