钾营养对番茄光合作用和产量形成的效应

用盆栽试验研究钾营养对番茄光合作用和产量形成的效应,结果表明适量施钾明显增大叶面积,且叶的维管束较发达,净光合率提高并可缓和“午休”现象,光合产物增多.净光合率的提高与气孔导度及水势的提高有一致趋势.电镜观察表明适当施钾的叶绿体呈扁圆形,基粒较多,而缺钾叶绿体则较小而圆,基粒较少,在叶绿体旁有较多线粒体及过氧化体;钾过多的处理在前期光合及生长均受抑制,电镜观察其叶绿体发现其中少量有片层结构失常的情况,积累大量淀粉粒.基粒结构不明显,但开花结实后抑制作用渐消失.施钾使植株上、中、下层叶片在结实期都保持较高叶绿素含量;单果重及单株果数均增高,产量明显增加,果实维生素C及红色素含量提高,品质较好.

Effect of Potassium on Photosynthesis and Yield Formation of Tomato Plants (Lycopersicon escul-entum)

The results of pot experiment indicated: Application of potassium resulted in increasing leaf area and net photosynthetic rate. The bundle of leaf was well developed and relaxed "nap" in leaf. The net photosynthetic rate was in accord with both stomatal conductance and water potential. Electron micrographs showed that the chloroplasts in leaf of tomato plants were oblate with grana under It-treatment, while the chloroplasts of K-dificient treatment wete small with less grana and more mito-chondria and peroxisome around chloroplasts. A lot of starch grains and unclear grana structure were found in some chloroplasts under a heavy K-treatment. The plant growth and ret photosynthetic rate were depressed with heavy K-treatmect application at vegetative growth stage, after flowering and fruit satting, the depression effect would gradually disappear. At fruit setting stage, the upper, middle and lower leaves still remained green with more chlorophyll content in leaves under K-treatment and heavy K-treatment.