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以甜心玉簪、紫萼玉簪为试材,采用CIRAS-2型光合仪,研究测定了重金属Cr(0、20、200、400mg/kg)胁迫对甜心玉簪、紫萼玉簪的光合日变化、光响应曲线及叶绿素含量的影响。结果表明:与CK相比,在Cr 20mg/kg胁迫下,叶绿素a、b含量升高、光能利用率和光适应能力最强;在Cr 200mg/kg和Cr 400mg/kg胁迫下,叶绿素a、b含量降低、光响应参数随Cr浓度增加而降低。在各胁迫处理下,2种玉簪净光合速率(Pn)均呈\\\"双峰型\\\"曲线,有明显的光合\\\"午休\\\"现象;净光合速率(Pn)与蒸腾速率(Tr)、气孔导度(Gs)呈正相关,与胞间CO2摩尔分数(Ci)呈负相关。根据不同浓度重金属Cr胁迫下2种玉簪叶绿素和光响应参数与CK比较,甜心玉簪耐重金属能力高于紫萼玉簪。
The photosynthetic diurnal variation and photoresponse of photosynthesis of Hosta somata and Hosta variegata were studied by using CIRAS-2 photosynthesis apparatus with Hosta sweetpot and Hosta variegata as test material. Curve and chlorophyll content. The results showed that chlorophyll a, b content increased under light irradiation of 20 mg / kg Cr, compared with CK. Under the stress of Cr 200 mg / kg and Cr 400 mg / kg, chlorophyll a, b content decreased, light response parameters with the increase of Cr concentration decreased. Under the stress treatment, the net photosynthetic rate (Pn) of the two species of Hosta were showed \"double peak\" curve, obvious photosynthesis \\ \"lunch break \\\" phenomenon; net photosynthetic rate (Pn) and transpiration rate Stomatal conductance (Gs) was positively correlated with the intercellular CO2 molar fraction (Ci) was negatively correlated. According to the chlorophyll and light response parameters of two species of Hosta in different concentrations of heavy metals Cr, the tolerance to heavy metals of Hosta somata was higher than that of Hosta variegata.