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Carbohydrate Allocation Patterns in Southern Minnesota Herbicide (endothal) treated Curlyleaf Pondweed (Potomogeton crispus) PopulationsErika Magnusson, Zach Gutknecht and Dr. Christopher Ruhland, PhD
Biology DepartmentMinnesota State University, Mankato
PlantWise et al 2013Frank Koshere et al. nd.Curlyleaf pondweed is the most widely-dispersed nuisance-forming non-native submersed aquatic plant in the state of Minnesota.
Native to Europe and Asia, curlyleaf pondweed is now thoroughly naturalized in North America.
P. crispus Turion BiologyRidged organs that provide:Protection against frostStore carbohydrates used for germinationCan photosynthesize
Peterson, M. et al 2003
Crow Wing Lakes Association et al. 2010
P. crispus BiologyWoolf, T. & Madsen, J. 2003.
Ideal time to initiate management and control efforts
Carbohydrate Low Points
Carbohydrate utilization from storage exceeds carbohydrate production
Plant Life Cycle Vulnerable Periods
My research is attempting to assess if endothall can effectively control P. crispus turions by decreasing carbohydrate concentrations. Purpose of Study
To analyze the effect of endothal on turion viability by measuring turion Total Nonstructural Carbohydrate concentrations (g/ m^2)
Analyze the difference: Between treated and untreated areas within Duck Lake and untreated areas of West Jefferson Lake, and Lake Ballantyne
Goals of This Study
Ballantyne LakeDuck LakeWest Jefferson LakeStudy Lakes
Colorimetric Methods for Determination of Sugars previously cited by Michel Dubois, K.A. Gilles, J.K. Hamilton, P.A. Rebers and Fred Smith (1955). West Jefferson Duck Lake treated Duck Lake untreated Lake BallantyneProcedure
Method Procedure Extraction: Ethanol (EtOH) method Starch Digestion: a amlyase- amyloglucosidase method Sugar analysis with a peroxidase-glucose oxidase/odianisidine reagent (PGO)
One-way Anova and the Post-Hoc is a Dunns method
ConclusionsIt is possible that endothal is affective at decreasing Curlyleaf Pondweed turion TNC Future Research: Endothal affect on Curlyleaf Pondweed turion itself and not just the plant portion. Noticed that turions collected had less ridigity (were softer) in Duck Lake treated areas than DU, WJ and BLDoes endothal prevent nutrient sources from forming in Turions?
BibliographyCrow Wing Lakes Association. (2010, April 29). Curly Leaf Pondweed. In The Website of the 10th and 11th Crow Wing Lakes Association. Retrieved April 14, 2013, from crowwing11.orgKoshere, F. (Photographer). Potamogeton crispus curly pondweed growing in Bone Lake, Wisconsin. [Image of photograph]. Retrieved April 14, 2013, from http://bioweb.uwlax.eduPeterson, M. (2003, May). Mature turions (seeds) that washed to shore. In Curly Leaf Identification. Retrieved April 14, 2013, from http://www.lakeorono.org/CurlyleafID.pdfWolf, T. E., & Madsen, J. D. (2003). Seasonal biomass and carbohydrate allocation patterns in Southern Minnesota curlyleaf pondweed populations. J. Aquat. Plant Manage, 41, 113-118.(2013). Europe; CABI. Retrieved April 14, 2013, from http://www.plantwise.org/
AcknowledgementsZachrie Gutknecht Christopher Ruhland, PhDUndergraduate Research Center-Minnesota State University, Mankato
**Curlyleaf pondweed forms thick monospecic beds.
The dense growth out-competes native aquatic vegetation, degrades lake water quality, and causes problems to navigation and recreation
Signicant time and resources are dedicated every year to the management of curlyleaf pondweed in the Midwest.
Problem: management efforts are often applied without taking into account the plants biology and ecology= inefcient or ineffective control.
*So going to understand a bit biology! need to understand the primary energy structure of Curlyleaf Pondweed.
The primary structure for energy storage is the turion.--- a vegetative propagule that is its main reproductive means
The majority of a turion is comprised of carbohydrates used for germination While the outer casing is designed for protection while in dormancy
Turion itself can photosynthesize.
Factors of Turion invasivenesseasily dispersed by water currentsTurions have a very high germination rateTurions remain viable in sediment for a number of years
On top of their main means of reproduction turions
Curlyleaf Pondweed can colonize in deep and shallow waterIts strong rhizome anchoring system allows it to grow in a variety of different locales and sediment typesPlant can tolerate extreme conditions Extreme conditions: low light and cold temperaturesFound growing under 20 inches of snow covered icePlants will grown from rhizomes of past plants
The major advantage for P. crispus is its life cycle that produces carbohydrate storage organs known as turions, assisting growth during the winter months
Turions sprout as a response to both light and temperature conditions.
Germination : Innate dormancy in summer and growth is blocked
Dormancy is broken by short days and low temperatures
Turions remain dormant in the sediment through summer until cooling water temp triggers germination in the fall
Start growing under iceSprouted turions can remain dormant under the ice
accelerated growth continues with the onset of early spring, when light and temperature conditions are best suitable for growth.
By late spring in Minnesota, culrlyleaf is at its maximum phase of growth By mid summer, the warm water conditions cause Curlyleaf to senesce or age,
dropping turions to the substrate while the rest of the plant rots. The release of nutrients by senescing Curlyleaf can cause problems with water quality (such as depletion of O2), and may further hinder native macrophyte growth
Curlyleaf out competes native Minnesota plants primarily because of its early season maturation ---its at its peak growth when most plants start growing
So it is not that P. Crispus produces turions other plants do that ,,, it is the lifecycle that makes it unique :
It is that the turions are a bonus to CPondweed lifecycle
Turion sprouting in and plant growth occurred in mid September 2001 and mid October 2002,
followed by little or no growth during ice-covered conditions.
Growth resumed in early spring generally speaking--- peak growth mid May and June. Peak biomass occurred at or near the time of peak turion production and plant senescence and summer dormancy soon followed.
*Where to start?
At most vulnerable point! this point the plant is the least capable of recovering from stress or disturbance, indicating the point where the success of management efforts will be maximized.
Previous studies have shown
In other words Low points of carbohydrate storage or the seasonal minimum of stored carbohydrates
indicate potentially vulnerable periods in the plants life cycle
=and may be the ideal time to initiate man- agement and control efforts. Exploiting these low points can lead to improved control of the target species (Madsen 1993a).
**2 goals how herbicides affecting turion viability
Difference between treated and untreated*Turions were randomly collected from Duck Lake and two other non-treated lakes (Ballantyne Lake and West Jefferson)
*Plant samples were analyzed for total nonstructural carbo- hydrates (TNC) in herbicide/non-herbicide treated Potomogeton crispus turions using a procedure called Colorimetric Methods for Determination of Sugars previously cited by Michel Dubois, K.A. Gilles, J.K. Hamilton, P.A. Rebers and Fred Smith (1955).
The dried biomass of turion samplings were separated in to four separate entitesTurions from West Jefferson Duck lake treatedDuck lake untreatedLake ballentyne
*The procedure involves extracting sugars using 80% EtOH from weighted Potomogeton crispus turions, Each of the turions ground and weighed at 25 mg
Starch Digestion: hydrolyzing starch to glucose
Digestive enzyme mixture a-amlylase + amyloglucosidase)
Sugar analysis: measuring glucose hydrolysate (allocated carbohydrate) of each Potomogeton crispus turion.
Samples were analyzed using spec at wavelength 450nm.Percent TNC dry weight and standard error were calculated for each plant component. Data combined for each turion sample batch (WJ, BL, DL_U, DL_T). Total TNC storage (g m -2 ) was calculated for turions
TNC Data analysis.
One- way Anova= Take all samples and tell us if there is a difference or not. Post hoc is going tell us which one is differentand on Sigma Plot..post Hoc is a Dunns method explanation*Explain X and Y axis --- GRAPH 333 took from different areas. WJ, BL, DL and then within DL Untreated and treated areas. Compared all of them based on their average grams of Turion Total Nonstructural Carbohydrates/ m2.
What do we see? DT areas are significantly different from areas in two control lakes: WJ and BL, AND other untreated areas within Duck Lake itself.
DT turions have significantly less turion TNC
.This tells us that herbicide (endothal) is having some affect on turions in DT area.
In DT areas there is a significant decrease in the turions ability to conserve energy for growth.
Conseq. treatments of endothall has not allowed new sprouts from existing turions to survive or new turions doesnt allow new turions to start growing
Endothall main job = disturb growth & photosynth of CLP b/c plant cant photosynth going to pull more carbohydrates from itS main carbohydrate storage organ= TURION!
Although we exp