Phytotoxic activity of selected Medicinal and Aromatic plants (MAPs)

Provelengiou S.1, Gavriil E.1, Fanouriou E.1, Tarantilis P.2, Economou G.11 Agricultural University of Athens (A.U.A.), Department of Crop Science, Iera Odos 75, 11855, Athens, Greece.

2Agricultural University of Athens (A.U.A.), Department of Food Science and Human Nutrition, Iera Odos 75, 11855, Athens, Greece.

The species of the botanical genus Origanum and Corydothymus are widespread in theMediterranean areas. Both plants produce hydrosols containing traces of bioactive essential oils.The aim of this study : Evaluation of the effectiveness of hydrosols (H) bioactivity extractedfrom two different MAPs: Origanum vulgare spp. hirtum (L.) (Fig. 1) and Coridothymus capitatus(L.) Reichenb. fil. (Fig.2)

Fig. 3,4: Hydrodistillation, essential oil & hydrosols Fig. 5: GC-MS

OBJECTIVES

Fig. 1: Origanum vulgare spp. hirtum (L.) Fig. 2: Coridothymus capitatus (L.) MATERIALS AND METHODS

7th International Weed Science Congress (IWSS)19-25 June 2016, Prague, Czech Republic.

ID: 805

REFERENCESG. Economou , I. Travlos, A. Folinas & A. Karamanos 2007. “Greek oregano (Origanum vulgare ssp. hirtum) as allelopathic plant.” J. of Food,Agriculture & Environment Vol.5 (1) : 348-351.

DILUTION: The hydrosols and aqueous dilutions of: 100%, 50%, 25%, 12,5%, 6,25%, 3,125% v/v were tested for their phytotoxicity on the weed:Lolium multiflorum Lam. and on the bioindicators: Avena sativa L., in Petri dishes and Lemna minor L. in screw cap vials . The applied quantity was2 ml/replicate and 3 replicates were used per dilution.

ORIGIN: The examined MAPs were originated from Ikaria, an island in the north Aegean sea and were cultivated in Agricultural University ofAthens for six years.

DISTILLATION: Air-dried parts (leaves and inflorescences) of the two studiedMAP’ were subjected to hydrodistillation for 4 h by using a conventionalClevenger-type apparatus (Fig 3). The essential oil was dried over anhydroussodium sulphate and stored (Fig 4). The existed essential oil in hydrosols wasanalyzed in GC-MS for qualitative and quantitative features.(Fig 5).

Results from GC-MS of O. vulgare spp. hirtum (Fig. 6a) andCoridothymus capitatus (Fig. 6b) essential oil.

RESULTS AND DISCUSSION

Estimating the Inhibitory Index (I 50%) based on dose response curves O. hirtum H appeared to be more phytotoxic compare to C. capitatus onL. multiflorum A. sativa. (Table 1.)

The H of O. hirtum (Fig 7a) exhibited higher bioactivity even in lowerconcentrations on L. multiflorum, A. sativa and L. minor compared to C. capitatus H (Fig 7b).

1 2

3

4

1 2

3

4

Fig. 6a Fig. 6b1. p-cymene

2. γ –terpinene

3. Carvacrol

4. Caryophyllene

Fig. 6a: Chromatograph of O. hirtum Fig. 6b: Chromatograph of C. capitatus

Higher concentrations of both MAPs H prevented the seedgermination and the seed radicle length, whereas lowerconcentrations amplified both physiological procedures whencompared to control.

The depolarization of L. minor was conducted faster in case of O. hirtumhydrosols (in 3 days) compared to C. capitatus (in 7 days). (Fig.8)

The increasing interest to obtain alternative new herbicidal agents for weedcontrol, the data showed that the MAPs have a great potential as“phytochemical pool”, due to their generalized environmentally acceptance asnatural biodegradable compounds

Fig. 7a,b: Effect of H of O. hirtum and C.capitatus on germination of L.multiflorum (7a) and A. sativa (7b) seeds.

Fig. 7a Fig. 7b

Tested speciesI 50% - Origanum

hydrosol

I 50% -Corydothymus

hydrosol

L. multiflorum 0.31 0.51

A. sativa 0.27 0.50

Table 1: I 50% of O. hirtum and C. capitatus hydrosols.

Fig. 8: Depolarization of L. minor