Seed Dormancy and Soil Seed Bank of the Two Alpine Primula Species in the Hengduan Mountains of Southwest China

doi:10.3389/fpls.2021.582536

KIB OpenIR

	Seed Dormancy and Soil Seed Bank of the Two Alpine Primula Species in the Hengduan Mountains of Southwest China
	Peng,De-Li ; Yang,Li-E ; Yang,Juan ; Li,Zhi-Min
	2021
发表期刊	FRONTIERS IN PLANT SCIENCE
ISSN	1664-462X
卷号	12 页码:582536
摘要	The timing of germination has long been recognized as a key seedling survival strategy for plants in highly variable alpine environments. Seed dormancy and germination mechanisms are important factors that determining the timing of germination. To gain an understanding of how these mechanisms help to synchronize the germination event to the beginning of the growing season in two of the most popular Primula species (P. secundiflora and P. sikkimensis) in the Hengduan Mountains, Southwest China, we explored their seed dormancy and germination characteristics in the laboratory and their soil seed bank type in the field. Germination was first tested using fresh seeds at two alternating temperatures (15/5 and 25/15 degrees C) and five constant temperatures (5, 10, 15, 20, and 25 degrees C) in light and dark, and again after dry after-ripening at room temperature for 6 months. Germination tests were also conducted at a range of temperatures (5-30, 25/15, and 15/5 degrees C) in light and dark for seeds dry cold stored at 4 degrees C for 4 years, after which they were incubated under the above-mentioned incubation conditions after different periods (4 and 8 weeks) of cold stratification. Base temperatures (T (b)) and thermal times for 50% germination (theta (50)) were calculated. Seeds were buried at the collection site to test persistence in the soil for 5 years. Dry storage improved germination significantly, as compared with fresh seeds, suggesting after-ripening released physiological dormancy (PD); however, it was not sufficient to break dormancy. Cold stratification released PD completely after dry storage, increasing final germination, and widening the temperature range from medium to both high and low; moreover, the T (b) and theta (50) for germination decreased. Fresh seeds had a light requirement for germination, facilitating formation of a persistent soil seed bank. Although the requirement reduced during treatments for dormancy release or at lower alternating temperatures (15/5 degrees C), a high proportion of viable seeds did not germinate even after 5 years of burial, showing that the seeds of these two species could cycle back to dormancy if the conditions were unfavorable during spring. In this study, fresh seeds of the two Primula species exhibited type 3 non-deep physiological dormancy and required light for germination. After dormancy release, they had a low thermal requirement for germination control, as well as rapid seed germination in spring and at/near the soil surface from the soil seed bank. Such dormancy and germination mechanisms reflect a germination strategy of these two Primula species, adapted to the same alpine environments.
关键词	alpine plant base temperature cold stratification dry storage light requirement alternating temperature
DOI	10.3389/fpls.2021.582536
WOS记录号	WOS:000644842500001
引用统计
文献类型	期刊论文
条目标识符	http://ir.kib.ac.cn/handle/151853/73384
专题	中国科学院昆明植物研究所
作者单位	1.Yunnan Normal Univ, Sch Life Scienoes, Kunming, Yunnan, Peoples R China 2.Yunnan Normal Univ, Fac Geog, Kunming, Yunnan, Peoples R China 3.Chinese Acad Sci, Natl Germplasm Bank Wild Species, Kunming Inst Bot, Kunming, Yunnan, Peoples R China
推荐引用方式 GB/T 7714	Peng,De-Li,Yang,Li-E,Yang,Juan,et al. Seed Dormancy and Soil Seed Bank of the Two Alpine Primula Species in the Hengduan Mountains of Southwest China[J]. FRONTIERS IN PLANT SCIENCE,2021,12:582536.
APA	Peng,De-Li,Yang,Li-E,Yang,Juan,&Li,Zhi-Min.(2021).Seed Dormancy and Soil Seed Bank of the Two Alpine Primula Species in the Hengduan Mountains of Southwest China.FRONTIERS IN PLANT SCIENCE,12,582536.
MLA	Peng,De-Li,et al."Seed Dormancy and Soil Seed Bank of the Two Alpine Primula Species in the Hengduan Mountains of Southwest China".FRONTIERS IN PLANT SCIENCE 12(2021):582536.