Laboratory experiments were performed to determine phytotoxic potentials of white top (Lepidium draba) methanol extracts (root, stem and leaf) on germination and early growth of corn (Zea mays) and redroot pigweed (Amaranthus retroflexus). Furthermore, the effects of different methanol extracts of L. draba on the phytohormone (indole-3-acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA) and zeatin) levels of corn and redroot pigweed were investigated. It was observed that all concentrations of methanol extracts of root, stem and leaf of L. draba inhibited germination, radicle and plumule elongation when compared with the respective controls. Besides this, the degree of inhibition was increased in concert with increasing concentrations of extracts used. On the other hand, phytohormone levels changed with the application of different extract concentrations. Comparing with the control, the GA levels significantly decreased while the ABA levels increased in all the application groups. Zeatin and IAA levels showed changes depending upon the applied extracts and concentrations.
AhnJKChungIM (2000) Allelopathic potential of rice hulls on germination and seedling growth of barnyardgrass. Agronomy Journal92: 1162–1167.
2.
BlumUShaferRLehmenME (1999) Evidence for inhibitory allelopathic interactions including phenolic acids in field soils: concept vs. an experimental model. Critical Reviews in Plant Sciences18: 673–693.
3.
BonMCHurardCGaskinJ. (2005) Polymorphic microsatellite markers in polyploid Lepidium draba L. subsp. draba (Brassicaceae) and cross-species amplification in closely related taxa. Molecular Ecology Notes5: 68–70.
4.
Bousquet-MelouALouisSRoblesC. (2005) Allelopathic potential of Medicago arborea, a Mediterranean invasive shrub. Chemoecology15: 193–198.
5.
CakmakIMarschnerHBangertF (1989) Effect of zinc nutritional status on growth, protein metabolism and levels of indole-3-acetic acid and other phytohormones in bean (Phaseolus vulgaris L.). Journal of Experimental Botany40: 404–412.
6.
ChonSUKimJD (2002) Biological activity and quantification of suspected allelochemicals from alfalfa plants parts. Journal of Agronomy and Crop Science188: 281–285.
7.
El-KhawasSAShehataMM (2005) The allelopathic potentialities of Acacia nilotica and Eucalyptus rostrata on monocot (Zea mays L.) and dicot (Phaseolus vulgaris L.) plants. Biotechnology4: 23–34.
8.
FujiokaSSakuraiAYamaguchiI. (1986) Flowering and endogenous levels of plant hormones in Lemna species. Plant and Cell Physiology27: 1927–1304.
9.
GaskinJFZhangDYBonMC (2005) Invasion of Lepidium draba (Brassicaceae) in the western United States: distributions and origins of chloroplast DNA haplotypes. Molecular Ecology14: 2331–2341.
10.
HierroJLCallawayRM (2003) Allelopathy and exotic plant invasion. Plant and Soil256: 29–39.
11.
JeffersonLVPennacchioM (2003) Allelopathic effects of foliage extracts from four Chenopodiaceae species on seed germination. Journal of Arid Environment55: 275–285.
12.
KamalJBonoA (2008) Allelopathic potential of sunflower (Helianthus annus L.) on soil metals and its leaves extracts on physiology of wheat (Triticum aestivum L.) seedlings. African Journal of Biotechnology7: 3261–3265.
13.
KuraishiSTasakiKSakuraiN. (1991) Changes in levels of cytokinin in etiolated squash seedlings after illumination. Plant and Cell Physiology32: 585–591.
14.
LyonsKE (1998) Element stewardship abstract for Cardaria draba (L.) Desv., heart-podded hoary cress, Cardaria chalepensis (L.) Hand-Maz., lens-podded hoary cress and Cardaria pubescens. (CA Meyer) Jarmolenko, globe-podded hoary cress. The Nature Conservancy Team, Arlington, VA. Available at: http://tncweeds.ucdavis.edu/esadocs/documnts/card_sp.html(accessed 15 November 2008).
15.
MulliganGAFranktonC (1962) Taxonomy of the genus Cardaria with particular reference to the species introduced into North America. Canadian Journal of Botany40: 1411–1425.
16.
MutluSAticiOEsimN (2010) Bioherbicidal effects of essential oils of Nepeta meyeri Benth on weed spp. Allelopathy Journal26(2): 291–300.
17.
QasemJR (1993) Allelopathic effects of some common weed species in cereal crops. Dirasat20B: 7–28.
18.
QasemJR (1994) Allelopathic effect of white top (Lepidium draba) on wheat and barley. Allelopathy Journal1: 29–40.
19.
QasemJR (2001) Allelopathic potential of white top and Syrian sage on vegetable crops. Agronomy Journal93: 64–71.
RiceEL (1979) Allelopathy: an update. Botanical Review45: 17–109.
22.
RidenourWCallawayRM (2001) The relative importance of allelopathy in interference: the effects of an invasive weed on a native bunchgrass. Oecologia126(3): 444–450.
23.
RiosJLVGarciaJFE (1998) Catalogo de Malezas de Mexico. Mexico DF: Universidad Nacional Autonoma de Mexico y el Fondo de Cultura Economica.
24.
RutherfordMCPowrieLW (1993) Allelochemic control of biomass allocation in interacting shrub species. Journal of Chemical Ecology19(5): 893–906.
25.
TurkerMBattalPAgarG. (2008) Allelopathic effects of plant extracts on physiological and cytological processes during maize seed germination. Allelopathy Journal21: 273–286.
26.
TurkerMDemirelKUzunY. (2005) Determination of phytohormones level in some dried and fresh macrofungi taxa. Phyton45: 145–157.
27.
UnyayarSTopcuoğluSFUnyayarA (1996) A modified method for extraction and identification of indole-3-acetic acid (IAA), gibberellic acid (GA3), abscisic acid (ABA) and zeatin produced by Phaneroochaete crysosporium ME446. Bulgarian Journal of Plant Physiology22: 105–110.
28.
USDA (2004) The Plants Database. Baton Rouge, LA: National Plant Data Center. Available at: http://plants.usda.gov(accessed 12 November 2008).
