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草业学报 ›› 2010, Vol. 19 ›› Issue (1): 50-58.

• 研究论文 • 上一篇    下一篇

青藏高原东缘海拔对植物种子大小的影响

郭淑青1,齐威2,王玉林1,马雄1,陈学林2 ,杜国祯2*   

  1. 1.甘肃民族师范学院化学与生命科学系,甘肃 合作 747000;
    2.兰州大学草地与农业生态教育部重点实验室,甘肃 兰州 730000
  • 收稿日期:2009-02-21 出版日期:2010-01-25 发布日期:2010-02-20
  • 作者简介::郭淑青(1980-),女,甘肃民勤人,讲师,在读博士。E-mail: guoshq04@lzu.c
  • 基金资助:
    国家自然科学基金项目(90202009)资助

Effects of altitude on seed size on the eastern Qinghai-Tibetan Plateau

GUO Shu-qing1, QI Wei2, WANG Yu-lin1 , MA Xiong1, CHEN Xue-lin2, DU Guo-zhen2   

  1. 1.Department of Chemistry and Life Science, Hezuo Minorities Teachers College,Hezuo 747000,
    China;
    2.Key Laboratory of Arid and Grassland Ecology of Ministry of
    Education, Lanzhou University, Lanzhou 730000, China
  • Received:2009-02-21 Online:2010-01-25 Published:2010-02-20

摘要: 以青藏高原东缘600种植物种子为对象,就海拔对种子大小的影响展开系统性地研究。结果表明,1)整个区系内,植物种子大小与海拔呈极显著的负相关关系(n=600, R2=0.029, P<0.001),并且在2 000~3 000 m海拔梯度中,种子大小有先增大后减小的趋势; 2)草本植物种子大小与海拔呈极显著的负相关关系(n=512,R2=0.026,P<0.001),但是灌木(n=72, R2=0.004, P=0.616)和乔木种子大小(n=16, R2=0.005, P=0.795)随海拔虽有减小的趋势但无显著相关性;3)海拔较高地区的草本植物种子大小比同属的海拔较低的植物种子大11.5%(df=131, t=2.724, P=0.007),小于阈值±30%,草本植物属内种子大小与海拔无关。在132个草本植物种对中,与同属的低海拔物种相比,40.9%(54种)高海拔物种种子大,另外19.7%(26种)小,39.4%(52种)没有变化,由此,认为在青藏高原东缘强烈的选择压力下,海拔和系统发育综合因子对植物种子大小的影响由具体的某个属本身的特性所决定,不存在单一的海拔与属的种子大小变异模式。

Abstract: Seed size was studied in relation to altitude, growth form and phylogeny across 600 species on the eastern Qinghai-Tibet Plateau. 1) Considering the whole flora, seed size decreased with altitude(n=600, R2=0.029, P<0.001), in accord with previous studies; 2) The decline in seed size with altitude was significant within grasses(n=512,R2=0.026,P<0.001), but not within shrubs(n=72, R2=0.004, P=0.616), or trees(n=16, R2=0.005, P=0.795). 3) t-tests found that seeds of higher region species were 11.5% larger than seeds from lower region species of the same genus(df=131, t=2.724, P=0.007), but smaller than the threshold ±30%, so, there was no significant effect between seed size and altitude within a genus. This is in contrast to other studies that have found a positive correlation. Compared with seed size of species collected from lower regions in the 132 grass species-pairs 40.9%(54 species) of, higher species had larger seeds, 19.7%(26 species)had smaller, and 39.4%(52 species)had no difference. There was no uniform pattern relating seed size to altitude. In different genera, seed size responses to environment have varied over long-term ecological time.

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