多胺对冬小麦籽粒灌浆的影响及其生理机制

以周麦18和西农538为材料研究表明，喷施精胺(Spm)或亚精胺(Spd)显著促进冬小麦籽粒灌浆，而喷施腐胺(Put)对冬小麦籽粒灌浆无显著影响；外源Spm或Spd显著提高旗叶叶绿素含量、光合作用以及抗氧化酶(SOD、POD、CAT)活性，同时显著降低旗叶丙二醛以及籽粒乙烯释放速率。说明不同类型多胺对冬小麦的影响不同，多胺对冬小麦籽粒灌浆的影响与叶片光合、衰老以及籽粒ETH释放速率密切相关。

Effect of Polyamine on Grain Filling of Winter Wheat and Its Physiological Mechanism

Grain filling in wheat is an important agronomic trait affecting grain weight. Polyamine is a plant growth regulator that is proved to participate in regulation of grain filling in rice and maize. In the present study, Zhoumai 18 and Xinong 538 were used to investigate the effect of polyamine on grain weight during filling process; besides, the photosynthetic characteristics, activities of antioxidant enzymes (SOD, POD, and CAT), malondialdehyde (MDA) content in flag leaves, and ethylene (ETH) content in grains were also measured for explaining the mechanism of such effect. The results showed that external spermidine (Spd) and spermine (Spm) significantly promoted grain filling, while external putrescine (Put) had no significant effect on grain filling. External Spm and Spd increased chlorophyll content, activities of antioxidant enzymes, and photosynthetic rate, but decreased MDA content in flag leaves and ETH level in grains. Therefore, we conclude that the effects on grain filling vary with polyamine species, and may relate to photosynthesis and senescence of leaves and ETH level of grains.