Hatice Çölgeçen

Plant regeneration of natural tetraploid Trifolium Hum pratense L.

The regeneration of natural tetraploid T. pratense, originated from Erzurum-Turkey, is reported in this study. This plant has low seed setting and hard seed problems due to polyploidy. Hypocotyl, cotyledon, apical meristems, epicotyl and young primary leaves were inoculated on MS and PC-L2 media containing different concentrations of BAP and NAA as growth regulators. The best shoot formation has been observed on explants initiated from apical meristem placed on PC-L2 medium that includes 2 mg dm(-3) BAP and 1 mg dm(-3) NAA. 94.4% of the shoots originated from calli were rooted on PC-L2 medium with 1 mg dm(-3) NAA. In vitro organogenesis has been accomplished in the natural tetraploid T. pratense regenerated plants successively transferred to the field.

Mericarp micromorphology and anatomy of Salvia hedgeana Dönmez, S. huberi Hedge and S. rosifolia Sm. (section Salvia Hedge, Lamiaceae)

Mericarp micromorphology and anatomy of Salvia hedgeana Dönmez, S. huberi Hedge and S. rosifolia Sm. (section Salvia Hedge, Lamiaceae) Mericarp (nutlet) micromorphology and pericarp structure of three morphologically similar endemic Salvia species; Salvia hedgeana, S. huberi and S. rosifolia were investigated using LM, SEM and TEM. Salvia hedgeana has larger mericarps and abscission scars than S. huberi and S. rosifolia. Mericarp length to width ratio ranges from 1.11 in S. hedgeana to 1.60 in S. huberi. Mericarp shape is mainly ovoid, rarely broadly ovoid in S. hedgeana, and oblong in S. huberi. The mericarp surface sculpturing pattern in all species is colliculate. However, exocarp cells are pentangular-hexangular in S. hedgeana, irregular in S. huberi and rounded and smaller in S. rosifolia. In Salvia huberi anticlinal walls are undulate whereas in S. hedgeana and S. rosifolia anticlinal walls are straight. Salvia hedgeana was distinguished from the others by the thickest pericarp (146-185 μm). The sclerenchymatous region significantly varied between the species. It was 84-99 μm in S. hedgeana, 56-82 μm in S. huberi and 27-61 μm in S. rosifolia. The mesocarp was also thicker in S. hedgeana. The wetted mericarps produced mucilage, but S. huberi differed from the others in having translucent-milky white opaque mucilage with fibres or radiating cordons.

In vitro isoflavonoid production and analysis in natural tetraploid Trifolium pratense (red clover) calluses

Isoflavones are polyphenolic phytoestrogens, predominantly found in leguminous plants. Trifolium pratense L., Fabaceae (red clover), is rich in isoflavones that possess estrogenic activity due to their similar molecular structure and effectiveness in preventing health conditions such as menopause, osteoporosis, cardiovascular disease, hypertension and hormone-dependent cancers. In this study, presence and amount of various phytoestrogens in the tetraploid plant and in the calluses derived from the plants were investigated. Calluses were generated from explants obtained from natural tetraploid T. pratense seedlings. The best callus formation was obtained from hypocotyl explants cultured in Phillips Collins and Gamborg B5 media containing different plant growth regulators. Flowers of plants and calluses were analysed for formononetin, biochanin A, genistein and daidzein contents using HPLC. In HPLC analysis, high levels of formononetin (0.249 µg/mg) were determined in natural tetraploid T. pratense flowers in addition to genistein and biochanin A. In calluses, highest isoflavone content (1.15 µg/mg formononetin) was observed in modified Gamborg B5 medium. Biochanin A content of calluses and the plant were found to be nearly the same. But formononetin and genistein contents of the calluses in this medium were found to be respectively 4.62 and 21.39 folds higher than the tetraploid plant.

Pollen characteristics and in vitro pollen germination of Cedrus libani A. Rich.

This study aims to determine the germination characteristics, pollen tube developments, effects of germination media and temperature and incubation durations of the pollens obtained from the four clones (11342, 11344, 11345 and 11351) of Cedrus libani A. Rich. (Lebanon Cedrus) obtained from clonal seed orchard (with national registration no: Eskisehir 117) between 2004 and 2006 as well as of those taken from clone no: 11351 in 2004. They were stored at 3°C for 13 months till they were investigated experimentally. MS medium was preferred for pollen germination for its relative superiority. Three-day incubation period at 33°C temperature, in dark was applied along with the MS medium. The highest germination rate in MS medium was achieved in clone no.11342 with 84.77% among the pollen samples of 2005. On the other hand the germination rate of the pollens taken from clone no: 11351 was determined as 49.95%.

Assessment of Graft Compatibility of Some Olive Cultivars on Gemlik Rootstock by Florescence Microscopy = تقييم التوافق التطعيمي في الزيتون بواسطة المجهر الفلوريسيني

A florescence microscopy was used to assess the graft compatibility of five scions of olives and one rootstock. The cultivars inspected were ‘Gemlik’, ‘Memecik’, ‘Sari Ulak’, ‘Nizip Yaglik’ and ‘Domat’ where the rootstock was ‘Gemlik’. Anomalies have been observed in some grafts, such as differences in the growth of scions and rootstock trunk diameters. The study reports the extent of callus growth, cambial differentiation, cambial continuity and formation of vascular tissues of these olive cultivars in applied grafts by florescence microscopy. A good callus growth was observed in the cambial development of vascular tissues in these samples. The formation of air pockets in side grafts was also found. Successful compatible grafts of ‘Gemlik’, ‘Memecik’, ‘Nizip Yaglik’, and ‘Sari Ulak’ cultivars were identified using ‘Gemlik’ rootstock. The scions of ‘Domat’ grafted onto ‘Gemlik’ induced limited callus and cambial development, resulting only in partial success of the grafts, and with the formation of air pockets. Weak grafts; dark brown necrotic regions along the lines of the graft in the callus tissue borders were also observed. Phenolic compounds causing necrosis in the graft zone were also identified by histochemical investigation.