不同饲用高粱品种群体光合性能指标变化的研究

研究了不同饲用高粱品种群体光合性能指标的变化规律。结果表明，在全生育期，饲用高粱的叶面积指数呈单峰曲线变化，以蒙农青饲1号叶面积指数最高。饲用高粱的光合势呈“单峰”曲线变化，拔节前增长缓慢，拔节后光合势呈直线上升。各品种按光合势峰值大小排序为蒙农青饲1号〉牧特利〉标兵〉苏波丹〉乐食。在全生育期牧特利呈“单峰”曲线变化，其余各品种净同化率均呈“双峰”曲线变化，各品种在出苗后31～44 d达到第一个峰值后开始下降。在全生育期牧特利的净同化率与群体生长率均呈“单峰”曲线变化，其余品种的净同化率与群体生长率均呈“双峰”曲线变化，各品种间乐食净同化率平均值最高，蒙农青饲1号群体生长率最高。单产之间比较，蒙农青饲1号单产最高，标兵和健宝次之，乐食产量最低。在呼和浩特地区及气候相似地区，蒙农青饲1号、健宝、标兵具有推广价值。

The Study on the Index of Community Photosynthesis Capability of Different Varieties of Forage Sorghum

The mutative rule of community photosynthesis capability of the different forage sorghum varieties was studied.The results demonstrated that during the all growth stages,the LAI of forage sorghum changed following a peak form,with Mengnong Qingsi No.1 having the largest peak value.The LAD of forage sorghum changed following a peak form,ascending slowly before the stem emerged and ascending on a linear trend after stem emergence.The order of the peak value of LAD for each variety was as follows: Mengnong Qingsi No.1 >Muteli> Pacemaker>Superdan>Everlush.At all growth stages,the net assimilation rate of each variety changed following the double peak form,except for Muteli,which had single peak form.The first rapid growth period for each variety occurred during the 31-44 day period.There were significant differences in assimilation rate among colonies of sorghum.Among the varieties,the mean of net assimilation rate of Mengnong Qingsi No.1 was highest at the all growth stages.Between per unit area yield comparison,Mengnong Qingsi No.1 per unit area yield highest,Jumbo and Pacemaker are next,the Everlush output is lowest.In the Huhhot area and the climate similar area,Mengnong Qingsi No.1,Jumbo,Pacemaker have the value for expansion and application.