Effect of allelopathic compounds produced by Cistus ladanifer on germination of 20 Mediterranean taxa

Abstract

In order to analyze the extent to which allelopathic action of Cistus ladanifer may influence the successional progression towards Mediterranean sub-climacic shrublands and the geographical distribution of other species, the inhibitory effect of Cistus ladanifer extracts on the germination of 20 Mediterranean species was analyzed. Five of the species tested were characteristic of maquis sub-climacic shrublands: Arbutus unedo, Adenocarpus argyrophyllus, Phillyrea angustifolia, Phillyrea latifolia, and Rhamnus alaternus. Tests were also carried out on 6 Cistaceae species in order to evaluate the auto-toxicity rate of allelopathic extracts: Halimium umbellatum subsp. viscosum, Halimium ocymoides, Cistus ladanifer, Cistus salvifolius, Cistus monspeliensis, and Cistus populifolius. Nine herbaceous species sharing the natural habitat with C. ladanifer were also examined. Results confirmed a clear inhibitory and delaying effect of aqueous C. ladanifer-leaf extracts on the germination of P. angustifolia, P. latifolia, R. alaternus, H. ocymoides, C. populifolius, Erysimum lagascae, Brassica barrelieri, Silene tridentata, and Moricandia moricandioides. Assays with soil collected below the canopy of the C. ladanifer community showed more pronounced inhibitory effect on sub-climacic shrub species than the aqueous extracts. In contrast, the opposite pattern was detected when analyzing the allelopathic effect of natural soil on Cistaceae and herbaceous species. Allelopathic compounds produced by C. ladanifer showed little auto-toxicity. The inhibitory effect of phytotoxic compounds accumulated in the jaral soil upon germination of A. unedo, B. barrelieri, and M. moricandioides was eliminated by heating soil at 150°C for 10 min. Phenolic compounds (i.e. ferulic, p-hydroxybenzoic, vanillic, p-coumaric, and caffeic acids) and terpenes (i.e.a and b-pinene) with allelopathic documented effect were detected in the aqueous extracts and soil samples used in the analyses. We suggest that the allelopathic effect of C. ladanifer may influence the composition and structure of Mediterranean communities where the species is present, since it hinders the establishment of some sub-climacic species and may reduce the area occupied by numerous herbaceous species.

Seed germination characteristics of Phillyrea angustifolia L. and P. latifolia L. (Oleaceae), two Mediterranean shrub species having lignified endocarp

“…These results are in agreement with optimal germination temperature for most Mediterranean shrub species ranging between 15 ºC and 20 ºC (Thanos et al 1992(Thanos et al , 1995. Alternating temperatures (20/7 ºC and 25/15 ºC) resulted in low germination percentages, although previous works stated that Phillyrea seeds germinated a 90% after 60 days at 20/7 ºC (Herranz et al 2006), or a 90%…”

Seed germination of Phillyrea angustifolia L., a species of difficult propagation

“…A variation in seed germination requirements among populations also could explain the great differences found in germination response to temperature when compared to previous works. In our assay, germination at 20/10 ºC was 75%, while previous assays with P. angustifolia seeds collected in a different Spanish population obtained values of 10% germination at 20/7 ºC (Mira et al, 2015b) or values of 90% at 20/10 ºC or 20/7 ºC (García-Fayos et al, 2001;Herranz et al, 2006). Intraspecific variation in seed response to GA3 also could explain that while our data show that GA3 is detrimental to seed germination, previous results indicated that GA3 allowed high germination (Mira et al, 2015b).…”

Fitotoxicidad De Aceites Esenciales Y Extractos Acuosos De Plantas Mediterráneas Para El Control De Arvenses

“…Los exudados secretados por las hojas de C. ladanifer mostraron actividad inhibitoria de la germinación de especies herbáceas, que no se encuentran normalmente en los jarales (Chaves et al, 1993;Chaves y Escudero, 1997;Chaves et al, 2001a;Chaves et al, 2001b;Chaves et al, 2003). Extractos acuosos de hojas de C. ladanifer se ensayaron frente a la germinación de 20 especies que normalmente comparten su hábitat (Herranz et al, 2006 En diferentes poblaciones de C. ladanifer se estudió la variación cuantitativa y cualitativa del exudado de sus hojas y tallos, incluyendo el contenido en geninas de flavonoides (Sosa et al, 2005). Fueron establecidos dos grupos de poblaciones, por las diferentes condiciones climáticas en que se desarrollaban.…”