Ten different plants of wormwood were collected in March 1997 from each one of the following four wild populations in the Spanish Pyrenees: Tallo de Aulet (prov. Huesca) and Pont de Suert, Sort and Farga de Moles (prov. Lleida). In three of the four populations studied, there was another chemotype, with 25-65% of cis-epoxyocimene and 15-50% of chrysanthenyl acetate. This chemotype, called chemotype B, was less frequent in the Pyrenees than the chemotype A, appearing only in 17% of the samples (two samples in TallO de Aulet and in Pont de Suert and three samples in Farga de Moles).

Two chemotypes were detected; a cis-epoxyocimene type (with more than 50% of this compound) which was predominant in all the populations, and a cis-epoxyocimene + chrysanthenyl acetate type (with 25-65% of cis-epoxyocimene and 15-50% of chrysanthenyl acetate). The distribution of these chemotypes had no relation with the altitude of the samples.

The experiments were performed in the experimental field of the Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences (Danzhou, Hainan, China; localization 19.52° N, 10⁹.50° E; altitude 118 m; annual average precipitation 1815 mm; annual average temperature 23.5 ℃ ;the soil characteristics are : "Organic matter (g/kg) 11.37;pH 4.94;N (g/kg) 0.51;P (mg/kg) 25.33;K (mg/kg) 33.89). The experimental B. balsamifera plants were one-year old, and were propagated by the seeds collected from B. balsamifera planted in the experimental field of the Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences. They were planted with a planting spacing of 80 cm × 80 cm. On the 20th day of each month (from September 2014 to December 2014, which is the traditional harvest time), 30 one-year old B. balsamifera plants were randomly collected. Their young leaves (leaves on young shoots), mature leaves (leaves which are mature but without yellow spots), senescent leaves (leaves with yellow spots and those with dark brown leaf tips), dead leaves (leaves that have turned dark brown), young shoots (stems from buds to 10-20 cm part without woody parts), and young stems (green stems and not completely woody) were collected. These samples were divided into three parts (replicates), dried under shade, and ground to a fine powder (20-mesh sieve), packed in zip-lock bags, and stored in the refrigerator (4 ℃ ) for oil extraction.

Time of growth and type of B. balsamifera plant organs influence the production of oil, its composition, and antioxidant activity. The essential oil level in the young leaves was the highest, followed by mature leaves and senescent leaves, and the oil content was higher in October. A total of 44 compounds were identified. In the essential oils of leaves, the main ingredient is l-borneol, and the content was the highest in senescent leaves and in December. Variations in oil yields did not show the same pattern as the percentages of l-borneol in the essential oil. In the essential oils of young shoots and young stems, the main composition was dimethoxydurene. Therefore, the time of harvest and type of plant organs should be distinguished based on the different harvesting purposes. To extract the volatile oil, the aboveground parts except stems in October should be chosen for harvest. To get a high content of l-borneol in volatile oil, it is more appropriate to select the leaves in December. The antioxidant activity was evaluated using DPPH and BCB assays in this study, and the results proved that the essential oils of B. balsamifera showed a certain antioxidant activity, and the beta-carotene bleaching activity is far stronger than the DPPH radical-scavenging capacity. The young leaves and young shoots showed stronger antioxidant activity due to the high content of dimethoxydurene, beta-caryophyllene, and alpha-caryophyllene.

Plant material: Samples of B. gibraltarium were gathered in November 1995 during the fruiting period (F), in May 1996 during the pre-flowering period (PF), in July 1996 during the full flowering period (FF), and in September 1996 during the late flowering period (LF) from El Zumbel area (UTM: 30SVG3278) . Every sample consisted in the whole aerial parts of five single plants growing wild near one to another. Once the plants reached the laboratory, they were airdried for seven to 15 days, and separated by parts, i.e., leaves, stems, umbel rays and, when present, fruits.

In the leaf oils, sabinene (12.0-33.9%) and limonene (7.8-23.4%) were the main components, the sabinene level being minimum in full flowering and maximum in fruiting. In stem oils, sabinene (4.7-21.6%) and 2,3,4-trimethylbenzaldehyde (9.3-13.6%) were the main components, the sabinene level being minimum in pre-flowering and maximum in full flowering. In umbel ray oils, sabinene (20.7-43.1%) was the first component in all the phenological periods, followed by alpha-pinene (7.3-28.2%). Both monoterpenes increased their levels in late flowering and reached minimum amounts in fruiting.

Four kinds of fresh sweet oranges were obtained in the same season, November 2000, in Guangzhou. Citrus sinensis var. Hongjiang (called 'hong jiang chen' in Chinese) and C. sinensis Osbeck var. Anliu (called 'luo gang chen') were obtained at an orchard in Luo gang in Guangzhou (25 km from the center of Guangzhou). Citrus sinensis var. Sihui (called 'sihui ju') was harvested at the Shigou Experimental Farm in Sihui City in Guangdong Province (75 km far away from Guangzhou). Citrus sinensis var. Washington navel (called 'qi chen') which was produced in Jiangxi Province (200 km from Guangzhou; bordering Guangdong Province), was purchased at the wholesale market in Guangzhou. All oranges were kept in a cold room until prepared a few days later.

The peel oil compositions of four kinds of sweet oranges in China, Citrus sinensis Osbeck var. Hongjian, C. sinensis Osbeck var. Anliu, C. sinensis Osbeck var. Sihui and C. sinensis Osbeck var. Washington navel, were investigated by GC and GC/MS. The essential oils were extracted by cold-pressing method. Forty-two to 53 compounds were quantitatively determined for each variety. Their percentages, respectively, were: > 97.3%, > 98.4%, > 97.5% and > 98.0% in hydrocarbons; > 1.5%, > 0.7%, > 0.8% and > 0.9% in total aldehydes; 0.8%, 0.5%, 0.5% and 0.5% in alcohols. Either cis-or trans-limonene oxide was detected in small amounts in each of the four samples, with Hongjiang containing both limonene oxides. delta-3-Carene was commonly quantified at a level of 0.1% in all the samples. The content of aliphatic aldehydes, including octanal, nonanal, decanal and dodecanal, exceeded that of terpene aldehydes, such as neral and geranial in Hongjiang (0.9%) and Washington navel (0.6%), whereas the aliphatic aldehydes in Anliu and Sihui were present to a lesser degree than the terpene aldehydes. Either alpha- or beta-sinensal was detected in trace amounts in each of the four samples. Linalool was the major alcohol in all the samples. Nootkatone was not detected.

The materials (dry palmarosa seeds with 12% moisture content of four cultivars 'Tripta', 'Trishna', 'PRC' and 'MP') and methods of gamma rays (15 Kr, 60CO source with dose rate 0.38 Mrads\h) and chemicals ethyl methane sulfonate (EMS - 0.4%) and ethyleneimine (EI-0.04%) induced mutagenesis. The seed of the four varieties had already been selfed for 4-5 flowering seasons before mutagenesis to maintain genetic homogeneity (or purity) and thereafter all the selected M1 generation suspected mutant plants were individually selfed by bagging to give rise to controlled M2 plant to progeny segregants for further selection. Oil content was estimated on freshly harvested herbage (stems, leaves and inflorescence) using a Clevenger-type apparatus.

The oil content was increased in all the 20 mutants as compared to their respective contols. Most M2 generation mutants were found to exhibit a straight relationship between high herbage (stem, leaves and inflorescence) yield, oil content (%) and oil quality in terms of major and trace constituents of the oil. Six mutants specifically were endowed with the desirable rosy note which remained predominant in the samples of Trishna-gamma-5, MP-gamma-13, Tripta-gamma-8, Tripta-Ethyl methane sulfonate (EMS)-19, Tripta-EMS-21 and PRC-Ethyleneimine (EI)-44. The fresh herbage and oil yield and odor criteria, i.e., rosy note were satisified by the three best mutants, viz., Trishna-gamma-5, MP-gamma-13 and Tripta-gamma-19. The results have been interpreted in the sense that induction of mutations brings about gene level changes from dominance to recessive and vice versa in morpho-economic traits having quantitative trait loci (QTL) under polygenic genetic control.

General plantation of citronella cv. Java 2 was maintained following recommended agricultural practices at the Experimental Farm of Central Institute of Medicinal and Aromatic Plants, Field Station, Hyderabad, India. The experimental station has a semi-arid tropical climate. The experiment was conducted in the same plantation for 2 consecutive years during the summer month of June 1996 and 1997, when the incidence of the disease was higher. In each year, 12 each of healthy and diseased plants were selected at random and harvested. The occurrence of the disease is generally observed during the hot summer season months, when the temperatures are in the range 36-43 ℃. Initial symptoms of the pest attack appear as yellow specks or blotches, mostly along leaf margins, that in later stages develop into yellow streaks running along the length of the affected leaves. Emerging young leaves are pale green to yellow coloured, twisted, crinkled, developed into whip-like structures and in severe cases of infection fail to open. Even if they do open, these leaves fail to exhibit a smooth leaf surface. Severely affected older leaves turn brown, dry and die. The overall growth and development of the infected plant is severely affected, giving it a dwarfed and unhealthy appearance.

The essential oil examined by GC and GC-MS from cultivated healthy plants contained citronellal (28.4%), geraniol (24.8%), citronellol (11.8%) and elemol (10.2%). The major components from diseased plants were geraniol (19.0-25.5%), elemol (15.3-20.4%), citronellal (13.4-19.1%) and citronellol (12.9-15.1%). Caryophyllene oxide (3.5-6.0%) was an important minor component.

It was collected in Lujan, Ayacucho Department, San Luis, Argentina, in the vegetative flowering stage (February 1997) and at flowering-fructification (April 1996).

Flowering and flowering-fructification, did not differ in regard to the composition of analyzed sesquiterpenes but showed variation in the relative concentration of one of its constituents. Twenty-four compounds were identified, which represented 93-5% of the oil in the flowering stage and 92.5% of it in the flowering-fructification one. The oil was found to contain beta-caryophyllene (14.3-12.0%), germacrene D (14.7-15.3%), curzerene (11.5-12.7%) and bicyclogermacrene (12.1-14.2%) as major compounds.

H. officinalis var. dectimbens was grown on Banon (Alpes de Haute-Provence, France). The fresh flowering tops were steam distilled at the beginning of October 1995. A sample of H. officinalis oil produced in Italy (Piedmont) by Agronatura was examined as a useful standard in accordance with the IS0 9841 Standard (1991 E).

The bicyclic monoterpene ketones, pinocamphone and isopinocamphone, were present in Piedmont, Italy (4.4% and 43.3%, respectively, in accordance with the ISO 9841 Standard, 1991 E), but their percentages were very low in Banon, France, where instead linalool (49.6%), 1,8-cineole (13.3%) and limonene (5.4%) were predominant.

The plant materials were collected for P1: 2900 m, Ait Akak, Oukaimden, Atlas Mts, Morocco, N. Achak, A. Romane and M. Mahroug, 3 trees, ns, 12/12/2003; P2, 2200 m, Plateau of Matat, Atlas Mts, N. Achak, A. Romane and M. Mahroug, 3 trees, ns, 18/03/2003; P3: 2000 m, Foret Islane, Oukaimden, Atlas Mts, N. Achak, A. Romane and M. Mahroug, 3 trees, ns,12/12/2003. A portion of the leaves from each of the three trees (per population) were air dried for 16 days at room temperature (ca. 22 &#8451) to produce the dried leaf samples.

The oil yields from fresh leaves showed on differences among geographical sources. Air dried leaves appeared to yield more oil at the highest elevation (1.03%, Ait Lkak, 2900 m) than lower sites (0.67%, Plateau of Matat, 2200 m; 0.57%, Foret Islane, 2000 m). The essential oils from each geographic site had very similar composition in fresh versus air dried leaves. The essential oils from provenance Ait Lkak and Plateau of Matat were very similar and characterized by a high sabinene content (21.2, 35.9%), in contrast to 10.% sabinene from the provenance Foret Islane. The oil from Foret Islane had a high delta-cadinene content with 12.7%, whereas Aik Akak and Plateau of Matat contained only 0.6 and 0.8%.

Dry leaves of Menlba piperita L. 'Kliment-63' and 'Zefir' of 1997 crop were used.

The oil yield from 'Zefir' was 0.97% and that from 'Kliment-63' was 0.54%. The oil from 'Zefir' was found to be rich in menthol (46.2-50.2%) and menthyl acetate (16.8-22.5%). In the oil from 'Kliment-63,' the content of these components was lower, while the menthone content was higher (20.0-23.1%).

The aerial parts of M. biflora collected during November 1993 and June 1994 were used for the investigation.

The major constituents of the oil were neral (25.3-32.2%) and geranial (26.7-41.3%). The oil produced in the winter was found to contain higher amounts of oxygenated monoterpenes than the oil produced in the summer.

Field experiment was initiated in June 2000 in the same block of the research farm. The experiment was laid out in a randomized block design with five treatments on stage of crop harvest (pre-flowering and 25%, 50%, 75% and 100% flowering) and four replications, individual plots being 3 × 6 m. Each plot received uniform dose of neem cake 900 g (0.5 t/ha), di-ammonium phosphate 155 g (40 Kg P₂O₅ /ha) and muriate of potash 120 g (40 kg K₂O/ha) as basal dose which was incorporated with 5 cm top soil using hand hoe. Ocimum gratissimum seedlings, six weeks old, were planted at 60 cm row-to-row and 45 cm plant-to-plant spacing in June 2000. The field was irrigated immediately after planting for early establishment of the seedlings. Thereafter, the field was irrigated 11 and 13 times in the first and second year of experimentation, respectively. Nitrogen at 120 kg/ha was applied in the form of urea spreading over all the harvests per annum. The crop received fi ve and four hand weedings during first and second year of experimentation. Apical part (25-35 cm) of all the branches was harvested in all the treatments as given below: (Pre-flowering Year1 September 20 and November 12, 2000 and January 16, March 17 and May 16, 2001; Year2 July 20, September 13 and November 17, 2001 and January 27, April 7 and June 16, 2002); (25% flowering Year1 September 26 and November 25, 2000 and February 3, April 9 and June 13, 2001; Year2 August 17, October 16 and December 26, 2001 and March 11 and May 25, 2002); (50% flowering Year1 September 30 and December 4, 2000 and February 17, April 28 and July 7, 2001; Year2 September 10 and November 14, 2001 and January 24, April 9 and June 23, 2002); (75% flowering Year1 October 7 and December 16, 2000 and March 6 and May 20, 2001; Year2 August 3, October 12 and December 21, 2001 and March 6 and May 25, 2002); (100% flowering Year1 October 15 and December 29, 2000 and March 24 and June 12, 2001; Year2 August 31 and November 14, 2001 and January 28, April 18 and July 7, 2002).

Harvesting at pre-flowering produced 12.5%, 24.1%, 35.5% and 50.0% higher biomass yield compared to harvesting at 25%, 50%, 75% and 100% flowering, respectively, in the first year of cropping. The respective increase was 16.8%, 22.0%, 38.2% and 63.2% in the second year. Late harvested crop (100% flowering) contained the highest amount of essential oil and it decreased in the order of harvesting at 100% flowering > 75% flowering > 50% flowering > 25% flowering > pre-flowering treatment. The total oil yield was, however, significantly higher (15.8-19.9% and 12.7-33.6% in first and second years, respectively) with pre-flowering compared to all other harvest treatments. Pre-flowering harvested crop produced oil containing the highest amount of eugenol and it decreased in the order of harvesting at pre-flowering > 25% flowering > 50% flowering > 75% flowering > 100% flowering treatment.

Five different populations of P. spicatus were collected in different geographical regions of the northeast of Brazil. Populations I: (Locality: Morro do Chapeu,Bahia, harvesting: 02.19.94); Populations II: (Locality: Maranguape,Ceara, harvesting: 06.01.97); Populations III: (Locality: Jacobina,Bahia, harvesting: 02.19.94); Populations IV: (Locality: Cocalzinho,Ceara, harvesting: 02.22.94); Populations V: (Locality: Sitio dos Moreiras,Pernambuco, harvesting: 02.22.94)

The aliphatic ketones 2-undecanone, 2-tridecanone and 2-pentadecanone were present in samples of all populations. 2-Tridecanone (1.7-84.7 %) was detected in 30 out of 34 samples analyzed. It was the main component in all samples of root barks, except one where 2-pentadecanone (24.7%) was the major component. 2-Undecanone, beta-eudesmol and sabinene were the major components of leaf oils.

The cultivars selected for this study are Sreekara, Vellanamban and one Indonesian cultivar Kutching grown in Kerala. These cultivars are commonly cultivated in the northern parts of Kerala. The fresh berries of the authenticated cultivars were collected from Indian Institute of Spices Research, Calicut and were dried in a cross flow drier at 45 ℃ and taken for the analysis.

The main components of vellanamban oil were sabinene (3.9-18.8%), beta-pinene (3.9-10.9%), limonene (8.3-19.8%) and beta-caryophyllene (28.4- 32.9%). Sreekara oil contained as major compounds beta-pinene (0-11.2%), limonene (20.1-22.1%) and beta-caryophyllene (16.8-23.1 %). Kutching oil contained alpha-pinene(2.3-5.4%), sabinene (6.7-13.3%), limonene (14.5-17.5%) and beta-caryophyllene (20.8-39.1%).

Ruta chalepensis seedlings were sown in the field in January 1999. Leaf materials were collected at vegetative stage (25th August 1999, plant height 60 cm, temp. min. 26.4 ℃, max. 35.6 ℃) and at budding stage (25th February 1999, plant height 115 cm, temp. min. 9.6 ℃, ma. 26.2 ℃). At flowering stage (2Sth March 2000, plant height 118 cm, temp. min. 14.3 ℃, max. 29.7 ℃), both leaves and flowers were collected; at fruiting stage (25th April 2000, plant height 119 cm, temp. min. 21.5 ℃, max. 39.1 ℃), leaves and fruits were again collected for oil isolation and analysis.

Analysis of the oils from R. chalepensis showed that the major constituents of oils were 2-undecanone, 2-nonanone, 2- nonyl-acetate and 2-dodecanone. 2-Undecanone was found to reach a maximum in the flower oil followed by fruit and leaf oils. The quantity of 2-undecanone was highest in the leaves when the plants were young and in the vegetative stage, and it gradually decreased when the plants started flowering and fruiting. 2-Nonanone, on the other hand, was at its maximum in the Leaf oil followed by flower and fruit oils. The quantity of 2-nonanone in the leaves gradually increased from the vegetative stage to the flowering stage and was highest during fruiting stage. The concentration of 2-nonyl acetate was observed to be highest in the leaves during the vegetative stage, while 2-dodecanone was at its maximum in the fruits. Lina-lool, an important aromatic compound, has been found to be highest in flowers. Gamma-Terpinene and 6-methyl-5-hepten-2-one were observed only in vegetative stage of the plants. During the flowering and fruiting stages they could not be detected. Pregeijerene was observed during flowering only, while geijerene was observed both during flowering and fruiting; however, this compound was found in leaves.

Clones of T. daenensis populations were collected from 11 locations including seven locations in Fars and four locations in Kohkiluyeh provinces of Iran. The clones of T. daenensis populations were transplanted to the farm at IANRRC Research Station, located in NajafAbad (18 km west Isfahan, 32° 36′ N, 51° 26′ E and 1612 m asl) in March 2002 . Clones were grown in 5 × 2 m plots with 50 × 50 cm planting density. Fertilizers were applied prior to planting at a rate of 60 kg P/ha and 50 kg N/ha. After 3 years (2004), the aerial parts of plants were harvested at full flowering stage, dried at room temperature, and stored until analysis inside paper bags in a cool and dark place. Td1 (Fars Province, Eghlid, Asepas; Altitude: 2000); Td2 (Fars Province, Sourian, Bavanat; Altitude: 2500); Td3 (Fars Province, Abadeh, Keverlar; Altitude: 2280); Td4 (Fars Province, Abadeh -Shiraz Rd, Kolikosh; Altitude: 2400); Td5 (Fars Province, Shiraz -Yasouj Rd, Komehr; Altitude: 2415); Td6 (Fars Province, Yasouj -Shiraz Rd, Margoon; Altitude: 2170); Td7 (Fars Province, Shiraz -Isfahan Rd, Pasargad; Altitude: 2190); Td8 (Kohkiluyeh Province, Sisakht, Gol; Altitude: 2570); Td9 (Kohkiluyeh Province, Kakan; Altitude: 2200); Td10 (Kohkiluyeh Province, Yasouj -Sepidan Rd, Mahparviz; Altitude: 2660); Td11 (Kohkiluyeh Province, Sepidar, Pazanan; Altitude: 2600).

Carvacrol, thymol and geraniol were found as the main constituents in the oils of the tested populations. Variation of the oils in populations was subjected to cluster analysis and three different chemotypes including carvacrol (47.3-80.1%), thymol (53.1-72.2%) and geraniol (65.6-75.7%) were identiified. Other important components were beta-caryophyllene (1.7-9%), p-cymene (0.1-10.9%) and gamma-terpinene (0.1-7.8%). Although Thymus is known as having high thymol content in its oil, it is revealed that T. daenensis subsp. daenensis has also a high potential for carvacrol and geraniol constituents in the oil. The largest similarity of the oil components of populations was detected between Td4 and Td7 and the lowest was revealed between Td8 and Td9. The differences in the oil content and composition of the populations could be attributed to their genetic variability and they could be a good genetic source for breeding purposes.

Wild growing Tanacetum dolichophyllum samples were collected during the period of full flowering, between September-October 2009 from high alpine meadows of Western Himalaya (Uttarakhand, India): Sample I (Dayara, altitude 3200 m) and Sample II (Tungnath, altitude 3800 m).

Plant collected from Dayara meadow (Sample I) afforded cis-lanceol (11.8%), beta-pinene (10.7%), (E)- beta-farnesene (7.4%), alpha-bisabolol (7.2%), beta-eudesmol (5.2%) and terpinen-4-ol (5.1%) as the major constituents, whereas in the sample collected from Tungnath (Sample II) beta-eudesmol (31.4%), alpha-bisabolol (10.7%) were the most abundant components followed by neryl acetate (5.8%) and (E)-beta-farnesene (5.7%). The composition was dominated by sesquiterpene hydrocarbons and oxygen containing sesquiterpenes (49.2-71.1%). The oils are clearly different from those of all other previously reported T. dolichophyllum oils.

The aerial parts of samples from collective populations of T. carnosus were collected during the vegetative phase (February 2000), at the beginning of the flowering phase (May 2000) and during the flowering phase (July 2000) at Quinta do Lago (Algarve). AQLM: collected in May, beginning of flowering phase; AQLJ: collected in July, flowering stage; AQLF: collected in Feb, vegetative stage.

All the oil samples collected in Quinta do Lago (QL) were dominated by borneol (26-31%) and camphene (9-18%), but the third main component varied according to the harvesting period. Bornyl acetate was the third main component (9-13%) in the flower oil and in the aerial parts oils collected in May and July, whereas terpinen-4-ol (8%) was the third main component in oil collected in February from vegetative phase plant material. A fourth main component, alpha-pinene (4-9%), was also present in relative high amounts in the QL oils.