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The aim of this research was to test the effects of vineyard soil management practices combined with deficit irrigation strategies on the performance of the grapevine (Vitisvinifera L.) red variety Tempranillo. Two soil management practices (soil tillage-ST and permanent resident vegetation-RV) were combined with three deficit irrigation treatments (regulated deficit irrigation-RDI, partial rootzone drying-PRD and conventional sustained deficit irrigation-DI) during two growing cycles. Compared to ST, RV reduced soil water content during spring, inducing a significant reduction in vine vegetative growth, yield and must titratable acidity. The effects of irrigation treatments were not much pronounced. Only in the second season RDI showed a significant reduction on vine vegetative growth, yield and must titratable acidity as compared to PRD and DI whose results were similar to one another. In a dry area such as ours and a low vigor vineyard, the combination of resident vegetation with deficit irrigation treatments should be carefully considered as it can reduce yield without any benefits to grape quality. In this site the conventional deficit irrigation should be preferred to RDI and PRD as it is technically the simplest deficit irrigation strategy and has enabled an efficient control of vegetative growth without negative impact on yield and berry composition as compared to the other irrigation treatments.

Eugenol (1-allyl-3-methoxy-4-hydroxybenzene; CAS No. 97-53-0), a compound extracted from clove oil and marjoram, is widely used as a food flavouring substance and is present in spices such as basil, cinnamon and nutmeg. It is also used in dentistry as an antiseptic and analgesic. Structural similarities with the class IIB IARC carcinogen safrole raises questions on its putative carcinogenicity. We evaluated the genotoxicity of eugenol in V79 cells using chromosomal aberrations (CAs), with and without rat liver biotransformation (S9). Eugenol induced CAs, with significant increases (3.5% aberrant cells) at 2500 microM, demonstrating cytotoxicity at higher doses. S9 increased the induction of CAs in a dose-dependent manner to 15% at 2500 microM, with a high frequency of chromatid exchanges. In particular, an increase of endoreduplicated cells was observed, from 0% at control levels to 2.3 and 5% at 2000 microM, without and with S9, respectively. Since endoreduplication has been linked to inhibition of topoisomerase II, the topoisomerase II inhibitor ICRF-193 was used as a control inducer of endoreduplication (0.1-0.5 microM), increasing the number of endoreduplicated cells from 0% (control) to 3.5% (0.5 microM). S9 did not influence endoreduplication by ICRF-193. Both eugenol and ICRF-193 were also assayed for inhibition of topoisomerase II, and both showed a dose-dependent inhibitory effect, with ICRF-193 being a more potent inhibitor. Our results confirm that eugenol is genotoxic and raises the possibility of it having topoisomerase II inhibiting activity.

Eighteen populations of the endangered aromatic and medicinal plant Mentha cervina (Lamiaceae) were sampled across its natural range, in the western half of the Iberian Peninsula, and inter-simple sequence repeats (ISSRs) markers were used to assess genetic diversity and population structure. M. cervina populations exhibited a relatively low genetic diversity (percentage of polymorphic loci PPB ¼ 14.2-58.3%, Nei's genetic diversity H e ¼ 0.135-0.205, Shannon's information index I ¼ 0.08 À 0.33). However, the genetic diversity at species level was relatively high (PPB ¼ 98.3%; H e ¼ 0.325; I ¼ 0.23). The results of the analysis of molecular variance indicated very structured populations, with 50% of the variance within populations, 44% among populations and 6% between regions defined by hydrographic basins, in line with the gene differentiation coefficient (G ST ¼ 0.532). A Mantel test did not find significant correlation between genetic and geographic distance matrices (r ¼ 0.064), indicating that isolation by distance is not shaping the present genetic structure. The levels and patterns of genetic diversity in M. cervina populations were assumed to result largely from a combination of evolutionary history and its unique biological traits, such as breeding system, low capacity of dispersion, small effective size and habitat fragmentation. The high genetic differentiation among populations indicates the necessity of conserving the maximum possible number of populations. The results also provide information to select sites for ex situ conservation. Optimal harvesting strategies, cultivation and tissue culture should also be developed as soon as possible to guarantee sustainable use of the species under study.