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.

Fresh leaves of the E. camaldulensis varieties(var. mysore and var. Catharine) were collected from 12 mature trees growing in Agodi Gardens, Ibadan, Nigeria.

The quantitatively significant constituents in die leaf oil of the two E. camaldulensis varieties were beta-pinene (9.0-17.5%), 1,8-cineole (32.8-70.4%), (Z)-beta-ocimene (11.6%) and alpha-pinene (8.8%). Monoterpenoids also made up the bulk of the two volatile oils (89.0-95.7%).

Aerial parts of Ocimum basilicum var. purpurascens Benth, Ocimum basilicum var. dianatnejadii Salimi at flowering stage were collected from plants grown in Experimental Station of Pykan Shahr, near Tehran. Elevation 1215 m above sea level, latitude 35° 42′ North, 51° 8′ East, average humidity 36% and climatic category semi-arid.

Methyl chavicol (43.0%) and linalool (28.9%) were identified as the major compounds in the oil of O. basilicum var. purpurascens, while methyl chavicol (37.6%), linalool (33.4%) and alpha-cadinol (5.7%) were the major constituents in the oil of O. basilicum var. dianatnejadii.

Experimental site: The present study was conducted at the experimental farm of the CSIR-Institute of Himalayan Bioresource Technology, Palampur (1325 m amsl, 32° 06′ 05″ N, 76° 34′10″ E), India, in 2011. Minimum temperature ranges from 3.5 ℃ to 19.8 ℃, maximum temperature ranges from 15.2 ℃ to 31.4 ℃, relative humidity varies between 62.2% and 94.1% in the morning and 45.0% and 87.2% in the evening, and bright sunshine hour ranges from 2.9 to 8.9 hours. Plant material: A population of approximately 50,000 plants raised from mixed stem cuttings collected from perennial rose plantations at the University of Agriculture, Udaipur, Rajasthan, India, and maintained in the field of the CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India, were utilized as an original gene pool of R. damascena. Two varieties, Jwala and Himroz were diversified through selections of desirable traits (morphological/oil content) across 25,000 plants. The five elites, three of R. damascena var. Jwala, (Indica, Super jwala and Jwala) and two of R. damascena var. Himroz (Hot himroz and Himroz) were developed through field selections and maintained at the Natural Plant Products Division Experimental Farm of the Institute. Rosa bourboniana plants were collected from the Fragrance and Flavour Development Centre, Kannauj, UP, India, during 1992 and maintained at the Natural Plant Products Division Experimental Farm of the Institute.

The essential oil content of the varieties of R. damascena varied from 0.037% to 0.051% and that of R. bourboniana was 0.017%. Super jwala recorded the highest oil content (0.051%). A total of 32 components were identified in the different varieties of rose oil. These components constituted 78.1-93.5% of the total rose oil species. The main components of rose oil were citronellol + nerol (16.3-30.1%), geraniol (15.8-29.3%), linalool (0.7-1.9%), rose oxide (0.9-2.6%), phenyl ethyl alcohol (0.1-0.4%), eugenol (0.3-2.2%), nonadecane (7.3-14.7%). The content of citronellol + nerol (30.1%) and geraniol (29.3%) was the highest in Himroz compared with other varieties.