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Changes in growth and distribution of inorganic mineral elements and organic active substances in seedlings of A. vera were examined under treatments of −0.44 and −0.88 MPa polyethylene glycol 6000 (PEG) and corresponding isosmotic sodium chloride (NaCl). All stress treatments inhibited plant growth, with NaCl severely inhibiting the growth of the seedlings than PEG. However, leaf biomass did not change significantly. The nitrogen concentration under PEG was maintained higher than that under NaCl. Salinity caused more severe ionic imbalance than dehydration. However, when the concentration of NaCl was increased, ion homeostasis was maintained. Stressors induced an increase in aloin concentration in leaves, especially in young leaves. Polysaccharide concentrations in leaves did not change under dehydration. However, the polysaccharide concentration decreased in the middle and base leaves under NaCl. A. vera exhibited high adaptability to suitable osmotic stress, which increases its main active ingr...

To make sure the feasibility of the three-point arc interpolation in any space after the MATLAB simulation, we applied it in FPGA (Field Programmable Gate Array, FPGA), finished the PCB board design, and used the arc interpolation controller to control the robot mechanical in this article. By analyzing the actual path, we found the results match the design requirements. The space controller guarantees the real-time and accuracy requirements of arc interpolation, and will have excellent practical value.

Phytoremediation is becoming a cost-effective technology for the in-situ clean up of sites polluted with hydrophobic organic contaminants (HOCs). The major factors limiting phytoremediation are the mass transfer, rate of plant uptake, and microbial biodegradation of HOCs. This article discusses the potential of surfactants to enhance desorption, plant uptake, and biodegradation of HOCs in the contaminated sites. Positive effects of surfactants on phytoremediation have been recently observed in greenhouse studies. The presence of some nonionic surfactants including polyoxyethylene sorbitan monooleate (Tween 80) and polyoxyethylene (23) dodecanol (Brij35) at relatively low concentrations resulted in significant positive effects on phytoremediation for pyrene-contaminated soil. However, the anionic surfactant (sodium dodecyl sulfate, SDS) and the cationic surfactant (cetyltrimethylammonium bromide, CTMAB) were not useful because of their phytotoxicity or low efficiency for surfactant-enhanced phytoremediation (SEPR). The mechanisms of SEPR for HOC-contaminated sites were evaluated by considering experimental observations. In view of concerns about the cost effectiveness and toxicity of surfactants to plants, more research is needed to enhance the use of SEPR technology.

Responses ofUlva proliferaandUlva linzato Cd2+stress were studied. We found that the relative growth rate (RGR), Fv/Fm, and actual photochemical efficiency of PSII (Yield) of twoUlvaspecies were decreased under Cd2+treatments, and these reductions were greater inU. proliferathan inU. linza.U. proliferaaccumulated more cadmium thanU. linzaunder Cd2+stress. WhileU. linzashowed positive osmotic adjustment ability (OAA) at a wider Cd2+range thanU. prolifera.U. linzahad greater contents of N, P, Na+, K+, and amino acids thanU. prolifera. A range of parameters (concentrations of cadmium, Ca2+, N, P, K+, Cl−, free amino acids (FAAs), proline, organic acids and soluble protein, Fv/Fm, Yield, OAA, and K+/Na+) could be used to evaluate cadmium resistance inUlvaby correlation analysis. In accordance with the order of the absolute values of correlation coefficient, contents of Cd2+and K+, Yield, proline content, Fv/Fm, FAA content, and OAA value ofUlvawere more highly related to their adaptation to Cd2+than the other eight indices. Thus,U. linzahas a better adaptation to Cd2+thanU. prolifera, which was due mainly to higher nutrient content and stronger OAA and photosynthesis inU. linza.

To investigate the physiological responses and adaptation mechanisms of Enteromorpha to seawater salinity stress, a laboratory experiment with Enteromorpha linza and E. prolifera was conducted to study their fresh mass (FM), relative growth rate (RGR), relative electrical conductivity (REC), chlorophyll (Chl) and carotenoid (Car) contents, Chl a/Chl b, Chl/Car, chlorophyll fluorescence parameters, and osmotic adjustment ability (OAA) under the stress of different salinity levels of diluted and concentrated seawater for 10 days. Compared with the control, 10%-200% salinity seawater increased the FM and RGR of the two Enteromorpha species obviously, 100% and 50% salinity seawater made the FM and RGR of E. linza and E. prolifera peaked, respectively, while 300% salinity seawater decreased the FM and RGR of E. linza and E. prolifera significantly, with the decrement being larger for E. linza. The biomass of E. linza and E. prolifer only had an increase in 50% and 100% sanity seawater and in 10%, 50%, 100%, and 200% salinity seawater, respectively. The Chl and Car contents and Chl a/Chl b of E. linza and E. prolifera had a significant increase in 10% salinity seawater, but decreased after an initial increase with the increasing salinity level of seawater. The Chl and Car contents and Chl a/Chl b of E. linza and E. prolifera peaked in 100% and 50% salinity seawater, respectively. With increasing salinity of seawater, the light use efficiency (alpha), maximal photochemical efficiency of PS II (F(v)/F(m)), actual photochemical efficiency of PS II in the light (Yield), maximal relative electron transport rate (rETR(max)), and half-saturation light intensity (I(k)) of E. linza and E. prolifera all showed the same variation trend as Chl. 10% -300% salinity seawater enabled E. linza and E. prolifera to express certain osmotic adjustment ability (OAA), and the OAA of E. linza and E. prolifer peaked in 100% and 50% salinity seawater, respectively. The growth of Enteromorpha had no correlation with Chl/Car, but was significantly negatively correlated with REC and positively correlated with Chl, Car, Chl a/ Chl b, F(v)/F(m), Yield, rETR(max), alpha, I(k), and OAA. To sum up, 100% salinity was the optimal salt concentration for the growth of E. linza, and 50% salinity was optimal for E. prolifera. E. prolifera could adapt to a wider range of salinity than E. linza. The parameters REC, Chl, Car, Chl a/Chl b, F(v)/F(m), Yield, rETR(max), alpha, I(k), and OAA could be used to evaluate the salt adaptation of Enteromorpha.

Taking the cultivars Nanyou 1, 2, and 3 of barbadosnut (Jatropha curcas L. ) with different genotypes that can grow and seed normally at the inshore land in Hainan as test materials, the characters of their seeds and the physicochemical characteristics of their seed oils were analyzed and compared. No significant differences were observed in the seed length, width, thickness, and surface area among the cultivars, but Nanyou 2 had greater 1000 seed mass and lower unsound kernel percentage than Nanyou 1 and Nanyou 3, suggesting that the seed satiation of Nanyou 2 was good and the fecundity was excellent. The kernel oil content of Nanyou 3 was significantly higher than that of Nanyou 1 and Nanyou 2, and there was no significant difference between Nanyou 1 and Nanyou 2. The seed oil peroxide value, refractive index, and saponification value of the three cultivars had no significant differences, but the acid value for Nanyou 2 was much lower than that for Nanyou 1 and Nanyou 3. The seed oil iodine value of the three cultivars was all below 100, and was significantly lower for Nanyou 2 than for Nanyou 1 and Nanyou 3. The fatty acids in the three cultivars seed oils were mainly oleic acid, palmitic acid, linoleic acid, stearic acid, and margaric acid, and dominated by unsaturated fatty acids. The contents of saturated fatty acids in Nanyou 2 seed oil were relatively higher than those in Nanyou 1 and Nanyou 3 seed oils, indicating that comparing with Nanyou 1, cultivars Nanyou 2 and Nanyou 3 had relatively good potential for application.

Si 2.0 mmol/L in irrigation solution alleviated significantly the inhibition of NaCl stress of 100 or 200 mmol/L to aloe growth. Exogenously applied Si decreased significantly Na(+) and Cl(-) contents, increased K(+) content and K(+)/Na(+) ratio and selectivity ratio of absorption (AS(K, Na)) and of translocation (TS(K, Na)) to K(+) and Na(+) in aloe plant under both NaCl 100 and 200 mmol/L stresses for 30 d. In this way, the ion homeostasis in aloe plant under NaCl stress was maintained, as was proved by X-ray microanalysis of root tip and leaf across sections. One of the mechanisms to achieve this may be the significant enhancement of H(+)-ATPase activities by the addition of silicate in plasma membrane and tonoplast, H(+)-pyrophosphatase (H(+)-PPase) activity in tonoplast isolated from aloe root tips under NaCl stress.

To evaluate salt tolerance of seedlings of 4 medicinal C. morifolium cultivars to be transplanted, and to expand the planting area.Seedlings were cultivated in hoagland nutrient solution containing various concentrations of NaCl for 30 days. The height, dry weight and chlorophyll content were investigated. Identification index mainly in relative growth rate, the evaluation of NaCl effects on the growth, K+, Na+ and Cl- distribution in seedlings were surveyed.The salt tolerance was difference among four cultivars of C. morifolium. The salt tolerance of "Dabaiju" and "Changbanju" was weak, while "Hongxinju" and "Xiaobaiju" was strong. "Hongxinju" and "Xiaobaiju" may be planted in salinte soil area.