Cymbopogon Species Research Articles

Pharmacognostic Study of various species of Cymbopogon of South canara, India

Aim of the present investigation is to carry out the macroscopy, microscopy, powder analysis, quantitative microscopy and physicochemical characteristics of three different species of Cymbopogon of South canara and they are Cymbopogon citratus, Cymbopogon flexuosus and Cymbopogon nardus. Anatomical studies showed isobilateral nature of Cymbopogon leaves. Powder study revealed presence of epidermal cells with stomata, fibres and vessels. Stomatal index and Physicochemical characters were also reported in the present study.

Inter and intra-specific molecular and chemical diversity of elite accessions of aromatic grasses Cymbopogons

Cymbopogon is an aromatic grass belongs to Poaceae family. To detect the polymorphism among seventeen accessions of Cymbopogons for genetic diversity in total, 20 RAPD primers and 16 microsatellite primers were used. 18 RAPD and 14 ISSR primers responded well and provided reproducible polymorphism 81.3% and 87.4%. PCs were able to explain 79.2% of the total variability. The Mantel test shows strong significant correlation (r = 0.80) between two similarity matrices calculated using both molecular analysis systems. Different species of Cymbopogon showed many variations in essential oil yield (0.4%–1.4%) as well as GC and GC/MS analyses for the identification of many constituents like neral, geranial, citronellal and geraniol. The present study was successful in predicting genetic and chemical diversity of the population of Cymbopogons.

Ethnobotanical survey and antibacterial screening of medicinal grasses in KwaZulu-Natal Province, South Africa

An ethnobotanical survey was undertaken from May 2015 to May 2016 to identify grasses used in traditional medicine in KwaZulu-Natal, South Africa. Indigenous knowledge was obtained from sixty traditional healers through questionnaires and face-to-face interviews. Thereafter, the different grass species were collected and identified at the herbarium at the University of KwaZulu-Natal, Pietermaritzburg, South Africa. Voucher specimens were also kept for preservation and future material reference. The survey revealed that 13 grass species are used for medicinal purposes; these grasses are mostly used as mixtures with other medicinal plants. The documented grass species are mostly used to cure skin diseases, body pains, urinary tract infections, teething troubles, body cleansing, skin diseases, bleeding and eye infections. In this study, the most commonly and frequently mentioned grass species were the Cymbopogon species which are used for skin disease and body cleansing. The 13 grass species identified were evaluated for antibacterial activity against six bacterial strains (Staphylococcus aureus, drug resistant S. aureus, drug resistant Klebsiella pneumoniae, multi-drug resistant Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis). Coix lacryma-jobi root and leaf hexane extracts, Setaria megaphylla root dichloromethane extract and Cynodon dactylon whole plant hexane, dichloromethane and methanol extracts had the highest antibacterial activity (0.6 mg/ml) against S. aureus. Cymbopogon species root (dichloromethane) extract had moderate activity (1.3 mg/ml) against three bacterial strains (S. aureus, multi-drug-resistant E. coli and E. faecalis). Overall, these findings partially validate the use of grasses in South African traditional medicine and highlight their potential as remedies against bacterial-related infections.

Cymbopogon citratus and Cymbopogon giganteus essential oils have cytotoxic effects on tumor cell cultures. Identification of citral as a new putative anti-proliferative molecule

Cymbopogon species are used as traditional remedies in Burkina Faso for treating several diseases. We aimed to study the effects of their essential oils on cancer cell lines. For that purpose, Cymbopogon citratus (DC.) Stapf. and Cymbopogon giganteus Chiov. were studied for their essential oils after various chemical extractions. Antioxidant, potential anti-inflammatory action (inhibition of lipoxygenase) and cytotoxic activities were also tested on various prostate cancer and glioblastoma cell lines. Thirty-three compounds were identified in the essential oil of C. giganteus: Limonene (19.33%), Mentha-1(7),8-dien-2-ol cis (17.34%), Mentha-1(7),8-dien-2-ol trans (13.95%), trans-Mentha-2,8-diene-para-ol 1 (13.91%) and Mentha-2,8-diene-1-ol, cis-para (8.10%) were the most abundant. C. citratus essential oil contained 15 compounds and the major ones were geranial/citral A (48.18%) and neral/citral B (34.37%). Essential oil of C. citratus showed the highest ability to scavenge DPPH+ radicals (approximately 68% at 8 mg/mL) while C. giganteus exhibited the highest capability to reduce ABTS+ (0.59μmolET/g). The essential oil of C. citratus was the most effective on prostate cell lines LNCaP (IC50 = 6.36 μg/ml) and PC-3 (IC50 = 32.1 μg/ml), and on glioblastoma cell lines (SF-767 (IC50 = 45.13 μg/ml) and SF-763 (IC50 = 172.05 μg/ml). Interestingly, the activity of essential oil of C. citratus was statistically equal to that of its major component, citral. Combination of both oils showed antagonist, additive, indifferent and synergistic effects on LNCaP, PC-3, SF-767 and SF-763 cell lines, respectively. In conclusion, plants from the traditional medicine in Burkina Faso could be of interest for identifying new compounds, such as citral, for the treatment of prostate cancer and glioblastoma.

Composition variation of essential oil of Cymbopogon spp. growing in Garhwal region of Uttarakhand, India

The present study was aimed to find out the chemical constituents of essential oils of cymbopogon species,viz. Cymbopogon martinii var motia, Cymbopogon flexuosus Nees., Cymbopogon winterianus Jowitt., growing in Garhwal region of Uttarakhand, India. The essential oils were obtained by hydro-distillationand subjected to detailed Gas Chromatography-Mass Spectroscopy (GC-MS) analysis in order to determine the variation in their volatile constituents. Twenty seven compounds are ?-pinene, ?-myrcene, Limonene, Cis-b-Ocimene, pCymene ,Terpinolene,6-Methyl hept-5-en-2-one, Citronellal, Linalool, Linalyl acetate, ?-Elemene, ?-Caryophyllene, Citronellyl acetate, Neral, ?– Terpineol, Borneol,Gerainal, ?-Cadinene,Geranyl acetate, Citronellol,Nerol,Geraniol, Caryophyllene oxide,Germacrene—D-4-ol,Elemol, Epi-?-cadinol, ?-Cadinol representing 92.24 to 95.86% of the oil compositions as identified. While comparing the common constituents of three different species of cymbopogon taxa , the remarkable variation in compositions of essential oil was observed and it was in concentration of nearl (0.40;34.9;1.6), gerainal (nil;47.5;0.96) geraniol (82.5;4.5;20.15) , citronellol (T;0.2;12.39) , citronellal (0.1;0.5;36.19) , and linalool (0.8;1.6;0.96) for C.martini, C.flexuosus, C. winterianus respectively

Ethnopharmacological use of Cymbopogon citratus (DC.) Stapf and Cymbopogon schoenanthus (L.) Spreng.: Anti-inflammatory potential of phenol-rich extracts

Aim: The aim of this work consisted on expanding the knowledge on the chemical composition of different extracts from Cymbopogon spp., and on the evaluation of their anti-inflammatory potential in cell and cell-free systems. Introduction: The ethnopharmacological use of Cymbopogon spp. dates back from ancient times. Traditionally used in tropical and semi-tropical countries for the repellent properties of their essential oil, the consumption of Cymbopogon spp. infusions is growing all over the world. This is not only due to the unique aroma, widely appreciated by the consumers, but also because of the antimicrobial, anti-inflammatory and sedative properties.1 Methods: The chemical characterization of infusions and ethanol:water (50:50, v/v) extracts from Cymbopogon citratus and Cymbopogon schoenanthus was achieved by HPLC-DAD. The anti-inflammatory potential of the extracts was assessed by cell and cell-free assays. Results: HPLC-DAD analysis allowed the identification of several caffeic acid derivatives and flavonoids in the infusions and in the ethanol:water extracts of both species. The different extracts displayed scavenging activity against superoxide anion and nitric oxide (NO) radicals, and capacity to significantly reduce NO production by LPS-stimulated macrophages (RAW 264.7 cell line). In addition, the extracts were able to prevent hyaluronic acid degradation via inhibition of hyaluronidase, an enzyme recognized to participate in a number of physiological and pathological processes, including inflammation.2 No toxicity was observed on human gastric adenocarcinoma and hepatocyte carcinoma cell lines, at a maximum concentration of 2.0mg lyophilised extract/mL. Conclusion: This study provided scientific evidence on the ethnopharmacological use of Cymbopogon species on inflammatory conditions, encouraging infusion consumption and future incorporation of Cymbopogon spp. extracts into nutraceuticals. Acknowledgements: This work received financial support from National Funds (FCT/MEC) through project UID/QUI/50006/2013, co-financed by FEDER through COMPETE, under the Partnership Agreement PT2020, and from NORTE 2020, under the PORTUGAL 2020 Partnership Agreement, through ERDF (NORTE-01-0145-FEDER-000024). MB is indebted to FCT for the grant (SFRH/BD/95861/2013).

Preparation and Characterization of Lemongrass Fiber (Cymbopogon species) for Reinforcing Application in Thermoplastic Composites

Lemongrass fiber was analyzed to determine the chemical proportion of its lignocellulosic components. Fibers’ thermal behavior, surface structures, and functionality were assessed by thermogravimetric analysis (TGA), scanning electron microscope (SEM), and Fourier transform-infrared spectroscopy (FT-IR), respectively. High-density polyethylene (HDPE) matrix composites filled with varying (10%, 20%, 30%, 40%, and 50%) fiber content were prepared and investigated. Composite wicker was made from HDPE and low density polyethylene (LDPE) blend-matrix and 10% alkaline modified fiber. Alkaline or maleic anhydride grafted polypropylene (MA-g-PP) was used to improve the compatibility between the fiber and matrices. The composites were evaluated by using TGA, SEM microscopy, and universal testing machine, respectively. The fiber was constituted by equitable amounts of lignocellulosic components with cellulose accounting for the highest proportion. It also exhibited high degradation temperature, which was further increased following alkaline modification. Superior thermal degradation behavior was measured for modified fiber composites. SEM showed that the modified fiber composites demonstrated better compatibility. Lemongrass fiber reinforcement substantially improved the mechanical properties of the composites.

Phytomedical assessment of two Cymbopogon species found in Nkonkobe Municipality: toxicological effect on human Chang liver cell line

BackgroundCymbopogon species are widely used as herbal remedies by the traditional healers living in Nkonkobe Municipality for the treatment and management of skin and respiratory infections. According to our survey, the plants seem to be very important because of the higher demands.MethodsThe leaves of C. validis and C. plurinodis were hydro-distilled and the resulted extracted oils were analyzed by GC/MS. Minimum inhibitory concentrations (MICs) ranging from 7.8 to 500.0 μg/ml of the extracted oils were tested against eight bacterial strains, using micro-well dilution method. The human Chang liver cell viability was determined using the CellTiter-Blue cell assay.ResultsGC-MS analysis of the C. validis essential oil amounted to 87.03%, major components identified were Linalyl alcohol (18.9%), 2-Nephthalenemethanol (6.67%), Longifolene (6.53%), Cubedol (6.08%). Total oil percentage of C. plurinodis was 81.47% and the main components were characterized as 3-Cyclohexane-1-ol (13.58%), Nerolidol (13.6%) and 2-Carene (12.6%). The essential oils from both plants were found to be active against the growth of Gram positive than the Gram negative bacterial tested. Lethal dose at 50 (LD50) of both plants showed 74.87 ± 1.41 and 81.66 ± 1.40 degree of toxicity at 24 h.ConclusionBoth plants extracts were toxic to human Chang liver cell lines.

A report on identification of sequence polymorphism in barcode region of six commercially important Cymbopogon species.

CYMBOPOGON: is an important member of grass family Poaceae, cultivated for essential oils which have greater medicinal and industrial value. Taxonomic identification of Cymbopogon species is determined mainly by morphological markers, odour of essential oils and concentration of bioactive compounds present in the oil matrices which are highly influenced by environment. Authenticated molecular marker based taxonomical identification is also lacking in the genus; hence effort was made to evaluate potential DNA barcode loci in six commercially important Cymbopogon species for their individual discrimination and authentication at the species level. Four widely used DNA barcoding regions viz., ITS 1 & ITS 2 spacers, matK, psbA-trnH and rbcL were taken for the study. Gene sequences of the same or related genera of the concerned loci were mined from NCBI domain and primers were designed and validated for barcode loci amplification. Out of the four loci studied, sequences from matK and ITS spacer loci revealed 0.46% and 5.64% nucleotide sequence diversity, respectively whereas the other two loci i.e., psbA-trnH and rbcL showed 100% sequence homology. The newly developed primers can be used forbarcode loci amplification in the genus Cymbopogon. The identified Single Nucleotide Polymorphisms from the studied sequences may be used as barcodes for the six Cymbopogon species. The information generated can also be utilized for barcode development of the genus by including more number of Cymbopgon species in future.

Biological activity of Cymbopogon citratus (DC) Stapf and its Potential Cosmetic Activities

​ The present work makes a general bibliographical review around a variety of issues around Cymbopogon citrates and tries to summarize the most important aspect and qualities of the plant that make it a potential element in the research and defining of cosmetics with natural ingredients. The biological antibacterial and antifungal activities of the species Cymbopogon citratus (DC) Stapf , have been identified by several authors by highlighting a potential action on a large number of pathogens, some of them related to dermal problems. Various other activities have been evaluated, such as antioxidant and insecticide; allowing the extract to be incorporated in cosmetic and insecticide formulations. Several studies consider the species for patented formulations that include microencapsulation as a viable option. Non-invasive in-vivo studies have been reviewed in this work to analyse any potential toxicology and to define the best concentrations of use.

A Short Review on Chemical Composition Therapeutic Use and Enzyme Inhibition Activities of Cymbopogon species

Background/Objectives: Cymbopogon species is a universally accepted oil bearing grass. It is very much valuable for both Industrial as because of its main components like Geraniol, Geranial, Citral, Myrcene, Neral, Nerol, and Citronellol, Limonene etc. and Medicinal value. Therefore, it is just a little attempt to survey the literature of this important grass. Materials and Methods: For this literature survey, basically library data was collected and digital resources were also included. From these sources we obtained reliable information about different works of Cymbopogon sp. Findings: These grasses have considerable medicinal importance as all parts of it are used extensively in Ayurvedic, unani and other some traditional health treatments. Studies by different researchers indicate that Cymbopogonspecies possesses various pharmacological activities such as anti-bacterial, anti-diarrheal, anti-amoebic, anti-filarial, anti-fungal and antiinflammatory properties, and various other effects like anti-mutagenicity, anti-malarial,anti-oxidants, anti-mycobacterial, hypoglycaemic etc. There are many literatures demonstrating the therapeutic use, enzyme inhibition activities of Citronella oil and also simultaneously analysed the different components of the oil. Application/Improvement: Till date very scanty information is available from different –different sources so, we try to collect this information in one review article. This review article gives an account of updated information on its chemical constituents, therapeutic uses, antimicrobial, antifungal and enzyme inhibitory activities of Cymbopogon species.

Genetic diversity study amongst Cymbopogon species from NE-India using RAPD and ISSR markers

Cymbopogon, an important genus of the family Poaceae, cultivated mainly for its essential oil, is a valuable medicinal and aromatic plant. Essential oils from this crop found a wide range of application including medicine, perfumery, ornamental, flavouring and therapeutic uses in pharmaceuticals and is emerging crop for bio fuel production. Many species of Cymbopogon cultivated worldwide but their identification is somewhat difficult since they do not have suitable genomic diversity information. Assessment of genetic diversity is therefore essential for conservation and management of this species. A total of 20 Randomly Amplified Polymorphic DNA (RAPD) and 15 Inter Simple Sequence Repeats (ISSR) primers were examined, of which 26 primers (13 RAPD and 13 ISSR) showed amplification and were used for further study. Unweighted Pair Group Method of Arithmetic Mean (UPGMA) derived dendrogram in both the analysis was more or less similar and cluster analysis (CA) based on RAPD, ISSR and their combined data clearly discriminated the genotypes into different clusters. Result of principal component analysis (PCA) was in agreement with cluster analysis with a few exceptions. DNA based markers (RAPD and ISSR) could be effectively used for genetic diversity evaluation among Cymbopogon species. Results of this study will help in the conservation and Cymbopogon improvement/breeding programe.

De Novo Sequencing and Analysis of Lemongrass Transcriptome Provide First Insights into the Essential Oil Biosynthesis of Aromatic Grasses.

Aromatic grasses of the genus Cymbopogon (Poaceae family) represent unique group of plants that produce diverse composition of monoterpene rich essential oils, which have great value in flavor, fragrance, cosmetic, and aromatherapy industries. Despite the commercial importance of these natural aromatic oils, their biosynthesis at the molecular level remains unexplored. As the first step toward understanding the essential oil biosynthesis, we performed de novo transcriptome assembly and analysis of C. flexuosus (lemongrass) by employing Illumina sequencing. Mining of transcriptome data and subsequent phylogenetic analysis led to identification of terpene synthases, pyrophosphatases, alcohol dehydrogenases, aldo-keto reductases, carotenoid cleavage dioxygenases, alcohol acetyltransferases, and aldehyde dehydrogenases, which are potentially involved in essential oil biosynthesis. Comparative essential oil profiling and mRNA expression analysis in three Cymbopogon species (C. flexuosus, aldehyde type; C. martinii, alcohol type; and C. winterianus, intermediate type) with varying essential oil composition indicated the involvement of identified candidate genes in the formation of alcohols, aldehydes, and acetates. Molecular modeling and docking further supported the role of identified protein sequences in aroma formation in Cymbopogon. Also, simple sequence repeats were found in the transcriptome with many linked to terpene pathway genes including the genes potentially involved in aroma biosynthesis. This work provides the first insights into the essential oil biosynthesis of aromatic grasses, and the identified candidate genes and markers can be a great resource for biotechnological and molecular breeding approaches to modulate the essential oil composition.

Essential Oil Yield, Chemical Composition, and Total Citral Content of Nine Cultivars of Cymbopogon Species from Western India

ABSTRACTThe essential oil composition of five elite Cymbopogon varieties (OD-19, Pragati, RRL-16, NLG-84) and a hybrid (CPK-25) and four new selections (LS-1 to LS-4) were determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The oil yield ranged from 0.31% to 1.0% with CPK-25 (1.0%) and LS-2 (0.95%) containing the highest. A total of 66 compounds, constituting 84.6–94.3% of the oils, were identified. The main compounds were geranial (29.9–41.6%), neral (25.8–32.5%), citronellol (0.3–12.8%), geranyl acetate (1.2–8.4%), and geraniol (1.8–8.2%). Of the cultivars, OD-19 (74.1%) had the highest and LS-3 (55.7%) contained the lowest amount of total citral. CKP-25 and LS-2 contained the highest amounts of oil (1.0% and 0.95%) with similar (67.9% and 68.3%) total citral concentrations. Essential oil yield in the CPK-25 cultivar was similar. LS-2, a new cultivar, had higher essential oil yield (0.95%) in the region, compared to the commercial cultivars Caveri (0.8%), OD-19 (0.7%), Pragati (0.7%), and Parman (0.8%) of Cymbopogon flexuosus.

Docking, characterization and investigation of β-cyclodextrin complexed with citronellal, a monoterpene present in the essential oil of Cymbopogon species, as an anti-hyperalgesic agent in chronic muscle pain model

BackgroundCitronellal (CT) is a monoterpene with antinociceptive acute effect. β-Cyclodextrin (βCD) has enhanced the analgesic effect of various substances. Hypothesis/PurposeTo evaluate the effect of CT both complexed in β-cyclodextrin (CT-βCD) and non-complexed, in a chronic muscle pain model (CMP) in mice. Study DesignThe complex containing CT in βCD was obtained and characterized in the laboratory. The anti-hyperalgesic effect of CT and CT-βCD was evaluated in a pre-clinical in vivo study in a murine CMP. MethodsThe complex was characterized through differential scanning calorimetry, derivative thermogravimetry, moisture determination, infrared spectroscopy and scanning electron microscopy. Male Swiss mice were pre-treated with CT (50mg/kg, po), CT-βCD (50mg/kg, po), vehicle (isotonic saline, po) or standard drug (tramadol4 mg/kg, ip). 60 min after the treatment and then each 1h, the mechanic hyperalgesia was evaluated to obtain the time effect. In addition, the muscle strength using grip strength meter and hyperalgesia were also performed daily, for 7 days. We assessed by immunofluorescence for Fos protein on brains and spinal cords of mice. The involvement of the CT with the glutamatergic system was studied with molecular docking. ResultsAll characterization methods showed the CT-βCD complexation. CT-induced anti-hyperalgesic effect lasted until 6h (p <0.001) while CT-βCD lasted until 8h (p <0.001vs vehicle and p <0.001vs CT from the 6th h). CT-βCD reduced mechanical hyperalgesia on all days of treatment (p <0.05), without changing muscle strength. Periaqueductal gray (p <0.01) and rostroventromedular area (p <0.05) showed significant increase in the Fos protein expression while in the spinal cord, there was a reduction (p <0.001). CT showed favorable energy binding (–5.6 and –6.1) to GluR2-S1S2J protein based in the docking score function. ConclusionWe can suggest that βCD improved the anti-hyperalgesic effect of CT, and that effect seems to involve the descending pain-inhibitory mechanisms, with a possible interaction of the glutamate receptors, which are considered as promising molecules for the management of chronic pain such as CMP.

Varietal Discrimination and Genetic Variability Analysis of Cymbopogon Using RAPD and ISSR Markers Analysis.

Cymbopogon is an important genus of family Poaceae, cultivated mainly for its essential oils which possess high medicinal and economical value. Several cultivars of Cymbopogon species are available for commercial cultivation in India and identification of these cultivars was conceded by means of morphological markers and essential oil constitution. Since these parameters are highly influenced by environmental factors, in most of the cases, it is difficult to identify Cymbopogon cultivars. In the present study, Random amplified polymorphic DNA (RAPD) and Inter-simple sequence repeat (ISSR) markers were employed to discriminate nine leading varieties of Cymbopogon since prior genomic information is lacking or very little in the genus. Ninety RAPD and 70 ISSR primers were used which generated 63 and 69% polymorphic amplicons, respectively. Similarity in the pattern of UPGMA-derived dendrogram of RAPD and ISSR analysis revealed the reliability of the markers chosen for the study. Varietal/cultivar-specific markers generated from the study could be utilised for varietal/cultivar authentication, thus monitoring the quality of the essential oil production in Cymbopogon. These markers can also be utilised for the IPR protection of the cultivars. Moreover, the study provides molecular marker tool kit in both random and simple sequence repeats for diverse molecular research in the same or related genera.

Attractiveness of essential oils of three Cymbopogon species to Tribolium castaneum (herbst) adults

Behavior bioassays were conducted in the laboratory (23 ? 1?C and 50 ? 5% r.h.) using the olfactometer to determine the effects of essential oils of three plant species in the Cymbopogon genus (Lemongrass), Cymbopogon nervatus, C. proximus and C. schoenanthus, on adults of Tribolium castaneum. The effect of essential oils was compared to a commercial biopesticide based on azadirachtin at three concentrations (0.0001, 0.001 and 0.01%). The results showed that all essential oils and the azadirachtin-based biopesticide had significant (p &lt;0.05) repellent effects on T. castaneum adults at all tested concentrations, except C. proximus essential oil which showed a neutral effect at the lowest concentration. The highest concentrations of the essential oils of C. nervatus and C. proximus had significantly stronger repellent effects (p &lt;0.05) than the lowest concentration. At the concentrations of 0.0001 and 0.001% all tested essential oils and azadirachtin showed a similar repellent effect without statistically significant difference, whereas the oil of C. nervatus had the highest repellent effect on adults of T. castaneum at the 0.01% concentration. Considering all tested variations, the essential oils of plants of the genus Cymbopogon showed similar or stronger repellent effects on T. castaneum adults than the biopesticide based on azadirachtin.

English

Aromatic grass species Cymbopogon citratus (‘serai biasa/serai makan’) and C. nardus (‘serai wangi’) can be commonly found throughout Peninsular Malaysia. C. citratus is used in traditional Malaysian cooking and brewed as tea, while C. nardus is used in traditional medicine for external application and in insect repellents. Due to similar morphologies, it can be difficult to tell apart the species at times. Based on DNA sequence alignments of three chloroplast DNA intergenic spacer regions, namely atpB-rbcL, trnH-psbA and trnL-trnF, we designed species-specific primers for multiplex PCR assays for rapid species discrimination between C. citratus and C. nardus. The method described here makes use of simple molecular techniques that are timeand cost-effective for large-scale application. Such an assay will be useful for the quality assurance of food and medicinal products.

Adaptability and stability based differentiation and selection in aromatic grasses (Cymbopogon species) germplasm

The investigation was carried out to determine the stability and adaptability pattern among seventeen clones of the six Cymbopogon species namely; C. khasianus cv. Suwarna, C. martini var. Motia cv. Harsh, C. flexuosus cv. Krishna, hybrid of C. pendulus×C. khasianus cv. CKP-25, C. winterianus cv. CIM Jeeva, C. citratus cv. T-1 and C. pendulus cv. Praman. The genotypes were examined in terms of quantified degree of adaptability and stability over years. The stable genotypes for high essential oil yield were identified over years within/between species by using AMMI analysis. Based on the AMMI model, genotypes C-9 of C. khasianus cv. CIMAP Suwarna, C-13 of C. flexuosus cv. Krishna, C-1 and C-4 of C. winterianus cv. CIM Jeeva and Manjari, C-11 of C. pendulus cv. Praman, and C-3 of C. martini var. Motia cv. CIMAP Harsh showed the widest adaptability (most stable genotypes). Therefore, these genotypes can be recommended for commercial exploitation.

Characterization of volatile compounds from three Cymbopogon species and Eucalyptus citriodora from Benin and their insecticidal activities against Tribolium castaneum

The chemical volatile profiles of four plant species from Benin were established via SDE/GC–MS and SPME/GC–MS, and were compared to chemical profiles obtained by hydrodistillation/GC–MS. Essential oils and selected identified compounds were used to perform fumigant tests and contact “no choice” tests against adults of the red flour beetle Tribolium castaneum, an important pest insect in stored products worldwide. The chemical profiles and the concentrations of the main compounds varied with the method used. Geranial (hydrodistillation, SPME) and geraniol (SDE) for Cymbopogon citratus, piperitone for Cymbopogon schoenanthus (hydrodistillation, SPME, SDE), E-p-mentha-1(7), 8-dien-2-ol for Cymbopogon giganteus (hydrodistillation, SPME, SDE), neo-isopulegol (SDE) and citronellal (hydrodistillation and SPME) for Eucalyptus citriodora, were identified as main volatile compounds. By fumigation, the LC50 values obtained after 24h for essential oils of C. citratus, C. giganteus, C. schoenanthus, E. citriodora, and for piperitone and citronellal were 4.2mL/L air, 2.3mL/L air, 2.1mL/L air, 2.0mL/L air, 0.5mL/L air and 1.2mL/L air, respectively. Furthermore, mortalities of 100%, 82%, 75%, 72%, 68% and 42%, respectively, were found for piperitone at 2.4mL/L air, citronellal at 2.1mL/L air, and essential oil extracted from E. citriodora, C. schoenanthus, C. giganteus and C. citratus, at 4mL/L air. By contact “no choice” test, the LC50 values for the crude oils after 72h were: 15% (w/v), 6% (w/v), 6% (w/v) and 5% (w/v) for C. citratus, C. giganteus, C. schoenanthus and E. citriodora, respectively. After 72hours, mortalities of 18%, 67%, 73%, 82%, 87% and 40% for essentials oils (8% w/v) of C. citratus, C. giganteus, C. schoenanthus, E. citriodora, piperitone at 4.7% w/v, and citronellal at 4.2% w/v, respectively, were obtained. The essential oil from C. schoenanthus and E. citriodora as well as piperitone and citronellal represent potential valuable alternative pesticides to conquer the resistance of T. castaneum to synthetic insecticides.