Effects of Planting Density on Photosynthetic Characteristics and Grain Yield of a Wheat Cultivar Shixin828

A field experiment was conducted to evaluate photosynthetic characteristics and grain yield in different planting densities of a winter wheat cultivar Shixin828 with sowing suitable late.It was studied under four different density levels;The photosynthetic characteristicsts were measured using CI-340 portable photosynthesis system and FMS-2 fluorescence monitoring system.The results indicated that the dsnsity can remarkably influence the Photosynthesis characteristies of flag leaf and yield level.The 330×104 basis seedlings per ha treatment had apparent advantages in chlorophyll content,photosynthesis rate,PSⅡpotential activity(Fv/Fo)and the maximal quantum efficiency of PSⅡphotochemistry(Fv/Fm)of the flag leaf at late growth period and the grain yield of it was higher than that of the others significantly.The 210×104 and 270×104 basis seedlings per ha treatments represent franfibility for gently drought as a result of less colony and the 330×104 basis seedlings per ha treatment influence individual growth with close microclimate as a result of great colony,both above reducing yield.The highest grain yield was observed in the treatment with 330×104 basis seedlings per ha applied.