风箱果(♀)×紫叶风箱果(♂)杂交种光合特性对干旱胁迫的响应

Response of photosynthetic gas exchange and chlorophyll fluorescence characteristics to drought stress in hybrid of Physocarpus amurensis Maxim(♀)×Physocarpus opulifolius “Diabolo”(♂)

为探明风箱果属植物的种间杂种优势,以风箱果(♀)×紫叶风箱果(♂)杂交获得的偏父本(♂)表型的杂交风箱果为试验材料,利用自然干旱的方法研究了杂交风箱果及其亲本光合气体交换参数及叶绿素荧光参数对干旱胁迫的响应。结果表明:1)杂交风箱果叶片的花色素苷含量较高,获得了紫叶风箱果(♂)的彩叶观赏效果,并且杂交风箱果叶片的叶绿素含量也较风箱果(♀)明显提高,从而导致其光合能力明显优于风箱果(♀),长势较风箱果(♀)更为旺盛。2)为适应干旱胁迫,3种风箱果叶片的气孔导度(Gs)和蒸腾速率(Tr)降低,这显著抑制了3种风箱果叶片的光合碳同化速率,虽然风箱果(♀)在正常水分条件下的光合能力较紫叶风箱果弱,但在干旱胁迫下风箱果(♀)叶片光合能力的降低幅度却显著低于紫叶风箱果(♂),杂交风箱果光合功能的敏感性较紫叶风箱果(♂)明显提高。3)干旱胁迫下3种风箱果叶片的PSII光化学活性降低,电子传递受阻,但风箱果(♀)叶片可以通过增加NPQ的方式来有效降低PSII反应中心的过剩光能。4)紫叶风箱果(♂)叶片PSII在干旱胁迫下光抑制程度明显大于风箱果(♀),而杂交风箱果在重度干旱胁迫下的PSII活性虽不及风箱果(♀),但却较紫叶风箱果(♂)明显提高。

To explore the hybrid vigor of the Physocarpus, hybrid Physocarpus amurensis Maxim of partial paternal phenotype hybridized from Physocarpus amurensis Maxim(♀)×Physocarpus opulifolius "Diabolo"(♂) were used in this study for investigating the response of photosynthetic gas exchange and chlorophyll fluorescence parameters on drought stress by using the natural drought method. The results presented that higher anthocyanin content in leaves was found in hybrid Physocarpus amurensis Maxim, with obtaining the colorful ornamental effect of Physocarpus opulifolius "Diabolo"(♂). The hybridization accelerated the chlorophyll content in leaves compared to Physocarpus amurensis Maxim(♀), which made the hybrid Physocarpus amurensis Maxim higher photosynthetic capacity and better growth than Physocarpus amurensis Maxim(♀). For adapting the drought stress, stomatal conductance(Gs) and transpiration rate(Tr) of the leaves were decelerated in all the three Physocarpus amurensis Maxim, which inhibited the photosynthetic carbon assimilation rate significantly. In the absence of drought stress, however, photosynthetic capacity is lower in Physocarpus amurensis Maxim(♀) than Physocarpus opulifolius "Diabolo"(♂), its decreasing scale facing drought stress is higher in Physocarpus opulifolius "Diabolo"(♂), indicating the hybridization improved the sensitivity of photosynthetic function. Though PS Ⅱ photochemical activity of leaves was decelerated in all three Physocarpus amurensis Maxim under drought stress, which blocked the electronic transmission rate, the excess light energy of PSⅡ reaction center could be effectively reduced by increasing NPQ.PS Ⅱ in leaves has more intensive photoinhibition under drought stress in Physocarpus opulifolius "Diabolo"(♂) than Physocarpus amurensis Maxim(♀), while in hybrid Physocarpus amurensis Maxim, the PSII activity was improved under drought stress compare to Physocarpus opulifolius "Diabolo"(♂) even though failing the competition to Physocarpus amurensis Maxim(♀).