不同砧木嫁接番茄光合特性的研究

采用LI-6400便携式光合作用系统对田间条件下嫁接番茄(珍红/砧木1号,珍红/桂砧1号)以及接穗(珍红)的光合作用特性进行了系统研究。结果表明:自根苗的光饱和点显著高于嫁接苗;自根苗和嫁接苗的光补偿点差异不显著,以珍红/桂砧1号最高(31.8μmolphotons·m-2·s-1),珍红/砧木1号最低(17.6μmolphotons·m-2·s-1);嫁接苗的CO2补偿点显著低于自根苗,且珍红/桂砧1号与自根苗的差异达极显著水平;表观量子效率变化范围为0.062~0.073;CO2饱和点在844~971μmolCO2·mol-1左右,CO2羧化效率变化范围为0.055~0.086molCO2·m-2·S-1;光合作用CO2补偿点珍红、珍红/砧木1号和珍红/桂砧1号分别为74.0、60.8和50μmolCO2·mol-1。嫁接苗的日平均光合速率和蒸腾速率高于自根苗,但两者的日进程曲线均为“单峰型”,其光合作用不存在“午休现象”。

Study on different rootstock on photosynthetic characteristics of grafted tomatoes

The photosynthetic characteristics of grafted tomatoes(Zhenhong/Rootstock 1,Zhenhong/Rootstock 11)and own root tomato(Zhenhong)under field conditions were studied by using the LI-6400 portable photosynthesis system. The results were as follows:The Zhenhong had the highest light saturation point(2 085 μmolphotons·m~ -2 ·s~ -1 ),the other two grafted species had lower light saturation point(1 195～1 390 μmolphotons·m~ -2 ·s~ -1 ). The Zhenhong/Rootstock 11 had the highest light compensation point(31.8 μmolphotons·m~ -2 ·s~ -1 ),the other two species(Zhenhong/Rootstock 1,Zhenhong)had low light compensation point(17.6 μmolphotons·m~ -2 ·s~ -1 ～18.9 μmolphotons·m~ -2 ·s~ -1 ). The apparent quantum efficiency between 0.062 and 0.073. Under suitable temperature and saturation light intensity condition,CO_2 saturation point ranged from 844 μmolCO_2·mol~ -1 to 971 μmolCO_2·mol~ -1 ,the carboxylation efficiency was between 0.055～0.086 mol CO_2·m~ -2 ·s~ -1 . The CO_2 compensation point of the Zhenhong,Zhenhong/Rootstock1,Zhenhong/Rootstock 11 were 74.0 μmolCO_2·mol~ -1 ,60.8 μmol CO_2·mol~ -1 ,50 μmol CO_2·mol~ -1 respectively. The photosynthetic diurnal variations in leaves of tomato had been studied. The diurnal variations of net photosynthetic rates and respiration rates exhibited“single peaked pattern”. They had the highest point at midday and existed no“midday depression”in the photosynthesis. The diurnal variations of internal CO_2 concentration were just opposite to net photosynthetic rates.