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Genetic Variation Assessed with Microsatellites in Mass Selection Lines of the Pacific Oyster (Crassostrea gigas) in China 被引量:2
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作者 WANG Xubo LI Qi +1 位作者 YU Hong KONG Lingfeng 《Journal of Ocean University of China》 SCIE CAS 2016年第6期1039-1045,共7页
Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the lev... Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas. 展开更多
关键词 Pacific oyster genetic variation MICROSATELLITE mass selection line effective population size
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Fault Line Selection Method Considering Grounding Fault Angle for Distribution Network 被引量:1
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作者 Li Si-bo Zhao Yu-lin +1 位作者 Li Ji-chang Sui Tao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2015年第1期58-65,共8页
In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line select... In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible. 展开更多
关键词 distribution network single-phase grounding fault fault line selection fault angle wavelet transformation
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Selection Progress of Wannan Native Chicken's Fast and Slow Feathering Lines 被引量:1
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作者 CHEN Xing-yong GENG Zhao-yu +2 位作者 NIU Juan-juan SUN Jian-wu LIU Ping 《Animal Husbandry and Feed Science》 CAS 2013年第3期112-114,共3页
[Objective]This experiment aimed to establish fast and slow feathering lines from purified and rejuvenated core breeding flock. [Method] Individual and family selection were used for continuous selection from zero to ... [Objective]This experiment aimed to establish fast and slow feathering lines from purified and rejuvenated core breeding flock. [Method] Individual and family selection were used for continuous selection from zero to the second generation. [Result]The results showed that in the fast feathering line,the average weight gain was improved by 108. 34 g per generation in roosters at the age of 20 weeks while a 54. 5 g increase was got per generation in hens. Hen housed egg production was increased from 150 to 170 at the age of 66 weeks,and the healthy rate of chicken flock was raised by 0. 7 percent. In the slow feathering line,the average weight gain was increased by 156. 6g per generation in roosters while a 38. 9 g increase was got per generation in hens,and the hen housed egg production was increased from 158 to 179 at the age of 66 weeks. [Conclusion] This research had a great significance in increasing native chicken's production performance and developing its market competitiveness. 展开更多
关键词 Wannan native chicken Fast and slow feathering lines selection
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The Application of Satellite Remote-sensing for Railway Line Selection
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《Aerospace China》 1998年第2期23-26,共4页
Thispaperintroducestheapplicationofsateliteremote┐sensingimagesintheevaluationofengineeringgeologyconditions... Thispaperintroducestheapplicationofsateliteremote┐sensingimagesintheevaluationofengineeringgeologyconditionsandstabilityofthe... 展开更多
关键词 The Application of Satellite Remote-sensing for Railway line selection
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Selection of wide compatible restorer lines and their application in hybrid rice breeding
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作者 XIE Xiaobo, ZHANG Shanqing, and FANG Hongming, CNRRI, Hangzhou 310006, China 《Chinese Rice Research Newsletter》 1997年第3期10-11,共2页
Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withide... Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withideal agronomic characters were identified. Weincorporated the WC gene into restorer linesby crossing these japonica WC lines with ob-tained indica lines. Some WC restorer lineswith indica-japonica medium type were ob-tained and their application value in intersub-specific hybrid rice breeding were evaluated. 1. Effect of crossing methods on selectionefficiencies of WC restorer lines 展开更多
关键词 line WC selection of wide compatible restorer lines and their application in hybrid rice breeding
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Evaluation of Tomato Lines Derived from Landraces of "Tomate Platense" and a Commercial Hybrid in La Plata, Argentina
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作者 Lisandro Emio Maria de la Merced Mujica 《Journal of Agricultural Science and Technology(B)》 2016年第2期78-82,共5页
In the city of La Plata (Argentina) and the surroundings, there are tomato landraces, widely known as "tomate platense" and particularly prized because of their flavor. The objective was to evaluate seven promisso... In the city of La Plata (Argentina) and the surroundings, there are tomato landraces, widely known as "tomate platense" and particularly prized because of their flavor. The objective was to evaluate seven promissory lines of "tomate platense" (TL) derived from local varieties and a commercial hybrid (CH) considering yield, fruit characters and their possible associations. Nine plants per treatment were arranged in a randomized complete block design (r = 4). The following parameters were determined: diameter (cm), height (cm), diameter/height (D/H) ratio, weight per fruit (g), number of locules, the average number of fruits per plant, the average weight of fruits per plant (kg/ptant), the yield (ton/ha) and the survival percentage. ANOVA, Tukey's test and Pearson correlation coefficient were applied. The TL showed greater (P ≤ 0.01) diameter, D/H ratio and number of locules than CH. In all materials, both diameter and height were associated (P ≤ 0.05) with the weight per fruit. Six of TL had greater (P ≤ 0.01) weight per fruit than HC. Respect to number of fruits per plant, weight of fruits per plant and yield, there were no significant differences among the materials. The survival for CH was lower (P ≤0.05) than that for TL. Although fruits with a smaller size and less flattened have been selected, the lines show enough similarity in these characters that identified their common origin. With the fruits smaller and more uniform, and having no joined fruits, these lines may be of interest to be cultivated under low-input system conditions and practical for low-income producers. 展开更多
关键词 Tomato landraces tomate platense selected lines fruit characters yield components low-input systems.
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Correlation and Path Analysis for Growth Traits in F_1 Population of Pearl Oyster Pinctada martensii 被引量:34
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作者 邓岳文 杜晓东 +2 位作者 王庆恒 符韶 黄荣莲 《Marine Science Bulletin》 CAS 2008年第2期68-73,共6页
120 pearl oysters (Pinctada martensii) were randomly sampled from F1 population, and shell length, shell width, shell height, shell weight and total weight of each sample were measured. Correlation and path analysis... 120 pearl oysters (Pinctada martensii) were randomly sampled from F1 population, and shell length, shell width, shell height, shell weight and total weight of each sample were measured. Correlation and path analysis were conducted on the basis of measurement data. The results showed that shell length, shell width, shell height, shell weight and total weight were significantly correlated (P 〈 0.05). Total weight was significantly and positively correlated with shell weight (r = 0.8970), shell height (r = 0.6974), shell width (r = 0.6521) and shell length (r = 0.5486). Shell weight, shell height, shell width and shell length had positive and direct effects on total wet weight, with the values of 0.6356, 0.1872, 0.1814 and 0.0599, respectively. The results indicated that growth traits (shell length, shell width, shell height, shell weight and total wet weigh) of the F1 population could be improved by direct or indirect selection. 展开更多
关键词 Pinctada martensii selected line F1 growth traits CORRELATION path analysis
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Growth Performance of Phoebe bournei Generations in Seedling Stage 被引量:3
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作者 吴际友 陈明皋 +5 位作者 唐爱民 董春英 黄明军 刘球 程勇 王旭军 《Agricultural Science & Technology》 CAS 2014年第7期1188-1190,1199,共4页
[Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in ... [Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in Yongzhou,Hunan Province,exploring growth indices and analyzing seedling height and ground diameter.[Result] As per the selection rate at 20%,PB17,PB9 and PB12 were selected from the 17 species.Specifically,the seedling height averaged 36.52 cm of the selected three seedlings,which was higher by 16.1% compared with average of 17 species (31.45%).As for ground diameter,the selected species averaged 2.6 mm,which was higher (13.0%) compared with the average level (2.3 mm).[Conclusion]Both of seedling height and ground diameter reached extremely significant differences,which indicated that half-sib families of Phoebe bournei have rich variations,with selection and breeding potential. 展开更多
关键词 Phoebe bournei Superior plus tree Characteristics in seedling stage line selection FAST-GROWING selection in early stagen
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Application of DC component to select fault branch in arc suppression coil grounding system 被引量:2
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作者 Zhi-Jie WANG Yan-Wen WANG 《Journal of Coal Science & Engineering(China)》 2013年第3期396-401,共6页
When single phase earth fault occurs in the arc suppression coil grounding system, the amplitude of the transient capacitance current is high and decays fast, but the attenuation of the transient inductance current is... When single phase earth fault occurs in the arc suppression coil grounding system, the amplitude of the transient capacitance current is high and decays fast, but the attenuation of the transient inductance current is much slower. This paper analyses the DC component of fault branch, and has found it is much bigger than that of the normal branches in transient state. All the simulation results obtained from three compensation types, different fault time and different wave cycles show that the DC component of fault branch is much higher than that of those normal branches. These results verify the effectiveness of taking the DC component as the method of fault line selection in the arc suppression coil grounding system. 展开更多
关键词 DC component arc suppression coil fault line selection transient state
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Frequency Variations of Power System Due to Switching of Renewable Energy Sources
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作者 Wendy L. Fuchs Ewald F. Fuehs 《Journal of Energy and Power Engineering》 2013年第1期1-9,共9页
Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can b... Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can be achieved by employing short-and long-term storage plants buffering and complementing renewable energy sources. A representative grid consists of a natural-gas-fired plant serving as frequency leader, long-term storage plant, wind-power farm with associated short-term storage plantfor energy buffering, and photovoltaic farm with associated short-term storage plant interconnected by a long transmission line to two load circuits. Transient analysis is performed with Mathemafica solving the differential equation system for frequency variation. Powerflow through the AC transmission line is limited by its impedance. The long transmission line must be segmented to achieve stability and voltage control over an 800 km distance. The renewable plants must be operated together with the storage plants in order tominimize frequency variations by smoothing the power output of renewable plants, achieving step-wise control of the transmission-line power. Although to date only AC Iransmission lines in Germany exist, it is anticipated that within the next 10 years these will beaugmented by DC high-voltage lines. 展开更多
关键词 Renewable sources frequency variations stability selection of transmission line.
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