Intermediate Epicotyl Physiological Dormancy in the Recalcitrant Seed of Quercus chungii F.P.Metcalf with the Elongated Cotyledonary Petiole

Forests

Xi-Ling Dai¹  Yi-Gang Song²  Gregor Kozlowski²  Xi-Qing Sun²  Bin-Jie Ge² 

[1] College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, SHH, China;Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai 201602, SHH, China;

关键词: Cyclobalanopsis chungii;    elongated cotyledonary petiole;    epicotyl dormancy;    Fagaceae, recalcitrant seeds;    seed germination;    shoot emergence;   

DOI  :  10.3390/f12030263

来源: DOAJ

【 摘 要 】

Control of seed germination and dormancy is important in seed plant adaptation and evolution. When studying seed dormancy of Quercus species, we observed a substantially delayed shoot emergence following a fast root emergence in Quercus chungii F.P.Metcalf. Since epicotyl physiological dormancy (PD) has not been reported in Quercus section Cyclobalanopsis, we examined seed morphology and germination in Q. chungii and aimed to document epicotyl PD in the seeds. The embryo was fully developed in fresh ripe seeds. The elongating cotyledonary petiole pushed the embryo axis out of the seed during germination, which differed from observations in other Quercus species. Shoots emerged from seeds with developing roots after 3 months of warm stratification (35/25 °C), reaching the highest percentage of shoot emergence in seeds after 5 months. Seeds were recalcitrant and displayed a yet unreported epicotyl PD type, for which we propose the formula C_nd(root) ‒ Cp’’ 2b(shoot). Early emergence and development of the root system in Q. chungii seeds with epicotyl PD appears to be a mechanism to maintain a constant water supply to the shoot during plumule development and emergence. Our documentation of seed germination will provide guidance for the conservation and restoration of this species from seeds.

【 授权许可】

Unknown