STORAGE DURATION AND SEED GERMINATION OF SMALL-FLOWERED OREGANO (ORIGANUM TYTTANTHUM) IN THE KARSHI REGION
Аннотация
Background. The development of Uzbekistan's pharmaceutical industry based on local natural raw materials, reduction of import dependence, and enhancement of export potential require the scientifically justified introduction of promising essential oil-bearing species into cultivation. The small-flowered oregano (Origanum tyttanthum Gontsch., Lamiaceae), endemic to Central Asia, is a valuable essential oil plant. Its essential oil is characterized by high contents of carvacrol, thymol, and other terpene components, which determine its antiseptic and technologically important properties. At the same time, natural populations of the species are subject to significant anthropogenic pressure, while the effective establishment of industrial plantations requires the development of a reliable seed production base. Key indicators of seed quality include storage duration and germination dynamics, which may vary substantially under the arid continental climate conditions of the Karshi region. This study aimed to determine the optimal age of O. tyttanthum seeds for sowing under the conditions of the Karshi region, to assess the effects of different storage regimes on laboratory and field germination, and to characterize the early growth dynamics of embryonic organs after spring sowing. Methods. Seeds of small-flowered oregano (O. tyttanthum), collected in 2020–2024 in the mountainous areas of the Kashkadarya region, were stored at room temperature (+18+22 °C) and under refrigerated conditions (+4 °C). Germination was determined under laboratory conditions (in Petri dishes) and in field experiments by counting seedlings emerging from the experimental plot. The growth dynamics of the embryo, cotyledons, and the hypocotyl–root complex were recorded over 30 days in sowings established on 25 March 2024. The obtained data were processed using descriptive statistical methods and presented as ranges of values. Results. When stored at room temperature, the laboratory germination of freshly harvested seeds of small-flowered oregano was 7-9%, increased to 32-38% by the third month, and reached a maximum of 78-82% by the twelfth month; field germination during this period was 74-80%. After 18 months of storage, a gradual decline in germination was observed (laboratory: 70-78%; field: 62-70%), while after 36 months, a sharp decrease in seed viability occurred (30-40% and 22-34%, respectively). Under refrigerated storage (+4 °C), seeds retained high viability even after 36 months of storage (86-89%). The most intensive growth of embryonic organs was observed between 22 and 30 days and showed a clear correlation with an increase in temperature to 24-28 °C and with higher soil moisture following irrigation. Conclusions. The optimal seed age of small-flowered oregano (O. tyttanthum) for sowing under the conditions of the Karshi region is 6-15 months after harvest. For long-term storage of seed material, a cold storage regime (+4°C) is recommended, as it significantly slows down aging processes. The obtained results are of practical importance for the development of a seed production base and the introduction of small-flowered oregano into cultivation.