不同粮饲兼用玉米品种光合性能指标变化研究

对5个不同粮饲兼用型玉米品种光合性能指标变化及其与产量关系的系统研究结果表明,不同类型粮饲兼用玉米品种叶面积指数呈“单峰”曲线变化,峰值出现在大喇叭口期至乳熟期(出苗后69~109 d),叶面积指数高值持续期长短及后期下降速度因品种而异。不同生育阶段光合势均以中晚熟品种较高,早熟品种较低。品种间群体生长率变化的差异主要在散粉期之后。相对生长率随生育进程呈现明显下降趋势。净同化率以拔节期最大,且品种间差异显著。不同品种叶片比叶重在大喇叭口期达到最大值。相关分析表明,不同粮饲兼用玉米品种鲜、干草产量与小喇叭口期和灌浆期的群体生长率(CGR)、相对生长率(RGR)、净同化率(NAR)均呈显著正相关。粮饲兼用型玉米品种金稷3号和承3359叶面积高值持续期长,总光合势高,CGR、NAR和RGR均较高,生物产量居前,在呼和浩特地区表现出较好的生态适应性。

Changes of Photosynthesis Indicators of Different Grain and Forage Maize

The results of photosynthesis indicators and yield experiment of 5 different grain and forage maize showed that Leaf Areas Index(LAI) changed as single-peak curve and the peak was in the large flare stage and milk stage(69d-109d after emergence),the peak sustained period and dropped rate were different in 5 cultivars.Leaf Areas Duration(LAD) of middle and later cultivars were higher than earlier cultivars in different stages.Colony growth rates(CGR) of different cultivars were different after pollen-scattering stage.Relative growth rates(RGR) decreased with the postponing of the growth period.The net assimilation rates(NAR) of different cultivars showed great difference and were highest in jointing stage.The stem/leaf weight(SLW) of different cultivars reached maximum in large flare stage.Through correlation analysis,the CGR,RGR and NAR in small flare stage and filling stage showed positive correlation with grass and hay yield to different cultivars.JJ-3 and C-3359 had longer LAD,higher CGR,NAR and RGR,and higher biomass,they are suitable in Hohhot.