脱落酸和烯效唑对菜心光合作用的影响

Effects of abscisic acid and uniconazole on photosynthesis of flowering Chinese cabbage

以油青四九菜心为材料，研究外源植物激素脱落酸和生长延缓剂烯效唑对菜心光合作用的影响。结果表明，叶面喷施适宜浓度的外源脱落酸和烯效唑在2～3叶期处理可显著提高菜心叶片叶绿素含量，增加气孔导度、光合速率和蒸腾速率，降低胞间CO2浓度，增强光合作用，促进光合产物的积累，从而增加菜心产量，4～5叶期处理效果次之，6～8叶期处理效果再次之。说明在植株不同生长期，脱落酸和烯效唑处理对菜心叶片光合特性的影响效果是不同的。处理中以2～3叶期A2B1、A2B2、A1B2处理光合速率最高。

The objectives of the present study were to investigate the effects of ABA and uniconazole on photosynthesis of flowering Chinese cabbage. Flowering Chinese cabbage （Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee cv Youqing 49） were sprayed with different concentrations of abscisic acid （ABA） and uniconazole at 2 ~3, 4-5, and 6-8 leaf stages, respectively. Leaf spray of appropriate concentrations of ABA and uniconazole at 2-3 leaf stage significantly increased the chlorophyll content, stomata conductance, net photosynthetic rate（Pn） and transpiration rate, but decreased the intracellular CO2 concentration, and thus improved photosynthesis and promoted photosynthetic product accumulation of plants, and increased the yield of flowering Chinese cabbage. The promotion effects induced by ABA and uniconazole were lower at 4-5 leaf stage, and the lowest at 6-8 leaf stage. The results showed that the effects of ABA and uniconazole on photosynthetic characteristics were different at different growth stage. Within all treatments, Pn was highest in the treatments A2B1, A2B2 and A1B2 at 2-3 leaf stage.