Connecticut State University

1997-98 University Research Grant Proposal Cover Sheet

Name: Ross E. Koning

University: Eastern CSU           Department: Biology

Address: Goddard Hall, Willimantic, CT 06226

Email: koning@ecsu.ctstateu.edu           Phone: 465-5327

Is this a joint proposal submitted with (an)other faculty member(s)? No
If YES, who are the other proposers? NA

Project Title: Allelopathic relations between Apiaceae species and Lactuca sativa

Abstract (limit to 100 words):

The proposed research continues an examination of potential allelopathic relationships between members of the carrot family (Apiaceae) and lettuce. In previous studies I have demonstrated that rape (Brassica rapa), radish (Raphanus sativus), carrot (Daucus carota), and celery (Apium graveolens) do not inhibit, while the seeds of fennel (Foeniculum vulgare) do inhibit seed germination. The proposed work will screen a range of other Apiaceae species for allelopathic potential. More importantly, it will determine whether fennel leaf and stem litter or soil taken from natural stands of fennel inhibit lettuce seed germination. This information is vital to any demonstration of natural allelopathy.


 

PROPOSAL NARRATIVE

Historical Significance. Allelopathy, a kind of chemical defense initiated by one plant to inhibit the growth of another species nearby is a controversial subject. Many authors have made claims that allelopathy is a natural interaction, but few studies have demonstrated this without interfering variables or considerable mis- or over-interpretation. Recently a student and I successfully refuted one claim about allelopathy in Raphanus (Santaniello and Koning, 1996). Much less is known about the chemistry of allelopathy. Allelopathy may improve colonization by successional species, or may explain the transitions to the next step in succession. It may also explain failure of crops produced in rotation sequences with other species in agriculture.

A Model System. Lactuca sativa, common garden lettuce, is an outstanding choice for studies on seed germination. The mechanism of its germination has been thoroughly studied. It is known, for example, that red (660 nm) light and gibberellic acid stimulate seed germination via a well-described mechanism involving the de novo synthesis of hydrolytic enzymes, including alpha-amylase. The seeds (botanically they are fruits--cypselas) are small and they germinate in less than two days. This rapid germination permits studies on seed germination to be completed in a very short time. This feature is helpful for the screening part of the project, but is critical to the field portion of the proposed research.

The allelopathic species to be tested include members of the family, Apiaceae (formerly Umbelliferae). This family includes some very common vegetable and herb plants: anise, caraway, carrot, celery, chervil, coriander, dill, fennel, lovage, parsley, parsnip, poison hemlock and water-hemlock. The family is known for its essential oils which are the source of the characteristic flavors of these plants and seeds. Interestingly these very oils are well known chemically and can be toxic in large doses.

The proposed work will screen members of the Apiaceae for potential allelopathic effects on lettuce seed germination. The seeds are commonly available and relatively inexpensive which is helpful since large numbers are required for the proposed work. Natural stands of certain species are available for testing parts of plants other than seeds for allelopathic potential.

Research Problem. The research foci are 1) to determine which species of Apiaceae may be allelopathic to lettuce seed germination, and 2) to demonstrate whether only seeds or leaf litter, stem litter, and soil found in natural stands of Apiaceae species can inhibit lettuce seed germination.

Proposed Research. The basic project test is fairly simple in design. A counted number of lettuce seeds is placed on Whatman #1 filter paper moistened with 5 mL distilled water in a 10 cm diameter Petri dish. After two days incubation in dim light, the number of germinated seeds is counted and expressed as percent germination. Many replicates permit statistical analysis and the software and hardware for statistical analysis is on-hand.

The manipulations include adding a counted number of seeds of another species, or adding a measured weight of leaf litter, stem litter, or soil from natural stands of other species prior to incubation. Dose responses to each of these variables are generated with regression analysis to show any genuine pharmacological effect.

The natural stands of Apiaceae include important stands of fennel and hedge-parsley near Whalebone Bay in Bermuda. Here the climate is Mediterranean and supports these naturalized populations. My assistant, Steven Lamoureux, and I have observed this stand in a previous trip to Bermuda. In May, Steven and I will conduct the first part of the field project on Bermuda in conjunction with the Tropical Biology (BIO 320/520) course. As this is Steven's second excursion with the course, he is to spend his nine days working on this project. The rapid germination of lettuce will allow us to finish the data collection in this time-frame.

The remaining field work and laboratory work will be completed over the summer research season: some before and the rest after the trip to Bermuda. The screening of the range of Apiaceae species available is also a rapid process thanks to our choice of lettuce as the test organism. It is expected that this project can be completed by September 1, 1997.

Publication. My prior publication on this subject took several months to reach print, so I suspect that this will be the case for the proposed work as well. The interest generated by the first article and its color version on the World-Wide-Web (http://koning.ecsu.ctstateu.edu) should make acceptance of the manuscript for this project likely. The article should be distributed by fall 1998.

Communication. The lag-time for publication is unacceptable. In plant physiology we rely on pre-publication communication of research findings at national meetings. The results will be reported at the summer 1998 meetings of the Botanical Society of America and/or the American Society of Plant Physiologists. The results will also be put on my HTTP server for broad review on the World-Wide-Web (http://koning.ecsu.ctstateu.edu). This form of communication, with colleague review and comment prior to traditional publication, is becoming an important avenue for the improvement of our discipline.

Concluding Remarks. In summary, the proposed research meets one of the priorities of the University Grants Committee. The project enhances the educational mission, visibility, and research stature of CSU and also assists me in completing my ongoing research project. It further provides a good experience in experimental laboratory and field research for a deserving CSU student.


 

PROPOSED BUDGET

Plant Culture Supplies
Seeds, Filter Paper,
Petri Dishes, Forceps, etc.
$ 350
Growth Analysis Supplies
Reticules and batteries for B&L Comparator$ 50
Computer software and hardware for data processing0
Publication Costs
Graphic Arts Films, Processing, Mounts$ 100
Student Assistant
Steven Lamoureux, Biology major$ 1,000
Personnel Stipend Support
Ross E. Koning, (Attached Curriculum Vitae)$ 2,000
Total Amount REQUESTED$ 3,500


 
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