The cadmium （Cd） contents in rice plants and Cd accumulation in different parts of rice under Cd stress were studied to screen out Cd-highly tolerant and high-yield rice varieties. With different vadeties of japonic...The cadmium （Cd） contents in rice plants and Cd accumulation in different parts of rice under Cd stress were studied to screen out Cd-highly tolerant and high-yield rice varieties. With different vadeties of japonica and indica rice as the research objects, Cd contents and Cd accumulation of different rice varieties in harvest time were discussed by pot experiment, under two treatments of no adding Cd and Cd stress. Under both the two treatments, the Cd contents in different parts of rice all ranked as root〉stem〉leaf〉husk〉grain, and Cd was manly concentrated in dce roots. Cd accumulation and distribution differed among different rice varieties, especially among grains of different rice varieties. Among the 8 rice varieties, the increase of grain Cd content of Chunyou 84 was the smallest, indicating a weaker Cd accumulation ability. At the same time, the Cd accumulation in japonica rice was higher than that in indica rice under Cd stress. Under Cd stress, the yield of indica rice decreased significantly, while that of japonica rice increased. The lowest grain Cd content of Chunyou 84 indicated significant Cd tolerance. Although its yield was affected, it can still be recommended to be promoted in the Cd-polluted region of Hunan Province, considering the Cd security.展开更多
The accumulative roll-bonding(ARB)process was applied on the strips of aluminum alloy 1050 in two processing conditions:cold ARB and warm ARB.The results of tensile tests and microhardness measurement show that the wa...The accumulative roll-bonding(ARB)process was applied on the strips of aluminum alloy 1050 in two processing conditions:cold ARB and warm ARB.The results of tensile tests and microhardness measurement show that the warm ARB process exhibits the lower tensile strength and microhardness,more homogeneous distribution of the microhardness,higher elongation,and especially superior planar isotropy of the tensile properties in comparison to the cold ARB,because of the intermediate heat treatment as well as the elevated temperature rolling in the warm ARB process.Furthermore,with increasing the cycles of both processes,the planar isotropy decreases progressively.展开更多
Callus cultures of Origanum vulgare L. were established from leaf discus on Murashige and Skoog （MS） medium containing different levels of growth regulators, i.e., 2,4-Dichlorophenoxyacetic acid （2,4-D）, Naphthale...Callus cultures of Origanum vulgare L. were established from leaf discus on Murashige and Skoog （MS） medium containing different levels of growth regulators, i.e., 2,4-Dichlorophenoxyacetic acid （2,4-D）, Naphthalene acetic acid （NAA）, Benzyl Adenine （BA） and Kinetin （Kn） and incubated under dark condition. Callus tissues were employed to study the influence of abiotic elicitors on the production of thymol. Constant weights of callus （300 mg） were cultured on accumulation medium treated separately with each one of elicitors used （50 g/L sucrose, 200 mg/L NaC1 and 50 or 100 mg/L proline）. The fresh and dry weights of callus were recorded after six weeks. The result indicated that maximum production of fresh and dry callus weight were 1,014 mg and 46.20 mg respectively achieved at 0.5 mg/L 2,4-D and 3 mg/L BA adding to the medium. Dry callus tissues were extracted with 70% methanol and analyzed by HPLC to determine the concentrations of thymol. The addition of abiotic elicitors to MS medium caused significant reduction in fresh weight of callus compared with control treatment. The concentration of thymol in the callus cultured on control treatment was 146.6 ppm. The data showed that 50 or 100 mg/L proline produced the highest yield of thymol 181.48 ppm and 174.58 ppm respectively, followed by sucrose 162.9 ppm, whereas the treatment with NaCI caused reduction in thymol concentration to percentage of 50.56% compared with the control.展开更多
文摘The cadmium （Cd） contents in rice plants and Cd accumulation in different parts of rice under Cd stress were studied to screen out Cd-highly tolerant and high-yield rice varieties. With different vadeties of japonica and indica rice as the research objects, Cd contents and Cd accumulation of different rice varieties in harvest time were discussed by pot experiment, under two treatments of no adding Cd and Cd stress. Under both the two treatments, the Cd contents in different parts of rice all ranked as root〉stem〉leaf〉husk〉grain, and Cd was manly concentrated in dce roots. Cd accumulation and distribution differed among different rice varieties, especially among grains of different rice varieties. Among the 8 rice varieties, the increase of grain Cd content of Chunyou 84 was the smallest, indicating a weaker Cd accumulation ability. At the same time, the Cd accumulation in japonica rice was higher than that in indica rice under Cd stress. Under Cd stress, the yield of indica rice decreased significantly, while that of japonica rice increased. The lowest grain Cd content of Chunyou 84 indicated significant Cd tolerance. Although its yield was affected, it can still be recommended to be promoted in the Cd-polluted region of Hunan Province, considering the Cd security.
文摘The accumulative roll-bonding(ARB)process was applied on the strips of aluminum alloy 1050 in two processing conditions:cold ARB and warm ARB.The results of tensile tests and microhardness measurement show that the warm ARB process exhibits the lower tensile strength and microhardness,more homogeneous distribution of the microhardness,higher elongation,and especially superior planar isotropy of the tensile properties in comparison to the cold ARB,because of the intermediate heat treatment as well as the elevated temperature rolling in the warm ARB process.Furthermore,with increasing the cycles of both processes,the planar isotropy decreases progressively.
文摘Callus cultures of Origanum vulgare L. were established from leaf discus on Murashige and Skoog （MS） medium containing different levels of growth regulators, i.e., 2,4-Dichlorophenoxyacetic acid （2,4-D）, Naphthalene acetic acid （NAA）, Benzyl Adenine （BA） and Kinetin （Kn） and incubated under dark condition. Callus tissues were employed to study the influence of abiotic elicitors on the production of thymol. Constant weights of callus （300 mg） were cultured on accumulation medium treated separately with each one of elicitors used （50 g/L sucrose, 200 mg/L NaC1 and 50 or 100 mg/L proline）. The fresh and dry weights of callus were recorded after six weeks. The result indicated that maximum production of fresh and dry callus weight were 1,014 mg and 46.20 mg respectively achieved at 0.5 mg/L 2,4-D and 3 mg/L BA adding to the medium. Dry callus tissues were extracted with 70% methanol and analyzed by HPLC to determine the concentrations of thymol. The addition of abiotic elicitors to MS medium caused significant reduction in fresh weight of callus compared with control treatment. The concentration of thymol in the callus cultured on control treatment was 146.6 ppm. The data showed that 50 or 100 mg/L proline produced the highest yield of thymol 181.48 ppm and 174.58 ppm respectively, followed by sucrose 162.9 ppm, whereas the treatment with NaCI caused reduction in thymol concentration to percentage of 50.56% compared with the control.
