自然光温和控制光温下玉米苗期叶片NSC比较及根系糖代谢日变化

Effects of Light and Temperature on the Leaf NSC and Root Sugar in Maize Seedling under Natural and Controlled Conditions

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,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;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 DM范围内波动。

Photosynthesis assimilated carbohydrates play key roles in the regulation of plant growth and devel- opment.Till now,effects of light and temperature on carbohydrate accumulation in maize leaf and root have not been clarified.Here,we compared the diurnal pattern differences of nonstructural carbohydrate(NSC)in leaves of maize seedlings under natural and controlled environments,and then the influences of light and temperature on NSC and the correlation among them were analyzed.Also,the diurnal changes of sucrose,soluble sugar and starch contents in seedling root were described.The results showed that NSC in leaves displayed mono-peak pattern and peaked at the end of light under all treatments.Both starch and soluble sugar contents accumulated under natural condition were higher than that under 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 contents at the later time point were also significant(R^2=0.77;R^2=0.90).The diurnal change of soluble sugar content in maize seedling root was obvious,while the starch content was constant in a range of 141.9-161.9 mg/g DM.