TY - JOUR
T1 - Distribution of three congeneric shrub species along an aridity gradient is related to seed germination and seedling emergence
AU - Lai, Liming
AU - Tian, Yuan
AU - Wang, Yongji
AU - Zhao, Xuechun
AU - Jiang, Lianhe
AU - Baskin, Jerry M.
AU - Baskin, Carol C.
AU - Zheng, Yuanrun
N1 - Publisher Copyright:
© The Authors 2015.
PY - 2015
Y1 - 2015
N2 - Environmental tolerance of a species has been shown to correlate positively with its geographical range. On the Ordos Plateau, three Caragana species are distributed sequentially along the precipitation gradient. We hypothesized that this geographical distribution pattern is related to environmental tolerances of the three Caragana species during seed germination and seedling emergence stages. To test this hypothesis, we examined seed germination under different temperature, light and water potentials, and monitored seedling emergence for seeds buried at eight sand depths and given different amounts of water. Seeds of C. korshinskii germinated to high percentages at 5: 15 to 25:35 °C in both light and darkness, while those of C. intermedia and C. microphylla did so only at 15: 25 and 25: 35 °C, respectively. Nearly 30 % of the C. korshinskii seeds germinated at -1.4 MPa at 20 and 25 °C, while no seeds of the other two species did so. Under the same treatments, seedling emergence percentages of C. korshinskii were higher than those of the other two species. The rank order of tolerance to drought and sand burial of the three species is C. korshinskii > C. intermedia > C. microphylla. The amount of precipitation and sand burial depth appear to be the main selective forces responsible for the geographical distribution of these species.
AB - Environmental tolerance of a species has been shown to correlate positively with its geographical range. On the Ordos Plateau, three Caragana species are distributed sequentially along the precipitation gradient. We hypothesized that this geographical distribution pattern is related to environmental tolerances of the three Caragana species during seed germination and seedling emergence stages. To test this hypothesis, we examined seed germination under different temperature, light and water potentials, and monitored seedling emergence for seeds buried at eight sand depths and given different amounts of water. Seeds of C. korshinskii germinated to high percentages at 5: 15 to 25:35 °C in both light and darkness, while those of C. intermedia and C. microphylla did so only at 15: 25 and 25: 35 °C, respectively. Nearly 30 % of the C. korshinskii seeds germinated at -1.4 MPa at 20 and 25 °C, while no seeds of the other two species did so. Under the same treatments, seedling emergence percentages of C. korshinskii were higher than those of the other two species. The rank order of tolerance to drought and sand burial of the three species is C. korshinskii > C. intermedia > C. microphylla. The amount of precipitation and sand burial depth appear to be the main selective forces responsible for the geographical distribution of these species.
KW - Caragana
KW - Geographical distribution
KW - Precipitation gradient
KW - Sand burial
KW - Seed germination
KW - Seedling emergence
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U2 - 10.1093/aobpla/plv071
DO - 10.1093/aobpla/plv071
M3 - Article
AN - SCOPUS:84939809473
VL - 7
JO - AoB PLANTS
JF - AoB PLANTS
IS - 1
M1 - plv071
ER -