Basilicum Cv Research Articles

A Culinary and Medicinal Gem: Exploring the Phytochemical and Functional Properties of Thai Basil.

This study aimed to comprehensively evaluate the potential health benefits of Thai basil extracts from two species, Ocimum basilicum var. thyrsiflorum and Ocimum basilicum cv. Jumbo 4320, by investigating their bioactivities, phytochemical composition, and in vitro antioxidant, antimicrobial, and antithrombotic activities. Thai basil extracts from two species (Ocimum basilicum var. thyrsiflorum and cv. Jumbo 4320) were obtained using water, ethanol, and ethyl acetate. Phytochemical analysis revealed chlorophylls, carotenoids, and diverse phenolic compounds. Its water extract boasted the highest total phenolics (459.62 ± 3.07 mg GAE/100 g), outperforming ethanol and ethyl acetate extracts (171.20 ± 1.10 and 66.02 ± 0.99 mg GAE/100 g, respectively). The ethanol extract of Jumbo 4320 also reigned supreme in total flavonoids (557.12 ± 14.27 mg CE/100 g), surpassing its counterparts (209.07 ± 23.31 and 131.41 ± 0.37 mg CE/100 g). O. basilicum cv. Jumbo 4320 extracts exhibited superior antioxidant activity by various assays. Jumbo 4320's water extract further dominated in the DPPH assay (IC50 48.52 ± 1.15 mg/mL), demonstrating superior free radical scavenging compared to ethanol and ethyl acetate extracts (IC50 60.54 ± 0.52 and 82.09 ± 3.18 mg/mL), respectively. While thyrsiflorum's ethanol extract claimed the top spot in the FRAP assay (0.0186 ± 0.00 mmol Fe2+/g), Jumbo 4320's water extract showcased the highest cellular antioxidant activity (80.62 ± 0.00% relative fluorescence intensity) in the DCFH-DA assay. Interestingly, Ocimum basilicum var. thyrsiflorum extracts demonstrated stronger antithrombotic activity at prolonging the prothrombin time at 78.3 ± 17.56 s. While the antimicrobial activity against most tested pathogens was limited, both species' extracts inhibited Bacillus cereus. These findings suggest the potential of Thai basil extracts, particularly from Jumbo 4320, as functional food ingredients with antioxidant and antithrombotic properties.

ECOPHYSIOLOGY AND GROWTH OF BASIL (<i>Ocimum basilicum</i>) UNDER SALINE STRESS AND SALICYLIC ACID

Salinity is one of the major problems of modern agriculture, affecting physiological, growth and plant production. Basil (Ocimum basilicum) is a plant widely used in cooking, and in the pharmaceutical and cosmetics industries. Salicylic acid can be a strategy to mitigate the harmful effects of saline stress on basil plant. The present study aimed to evaluate plants with, gas exchange, chlorophyll a fluorescence and chlorophyll indices of basil (cv. Cinnamon) plants under saline stress and salicylic acid. The experimental design was a randomized block design in a 5x5 incomplete factorial scheme generated through the central composite design. The factors we five electrical conductivities of irrigation water (ECw– 0.5, 1.3, 3.25, 5.2 and 6.0 dS m-1) and five doses of salicylic acid (SA– 0.0, 0.29, 1.0, 1.71 and 2.0 mM), with five replications and two plants per replicate. Growth, gas exchange, chlorophyll a fluorescence and chlorophyll indices of O. basilicum cv. Cinnamon were evaluated. Canonical variables analysis and confidence ellipses (p ≤ 0.01) were performed to study the interrelationship between variables and factors. Salicylic acid alleviated the deleterious effects of salt stress on growth, gas exchange, chlorophyll fluorescence and chlorophyll indices of basil.

Yield, resource use efficiency or flavour: Trade-offs of varying blue-to-red lighting ratio in urban plant factories

With increasing urbanisation and consumer concerns over food miles, indoor urban plant factories are gaining popularity. These offer precise regulation of the crop environment, but optimal light requirements vary between species and according to grower specifications. Here we introduce a novel assessment framework to optimise light quality in urban plant factories accounting for yield, resource use efficiency and flavour, factors that have only been studied separately in previous research. Yield, water and energy use efficiency and flavour of sweet basil (Ocimum basilicum cv. Genovese) and tomato (Solanum lycopersicum cv. Micro-Tom) were determined for plants grown supplied with 100% blue, 66% blue + 33% red, 33% blue + 66% red, or 100% red lighting. In both species, 66% red and 100% red optimised water use efficiency and energy use respectively. For basil, 100% blue light maximised leaf biomass, while 66% red enhanced leaf flavouring volatiles. In Micro-Tom, all treatments produced similar fruit biomass, but 100% red light enhanced flavour-related volatiles in foliage. By considering trade-offs between yield, efficiency and flavour, growers can select bespoke lighting treatments to optimise their product according to specific market demands and minimise environmental impacts.

Variations in composition and bioactivity of Ocimum basilicum cv ‘Aroma 2’ essential oils

The goal of this paper is to study the seasonal influence on the phytochemical composition and bioactivity of Ocimum basilicum L. cv 'Aroma 2' essential oils (EOs), due to considerable interest of this cultivar for the preparation of sauces. By GC-MS analysis, the chemical profiles of EOs from plants harvested in May and in October, were characterized and biological activities were determined. The phytotoxicity on radish (Raphanus sativus L.), lettuce (Lactuca sativa L.), tomato (Solanum lycopersicum L.), and garden cress (Lepidium sativum L.), the antioxidant and the antibacterial properties (towards Gram-positive and Gram-negative strains) as well as the antibiofilm capability, were evaluated. In addition, the total phenolic content was determined. The chemical composition of the oils was influenced by the season, so that the essential oil from plants harvested in May was mainly composed of linalool (48.1 %), while in the October sample eugenol (76.8 %) was the main constituent. Essential oils did not show significant activity against the germination of tested seeds; instead, the radicle growth was inhibited. Both EOs showed good antioxidant activity with an half maximal inhibitory concentration (IC50) 'Aroma 2' May = 6.1 μg/mL, IC50 'Aroma 2' October = 6.6 μg/mL), comparable to vitamin C (IC50 = 3.0 μg/mL). The total phenolic content, with a value of 484.9 mg/g gallic acid equivalent (GAE), confirmed a high antioxidant activity of 'Aroma 2' October essential oil. The EOs and their major compounds, linalool and eugenol, showed a variable degree activity on the tested bacterial strains, in some cases comparable to tetracycline. Both EOs, at the highest dose tested, demonstrated good inhibitory activity of the biofilm produced by all tested strains, with inhibitory percentages not inferior than 58 %. The test of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was employed to evaluate the effect of the oils on cellular metabolism: Pseudomonas aeruginosa was found to be the most sensitive strain.

The effect of reversible permeabilization and post-electroporation resting on the survival of Thai basil (O. Basilicum cv. thyrsiflora) leaves during drying

Horticultural crops have a low tolerance to dehydration. In this paper, we show that the reversible electroporation (200 monopolar, rectangular pulses of 50 µs pulse duration, 760 µs between pulses and nominal field strength of 650 V/cm) of Thai basil leaves followed by 24 h resting before hot air drying at 40 °C enhanced the survivability of the tissues at certain levels of dehydration (moisture ratio = 0.2 and 0.1). However, this increased survival was rather limited. Through measurements of metabolic heat production during resting, rehydration kinetics, respiration and photosynthesis of the rehydrated leaves, we show that resting after the application of a reversible pulse-electric field (PEF) may allow a phase of hardening that has a protective effect on the cells, thus decreasing damage during the subsequent drying phase. Increased preservation of cell vitality would be associated with a more turgid and fresh-like rehydrated product, as cells would have the capacity to retain the rehydration water.

The Short-Term Metabolic Modulation of Basil (Ocimum basilicum L. cv. 'Genovese') after Exposure to Cold or Heat.

Chilling stress in spring and mid-season heat stress are important environmental stresses that can significantly affect plant productivity. The objectives of this study were to understand the effects of cold (4 and 10 °C) or heat (30 and 40 °C) stress on biochemical and physiological traits in leaves and roots of basil (Ocimum basilicum L. cv. ‘Genovese’) young plants. After short-time exposure to mild and severe temperature stresses, both photosynthetic pigments’ and protein, as well as enzymatic and non-enzymatic defense components in basil leaves and roots, were quantified and compared with the control non-stressed plants. It was shown that both cold and heat treatment increase the content of chlorophyll a, chlorophyll b, and carotenoids. Chilling correlated with higher content of soluble proteins in leaves, whereas the concentration of these osmoprotectants in roots was higher under both cold and heat stress. For all tested antioxidant enzymes, higher activity was measured in leaves, and activity was related to temperature stress. SOD, CAT, A-POX, and P-POX activities was induced under heat stress, while the higher activity of SOD, CAT, P-POX, and G-POX was recorded under cold stress, compared to the control. In addition to the induced activity of enzymatic components, the content of secondary metabolites including total phenolics, flavonoids, and total anthocyanins, was several times higher compared to the non-stressed plants. Furthermore, total phenolic content was higher in roots than in leaves. Significant positive correlation can be seen among photosynthetic pigments, SOD, total phenolics, and flavonoids under severe temperature stress (4 or 40 °C) in basil leaves, while for roots, positive correlation was found in the content of secondary metabolites and activity of CAT or peroxidases. Obtained results are discussed in terms of phenotyping of O. basilicum cv. ‘Genovese’ response to heat and chilling stress, which should contribute to a better understanding of merged responses to cold and heat tolerance of this valuable crop.

Changes in growth and essential oil composition of sweet basil in response of salinity stress and superabsorbents application

To evaluate the effect of superabsorbent polymers (SAPs) on the growth, some physiological traits, essential oil (EO) content and composition of sweet basil (Ocimum basilicum cv. Keshkeni luvelu) under salinity stress, a pot factorial experiment in randomized complete design with three replications was done. Treatments included salinity stress levels (0, 40, 80, and 120 mM NaCl) and superabsorbents (Ackoasorb, Terracottem, Stockosorb, and control). The results showed that the growth characteristics, SPAD, K+, and K+/Na+ ratio were decreased by severity of NaCl stress, whereas the application of SAPs have increased them. On the other hand, EO content, membrane permeability, MDA, proline, and Na+ contents were increased under severity of NaCl stress and SAPs application were decreased them, except EO content. At the highest salinity level (120 mM NaCl), the application of the Terracottem reduced membrane permeability and Na+, however, shoot dry weight, shoot to root weight ratio, leaf dry matter and the EO content increased by the Terracottem application. In addition, the Stockosorb application decreased MDA and proline contents, but the percentages of oxygenated monoterpenes, especially linalool and tau-muurolol increased under Stockosorb application. In conclusion, the application of SAPs can alleviate the harmful effects of salt stress on quantity and quality yields of sweet basil.

Characteristics of in vitro seed germination of three basil genotypes under different nutrition

The present study was designed to investigate the effects of different basal medium composition on germination characteristics in three basil genotypes under in vitro conditions. Ocimum basilicum var. basilicum cv. Genovese, Ocimum basilicum var. purpurascens cv. Dark Opal and Ocimum x citriodorum seeds were grown in media with a quarter, half, and full-strength of macroand micronutrients and under different levels of nitrate alone or in combination with different levels of ammonium. Evaluated parameters included germination percentage, mean time to germination, rate of germination, and germination uniformity. Seeds of the studied basil genotypes demonstrated significant differences in germination characteristics depending on the availability of nutrients, but also the nitrogen form used. It was concluded that in order to obtain a high level of germinated seeds with significant speed and uniformity of germination under in vitro conditions culture media composition must be adjusted according to the investigated genotype. The results of this study could improve overall tissue culture conditions for a particular basil genotype.

Integrated nutrient regimes ameliorate crop productivity, nutritive value, antioxidant activity and volatiles in basil (Ocimum basilicum L.)

Basil is a fragrant edible herb with abundant minerals, micronutrients, and pharmacological activities. The effect of organic and chemical fertilizers on the crop biomass, essential oil yield and composition, plant mineral nutrition and antioxidant activity in Ocimum basilicum cv. CIM-SAUMYA (basil) was studied under field conditions. The nutritional quality and antioxidant value of the basil enhanced with the use of different organic and chemical regimes. The field study reveals that the integrated nutrient management comprising poultry manure (PM), farmyard manure (FYM), and chemical fertilizer (CF) gives higher crop yield in basil. PM+CF and FYM+CF treatments produce crop yields that are 60% and 34% higher over the control, respectively. PM+CF resulted in the maximum mean values of chlorophyll-a (0.55mgg−1) and chlorophyll-b (0.063mgg−1). The application of chemical fertilizers culminated in significant changes (p<0.05) in N, P and K contents of basil leaves that were respectively 28%, 36%, and 50% higher over the control. The application of organic fertilizers improved Ca, Mg and vitamin C contents, and antioxidant activity in the basil leaf. The highest level of vitamin C was achieved in the organically amended treatments, i.e., vermicompost (VC) and PM that were 3% higher over the control. The major volatile constituents of the basil oil were methyl chavicol (70.35%–72.60%) and linalool (21.49–30.89%). Other volatile components, i.e., chavicol, β-caryophyllene, α-cadinene, (E)-β-farnesense and γ-muurolene were in a minor amount.

The First Report of Downy Mildew Caused by Peronospora belbahrii on Sweet Basil in Greenhouses in the Czech Republic.

Sweet basil (Ocimum basilicum L.) is an aromatic plant that is cultivated as a pot plant in greenhouses or in fields in the Czech Republic. The plants are intended for direct consumption or for drying. In April of 2012, the first large chlorotic from the middle necrotic spots occurred gradually on leaves of pot plants O. basilicum cv. Genovese in greenhouses in Central Bohemia. The characteristic gray to brown furry growth of downy mildew appeared on abaxial surfaces of leaves in the place of chlorotic spots within 3 to 4 days. The infested leaves fell off in the late stages of pathogenesis. The infestation gradually manifested itself in ever-younger plants and in July, cotyledons and possibly the first true leaves were already heavily infected and damaged and these plants rapidly died. The plant damage reached 80 to 100%, so it was necessary to stop growing the plants in the greenhouse at the end of July. The causal agent was isolated and identified as Peronospora belbahrii Thines by means of morphological and molecular characters (2,3). Conidiophores were hyaline, straight, monopodial, 280 to 460 μm, branched three to five times, ended with two slightly curved branchlets with a single conidia on each branchled tip. The longer branchlets measured 13 to 24 μm (average 18.2 μm), the shorter one 4 to 15 μm (average 9.7 μm). Conidia were rounded or slightly ovoid, from brownish to dark brownish, measured 22 to 31 × 20 to 28 μm (length/width ratio 1.2). A pathogen-specific sequence was detected with the help of the pathogen ITS rDNA specific primers in symptomatic leaves (1). DNA from plant tissues was isolated using the DNeasy plant Mini Kit (Qiagen, Germany) following the standard protocol. PCR was performed using KAPA2G Robust HotStar kit (Kapa Biosystems, United States) according to the conditions recommended in Belbahri et al. (1). The specific products were visualized by electrophoresis through 1.5% agarose gels. Leaves of 20-day-old potted plants O. basilicum 'Genovese' were inoculated by spraying with 5 × 105 conidia/ml of the pathogen. Each pot contained 10 plants. Sterilized distilled water was applied to control plants. Plants were covered with polyethylene bags during the entire incubation period to maintain high humidity, and kept at a temperature of 22 to 24°C. Typical disease symptoms appeared on leaves 5 to 9 days after inoculation. Control plants were symptomless. P. belbahrii was re-isolated from the lesions of inoculated plants, thus fulfilling Koch's postulates. Downy mildew on sweet basil was reported in countries in Africa, Europe, and South and North America (4). To our knowledge, this is the first report of downy mildew on sweet basil in the Czech Republic.

Propriedades do pólen e do estigma de Ocimum basilicum L. (cultivar Maria Bonita) para aumentar a eficiência de cruzamentos em programas de melhoramento

Ocimum basilicum, cv. Maria Bonita (Lamiaceae), conhecido como manjericão, é espécie que apresenta propriedades aromáticas, condimentares e medicinais, por ser rico emóleos essenciais. É muito usado nas indústrias farmacêuticas e de alimentos em geral. O objetivo deste trabalho foi estudar as propriedades do pólen e estigma do manjericão (cultivar Maria Bonita) identificando procedimentos simples que possam contribuir para programas de melhoramento. Para análise da disponibilidade, viabilidade do pólen e receptividade de estigma, botões florais foram coletados de hora em hora ao longo do dia, e lâminas eram montadas e coradas, para observação em microscópio óptico. Foi verificado que o manjericão apresenta antese diurna, assincrônica e com a maioria das flores se abrindo entre 10:00 e 11:00 horas. Quanto ao estudo do pólen foi verificado que a viabilidade manteve-se elevada ao longo do dia e a conservação por até 90 dias demonstrou bons níveis de viabilidade. O estigma apresentou receptividade desde a pré-antese até a pós-antese. Estas informações são relevantes para os melhoristas que desejam fazer seleção de genótipos ou hibridações em programas de melhoramento, contribuindo para aumentar o potencial da espécie que já se destaca como produtora de óleos essenciais.

Levels of antioxidants and nutraceuticals in basil grown in hydroponics and soil

Owing to the traditional phytotherapeutic use of basil and its importance as a basic component of the Mediterranean diet, this research aimed to study the nutraceutical properties of basil ( Ocimum basilicum cv. Genova) grown in hydroponics in comparison with that grown in soil. The antioxidant activities of aqueous and lipid extracts of basil leaves were evaluated both by spectrophotometric detection with the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS + ) and by electron paramagnetic resonance (EPR) detection with the stable radicals peroxylamine disulphonate (Fremy’s salt, hydrophilic) and 1,1-diphenyl-2-picrylhydrazyl (DPPH , lipophilic). From EPR decay kinetics analysis, it was possible to distinguish (in the lipid extract) a fast rate constant and a slow rate constant, likely attributable to two different kinds of lipophilic antioxidants. Hydroponic cultivation improved antioxidant activity of both aqueous and lipid extracts, increasing the contents of vitamin C, vitamin E, lipoic acid, total phenols and rosmarinic acid.

Content, Composition, and Bioactivity of theEssential Oils of Three Basil Genotypes as aFunction of Harvesting

A study was conducted to evaluate the effect of cut on biomass productivity, oil content, composition, and bioactivity of Ocimum basilicum L. (cvs. German and Mesten) and O. sanctum L. (syn. O. tenuiflorum L.) (cv. Local) in Mississippi. Yields of basil herbage and essential oil were high and comparable to those reported in the literature. Essential oil content of O. basilicum cv. German varied from 0.40 to 0.75%, the oil content of cv. Mesten varied from 0.50 to 0.72%, and the oil content of cv. Local (of O. sanctum) ranged from 0.17 to 0.50% in air-dried basil. Herbage and essential oil yields of cvs. German and Mesten of O. basilicum increased with the second and then again with the third cut, whereas herbage and oil yields of cv. Local of O. sanctum increased with the third cut relative to the previous cuts. Overall, essential oil yields were 115, 123, and 51 kg/ha for the cvs. German, Mesten, and Local, respectively. The major oil constituents of cvs. German and Mesten (of O.’basilicum) were (−)-linalool (30–40%) and eugenol (8–30%), whereas the major oil constituents of cv. Local (of O. sanctum) were eugenol (8–43%) and methylchavicol (15–27%). Essential oils from both species grown in Mississippi showed in vitro activity against Leishmania donovani (IC50) 37.3–49.6 µg/mL), which was comparable to the activity of commercial oil (IC50) 40–50 µg/mL). Minor basil oil constituents (+)-δ-cadinene, 3-carene, a-humulene, citral, and (−)-trans-caryophyllene had antileishmanial activity, whereas other constituents were ineffective.

Content, Composition, and Bioactivity of the Essential Oils of Three Basil Genotypes as a Function of Harvesting

A study was conducted to evaluate the effect of cut on biomass productivity, oil content, composition, and bioactivity of Ocimum basilicum L. (cvs. German and Mesten) and Ocimum sanctum L. (syn. O. tenuiflorum L.) (cv. Local) in Mississippi. Yields of basil herbage and essential oil were high and comparable to those reported in the literature. Essential oil content of O. basilicum cv. German varied from 0.40 to 0.75%, the oil content of cv. Mesten varied from 0.50 to 0.72%, and the oil content of cv. Local (of O. sanctum) ranged from 0.17 to 0.50% in air-dried basil. Herbage and essential oil yields of cvs. German and Mesten of O. basilicum increased with the second and then again with the third cut, whereas herbage and oil yields of cv. Local of O. sanctum increased with the third cut relative to the previous cuts. Overall, essential oil yields were 115, 123, and 51 kg/ha for the cvs. German, Mesten, and Local, respectively. The major oil constituents of cvs. German and Mesten (of O. basilicum) were (-)-linalool (30-40%) and eugenol (8-30%), whereas the major oil constituents of cv. Local (of O. sanctum) were eugenol (8-43%) and methylchavicol (15-27%). Essential oils from both species grown in Mississippi showed in vitro activity against Leishmania donovani (IC50 = 37.3-49.6 microg/mL), which was comparable to the activity of commercial oil (IC50 = 40-50 microg/mL). Minor basil oil constituents (+)-delta-cadinene, 3-carene, alpha-humulene, citral, and (-)- trans-caryophyllene had antileishmanial activity, whereas other constituents were ineffective. None of the oil was cytotoxic to mammalian cells.

Stereoselective oxidation of racemic 1-arylethanols by basil cultured cells of Ocimum basilicum cv. Purpurascens

The biotransformation of racemic 1-phenylethanol (30 mg) with plant cultured cells of basil (Ocimum basilicum cv. Purpurascens, 5 g wet wt) by shaking 120 rpm at 25 degrees C for 7 days in the dark gave (R)-(+)-1-phenylethanol and acetophenone in 34 and 24% yields, respectively. The biotransformation can be applied to other 1-arylethanols and basil cells oxidized the (S)-alcohols to the corresponding ketones remaining the (R)-alcohols in excellent ee.

Chemical Investigation of a New Cultivar of Purple Basil (Ocimum basillcum cv. Opal) from Iran

The oil isolated by hydro-distillation of the flowering aerial parts of Ocimum basilicum cv. Opal in an all glass Clevenger-type apparatus gave light-yellowish oil with yield of 0.53% (W/W) based on dry weight. Twenty-one compounds were identified in our investigation in the oil of purple basil cv. Opal. The major components were found to be linalool (49.41%), methyl chavicol (19.41%), 1,8-cineole (13.70%), epi-α-cadinol (2.60%) and eugenol (2.20%).

First Report of Downy Mildew Caused by Peronospora sp. on Basil (Ocimum basilicum) in France.

Sweet basil (Ocimum basilicum) is an economically important herb in several Mediterranean countries. Approximately 30 ha are grown annually in France for fresh and processed consumption. During the spring and fall of 2004, a damaging foliar disease was observed in some crops near Saint Tropez in the French Riviera Region. More than 50% of plants were affected in an organically produced field-grown crop at an altitude of 250 m. Leaves of infected plants were initially slightly chlorotic, especially near the central vein. Within 2 to 3 days, a characteristic gray, furry growth was evident on the lower leaf surface and sometimes on the upper leaf surface. The appearance and severity of the disease was affected by overhead sprinkler irrigation. Basal leaves were severely affected. Microscopic observations revealed sporangiophores branching two to seven times. Sporangiophores, with a length of 250 to 500 μm (average 350 μm), ended with sterigmata bearing single sporangia. Sporangia measured 15 to 25 × 20 to 35 μm (average 22 × 28 μm), were elliptical and grayish in mass. The pathogen was identified as Peronospora sp. on the basis of its morphological characteristics (4). Pathogenicity was confirmed by inoculating leaves of 40-day-old healthy plants with a sporangial suspension (1 × 105 conidia/ml). Three containers with 150 plants each of O. basilicum cv Genovese gigante were used as replicates. Noninoculated plants served as controls. Plants were maintained in a growth chamber at 20°C (12 h of light per day) and 90 to 95% relative humidity. The pathogenicity test was carried out twice. After 6 days, typical symptoms of downy mildew developed on the inoculated plants, and Peronospora sp. was observed on the leaves. Noninoculated plants did not show symptoms. To our knowledge, this is the first report of Peronospora sp. on basil in France. Peronospora sp. was previously reported on sweet basil in Italy (1) and P. lamii on sweet basil in Uganda (3). Seed transmission (2) is suspected as the reason for recent outbreaks in Europe.

First Report of Downy Mildew on Basil (Ocimum basilicum) in Italy.

Sweet basil (Ocimum basilicum) is an economically important herb in several Mediterranean countries. Approximately 80 ha are grown annually in Italy for fresh and processed consumption. In 2003, a damaging foliar disease was observed in several greenhouses located in the Liguria Region of northern Italy. More that 50% of the plants were affected. Leaves of infected plants were initially slightly chlorotic, especially near the central vein. Within 2 to 3 days, a characteristic gray, furry growth was evident on the lower surface of infected leaves. These symptoms sometimes occurred on the top sides of leaves. Although the distribution of the disease was generally uniform, symptoms appeared first in a patchy pattern in the central part of the greenhouses where air temperature and relative humidity were highest. Where air circulation was apparently poor, bottom leaves were severely affected by the disease. Microscopic observations revealed conidiophores branching two to seven times. Conidiophores with a length of 250 to 500 μm (average 350 μm) ended with sterigmata bearing single conidia. Conidia measured 15 to 25 × 20 to 35 μm (average 22 × 28 μm) and were elliptical and grayish in mass. The pathogen was identified as a Peronospora sp. based on its morphological characteristics (3). Pathogenicity was confirmed by inoculating leaves of 40-day-old healthy plants with a conidial suspension (1 × 105 conidia per ml). Three containers containing 150 plants each of O. basilicum cv. Genovese gigante were used as replicates. Noninoculated plants served as controls. Inoculated and noninoculated plants were maintained in a growth chamber at 20°C (12 h of light per day) and 90 to 95% relative humidity. The pathogenicity test was carried out twice. After 6 days, typical symptoms of downy mildew developed on the inoculated plants and a Peronospora sp. was observed on the leaves. Noninoculated plants did not show symptoms. To our knowledge, this is the first report of a Peronospora sp. on basil in Italy. Peronospora sp. and P. lamii were previously reported on sweet basil in Uganda (1,2).

First Report of an Isolate of Pelargonium zonate spot virus in Commercial Glasshouse Tomato Crops in Southeastern France.

In summer 2000, symptoms similar to Pelargonium zonate spot virus (PZSV) were observed for the first time on tomato plants in southeastern France. The plants were from commercial glasshouse fresh-market crops. Symptoms observed were chlorotic mottling with bright yellow distinct rings on leaves and curved line patterns on stems. Fruit symptoms included chlorotic and necrotic spotting, marked concentric ring patterns, and distortions. Diagnosis was made from symptomatic leaves and fruits by mechanical inoculation on a set of host plants. Local chlorotic and necrotic lesions were observed on Chenopodium amaranticolor, C. quinoa, Cucumis sativus cv. Marketer, Cucumis melo cv. Vedrantais, Phaseolus vulgaris cv. Pinto, Vicia faba cv. D'Aguadulce, Vigna unguiculata cv. Black Eye, and systemic symptoms were observed on Capsicum annuum cvs. Yolo Wonder, Yolo Y, Florida VR2, and Criollo de Morelos 334, Datura stramonium, Lycopersicon esculentum cvs. Momor and Stevens, L. hirsutum (PI 134417 and PI 247087), Nicotiana benthamiana, N. clevelandii, N. tabacum cv. Xanthi nc, Ocimum basilicum cv. Latino, Petunia hybrida cv. Rose du ciel, and Physalis floridana. No reaction was observed on Pisum sativum cv. Douce Provence, Salvia splendens cv. Etna, or Zinnia elegans cv. Liliput. Symptoms on tomato of PZSV, Parietaria mottle virus (PMoV), and Tomato spotted wilt virus (TSWV) are similar, particularly those elicited in fruits. Therefore, the field samples were checked using double-antibody sandwich enzyme-linked immunosorbent assay against antisera of the type-strain of PZSV and tomato strain of PMoV and their homologous antigenes, which were supplied by D. Gallitelli and P. Roggero respectively, and our antiserum of TSWV. Electron microscopy of negatively stained preparations from leaves of tomato and D. stramonium showed that the sap contained very few paraspheric shaped particles, 26 to 29 nm in diameter. Three isolates collected from two different regions (Vaucluse and Bouches du Rhône) showed a very close serological relationship with the Italian type-strain of PZSV and tested negative against antisera of PMoV and TSWV. The French isolates were biologically different from the type-strain, but were similar to the Spanish strain of PZSV because they infected D. stramonium, N. benthamiana, O. basilicum, and V. unguiculata (2). Moreover, in transverse tissue sections, virions were not observed in the nucleus and tubular structures, unlike the Italian isolates, (1) but were present in the cytoplasm and particularly in the mesophyll cells. There are only a few records of the occurrence and distribution of PZSV in Mediterranean countries.

Methyleugenol in Ocimum basilicum L. Cv. genovese gigante.

Ocimum basilicum cv. Genovese Gigante is the basil cultivar used the most in the production of a typical Italian sauce called pesto. The aromatic composition of plants at different growth stages was determined. Plants from different areas of northwestern Italy were analyzed at 4 and 6 weeks after sowing and showed methyleugenol and eugenol as the main components. The content of these compounds was correlated with plant height rather than plant age. Particularly, methyleugenol was predominant in plants up to 10 cm in height, whereas eugenol was prevalent in taller plants. These results are important in the evaluation of risk to human health posed by dietary ingestion of methyleugenol contained in pesto.