两种青葙属植物对土壤锰的耐受性和富集差异

以锰超富集植物青葙和同属的非富集植物台湾青葙为对象,在0,50,100,200,300,500 mg/kg 6个浓度梯度下,研究了两种青葙属植物对土壤锰污染的耐受和富集差异。当锰处理浓度为500 mg/kg时,台湾青葙死亡,而青葙仍正常生长。锰胁迫下,青葙的初始荧光(F_0)、光合电子传递速率(ETR)差异不显著(p>0.05),而台湾青葙的F_0显著上升,ETR显著下降(p<0.05)。当锰处理浓度为300 mg/kg时,青葙的总生物量与对照相比增加了11.5%,而台湾青葙的总生物量降低了29.4%。另外,相同的锰处理浓度下,青葙较台湾青葙富集的锰更多,并将85.4%的锰从根部向地上部转移。结果表明,青葙对锰的耐受性和富集性均显著高于台湾青葙,主要是因为青葙具有更强的光合系统保护机制和锰转运能力。

Differences in Accumulation and Tolerance to Soil Mn for Two Celosia Genus Plants

The accumulation and tolerance to Mn in a hyperaccumulator and Celosia argentea,were compared with those in a non-hyperaccumulator C.taitoensis using a pot experiment.The plants were exposed to the soils spiked with 0,50,100,200,300,and 500 mg/kg Mn.C.taitoensis was unable to survive,while C.argentea still grew well when Mn supply concentrations at 500 mg/kg.Under Mn tress,the initial fluorescence(F 0)and the photosynthetic electron transport rate(ETR)in C.argentea did not significantly change(p>0.05);however,F 0 was significantly increased and ETR was significantly decreased in C.taitoensis(p<0.05).At 300 mg/kg Mn treatment,the biomass increased by 11.5%in C.argentea,while this value decreased by 29.4%in C.taitoensis.Furthermore,C.argentea can accumulate more Mn than C.taitoensis,and 85.4%of the Mn was transported from root to shoot.These results indicated that C.argentea has greater accumulation and tolerance to Mn than C.taitoensis.Why Celosia argentea has stronger accumulation and tolerance to Mn than Celosia taitoensis is that it has stronger photosynthetic system protection mechanisms and Mn transportation from root to shoot.