Uman National University | today: 06/27/2025
| Author(s) |
Граждан С. В., , , Ковальчук О. В., , , Сидоряк Р. Б. , , , Сержук О. П., , , |
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| Category | The Agronomy | ||
| year | 2025 | issue | Issue 106 Part 1 |
| pages | 636-641 | index UDK | 581.165: 634.17 | DOI | 10.32782/2415-8240-2025-106-1-636-641 (Link) |
| Abstract | This study investigated the physiological dormancy dynamics and optimal timing for in vitro culture initiation of four Crataegus L. species (C. almaatensis, C. arnoldiana, C. chlorosarka, C. phaenopyrum) from the National Dendrological Park “Sofiyivka” collection. Research was conducted during winter-spring period, when plants transition from deep dormancy to enforced dormancy. To determine dormancy release dates, shoots were sampled weekly and incubated in water at ~20 °C until bud break within seven days occurred. In vitro culture initiation was performed on three dates: February 15, March 1, April 1. One-year-old hawthorn shoots were collected, buds sterilized, and placed on modified Murashige and Skoog nutrient medium. Explant morphogenesis was assessed 20 days after culture initiation by calculating percentage of explants showing visible growth structures. Results demonstrated significant variation in dormancy release timing among species: C. chlorosarka exited deep dormancy first (January 3, 2023), followed by C. arnoldiana (January 31), C. almaatensis (February 7), and C. phaenopyrum (February 21). Despite differences in dormancy release, bud swelling in all species began almost simultaneously by late March 2023. Bud break phases showed greater genetic differentiation, with C. arnoldiana and C. chlorosarka initiating earlier and C. phaenopyrum last. In 2024, all phenological phases occurred earlier than in 2023, maintaining the same interspecies pattern. Explant development activation in vitro varied substantially with culture initiation timing and species. Early initiation during deep dormancy (February 15) resulted in minimal morphogenic activity (0–6%), especially for species still dormant. Cultures started March 1 showed moderate activation (5–45%), with C. almaatensis and C. phaenopyrum lagging behind C. arnoldiana and C. chlorosarka. Cultures initiated April 1, near vegetation renewal, exhibited high activation rates (80–85%) across species. Similar trends appeared in 2024 with minor quantitative differences. The study concludes that initiating in vitro culture of hawthorn buds is most effective when timed close to natural vegetation renewal. Initiation during deep dormancy or early enforced dormancy phases is ineffective for explant morphogenesis, highlighting the importance of physiological state monitoring for successful micropropagation of Crataegus L. species | ||
| Key words | hawthorn, species, explant, in vitro culture | ||