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Li M.,China Agricultural University | Tian L.,Changchun City Academy of Agricultural science | Wang C.,China Agricultural University | Hao L.,Jilin University
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2014

PhaR gene knock-out mutants of Comamonas testosterone, with high genetic stability, were constructed based on homologous integration. The expression of 3,17β-HSD in the cells cultured under different conditions was also determined. The results show that one mutant strain PK-4 was obtained by the electroporation method. ELISA method was established for the determination of 3,17β-HSD. The ELISA results indicated that the expression of 3,17β-HSD was induced by testosterone in cells of wild type and mutant PK-4 of Comamonas testosteroni, but estradiol and cholesterol showed no induction effect. Under the condition of testosterone induction, the amount of 3,17β-HSD in the cells of mutant PK-4 was 2.6 times the amount in the cells of wide type Comamonas testosteroni. Moreover, the expression of 3,17β-HSD in the cells of mutant PK-4 was also higher than that in the cells of wide type Comamonas testosteroni. This indicates that PhaR might be a repressor for the expression of 3,17β-HSD in Comamonas testosteroni. The addition of estradiol and cholesterol significantly inhibited induction effect of testosterone on the 3,17β-HSD expression. However, in the same condition, the expression level of 3,17β-HSD in mutant PK-4 cells was still higher than that in wild type Comamonas testosteroni cells. The above results show that PhaR gene has important significance in the regulation of 3,17β-HSD in Comamonas testosteronei. The PhaR gene knock-out mutant PK-4 has potential application value in the treatment of polluted environment with androgenic hormones. ©, 2014, Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae. All right reserved.

Zhou L.-N.,Jilin University | Zhou L.-N.,Changchun University of Science and Technology | Yu H.-Y.,Jilin University | Zhang L.,Jilin University | And 3 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2014

In order to detect rice blast more rapidly, accurately and nondestructively, the identification and early warning models of rice blast were established in the present research. First of all, rice blast was divided into three grades according to the relative area of disease spots in rice leaf and laser-induced chlorophyll fluorescence spectra of rice leaves at different disease levels were measured in the paddy fields. Meanwhile, 502~830 nm bands of laser-induced chlorophyll fluorescence spectra were selected for the study of rice blast. Savitzky-Golay (SG) smoothing and First Derivative Transform (FDT) were applied for the pretreatment of laser-induced chlorophyll fluorescence spectra. Then the method of Principal Components Analysis (PCA) was used to achieve the dimension reduction on spectral information, three principal components whose variance are greater than 1 and cumulative credibility is 99.924% were extracted by this method. Furthermore, the tentative data were divided into calibration set and validation set, the levels of rice blast were taken as the predictors. Combined with the calibration set which contains the disease and spectral information of 133 leaves, Discriminant Analysis (DA), Multiple Logistic Regression Analysis (MLRA) and Multilayer Perceptron (MLP) were used respectively to establish the identification and early warning models of rice blast. The Prediction examinations of the three models were made based on the validation set which contains the disease and spectral information of 89 leaves. The results show that all the models of PCA-DA, PCA-MLRA and PCA-MLP can carry on the prediction of rice blast, and the average prediction accuracy of PCA-MLP prediction model is 91.7% which is improved compared with PCA-DA and PCA-MLRA.

Zhou L.,Jilin University | Zhou L.,Changchun University of Science and Technology | Yu H.,Jilin University | Yu L.,Changchun City Academy of Agricultural science | And 3 more authors.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2014

Light use efficiency of rice leaves were analyzed using chlorophyll fluorescence spectra in the present research. First of all, photosynthetic rate (net CO2 assimilation rate) of individual leaves and incident photosynthetic active radiation were accessed, and photosynthetic light use efficiency was calculated with them. Meanwhile, laser induced chlorophyll fluorescence emission spectra of leaves of rice under different light use efficiency were measured using a compact fiber-optic fluorosensor with a solid-state laser at 473 nm as exciting source and an integrated fiber-optic spectrometer at ambient temperature. Then, specific fluorescence spectral bands of leaves were selected to analyze light use efficiency. Significant relations of light use efficiency with F685, F732 and the fluorescence ratio F685/F732 were found, thus indicating functional relations among these parameters. The results show that the precision of the function based on the fluorescence ratio F685/F732 is higher. The assimilation process of CO2 is affected by stomatal conductance and the temperature of leaves is a signature of stomatal conductance. An inverse relation was also found between light use efficiency and temperature of leaves. So measured fluorescence spectra were fitted with a linear combination of regression function corrected by the temperature of leaves to predict light use efficiency, R2=0.885.

Zao X.,Jilin University | Huang Fu Y.H.,Jilin University | Sun Q.,Jilin University | YU L.-J.,Changchun City Academy of Agricultural science
Applied Mechanics and Materials | Year: 2014

In this paper, the 5-9 months of 2000-2011 temperature and humidity data, used the detrended fluctuation analysis, obtained how the two data series’ non-uniform scaling index changes with time. In order to comprehensive influence of temperature and relative humidity of the two meteorological factors, the temperature and humidity coefficient is introduced. We also proposed a new non- uniform scaling index taking into account the information of temperature and relative humidity, and discusses the possible correlation between temperature and humidity and rice blast. The preliminary results show, A long-range power-law correlation can be found in the time series of temperature and humidity. About 5-15 days before the occurrence of rice blast will appear anomalies of non-uniform scaling index. It reflects the rice blast made a difference of statistical significance to the characteristic of nonlinear system internal of temperature and humidity coefficient. It can predict the occurrence and prevalence of rice blast according to the abnormal changes of temperature and humidity coefficient scaling exponent. © (2014) Trans Tech Publications, Switzerland.

Cui D.,Chinese Academy of Agricultural Sciences | Xu C.-Y.,Changchun City Academy of Agricultural Science | Tang C.-F.,Yunnan Academy of Agricultural Sciences | Yang C.-G.,Jilin Agricultural University | And 6 more authors.
Euphytica | Year: 2013

Cold tolerance at booting stage is one of the major determinants for a stable yield of rice (Oryza sativa L.) in many high elevation or high latitude regions. Understanding the genetic basis of cold tolerance is crucial for the improvement of cold tolerance through breeding. In this study, association mapping was performed in 347 rice accessions worldwide with different statistical models in order to identify the genetic marker loci/QTL associated with cold tolerance traits at the booting stage. The evaluation of cold tolerance for all the traits was conducted under natural low temperature in Yunnan and cold water irrigation in Jilin. The 148 SSRs were used for the genotyping. Population structure analysis identified three main subpopulations for the accessions that corresponded to major geographic origins. The relative kinship analysis revealed a weak or no relationship for most of the individual pairs. Model comparisons indicated that the Q+K model controlling both population structure (Q) and the relative kinship (K) was performed better than other models in association mapping. In total, 24 markers were identified that were significantly associated with cold tolerance, including five markers in Yunnan and 19 markers in Jilin. Moreover, RM282, RM252, RM335 and RM6824 were identified in multiple environments or years. Many of these identified markers were located either in or nearby the regions where the QTLs have been reported for cold tolerance at booting stage. These results highlighted the targeted regions for future studies and might be subsequently used in breeding programs to trace and select the useful alleles by MAS. © 2013 Springer Science+Business Media Dordrecht.

Cui D.,Chinese Academy of Agricultural Sciences | Xu C.-Y.,Changchun City Academy of Agricultural Science | Yang C.-G.,Jilin Agricultural University | Zhang Q.-X.,Hebei Academy of Agriculture and Forestry science | And 6 more authors.
Genetic Resources and Crop Evolution | Year: 2015

Salinity and alkalinity seriously threaten global rice production. As a consequence, elucidation of the genetic basis of salinity and alkalinity tolerance is crucial for rice breeding. To identify genetic marker loci/QTLs associated with salinity and alkalinity tolerance, we performed association mapping based on different statistical models using 347 rice accessions from all over the world. Salinity tolerance for all traits was evaluated on saline land along the seashore of Hebei, while alkalinity tolerance at the seedling stage was assessed in the alkaline soil of paddy fields in Jilin. A total of 148 SSRs were used for genotyping. Within the entire population, 64.1 % of SSR locus pairs were in significant linkage disequilibrium (LD) (P < 0.05). Most of this LD was due to the overall population structure, as the percentage of locus pairs in LD was much lower within each subpopulation, ranging from 21.2 to 32.4 %. LD decayed with genetic distance, indicating that linkage was a main cause of LD. Model comparisons indicated that the Q + K model, which controls for both population structure (Q) and relative kinship (K), performed better than other models. A total of 40 markers were identified: 25 related to salinity tolerance and 15 related to alkalinity tolerance. Of the identified markers, 17 were located either in or near regions in which QTLs for salinity and alkalinity tolerance have been previously reported. Furthermore, we identified three of these markers—RM475, RM567, and RM505—in rice under both salinity and alkalinity stress conditions. These results highlight target regions for fine mapping, cloning and molecular breeding by design for rice salinity and alkalinity tolerance. © 2014, Springer Science+Business Media Dordrecht.

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