The key for rice plant survival under Na Cl salt stress is maintaining a high K^+/Na^+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in br...The key for rice plant survival under Na Cl salt stress is maintaining a high K^+/Na^+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in breeding. Use of molecular markers in tandem with physiological studies will help in better identification of salt tolerant rice accessions. Eight rice accessions along with the check Dongjin were screened using 1/2 Yoshida solution with 50 mmol/L NaCl at the seedling stage. The accessions IT001158, IT246674, IT260533 and IT291341 were classified as salt tolerant based on their K^+/Na^+ ratios. Seventeen SSR markers reported to be associated with K^+/Na^+ ratio were used to screen the accessions. Five SSR markers(RM8053, RM345, RM318, RM253 and RM7075) could differentiate accessions classified based on their K^+/Na^+ ratios. Banding pattern of the accessions was scored compared to the banding pattern of Dongjin. The study differentiated accessions based on their association of K^+/Na^+ ratio with molecular markers which are very reliable. These markers can play a significant role in screening large set of rice germplasms for salt tolerance and also help in identification of high-yielding varieties with better salt tolerance. The salt tolerant accessions can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.展开更多
The K_xNa_((1-x))NbO_3(x=0.45, 0.46, 0.47, 0.48, 0.49, 0.50) lead-free piezoelectric ceramics was fabricated by conventional solid-state sintering method. It was found that the ratio of alkaline metal would affect the...The K_xNa_((1-x))NbO_3(x=0.45, 0.46, 0.47, 0.48, 0.49, 0.50) lead-free piezoelectric ceramics was fabricated by conventional solid-state sintering method. It was found that the ratio of alkaline metal would affect the microstructure, bulk density, and optimum sintering temperatures of ceramics. Meanwhile, the electrical properties were also influenced by modulating the K/Na ratio, exhibiting corresponding composition-dependent properties. The optimum electrical properties of K_xNa_((1-x))NbO_3 such as piezoelectric constant d_(33) = 115 pC/N, mechanical quality factor Q_m = 20, Curie temperature Tc = 365 ~oC, ε_(33)~T/ε_0= 588.1, dielectric loss tan δ = 0.024, bulk density(ρ) = 3.08 g/cm^3, remnant polarization(P_r) = 8.87 μC/cm^2 and coercive field(Ec) = 13.79 kV/cm were obtained at x = 0.46.展开更多
基金supported by the research fund of Rural Development Administration, South Korea (Grant No. PJ012281)
文摘The key for rice plant survival under Na Cl salt stress is maintaining a high K^+/Na^+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in breeding. Use of molecular markers in tandem with physiological studies will help in better identification of salt tolerant rice accessions. Eight rice accessions along with the check Dongjin were screened using 1/2 Yoshida solution with 50 mmol/L NaCl at the seedling stage. The accessions IT001158, IT246674, IT260533 and IT291341 were classified as salt tolerant based on their K^+/Na^+ ratios. Seventeen SSR markers reported to be associated with K^+/Na^+ ratio were used to screen the accessions. Five SSR markers(RM8053, RM345, RM318, RM253 and RM7075) could differentiate accessions classified based on their K^+/Na^+ ratios. Banding pattern of the accessions was scored compared to the banding pattern of Dongjin. The study differentiated accessions based on their association of K^+/Na^+ ratio with molecular markers which are very reliable. These markers can play a significant role in screening large set of rice germplasms for salt tolerance and also help in identification of high-yielding varieties with better salt tolerance. The salt tolerant accessions can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.
基金Funded by the National Natural Science Foundation of China(No.51302199)Key Natural Science Foundation of Hubei Province of China for Distinguished Yong Scholars(No.2014CFA044)+2 种基金Cultivation Plan for Science and Technology Talents of Wu Han City(No.2014072704011253)MOST Special Fund from the State Key Laboratory of Geological Process and Mineral Resources(No.MSFGPMR201204)Natural Science Foundation of Hubei Province(No.2014CFB809)
文摘The K_xNa_((1-x))NbO_3(x=0.45, 0.46, 0.47, 0.48, 0.49, 0.50) lead-free piezoelectric ceramics was fabricated by conventional solid-state sintering method. It was found that the ratio of alkaline metal would affect the microstructure, bulk density, and optimum sintering temperatures of ceramics. Meanwhile, the electrical properties were also influenced by modulating the K/Na ratio, exhibiting corresponding composition-dependent properties. The optimum electrical properties of K_xNa_((1-x))NbO_3 such as piezoelectric constant d_(33) = 115 pC/N, mechanical quality factor Q_m = 20, Curie temperature Tc = 365 ~oC, ε_(33)~T/ε_0= 588.1, dielectric loss tan δ = 0.024, bulk density(ρ) = 3.08 g/cm^3, remnant polarization(P_r) = 8.87 μC/cm^2 and coercive field(Ec) = 13.79 kV/cm were obtained at x = 0.46.
