摘要
以河套蜜瓜为试材,在果实迅速膨大期通过去果处理改变库源关系,研究源叶净光合速率,蔗糖、还原糖和淀粉含量及其代谢相关酶活性的昼夜变化规律。结果表明:(1)源叶的净光合速率为单峰曲线,无明显的"光合午休"现象,去果处理对其无影响。(2)源叶中蔗糖和还原糖含量的昼夜变化为单峰曲线,蔗糖磷酸合成酶和蔗糖合成酶合成方向活性的昼夜变化为双峰曲线,蔗糖合成酶分解方向、酸性转化酶和中性转化酶活性的昼夜变化无明显规律,改变库源关系对这些指标均无显著影响;蔗糖含量升高受蔗糖磷酸合成酶和蔗糖合成酶合成方向正调控,而蔗糖含量降低则受多种酶的共同调节。(3)源叶中淀粉含量和腺苷二磷酸葡萄糖焦磷酸化酶活性的昼夜变化为单峰曲线,去果处理可以显著提高淀粉含量和腺苷二磷酸葡萄糖焦磷酸化酶活性,淀粉含量升高受腺苷二磷酸葡萄糖焦磷酸化酶正调控。
Day and night variations of net photosynthetic rate,sucrose content,reducing sugar content,starch content and the activities of related enzymes in carbohydrate metabolism in source leaves in response to sink-source manipulation by defruiting and retaining fruits were studied when fruits removed 7 d during fruit expansion period（Cucumis melo L.cv.Hetao）.The results indicated that：（1）Day and night variation of net photosynthetic rate was typical single peak curve and showed no evidence of midday depression.There was no significant difference between defruiting and retaining fruits in net photosynthetic rate;（2）Single peak curve variations in contents of sucrose and reducing sugar in leaves were found in day and night changes.Day and night variations of activities of sucrose phosphate synthase（SPS） and sucrose synthase on synthesis（SS＋） in leaves showed bimodal curves.There were no significant curve variations in activities of sucrose synthase on cleavage（SS-）,neutral invertase（NI） and acid invertase（AI） in leaves.All of those physiological indices showed no significant differences between defruiting and retaining fruits.Content of sucrose in leaves increased was related to the activities of SPS and SS＋,but which decreased regulated by many factors;（3）Single peak curve variations in content of starch and activity of adenosine diphosphate-glucose pyrophosphorylase（ADPGPPase） in leaves were found in day and night changes.Content of starch and activity of ADPGPPase in leaves of defruiting treatment were higher than those of retaining fruits.Content of starch in leaves increased was related to the activity of ADPGPPase.
出处
《西北植物学报》
CAS
CSCD
北大核心
2012年第9期1774-1780,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
内蒙古自然科学基金项目(200711020314)
关键词
河套蜜瓜
库源关系
净光合速率
碳水化合物代谢
昼夜变化
Cucumis melo L. cv. Hetao
sink-source relationship
net photosynthetic rate
carbohydrate me-tabolism
day and night variations
