Dormancy-Breaking and Germination Requirements for Seeds of Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae), a Mesic Forest Tree with High Ornamental Potential

Abstract

Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae) is an economically important tree in the temperate forests of Eastern China. In recent decades, ever-increasing use and modification of forestlands have resulted in major degeneration of the natural habitat of S. alnifolia. Moreover, S. alnifolia seeds germinate in a complicated way, leading to a high cost of propagation. The current study aimed to determine the requirements for breaking seed dormancy and for germination as well as to characterize the type of seed dormancy present in this species. Moreover, the roles of temperature, cold/warm stratification, and gibberellic acid (GA3) in breaking dormancy were tested combined with a study of the soil seed bank. The results showed that intact seeds of S. alnifolia were dormant, requiring 150 days of cold stratification to achieve the maximum germination percentage at 5/15 °C. Exposure of the seeds to ranges of temperatures at 15/25 °C and 20/30 °C resulted in secondary dormancy. Scarifying seed coat and partial removal of the cotyledon promoted germination. Compared with long-term cold stratification, one month of warm stratification plus cold stratification was superior in breaking dormancy. Application of GA3 did not break the dormancy during two months of incubation. Seeds of S. alnifolia formed a transient seed bank. The viability of freshly matured S. alnifolia seeds was 87.65% ± 11.67%, but this declined to 38.25% after 6-months of storage at room temperature. Seeds of S. alnifolia have a deep physiological dormancy; cold stratification will be useful in propagating this species. The long chilling requirements of S. alnifolia seeds would avoid seedling death in winter.

Cool–Warm Temperature Stratification and Simulated Bird Digestion Optimize Removal of Dormancy in Rosa rugosa Seeds

“…Furthermore, non-enzymatic reactions that remove germination inhibitors, reactive oxygen species and antioxidants ( Bailly, 2004 ), membrane alterations ( Hallett and Bewley, 2002 ), and degradation of specific proteins via proteasomes may also be important. In addition, compared with long-term cold stratification, 1 month of warm stratification plus cold stratification was superior in breaking the deep physiological dormancy of Sorbus alnifolia (Rosaceae) ( Tang et al, 2019 ). R. canina seeds reach maximum percent germination under H 2 SO 4 for 15 min followed by 4 weeks of warm stratification altered with 20 weeks of cold stratification ( Iakovoglou and Radoglou, 2015 ).…”

“…The five classes of dormancy are physiological, physical, combinational, morphological, and morphophysiological, and each requires specific cues to alleviate the dormancy and enable germination ( Finch-Savage and Leubner-Metzger, 2006 ; Kildisheva et al, 2020 ). In Rosaceae, dormancy of apple ( Daskalyuk, 2002 ) seeds is combinational (physical and physiological), while seeds of Sorbus alnifolia have a deep physiological dormancy ( Tang et al, 2019 ), and germination increases with stratification or when growth regulators are used. With removal of physiological dormancy, seed respiration, cell differentiation and division, and concentration of gibberellin, which promotes germination, increase, whereas abscisic acid content, which inhibits germination, decreases ( Finch-Savage and Leubner-Metzger, 2006 ).…”

Assessing the importance of seed priming for seed germination in Muscari.

“…Our results conclude that 5 min sulfuric acid plus 45-day stratification treatment on M. neglectum seed decreases germination time to 15 days in optimum temperature. Seeds of different plants require 4-28 weeks of stratification to break their dormancy, depending on the species (Tang et al, 2019). Stratification plays an important role as a stimulator that helps to break dormancy.…”

Equilibrio higroscópico en semillas forestales de zonas áridas y su efecto en la calidad fisiológica

“…En semillas de Agave lecheguilla Torr., Lippia graveolens Kunt. y Nolina cespitifera Trel., que fueron almacenadas a 15 °C en condiciones de baja humedad relativa (60 y 75%), PN no disminuyó de manera significativa, esto coincide con lo encontrado por Tang et al (2019) quienes reportaron que hasta los seis meses de almacenamiento las semillas de aliso (Alnus acuminata), solera (Cordia gerascanthus) y cedrillo (Guarea guidonia) mantuvieron constante el porcentaje de germinación cuando se conservaron a 12 °C.…”