جستجوی مقالات مرتبط با کلیدواژه « سطح پلوئیدی » در نشریات گروه « باغبانی »

In order to evaluate several ecological factors, morphological traits, essential oil productivity and ploidy levels of Thymus eriocalyx (Ronniger) Jalas with uses of DSS method ten natural habitats were selected  in Lorestan, Markazi, Hamadan, Kermanshah and Kurdestan provinces  in Iran. To study and evaluate morphological characters, five complete plant samples and flowering branches were collected from each locality at flowering stage for essential oil extraction in spring season of 2008. Ecological data of ten localities were also recorded. Vegetative and reproductive traits and essential oil quantity of each population were studied. Seeds were also collected in the seed production season to study seed characters, chromosome counting and ploidy level. At least 10 mitotic cells of each population were studied to determine chromosome numbers and ploidy levels. All populations were classified in 4 groups. Results revealed that specimens from "Te9 population" had the highest average length and width of inflorescence leaf, inflorescence leaf length to width ratio, stem leaf length to width ratio, petiole length, calyx tube length, corolla length and the highest average length and width of bracteole. The results of chromosome counting showed that specimens of Te1, Te2, Te3, Te4, Te5, Te6 and Te8 populations were diploid (2n=2x=30) and specimens of Te7, Te9 and Te10 populations were tetraploid (2n=4x=60). The highest essential oil production belonged to Te5 population (3.04%).

In order to induce autopolyploidy in basil (Ocimum basilicum) two separate experiments (seed treatment and cotton plug method on apical meristem) was conducted in a factorial experiment based on completely randomized design including colchicines concentrations (0, 0.05%, 0.1% and 0.2%) and the treatment time (6, 12 and 24 h) with four replications. On seed treatment all plants except control were perished. Morphological characteristics and flowcytometry data were used to detect and confirm polyploidization. The morphological and microscopic results showed that colchicines concentrations significantly affect autoploidy induction and the most cases (3.63%) observed on 0.05% concentration. Treatment time and interaction between concentration and time did not show a significant effect on this character. However the simple effects of concentration and treatment time were significantly different on survival percentage. Also concentration X time interaction showed a significant effect on this trait. Among the colchicines concentration levels, the second level (0.05%) showed the maximum survival percentage (47.7%) after the control. Higher concentrations caused more death in plants. Also the highest survival percentage (60.5%) appears in 12h duration of treatment. Generally, the best results to induce polyploidy obtained in 0.05% colchicines concentration for six hours when the treatment was treated using cotton plug.

In order to evaluate sثرثقشم ecological factors and morphological traits and also to determine ploidy levels and chemical composition of essential oil of Thymus pubescens Boiss. & Kotschy ex Celak two natural habitats, Bostan-Abad and Yam habitats, were chosen in East Azerbaijan province. To study and evaluate quantitative morphological characters, five complete plants and flowering branches were collected from each locality at flowering stage for essential oil extraction. Seeds also were collected in seed production season to study seed characters and chromosome counting. Ecological data of both localities also were recorded. Vegetative and reproductive traits of each population were studied and essential oil of each locality was analyzed by combination of GC-FID and GC-MS. At least 10 mitotic cells of each population were studied to determine chromosome number and ploidy levels. Results revealed that specimens from “Yam” had the longest flowering stems, the largest leaves and flowers, and also the highest number of flowers per inflorescence. Chromosome count results showed that specimens from Bostan-Abad were hexaploid (2n = 6x = 90) and those of Yam were tetraploid (2n = 4x = 60). The total yield of oils based on dry weight was 1. 3% and 2. 2% (w/w) from Bostan-Abad and Yam, respectively. Thymol was the main valuable phenolic compound similar to most of the species of genus Thymus (Bostan-Abad: 57. 6% and Yam: 44. 9%).