TY - JOUR
T1 - Seed dormancy-breaking in a cold desert shrub in relation to sand temperature and moisture
AU - Liu, Huiliang
AU - Abudureheman, Buhailiqiemu
AU - Zhang, Lingwei
AU - Baskin, Jerry M.
AU - Baskin, Carol C.
AU - Zhang, Daoyuan
N1 - Publisher Copyright:
© The Authors 2017.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Seasonal periodicity of seed germination and its relationship to seasonal changes in temperature and soil moisture have been well studied in seeds of species with physiological dormancy. However, relatively little information is available on the role of these environmental factors in controlling germination of seeds with physical dormancy (PY). Our primary aim was to determine if seeds of the cold desert sand dune semi-shrub Eremosparton songoricum exhibits seasonal periodicity of seed germination and the relationship between seed dormancy break and soil temperature and moisture. In the laboratory, seeds incubated on dry, wet, wet-dry and dry-wet sand were exposed to a 1-year sequence of temperature regimes simulating those in the field. In the field, seeds were buriedat different depths on a sand dune, and germination of periodically exhumed seeds was tested at five temperature regimes during a 2-year period. In the 1-year sequence of simulated natural temperature regimes, breaking of PY was more effective under constantly wet than under constantly dry conditions, and germination percentage was significantly higher under dry-wet than under wet-dry conditions. Seeds buried in the field exhibited a distinct peak ofgermination in spring and little or no germination in other seasons. The final (2-year) monthly cumulative germination percentage differed among burial depths and temperature, and it was highest (47 %) in seeds buried at 3 cm and tested at 25/10 C. A seed cohort of E. songoricum likely exhibits a long-term annual periodicity of spring germination in the field, and dormancy break appears to be driven by low (winter) temperatures and relatively high sand moisture content. To our knowledge this is the first study to document seasonal periodicity in seed germination in a cold desert species with PY and to identify the mechanism (at the whole-seed level) of its occurrence.
AB - Seasonal periodicity of seed germination and its relationship to seasonal changes in temperature and soil moisture have been well studied in seeds of species with physiological dormancy. However, relatively little information is available on the role of these environmental factors in controlling germination of seeds with physical dormancy (PY). Our primary aim was to determine if seeds of the cold desert sand dune semi-shrub Eremosparton songoricum exhibits seasonal periodicity of seed germination and the relationship between seed dormancy break and soil temperature and moisture. In the laboratory, seeds incubated on dry, wet, wet-dry and dry-wet sand were exposed to a 1-year sequence of temperature regimes simulating those in the field. In the field, seeds were buriedat different depths on a sand dune, and germination of periodically exhumed seeds was tested at five temperature regimes during a 2-year period. In the 1-year sequence of simulated natural temperature regimes, breaking of PY was more effective under constantly wet than under constantly dry conditions, and germination percentage was significantly higher under dry-wet than under wet-dry conditions. Seeds buried in the field exhibited a distinct peak ofgermination in spring and little or no germination in other seasons. The final (2-year) monthly cumulative germination percentage differed among burial depths and temperature, and it was highest (47 %) in seeds buried at 3 cm and tested at 25/10 C. A seed cohort of E. songoricum likely exhibits a long-term annual periodicity of spring germination in the field, and dormancy break appears to be driven by low (winter) temperatures and relatively high sand moisture content. To our knowledge this is the first study to document seasonal periodicity in seed germination in a cold desert species with PY and to identify the mechanism (at the whole-seed level) of its occurrence.
KW - Burial depth
KW - Eremosparton songoricum
KW - Fabaceae
KW - Physical dormancy
KW - Seed germination phenology
KW - Wet-dry cycles
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U2 - 10.1093/aobpla/plx003
DO - 10.1093/aobpla/plx003
M3 - Article
AN - SCOPUS:85040176739
VL - 9
JO - AoB PLANTS
JF - AoB PLANTS
IS - 1
M1 - plx003
ER -