摘要
以玉米面、小米面和绿豆粉 (质量比为 5∶3∶2 )的混合食物饲喂青藏高原地区特有种高原鼠兔 ,4 0d后断头杀死 ,取其后腿肌肉测定稳定性碳和氮同位素组成。结果表明 ,用混合食物饲喂后 ,高原鼠兔的稳定性碳同位素比值显著升高 ,由对照的 (- 2 4 6 6± 0 2 5 )‰上升为 (- 19 0 5± 0 0 9)‰ ;稳定性氮同位素的组成变化较小 ,仅由对照的 (3 2 8± 0 13)‰增加为饲喂后的 (3 6 1± 0 32 )‰。经人工食物饲喂后 ,高原鼠兔与其食物间稳定性碳同位素的分馏效应为 4 73‰ ,稳定性氮同位素的分馏效应为 2 79‰。C4组分食物的加入影响高原鼠兔的稳定性同位素 (特别是氮同位素 )代谢模式 ,其稳定性同位素代谢周转率可能高于原来预测的 4 0d。
To better understand stable isotope enrichment and metabolism of small mammals and to provide alternative for their dietary information analysis,a controlled feeding experiment was conducted on plateau pikas (Ochotona curzoniae) with mixture of flours of corn (C 4 plant),millet (C 4 plant) and mung bean (C 3 plant).Muscles of back legs were collected from plateau pikas for stable isotope analyses after 40 days' artificial feeding.The results demonstrated that stable carbon and nitrogen isotopes showed great variations after introduction of artificial food.Stable carbon isotope ratios of treatment groups became less negative compared with the control [(-19.05±0.09)‰ to (-24.66±0.42)‰] and showed great differences (t=-31.528,df=6,P=0.000).Stable nitrogen isotope ratios of treatment groups were a little bit positive compared with the control [(3.61±0.32)‰ to (3.28±0.13)‰] (t=1.427,df=7,P=0.197).Fractionations of stable carbon and nitrogen isotopes between plateau pikas' muscles and their diets were 4.73‰ and 2.79‰ respectively.Introduction of C 4 food had strong effect on stable isotope metabolism (especially for stable nitrogen isotope) of plateau pikas.Turnover rate of stable carbon and nitrogen isotopes for plateau pikas might be much more than forty days as respected.
基金
国家自然科学基金资助项目 (No 3 0 2 70 2 17)
关键词
人工食物
高原鼠兔
碳
氮
同位素
代谢
Controlled feeding
Stable carbon and nitrogen isotope
Plateau pika
Isotope metabolism
