Medicinal Plants
Ghasem Esmaeili; Majid Azizi; Hossein Arouiee; Jamil Vaezi
Abstract
Introduction: The genus Salvia L. (Lamiaceae) is one of the most interesting plant genera with a variety of annual, biennial, perennial and shrub forms. According to recent reports, there are 61 species of Salvia genus in Iran, among which 18 species are endemic. The use of Salvia species dates back ...
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Introduction: The genus Salvia L. (Lamiaceae) is one of the most interesting plant genera with a variety of annual, biennial, perennial and shrub forms. According to recent reports, there are 61 species of Salvia genus in Iran, among which 18 species are endemic. The use of Salvia species dates back to ancient times, and they are now being used for different purposes such as antimicrobial, anthelmintic, anti-inflammatory, tonic, carminative, digestive, Alzheimer’s disease, antispasmodic as well as for traditional medicines and food industries. Compared to crop plants, the breeding programs of medicinal plants are still in nascent stages due to high biological and biochemical variations. Since breeding programs, especially in medicinal plants, are expensive, suitable mating can help reduce the costs of breeding programs. Understanding the flowering biology, reproductive systems and pollination mechanism is essential to management and protection of ecosystems and mating programs. Despite the high diversity of Salvia genus in Iran, there is a paucity of studies on reproductive biology.Materials and methods: seeds of seven Salvia species including S. virgata (with four accessions), S. frigida, S. nemorosa, S. atropatana, S. macrosiphon, S. sclarea, and S. syriaca were collected from different geographical regions. The seeds were treated by various methods such as washing, cold treatment (stratification), scarification (sand and sulfuric acid), Gibberellic acid (GA3) and KNO3 to enhance germination. The seedlings were produced at the greenhouse and after growing as high as 15 cm or reaching the10-leaf stage, the seedlings were transferred to the farm. Plants phenology and flowering duration were recorded in the second year. Furthermore, some flower characteristics and pollinator were monitored. The Various pollination treatments were designed to investigate the breeding system of Salvia species including open pollination, spontaneous autogamy, geitonogamy, xenogamy, apomixis, and control. The self-incompatibility index (ISI) was calculated for each species in different pollination treatment.Results and discussion: The germination study exhibited that washing seeds for 24 h and applying 250 ppm GA3 exerted the highest effect on seed germination. The seedlings in early growth stages required medium to high porosity (high permeability to water and air) like natural habitat, but they were sensitive to dry and high EC at these stages. The phenology studies were shown Salvia virgata (all accessions) and S. nemorosa flowered three months after cultivation and other species flowered in the second year. The results showed that all species had long flowering periods ranging from 15 (S. atropatana) to 41 days (S. virgata). Increased flowering period led to the enhancement of flower over-lapping and the sharing of the pollen among different plants or species. Two species including S. atropatana and S. syriaca had heterostyly flowers (long-styled morph). The staminal-lever-mechanism was observed in all species. The results of manual pollination indicated that open pollination provided the best treatment with the highest average of seed set (73.63%) in all species. Salvia virgata (A1) with a seed set of 90.3% was the best species, and S. syriaca with a seed set of 51.5% demonstrated the poorest performance in open pollination system. The seed set in the xenogamy treatment of different species and accessions was in the range of 10.2 (S. syriaca) to 32.5% (S. frigida). It was observed that seed set among different species in geitonogamy and spontaneous autogamy varied widely from 2.60 - 17.30% and 2.98 - 12.18%, respectively. In treatments with a wide variety of pollen sources, the fruit set was higher, indicating that the pollen limitation triggered low seed set.Conclusion: Salvia species in the present study have a high potential for cultivation as medicinal and ornamental due to suitable adaptability and long flowering period. Salvia species were relatively self-incompatible that intention to the out-crossing and breeders can use in breeding programs as a valuable characteristic. The self-incompatible and specific structure in flower and pollination are the reasons for the diversity of this taxa.
Samane Mohammadi; Majid Azizi; Jamil Vaezi
Abstract
Introduction: Thyme is a perennial plant belongs to Lamiaceae. Thymus is a well–known medicinal plant, native to Southern Europe and its essential oil is manufactured commercially for use in cough drops, mouth-washes, liniments, toothpastes, detergents and perfumes. The herb is approved by Commission ...
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Introduction: Thyme is a perennial plant belongs to Lamiaceae. Thymus is a well–known medicinal plant, native to Southern Europe and its essential oil is manufactured commercially for use in cough drops, mouth-washes, liniments, toothpastes, detergents and perfumes. The herb is approved by Commission E in the treatment of bronchitis, whooping cough and upper respiratory inflammation. The Thymus genus comprises over 300 species of which, 18 are found in Iran, which grow wild in many regions and four of them are endemic. There are serious difficulties in the taxonomical interpretation of the taxa belonging to the genus Thymus owing to the high variability of populations with respect to many morphological and micro-morphological traits. The morphology and different components of essential oils in different species of Thymus are variable due to hybridization and polyploidization, despite its rare self-pollination. In general, intraspecific hybrids of the genus Thymus seem to possess intermediate morphological characteristics and composition of essential oil in comparison with the relevant characteristics of the parent plants. The accumulation of the essential oil takes place in gland hairs, which are distributed on the surface of the epidermis of the aerial parts of the plant. The content of the essential oil can depend on origin, climate, harvest, as well as drying and storage conditions. By carefully examining the structural, phenotypic, chemical and genetic aspects of the natural populations of a plant, it is possible to select either them or samples from them as an important step in the process of breeding the desired medicinal plant.
Material and Methods: In order to have a comparison microscopically and morphologically characteristics of Thymus vulgaris, two landraces of Thymus transcaspicus were studied in completely randomized design with four replications at the faculty of Agriculture in Ferdowsi University of Mashhad. Inflorescence length, number of flowers per inflorescence, shoot height, leaf, bud and flower length, leaf width, the largest diameter of canopy, weight, fresh and dry herb yield, percent of essential oil, distinct and type of trichomes, were measured. For glands morphological and structure analysis leaves were processed according to conventional techniques for scanning electron microscopy (SEM). In order to obtain comparable results the leaves from the third node of the apex were used for SEM analyses. Leaf samples were fixed in glutaraldehyde and paraformaldehyde. After being dehydrated, they were coated with gold in the vacuum evaporator. Finally, the preparations were observed and photographed with a KYKY-2800B SEM.
Results and Discussion: The ANOVA of the data showed that there was considerable variation for all studied characters. Results of mean comparisons showed that the highest height, the largest diameter of canopy and percent of essential oil were for T. vulgaris. Maximum inflorescence length, number of flowers per inflorescence, leaf, bud and flower length, leaf width, was also recorded for T. transcaspicus. Results of essential oil (EOs) analysis by GC/MS showed that thymol and carvacrol were the major compounds of all EOs samples, with highest and lowest content observed thymol and carvacrol in T. vulgaris (64.75 and 6.78 %). T. vulgaris produced more essential oil as compared to another thyme species. Two types of glandular trichomes are distributed on the outside surface of leaf, namely, peltate ones (PGTs) and capitate ones (CGTs). The glandular hairs of Lamiaceae likely release various secretions, such as the essential oil and polysaccharide. When trichomes got matured, essential oil could be found on all of the glandular trichomes on aerial organs of Thymus. Besides essential oil, what else trichomes could secrete needs further study.
Conclusion: The essential oil is highly complex chemical compounds. The content and composition of it vary depending on season, growing conditions, and plant species. High essential oil content is related to a much secretion of glandular trichomes. An application for variety protection was filed for ‘T. vulgaris’, now recommended to producers in Mashhad interested in a thymol-rich thyme. We can carry out a selection program to optimize quality and yield of thyme (T. transcaspicus L.) landraces, with used of T. vulgaris and crossing with clones of T. transcaspicus.
