密度对饲用玉米蔗糖合成和积累的影响

以4个饲用玉米品种为材料，研究玉米生长发育过程中密度对蔗糖合成和积累的影响，探讨蔗糖合成酶(SS)、磷酸蔗糖合成酶(SPS)与蔗糖间的相关性，明确蔗糖合成机理。研究结果表明，拔节期至成熟期蔗糖含量随密度的增加而降低，孕穗期至灌浆期SS活性随密度的增大而减小，SPS活性在孕穗期至灌浆期随密度的增大而减小；子粒蔗糖含量因密度和品种而异，SS活性随着密度的增大而减小，子粒SPS活性在整个灌浆过程呈逐渐降低趋势，在吐丝42 d以前酶活性均随密度的增加而降低；功能叶片SPS活性、SS活性与蔗糖含量间在孕穗期至成熟期呈极显著正相关，子粒SPS活性与蔗糖含量在吐丝7～42 d呈极显著正相关，子粒SS活性与蔗糖含量在吐丝后(除吐丝42 d呈显著正相关外)呈极显著正相关。

Effects of Density on Sucrose Synthesize and Accumulation of Forage Maize

The study was carried out about effects of density on sugar synthesize and accumulation by four varieties of forage maize, and discussed the relationship between SS, SPS and sugar. It made clearly the sucrose synthesize mechanism and established the high efficient production of forage maize. The results showed that sucrose contents in functional leaves of forage maize decreased with the increasing density from elongation stage to ripening forage. The SS and SPS activity declined with the increasing density from booting stage to grain stage. The sucrose contents in grains were different on different density and varieties. The SS activity in grains declined with the increasing density. The SPS activity in grains had a decreasing trend in the whole graining progress. The enzymes activities were declining with the increasing density before 42th after silking. The activity SPS and SS in functional leaves of forage maize were supreme significantly positively correlated with the sucrose contents between booting stage and ripening stage; the SPS activity in grain was supreme significantly positively correlation between 7th and 42th after silking, but the SS activity was supreme positive correlation with the sucrose content in grains of forage maize after silking (except positive correlation in the 42th after silking).