Effects of Different Planting Density on Photosynthetic Characteristics of Potato Variety Jizhangshu No.8

Jizhangshu No.8 was used to study the growth,photosynthetic parameters and yield in different planting densities.The results showed that the leaf net photosynthetic rate, transpiration rate and stomatal conductance quickly increased in four treatments(m1,m2,m3,m4), which reached the peak values of 23.0, 24.3, 22.1 and 21.8 μmolCO2/(m2·s),7.2, 7.9, 6.5and 6.0 mmol H2 O /(m2·s),492.0, 508.0, 411.0 and 405.0 mmol /(m2·s) at the flowering period and decreased in final flowering period reaching the minimum value in mature period with 10.9, 12.3, 8.5 and 8.0 μmolCO2/(m2·s),0.9, 1.5, 0.8and 0.8 mmol H2 O /(m2·s),184.0,224.0,128.0 and 127.0 mmol /(m2·s). The change of intercellular CO2 concentration was opposite comparing with photosynthetic rate and the minimum values were 112.0, 105.0, 118.0 and 126.0 μmol / mol, respectively. During the whole growth period, the photosynthetic rate, transpiration rate, stomatal conductance and yield of m2 treatment were higher than that of other treatments.