| Stachys floridana Schuttl. ex Benth. is local characteristic vegetable and eat its subterranean stem. It has mang proteins, carbohydrates, amino acids, ect. So it can help digestion, relax the bowels and reduce blood pressure. Using stems and leaves of Stachys floridana as test material. Effects of different cadmium or plumbum concentrations on physiological ecology, quality and heavy metal residue content were studied with the pot experiment. The main results obtained as bellow:⑴Stachys floridana has been introduced in Xinxiang successfully. Whether the experimental plots or greenhouse were all growing better, but in the experimental plots sown growth slowly,low and strong. However,in the greenhouse,the plant grown highter but weaker. As a result, both can flower properly.⑵It's inhibit effect to the growth of Stachys floridana when they were under cadmium, lead stress treatment. And yellowing of the leaf edge, a few brownness, dry and even death. The height, stem diameter, leaf length and wide leaf blade were decreased with increase of cadmium or lead concentration. And the height was decreased by 7.17 cm under cadmium stress, stem diameter, leaf length and wide leaf blade were decreased by 27.66%, 7.68% and 27.69% respectively. With the increasing of cadmium concentration, the biomass of Stachys floridana decreased significantly, and significant difference betweent reatment and the control.⑶The chlorophyⅡcontent of Stachys floridana were significantly decreased with increase of cadmium or lead concentration, and Malondialdehyde (MDA) showed a positive relationship with the cadmium concentration. The cell membrane permeability was significantly enhanced with the increase of treatment time, which reached 82.60%. The activitie of Superoxide Dismutase (SOD) and Peroxidase (POD) in leaves showed a significantly positive relationship with the stress, and the photosynthetic rate(Pn), stomatal conductance(Gs)and transpiration rate(Tr) were reduced. The water use efficiency (WUE) was firstly increased, and then decreased, and the intercellular CO2 concentration (Ci) was gradually escalate.⑷The contents of soluble sugar,titratable acid and soluble protein were all showed a negative relationship with the cadmium concentration. The soluble solids and Vitamin C, firstly increased ,and then decreased. Crude fiber was gradually escalated with the higher cadmium concentration, but the increasing was relatively less. the contents of reducing sugar,titratable acid,soluble solids and Vitamin C were significantly decreased with increase of lead concentration, and free amino acids was radually escalate,and with a very significant difference.⑸The sequence of the content of heavy metals in leaves and aerial stems was as following:Fe > Zn > Mn > Cu > Pb,Cd; However,the sequence of the content of heavy metals in subterranean stems was as following:Zn > Fe > Cu > Mn > Cd > Pb. Besides Cu, the contents of a element order was:leaves > aerial stem > subterranean stem.⑹Under cadmium stress, Ca,Fe,Mg in leaves were increased gradually with increase of cadmium concentration,however the elements of K,Cu,Zn displayed contrary tendency. The elements of Ca,K,Cu in aerial stem,firstly increased,and then decreased, and Mg,Mn increased.In subterranean stem,the Fe,Mg decreased, Ca increased gradually,and K,Cu,Na firstly increased and then decreased. Elements of Mn,Zn were not difference betweent reatment and the control. Ca in leaves and aerial stems and Fe in aerial stems were positive correlation with increase of lead concentration, Mg, K in leaves and aerial stems and Ca,K,Mg in subterranean stem were negative correlation. Cu in leaves, aerial stems and subterranean stem were decreased, Mn in leaves and aerial stems were increased, Na increased in leaves and decreased in subterranean stem, Zn decreased gradually in leaves, not difference betweent reatment and the control in aerial stems and subterranean stem.⑺The contents of Cd,Pb in each parts of Stachys floridana were increased with the increasing of cadmium or lead concentration,and showed very significant difference. Treatment group exceeded national sanitary standard level, and cadmium stress has not direct influence on lead content, but cadmium content increased under lead stress. The contents of Cd,Pb in subterranean stem were lower than national sanitary standard level, and they were 16.46 times,16.9 times respectively exceeded national sanitary standard level under cadmium or lead stress.⑻With the increasing of cadmium or lead concentration, the contents of stachyose decreased, and showed very significant difference in High-concentration. Under the highest treatments of cadmium or lead reduced the content of stachyose in subterranean stem to 67.37%, 80.61% respectively. |
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