Assessment of the Allelopathic Potential of Juniperus ashei on Germination and Growth of Bouteloua curtipendula

Abstract

Potential allelopathic compounds of Juniperus ashei Buchh. (Ashe juniper) and their effect on a native grass were determined in laboratory and field studies. Solid-phase microextraction and gas chromatography/mass spectrometry were used to determine if monoterpenes found in the essential oils of J. ashei are released in leaf and litter leachate, as well as volatilized from leaf tissue. Camphor, bornyl acetate, and limonene were found in leaf and fresh litter leachates; however, degraded litter did not contain any of these compounds. Camphor was the most common potentially allelopathic compound found in J. ashei leaf and litter leachate and in volatiles from leaf tissue. The effects of leaf and litter tissue on the germination of Bouteloua curtipendula (Michx.) Torr. (side-oats grama) was tested by using the "sandwich agar method". The highest germination of B. curtipendula (29.6%) occurred in the control, which was significantly higher than fresh litter (13.2%) and degraded litter (16.2%). The lowest germination (6.2%) occurred with J. ashei leaves. In the field experiment, aboveground dry mass of B. curtipendula was evaluated in relation to position within the canopy and intercanopy of J. ashei adult trees when light and water were held constant across locations. Aboveground dry mass of B. curtipendula was significantly greater in the intercanopies of J. ashei (163.7 g m(2)) compared to the dry mass in the understory (44.8 g m(2)) and dripline (44.5 g m(2)), suggesting some negative influence by J. ashei. Chemical analyses indicate that monoterpenes are released through leaching and volatilization from J. ashei, and germination and field studies suggest that these compounds inhibit B. curtipendula.

Chemical characterization and allelopathic potential of volatile oil ofEucalyptus tereticornisagainstAmaranthus viridis

“…In nature, allelochemicals released from plants show synergistic, antagonistic, or additive effects and bring about allelopathic expressions (Einhellig 1996). Nevertheless, our findings are in agreement with earlier reports of allelopathic potential of volatile oils/constituent monoterpenes against other plants (Angelini et al 2003;Azirak and Karaman 2008;Kordali et al 2009;Young and Bush 2009;Kaur et al 2010). Batish et al (2004Batish et al ( , 2006aBatish et al ( , 2006b reported allelopathic potential of monoterpene-rich oil from another species of Eucalyptus, i.e.…”

Allelopathic effect of Schinus molle essential oils on wheat germination

“…Nevertheless, literature data could provide precious information to discuss the observed results. So, previous studies have reported that essential oils and individual monoterpenes, such as limonene, a-pinene, terpinen-4-ol, bornyl acetate, citronellal, camphor, 1,8-cineole, thymol, geraniol, menthol, borneol and a-terpineol strongly inhibit seed germination and plant growth of some agricultural crops and weeds (Vaughn and Spencer 1993;Abrahim et al 2000;Romagni et al 2000;De Feo et al 2002;Scrivanti et al 2003;Batish et al 2004;Bulut et al 2006;Singh et al 2006;Kordali et al 2009;Young and Bush 2009). The exact mechanism by which germination and radicle elongation is affected by S. molle volatile oil is unknown.…”

“…The allelopathic potential of some essential oils has been previously reported (De Feo et al 2002;Gniazdowska and Bogatek 2005;Mao et al 2006;Young and Bush 2009). Scrivanti et al (2003) investigated the allelopathic potential of the essential oil of the closely related species, S. areira, and found strong inhibitory activity of the root growth of Zea mays seedlings.…”

“…More recently, Kordali et al (2009) showed that the essential oils from two Achillea species have inhibitory effects on the germination and seeding growth of Amaranthus retroflexus, Cirsium arvense and Lactuca serriola. In laboratory and field studies, Young and Bush (2009), reported that the volatile essential oils of Juneperus ashei inhibit the germination and growth of Bouteloua curtipendula. To the best of our knowledge, until now, no data about the allelopathic effects of S. molle essential oils are reported.…”

Allelopathy of a native grassland community as a potential mechanism of resistance against invasion by introduced plants

“…Given that invasive plants are obviously native in some parts of the world, it is certainly not surprising that native plants can also produce allelopathic chemicals (Reichard and White 2001;Young and Bush 2009). However, despite the fact that Rabotnov's hypothesis was posed more than three decades ago (Rabotnov 1982), there is little knowledge about the impact of allelopathic chemicals of native plants on introduced plants.…”