Changes inEucalyptus camaldulensisessential oil composition as response to drought preconditioning

Abstract

Water deficit, a common constraint in forestry, is the main cause of plant stress during plantation. The survival and growth of seedlings is also compromised by herbivory during establishment. The potential of nursery preconditioning to enhance survival chances of future trees by reducing palatability or attracting beneficial insects as a result of changes in chemical defences may be an answer to overcome this situation. Changes in essential oil production and composition were evaluated by GC and GC-MS in Eucalytus camaldulensis seedlings submitted to drought during four weeks at the last stage of nursery period (20 weeks). Significant changes in essential oil relative composition were found. Seedlings (young leaves) submitted to drought developed a terpenoid blend, which has been previously associated to mature leaves and related to their higher resistance towards herbivory. Total amount of non-oxygenated terpenes decreased by 44%, whereas some oxygenated sesquiterpenes (globulol, epiglobulol and ledol) were doubled, and 1,8-cineole content was enhanced by 28.3%.

Insecticidal activity of three plants extracts against Myzus persicae (Sulzer, 1776) and their phytochemical screening

“…Miresmailli et al (2006) and Verma (2012) pointed out the presence of monoterpenes in rosemary whereas Zhang et al (2014) reported its richness in diterpenoid and triterpenoid glycosides. Terpenoids are abundant also in the foliage of E. camaldulensis, providing the characteristic smell as well as being valuable economically and influencing ecological interactions (Leicach, 2010;Külheim et al, 2015). Moreover, in E. camaldulensis oil, monoterpenes were prevalent while sesquiterpene hydrocarbons and oxygenated sesquiterpenes were less represented (Mediouni Ben Jemâa, 2012).…”

Chemical Defenses in Eucalyptus Species: A Sustainable Strategy Based on Antique Knowledge to Diminish Agrochemical Dependency

“…Leaves from seedlings submitted to drought developed an essential oil composition that has been previously reported to be characteristic of mature leaves (Silvestre et al 1997) and related to their higher resistance to herbivory. Total amount of oxygenated terpenes were significantly increased as a result of water deficiency; globulol, epiglobulol, and ledol abundances were doubled, and 1,8-cineole content was enhanced by 28.3%, whereas total amount of non-oxygenated terpenes was significantly decreased (44%) (Leicach et al 2010).…”

“…Potential of nursery preconditioning to enhance survival chances of future trees by reducing their palatability or by attracting www.intechopen.com beneficial insects as a result of changes in chemical defenses may be an answer to overcome environmental adversities (Leicach et al 2010). It can affect leaves quality by modulating their chemical composition, a determinant feature, besides tissues hardness, towards herbivory.…”

“…Alkaloids, terpenoids, glucosinolates, hydroxamic acids, tiophenes, cyanogenic glycosides, disulfures and sulfoxides are less distributed and restricted to particular genera, (Leicach et al, 2009a, Leicach et al 2010, Yaber Grass et al 2011.…”

The interaction between the gall wasp Leptocybe invasa and Eucalyptus camaldulensis leaves: A study of phyto-volatile metabolites

“…The fresh gall wasp-attacked and healthy leaves (100 g each) were cut and immediately subjected to hydrodistillation using Clevengertype apparatus for 3 h (Leicach et al, 2010). The volatile fraction was recovered by decantation and dried over anhydrous sodium sulphate and stored at -20°C until analysis.…”