大田和控制光温下玉米苗期叶片NSC比较及根系糖代谢日变化
光合碳同化物在植物生长发育中起着重要的调控作用。有关自然和控制条件下光温对玉米叶片光合碳同化物累积特性影响的比较研究和玉米根系非结构性碳水化合物（NSC）日动态变化的研究较少。本文通过对比玉米苗期叶片在田间和室内条件下NSC日变化特征，分析了自然条件下光照和温度变化与光合碳同化产物间的关联性；同时，对室外水培条件下玉米苗期根系蔗糖、总可溶性糖和淀粉日变化特性进行了探讨。结果表明，玉米苗期叶片NSC累积呈先升高后降低的特征，不同处理NSC峰值均出现在光照结束阶段左右；田间光温条件下淀粉和可溶性糖累积浓度均高于室内水培。光温变化对NSC积累的影响达到极显著水平（P < 0.01）；前一时间点的光照与后一时间点的淀粉和可溶性总糖之间相关性均达到极显著水平（R2 = 0.77；R2 = 0.90）。根系中可溶性糖浓度呈明显的日变化特征，淀粉则在141.9-161.9 mg g-1 DM范围内波动。总之，玉米苗期叶片淀粉和可溶性糖呈明显的日变化特征，但不同光温条件下的积累量存在差异；根系蔗糖和淀粉浓度较为稳定而可溶性糖积累趋势与叶片相似。
英文摘要:
Photosynthesis assimilated carbohydrates play key roles in the regulation of plant growth and development. Comparative studies of influences of light and temperature on carbohydrate accumulation for maize leaf between natural and controlled conditions are scarce. Meanwhile, diurnal patterns of sugar concentrations for maize root system have not been clarified. Here, we compared the differences in diurnal pattern of nonstructural carbohydrate (NSC) for seedling leaves of maize under natural and controlled environments, and by which the influences of light and temperature on NSC and the correlation within them were analyzed. Also, the diurnal changes in sucrose, soluble sugar and starch for seedling root had been described. The results showed that the NSC in leaves displayed mono-peak changes and the peak values were at the end of light, irrespective of treatments. Both starch and soluble sugar contents accumulated in nature were higher than that of controlled environment. Diurnal changes of light and temperature had remarkable influences on NSC pools (P < 0.01), and the correlation coefficients between light density at last sampling time and starch and soluble sugar at the later time point were also significant (R2 = 0.77; R2 = 0.90). There is also staring diurnal change of soluble sugar in maize seedling root, while starch was constant in a range of 141.9-161.9 mg g-1 DM. In conclusion, variations of light and temperature significantly influenced the amount of leaf starch and soluble sugar, which performed obviously diurnal change. Similar diurnal pattern of soluble sugar has also been founded in maize seedling roots, while in which, starch and sucrose kept relative constant during the day and night.
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