Hyacinth Plants Research Articles

Does water hyacinth ( Eichhornia crassipes) compensate for simulated defoliation? Implications for effective biocontrol

Biocontrol agents of water hyacinth ( Eichhornia crassipes), one of the most ubiquitous invasive aquatic species in the world, were introduced in the waterways of Florida, USA, more than 30 years ago but have not been as successful as expected. The high nutrient, high light, warm year-round temperatures and lack of natural predators provide an optimal growth environment for the plant. The current study was designed to test if a compensatory response by the water hyacinth plants to low levels of biomass removal was one of the reasons for the ineffectiveness of biocontrol agents in the successful control of water hyacinth. The plants were exposed to two levels of nutrient (high and low) and three levels (0%, 10% and 80%) of simulated herbivory treatment. The effect of the nutrient and repeated (i.e., chronic) defoliation treatments was determined after 6 weeks. Plants with 10% defoliation did not show any significant difference from control plants in biomass allocation or relative growth rate (RGR) in either nutrient concentration, while 80% defoliation caused a significant decrease in the final RGR under high and low nutrient treatments. High nutrient treatment resulted in higher RGR and allocation to asexual reproduction resulting in higher biomass accumulation compared to the low nutrient treatment, which had higher root growth and allocation to sexual reproduction. Results from this study indicate that water hyacinth can fully compensate for low levels of continuous defoliation regardless of the nutrient concentration, which has implications and important considerations for biocontrol strategies.

Ecophysiological adaptation and metal accumulation in water hyacinth from two tropical rivers

The ecophysiological adaptations of water hyacinth (metal hyperaccumulator) under adverse environmental conditions are not yet clearly elucidated. This work evaluated photosynthetic pigments and chlorophyll a fluorescence in water hyacinth plants sampled in different regions (upper, middle and lower) of Paraíba do Sul river (PSR) and Imbé river, Brazil. Additionally Mn, Fe, Zn, Cu, Cr, Pb and Ni were quantified on the shoots and roots. Roots were the preferential site of metal accumulation. Cromium was not detected in the shoots. Iron and Mn were the elements detected in higher concentrations in all samples. Zinc and Cu were detected in higher concentrations in roots of plants from middle and upper PSR, sites of higher anthropogenic activity. The highest concentrations of almost all metals were verified in plants from middle PSR. Regarding photosynthetic adaptations, plants from middle and upper PSR showed the highest concentrations of photosynthetic pigments, as well as the highest values of Fv/Fm and Fv/F0. The photosynthetic performance of plants suggests that they are not under stress conditions, even in regions of higher anthropogenic activity. Positive correlation was observed among nonphotochemical quenching and carotenoids, suggesting dissipation of energy in the form of heat as an strategy to keep the stable photochemical photosynthesis functioning, confirmed by values of the Fv/Fm. It is possible that such adaptative strategy is efficient as a long term response to stress factors, once literature data suggest that this is not a preferential path for photosynthesis in stress circumstances under short time controlled conditions.

Evaluation of nitrogen reduction in water hyacinth ponds integrated with waste stabilization ponds

In this paper, a combined aquatic treatment process coupling waste stabilization ponds (WSPs) with water hyacinth ponds (WHPs) was investigated as means to upgrade secondary effluent from a waste water treatment plant (WWTP). Naturally-occurring nitrification and denitrification phenomena were monitored and evaluated on a quantitative basis. The WSP supplied oxygen to the post process WHP, while the inside of the WHP provided a unique denitrification environment caused by respiration and biodegradation of the algae separated by hyacinth plant roots. The nitrification and denitrification rates were 0.04 and 0.02 g/kg day at 20 °C (wet weight basis), respectively, and were strongly affected by seasonal change. The temperature-dependent coefficients Θ were 1.06, which were approximately similar to frequently reported values from other biological nitrogen removal studies. Nitrification and denitrification were expected to occur as the water temperature was maintained between 20° to 30 °C. As plant density increased, their rates were also enhanced. Alkalinity balance corresponded fairly well with nitrogen behaviour during most of the operational period. Oxygen balance test results validated that the water hyacinth was crucial not only for separating algal particles from the WSP, but also for biological nitrogen reduction.

Effect of feeding by two Neochetina species or infestation with Tetranychus urticae Koch on histological structure of water hyacinth leaves

Both weevils, Neochetina bruchi (Hustache) and Neochetina eichhorniae Warner feed on water hyacinth plants as a biocontrol agents. Tetranychus urticae Koch infested the plants grown under light and thermostatic controlled aquatic weed green house, and caused repellency of the weevils. Studying some histological structure, of water hyacinth leaves infested with mites , showed increase of the thickness of upper epidermis, number of palisade cell and thickness of leaf petiole, compared with the control and leaves infested with weevils which recorded decrease in the thickness of leaf petiole and increase in lower palisade tissue. The mites infested plants lost chlo rophyll, turned brownish and lost size of vacuoles or air chambers used to store the oxygen. The volume of these vacuoles was very small in case of mite infested plants compared with leaves infested with weevils as the same as control. The weevils feeding reflected in increase in both, length and width of fed upon leaves.

Efeito de pontas de pulverização e de arranjos populacionais de plantas de Eichhornia crassipes e Salvinia auriculata na deposição de calda de pulverização sobre plantas de Pistia stratiotes

Este trabalho teve por objetivo avaliar o depósito de calda pulverizada por dois tipos de pontas de pulverização sob plantas de alface-d'água (Pistia stratiotes) dispostas em diferentes arranjos populacionais com plantas de aguapé (Eichhornia crassipes) e salvínia (Salvinia auriculata). Para isso, foi conduzido um experimento em condições de caixas-d'água em delineamento experimental inteiramente casualizado, com quatro repetições. Os tratamentos estiveram dispostos em esquema fatorial 2 x 8, sendo dois tipos de pontas de pulverização (ConeJet TXVK-8 e TeeJet DG 11002 VS) e oito proporções entre as plantas aquáticas, a saber: dominância total da área correspondente a 100% de cobertura da caixa-d'água pelas plantas de alface-d'água; e as proporções entre plantas de alface-d'água e plantas de aguapé ou salvínia a 75%:25%, 50%:50% e 25%:75%. Também foi utilizada uma densidade tripla, na qual as três espécies estiveram igualmente dispostas na proporção de 33,33%. Soluções dos corantes Amarelo Tartrasina FDC-5 a 3.500 ppm e Azul Brilhante FDC-1 a 1.000 ppm foram utilizadas como traçadores para as pontas TXVK-8 e DG 11002VS, respectivamente. A pulverização de ambas as soluções foi efetuada na mesma unidade experimental, com um intervalo de 30 minutos entre si, utilizando-se um pulverizador costal pressurizado com CO2, calibrado de modo a proporcionar um volume de aplicação aproximado de 200 L ha. Após a pulverização, as plantas presentes nos reservatórios foram lavadas com água destilada, até remoção total dos corantes. Os depósitos totais de calda foram estimados em μL por planta, e os depósitos unitários, em μL cm-2 de superfície foliar. O aumento na proporção de plantas de aguapé na associação proporcionou menores depósitos de calda de pulverização sobre as plantas de alface-d'água. Em contrapartida, o aumento na proporção de salvínia na associação propiciou maiores depósitos de calda de pulverização, independentemente do tipo de ponta de pulverização. A ponta TXVK-8 proporcionou depósitos unitários e totais de calda de pulverização superiores aos da ponta DG 11002VS.

Physiological responses of Eichhornia crassipes [Mart.] Solms to the combined exposure to excess nutrients and Hg

In the present study the physiological response of water hyacinth (Eichhornia crassipes [Mart.] Solms) to the combined exposure of excess nutrients and Hg was examined. Young water hyacinth plants were exposed to a range of HgCl2 and KNO3 concentrations. After eight weeks, submerged plant tissues reached an Hg concentration of 4 mg g-1. The accumulation of P and S was reduced by the addition of HgCl2, and also the P and K concentrations in emerged and submerged parts decreased. In contrast, the addition of HgCl2 increased Ca and Mg concentrations in submerged parts. Furthermore, the concentration ratios of submerged/emerged parts for Ca, Mg and P were also reduced by the addition of HgCl2. The interaction of HgCl2 and KNO3 was synergistic and decreased Fv/Fm, total chlorophyll content and P and Mn concentrations in emerged parts. In submerged plant parts Ca concentration increased and K content stabilized as a result of the above interaction. However, the total accumulation of Hg per plant was not reduced, thereby confirming the water hyacinth as a promising candidate for the heavy metal phytoremediation of eutrophic waters.

Eichhornia crassipes

<i>Eichhornia crassipes</i>

Removal of microbial biofilm on Water Hyacinth plants roots by ultrasonic treatment

The capacity of floating aquatic plants to purify sewage effluents drops rapidly as a result of biofouling processes that occur on the plant roots. This is due to the high concentration of microorganisms (MO) present in the wastewater. The possibility to apply low frequency (20 kHz) in sonification was examined under laboratory conditions. The ability of US to remove MO from the roots was studied using commercially available sonicators at intensity levels ranging from 2.7 W/cm 2 to 81.4 W/cm 2, (corresponding power levels ranging from 75 W to 500 W) while varying application periods between 5 and 60 min. The results show that MO can be removed effectively (up to 98%) by exposing the Eichhornia crassipes roots to US for 5 min at the intensity level of 64.5 W/cm 2. The efficiency of the wastewater treatment increased with exposure time and power input. The study proved that the US treatment is effective in removing MO that otherwise adhere to the roots, by more then two orders of magnitude.

Identification of a retardant dose of glyphosate with potential for integrated control of water hyacinth, Eichhornia crassipes (Mart.) Solms-Laubach

Water hyacinth, Eichhornia crassipes (Mart.) Solms-Laubach (Pontederiaceae) has a negative impact on aquatic ecosystems in South Africa. Attempts to use biological control against the weed have been hampered by low temperatures, with slow development of biocontrol agents, and excessively eutrophic waters which enable the plants to proliferate and grow at greater rates than the agents. The failure of biological control has encouraged the use of herbicides which also hinder the biocontrol agents, predominantly by destroying their food source. This study tested a broad spectrum herbicide, glyphosate, to identify whether there is a dose which will retard vegetative growth (production of ramets and leaves) but not kill the water hyacinth plants. A concentration of 0.8% achieved this goal while having no direct detrimental effects on two water hyacinth biocontrol agents, Neochetina eichhorniae and N. bruchi. The results show that application of retardant doses of herbicide might be used for integrated control of E. crassipes and this needs to be tried under natural field conditions.

The effect of two biological control agents, the weevil Neochetina eichhorniae and the mirid Eccritotarsus catarinensis on water hyacinth, Eichhornia crassipes, grown in culture with water lettuce, Pistia stratiotes

We assessed the effect of two biological control agents, the mirid Eccritotarsus catarinensis (Carvalho) and the weevil Neochetina eichhorniae (Warner), singly or in combination, on the competitive ability of their host plant, water hyacinth, Eichhornia crassipes (Mart.) Solms-Laub., grown in a screen house, in competition with another aquatic plant (Pistia stratiotes L.). Water hyacinth plant growth characteristics measured included fresh weight, leaf and petiole lengths, number of inflorescences produced, and new shoots. Without herbivory, water hyacinth was 18 times more competitive than water lettuce (across all experimental combinations of initial plant densities), as estimated from fresh weights. Both insect species, singly or in combination, reduced water hyacinth plant growth characteristics. E. catarinensis alone was less damaging than the weevil and under normal conditions, i.e., floating water hyacinth, is not expected to increase control of water hyacinth beyond that of the weevil. When combined with the weevil, half the inoculum of weevils and half the inoculum of mirids produced the same growth reduction as the full inoculum of the weevil. Under conditions where the weevils are not effective because water hyacinths are seasonally rooted in mud, the mirid, which lives entirely on leaves, should become a useful additional biological control agent.

Hg L3 XANES Study of Mercury Methylation in Shredded Eichhornia crassipes

Eichhornia crassipes (water hyacinth) is a non-native plant found in abundance in the Sacramento-San Joaquin River Delta (hereafter called Delta). This species has become a problem, clogging waterways and wetlands. Water hyacinth are also known to accumulate mercury. Recent attempts to curb its proliferation have included shredding with specialized boats. The purpose of this research is to better understand the ability of water hyacinth to phytoremediate mercury and to determine the effect of shredding and anoxic conditions on mercury speciation in plant tissue. In the field assessment, total mercury levels in sediment from the Dow Wetlands in the Delta were found to be 0.273 +/- 0.070 ppm Hg, and levels in hyacinth roots and shoots from this site were 1.17 +/- 0.08 ppm and 1.03 +/- 0.52 ppm, respectively, indicating bioaccumulation of mercury. Plant samples collected at this site were also grown in nutrient solution with 1 ppm HgCl2 under (1) aerobic conditions, (2) anaerobic conditions, and (3)with shredded plant material only. The greatest accumulation was found in the roots of whole plants. Plants grown in these conditions were also analyzed at Stanford Synchrotron Radiation Laboratory using Hg L3 X-ray Absorption Near Edge Spectroscopy (XANES), a method to examine speciation that is element-specific and noninvasive. Least-squares fitting of the XANES data to methylated and inorganic mercury(II) model compounds revealed that in plants grown live and aerobically, 5 +/- 3% of the mercury was in the form of methylmercury, in a form similar to methylmercury cysteine. This percentage increased to 16 +/- 4% in live plants grown anaerobically and to 22 +/- 6% in shredded anaerobic plants. We conclude that shredding of the hyacinth plants and, in fact, subjection of plants to anaerobic conditions (e.g., as in normal decay, or in crowded growth conditions) increases mercury methylation. Mechanical removal of the entire plant is significantly more expensive than shredding, but it may be necessary to avoid increased biomagnification of mercury in infested areas.

Experimental and kinetic modelling studies on the acid-catalysed hydrolysis of the water hyacinth plant to levulinic acid

A comprehensive experimental and modelling study on the acid-catalysed hydrolysis of the water hyacinth plant ( Eichhornia crassipes) to optimise the yield of levulinic acid (LA) is reported ( T = 150–175 °C, C H 2 SO 4 = 0.1 – 1 M , water hyacinth intake = 1–5 wt%). At high acid concentrations (>0.5 M), LA was the major organic acid whereas at low acid concentrations (<0.1 M) and high initial intakes of water hyacinth, the formation of propionic acid instead of LA was favoured. The highest yield of LA was 53 mol% (35 wt%) based on the amount of C6-sugars in the water hyacinth ( T = 175 °C, C H 2 SO 4 = 1 M , water hyacinth intake = 1 wt%). The LA yield as a function of the process conditions was modelled using a kinetic model originally developed for the acid-catalysed hydrolysis of cellulose and good agreement between the experimental and modelled data was obtained.

Fusarium rot of hyacinth caused by Gibberella zeae (anamorph: Fusarium graminearum)

Severe rot of leaves, peduncles and flowers caused by Gibberella zeae (anamorph: Fusarium graminearum) was found on potted plants of hyacinth (Hyacinthus orientalis), a liliaceous ornamental, in greenhouses in Kagawa Prefecture, Japan, in January 2001. This disease was named “Fusarium rot of hyacinth” as a new disease because only the anamorph, F. graminearum, was identified on the diseased host plant.

ENHANCED DISAPPEARANCE OF DICOFOL BY WATER HYACINTH IN WATER

The efficiency and primary mechanism of phytoremediation of water contaminated with dicofol, an organochlorine pesticide, by water hyacinth (Eichhornia crassipes) was investigated. After 10 days of incubation in nutrient solution at 25±1°C, the remaining dicofol which was spiked initially at 1 mg l−1 was 0.05 and 0.26 mg l−1 in the non‐sterile planted and non‐sterile unplanted, 0.07 and 0.31 mg l−1 in the sterile planted and sterile unplanted treatments, respectively. The half‐life of dicofol in nutrient solutions was reduced to 59–68 h in the planted treatments from 118–137 h in the unplanted treatments. The accumulated dicofol in water hyacinth plant decreased by 41–53% after the plant had grown for 7 days in dicofol‐free nutrient solution. Two phytoprocesses were found to be most important in the remediation of dicofol contaminated water: (i) uptake, accumulation and phytodegradation of dicofol by the plant, accounted for 50% of the removal of the spiked dicofol, and (ii) microbial degradation associated with the rhizosphere, contributed about 7% to dicofol removal. Water hyacinth may thus be a good candidate for development as a phytoremediation system for dicofolcontaminated water.

Herbivory-induced reduction in photosynthetic productivity of water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), is not directly related to reduction in photosynthetic leaf area

The purpose of this investigation was to determine whether the reduced photosynthetic productivity of water hyacinth plants subject to N. eichhorniae adult feeding was simply the result of reduced leaf area, or if more complex mechanisms were involved.

Modeling of Heavy Metals Removal from Municipal Landfill Leachate Using Living Biomass of Water Hyacinth

Water Hyacinth, Eichhornia crassipes, a fast-growing floating aquatic macrophyte; was used for the removal of heavy metals from a municipal landfill leachate. The leachate was spiked with different mixtures of five heavy metals (Cd, Cr, Cu, Pb and Ni), at a range of concentrations to cover the ranges reported in literature. The initial concentrations of the total heavy metals in leachate ranged from 0.06 to 5.5 mequiv L−1. All experiments were carried out in batch reactors in a greenhouse environment. The water hyacinth plants showed a very promising ability to remove and accumulate these metals from the leachate (24% to 80% removal of total heavy metals). Generally, the reduction in concentration of total heavy metals followed two distinct patterns, a rapid initial decrease followed by a slower decrease. An exponential mathematical model was established to estimate the remaining concentration of total heavy metals in the leachate over time for the rapid initial decrease. Also, a linear relationship was established to estimate the concentration of total heavy metals over time for the slower decrease. In addition, Langmuir and Freundlich isotherms were applied to the observed data and the constants of each isotherm were obtained.

Agrobacterium-mediated transformation of Hyacinthus orientalis with thaumatin II gene to control fungal diseases

Transgenic plants of hyacinth (Hyacinthus orientalis L.) cvs. Edisson and Chine Pink have been obtained by Agrobacterium-mediated transformation. Leaf explants of the both hyacinth cultivars regenerated shoots on MS medium containing 2.2 μM BAP and 0.3 μM NAA at a frequency of 95%. A. tumefaciens strain CBE21 carrying binary vector pBIThau35 was used for transformation. Plasmid pBIThau35 has been produced by cloning preprothaumatin II cDNA into pBI121 instead of uidA gene. Inoculated leaf explants formed calli and shoots at high frequency on selective medium with 100 mg l−1 kanamycin. Four hyacinth transgenic lines of cv. Chine Pink and one line of cv. Edisson have been selected on medium containing 200 mg l−1 kanamycin. The insertion of thaumatin II gene into hyacinth genome has been confirmed by PCR-analysis. All transgenic plants expressed substantial amounts of thaumatin II (between 0.06 and 0.28% of the total soluble protein). Hyacinth transgenic lines were assayed for resistance to the pathogenic fungi Fusarium culmorum and Botrytis cinerea. There were no significant differences between nontransformed control and transgenic leaves of both cultivars. At the same time the bulbs of the transgenic line Н7401 cv. Chine Pink showed the higher level of resistance to B. cinerea, the bulbs of the transgenic line Н7404 were more resistant to F. culmorum. In both cases the signs of the fungal disease were developed more slowly. The resistance of the bulbs cv. Edisson line to these fungi was not changed. All transgenic hyacinth plant were successfully transferred to soil for further evaluation.

Contribution of water hyacinth ( Eichhornia crassipes (Mart.) Solms) grown under different nutrient conditions to Fe-removal mechanisms in constructed wetlands

Severe contamination of water resources including groundwater with iron (Fe) due to various anthropogenic activities has been a major environmental problem in industrial areas of Sri Lanka. Hence, the use of the obnoxious weed, water hyacinth ( Eichhornia crassipes (Mart.) Solms) in constructed wetlands (floating aquatic macrophyte-based plant treatment systems) to phytoremediate Fe-rich wastewaters seems to be an appealing option. Although several studies have documented that hyacinths are good metal-accumulating plants none of these studies have documented the ability of this plant grown under different nutrient conditions to remove heavy metals from wastewaters. This paper, therefore, reports the phytoremediation efficiencies of water hyacinth grown under different nutrient conditions for Fe-rich wastewaters in batch-type constructed wetlands. This study was conducted for 15 weeks after 1-week acclimatization by culturing young water hyacinth plants (average height of 20±2 cm) in 590 L capacity fiberglass tanks under different nutrient concentrations of 1-fold [28 and 7.7 mg/L of total nitrogen (TN) and total phosphorous (TP), respectively], 2-fold, 1/2-fold, 1/4-fold and 1/8-fold with synthetic wastewaters containing 9.27 Fe mg/L. Another set-up of hyacinths containing only Fe as a heavy metal but without any nutrients (i.e., 0-fold) was also studied. A mass balance was carried out to investigate the phytoremediation efficiencies and to determine the different mechanisms governing Fe removal from the wastewaters. Fe removal was largely due to phytoremediation mainly through the process of rhizofiltration and chemical precipitation of Fe 2O 3 and Fe(OH) 3 followed by flocculation and sedimentation. However, chemical precipitation was more significant especially during the first 3 weeks of the study. Plants grown in the 0-fold set-up showed the highest phytoremediation efficiency of 47% during optimum growth at the 6th week with a highest accumulation of 6707 Fe mg/kg dry weight. Active effluxing of Fe back to the wastewater at intermittent periods and with time was a key mechanism of avoiding Fe phytotoxicity in water hyacinth cultured in all set-ups. Our study elucidated that water hyacinth grown under nutrient-poor conditions are ideal to remove Fe from wastewaters with a hydraulic retention time of approximately 6 weeks.

Impact of nutrients and herbivory by Eccritotarsus catarinensis on the biological control of water hyacinth, Eichhornia crassipes

Many water hyacinth infestations in South Africa are the symptom of eutrophication, and as a result, biological control of this weed is variable. This study examined the effects of herbivory by the mirid, Eccritotarsus catarinensis, on water hyacinth grown at high, medium and low nitrogen (N) and phosphorus (P) nutrient concentrations. Water nutrient concentration appears to be the overriding factor affecting plant growth parameters of water hyacinth plants—at high nutrient concentrations, leaf and daughter plant production were more than double than at low nutrient concentrations, while stem length was twice as great at high nutrient concentrations compared to low concentrations. Chlorophyll content was also twice as high at high nutrient concentrations than low concentrations. Conversely, flower production at high nutrient concentrations was less than half that at low concentrations. Herbivory by E. catarinensis did not have as great an effect on water hyacinth vigour as nutrient concentration did, although it significantly reduced the production of daughter plants by 23 ± 9%, the length of the second petiole by 13 ± 5%, and chlorophyll content of water hyacinth leaves by 15 ± 6%. In terms of insect numbers, mirids performed better on plants grown under medium nutrient conditions (99 ± 28 S.E.), compared to high nutrient concentrations (52 ± 27 S.E.), and low nutrient concentrations (25 ± 30 S.E.). Thus, these results suggest that the fastest and most significant reduction in water hyacinth proliferation would be reached by lowering the water nutrient concentrations, and herbivory by E. catarinensis alone is not sufficient to reduce all aspects of water hyacinth vigour, especially at very high nutrient concentrations.

Compression Characteristics of Water Hyacinth Plant

Studies were carried out to observe the effect of compression pressure on compression characteristics of water hyacinth (Elchhorma crassipes) plant. There was rapid reduction in volume and weight and bulk density of the compressed plant during initial and later stages of compression process. Compression pressure of 2.63 MPa was required to get maximum volume (94 %) and weight (29.76 %) reduction of water hyacinth.