不同遮光处理对马铃薯光合作用和产量的影响

Effects of different shading treatments on photosynthesis and yield of potato

为探究遮光处理对马铃薯植株光合作用和产量的影响,以12个马铃薯品种原原种为试验材料,苗齐后设置正常光照(CK)、单层遮光网遮盖处理(Z_(1))、双层遮光网遮盖处理(Z_(2)),间隔取样测量期为14d,分别测定叶绿素相对含量(SPAD)、荧光参数(F_(v)/F_(m))、光合生理指标(蒸腾速率T_(r)、气孔导度G_(s)、净光合速率P_(n)和胞间CO_(2)浓度C_(i))、单株产量、干物质含量和单株块茎干物质质量。结果表明,遮光处理导致叶片的SPAD下降,部分品种在遮光处理下叶片提早枯萎;遮光处理初期Z_(1)和Z_(2)叶片的F_(v)/F_(m)高于CK,而随着处理时间的延长Z_(1)和Z_(2)叶片的F_(v)/F_(m)显著低于CK;除‘大西洋’外,其余品种的T_(r)、G_(s)和P_(n)随遮光程度加重而下降但C_(i)相反,Z_(2)的P_(n)比CK低12.20%-82.69%、C_(i)比CK高11.52%-76.55%;且Z_(1)和Z_(2)的单株产量比CK低38.44%-100.00%,Z_(2)的块茎干物质含量比CK低66.88%-100.00%,Z_(1)和Z_(2)的单株块茎干物质质量比CK低42.06%-100.00%。

To study the effects of shading treatments on the photosynthesis and yield of potato,12 potato virus-free varieties were taken as experimental materials.After the seedling emergence,the control group(CK)was planted under normal light,treatment Z_(1) was covered by a single-layer shading net,and treatment Z_(2) was covered by a doublelayer shading net.The sampling interval for was 14 days,and the relative content of chlorophyll(SPAD),fluorescence parameters(F_(v)/F_(m)),photosynthetic physiological indexes(transpiration rate T_(r),stomatal conductance G_(s),net photosynthetic rate P_(n) and intercellular CO_(2) concentration C_(i)),yield per plant,dry matter content and weight of dry matter per plant tuber were measured,respectively.The results showed that:The SPAD of leaves was decreased in treatments Z_(1) and Z_(2),and the leaves of some varieties withered earlier.F_(v)/F_(m)of the leaves of plants in treatments Z_(1) and Z_(2)in the early stage was higher than that of CK,while with the extension of treatment time,the F_(v)/F_(m)of leaves of plants in Z_(1) and Z_(2)was significantly lower than that of the control.T_(r),G_(s) and P_(n) of other varieties except“Atlantic”decreased in Z_(1) and Z_(2),while Ciwas the opposite.P_(n) of Z_(2) was significantly lower than that of CK 12.20%-82.69%,and Ciwas significantly higher than that of CK 11.52%-76.55%.Moreover,the yield per plant of Z_(1) and Z_(2) was38.44%-100.00% lower than that of CK,the tuber dry matter content of Z_(2) was 66.88%-100.00% lower than that of CK,and the weight of dry matter per tuber of Z_(1) and Z_(2) was 42.06%-100.00%lower than that of CK.