Growth is an economically important trait in aquaculture.To improve growth trait of the Asian seabass(Lates calcarifer)we have been carrying out,since 2004,a selective breeding program.This study focuses on growth tra...Growth is an economically important trait in aquaculture.To improve growth trait of the Asian seabass(Lates calcarifer)we have been carrying out,since 2004,a selective breeding program.This study focuses on growth traits in the F2 fish generation,comprised of offspring from 23 mass crosses from 383 F_(1) brooders.Using genotyping analysis for 10 microsatellites from both brood stock and progeny we have reconstructed the pedigree of each mass-cross.For F_(2) generation at 90 days post hatch(dph),we have recorded body weight(BW)for 12,117 individuals and total length(TL),standard length(SL)and condition factor(K_(tl) and K_(sl))for 3530 individuals;and all five traits for 2136 individuals at 270 dph.At 90 dph the average BW was 46.88±20.95 g.Combining pedigree information,recorded growth traits and Restricted Maximum Likelihood method,we have estimated that the narrow sense heritability(h^(2))in F_(1) fish for BW,TL,SL,K_(tl) and K_(sl) was at,90 dph,0.12±0.03,0.11±0.03,0.10±0.03,0.20±0.04 and 0.11±0.03,respectively and,at 270 dph,0.34±0.07,0.32±0.07,0.30±0.06,0.13±0.04 and 0.11±0.04,respectively.At 90 dph the realised heritability for BW was 0.13.Comparing with F_(1) generation,the growth performance of F_(2) fish was increased by 14.4%.Heritability of growth traits will be useful for future genetic improvement programmes of the Asian seabass.展开更多
Through analysis of microscopic characteristics,mineral components,elements and isotopes,the genetic mechanism of carbonates in the deep lacustrine source rocks in the upper submember of Member 4 and lower submember o...Through analysis of microscopic characteristics,mineral components,elements and isotopes,the genetic mechanism of carbonates in the deep lacustrine source rocks in the upper submember of Member 4 and lower submember of Member 3 of Shahejie Formation in Dongying sag,is well investigated.The results show that four types of carbonates in the deep lake,i.e.,lenticular coarse crystalline carbonate,lamellar micro-fine crystalline carbonate,lamellar cryptocrystalline carbonate and massive cryptocrystalline carbonate.Of which,the lenticular coarse crystalline carbonate is formed by diagenetic recrystallization.For the lamellar micro-fine crystalline carbonate and the lamellar cryptocrystalline carbonate,through the alga photosynthesis,the carbon dioxide(CO_(2))is constantly extracted from water,thus the concentration of CO_(3)^(-2) ion in water increases,and then the CO_(3)^(-2) ion reacts with Ca2+ ion in lake water surface to form the carbonates;the saline water environment is favorable for preservation of carbonate particles which mostly occur in lamellar micro-fine crystalline;in the brackish water environment,the water is deep,and the carbonate crystalline beneath the carbonate compensation depth surface is usually is dissolved,and most of lamellar cryptocrystalline are preserved.The massive cryptocrystalline carbonate is formed by the sedimentary carbonate which transport from shallow water to deep water by gravity flow.To some extent,the carbonates control reservoir property and compressibility of muddy shale in the upper submember of Member 4 and lower submember of Member 3 of Shahejie Formation in Dongying sag,and provide important information for reconstruction of sedimentary environment of the ancient lake.展开更多
Cultivated land quality(CLQ)is related to national food security.Rapid and high-precision monitoring of CLQ is crucial for the sustainable development of agriculture.However,current satellite image-based evaluation me...Cultivated land quality(CLQ)is related to national food security.Rapid and high-precision monitoring of CLQ is crucial for the sustainable development of agriculture.However,current satellite image-based evaluation methods that only consider the crop's spatial spectrum characteristics in the key growth stages cannot accurately estimate CLQ.This study proposes a new method based on time-series spectral data of crop growth to improve the accuracy of CLQ estimation.This study was conducted in the Conghua District of Guangzhou,Guangdong Province,China.The results showed that seven spectral indicators were determined as the optimal indicators based on the gradient boosting decision tree(GBDT)and variance inflation factor(VIF).And the genetic algorithm-back propagation neural network(GA-BPNN)model provided more accurate CLQ estimates than the partial least squares regression(PLSR)model,indicating a nonlinear relationship between CLQ and the indicators.In addition,the GA-BPNN model with a normalized root mean square error(NRMSE)of 9.91%demonstrates the excellent potential for mapping CLQ over large areas.The model based on the seven optimal indicators of crop phenology provided higher accuracy than the GA-BPNN model based on the normalized difference vegetation index(NDVI)indicators in the spatial domain,significantly decreasing the NRMSE of the CLQ estimates by 3.17%.This further implied that the spectral indicators in the spatial frequency domain can improve the accuracy of estimating CLQ.展开更多
基金This study was supported by the project“Selective Breeding of Marine Food Fish”funded by AVA,Singapore and by the Singapore National Research Foundation under CRP Award No.NRF-CRP7-2010-01.
文摘Growth is an economically important trait in aquaculture.To improve growth trait of the Asian seabass(Lates calcarifer)we have been carrying out,since 2004,a selective breeding program.This study focuses on growth traits in the F2 fish generation,comprised of offspring from 23 mass crosses from 383 F_(1) brooders.Using genotyping analysis for 10 microsatellites from both brood stock and progeny we have reconstructed the pedigree of each mass-cross.For F_(2) generation at 90 days post hatch(dph),we have recorded body weight(BW)for 12,117 individuals and total length(TL),standard length(SL)and condition factor(K_(tl) and K_(sl))for 3530 individuals;and all five traits for 2136 individuals at 270 dph.At 90 dph the average BW was 46.88±20.95 g.Combining pedigree information,recorded growth traits and Restricted Maximum Likelihood method,we have estimated that the narrow sense heritability(h^(2))in F_(1) fish for BW,TL,SL,K_(tl) and K_(sl) was at,90 dph,0.12±0.03,0.11±0.03,0.10±0.03,0.20±0.04 and 0.11±0.03,respectively and,at 270 dph,0.34±0.07,0.32±0.07,0.30±0.06,0.13±0.04 and 0.11±0.04,respectively.At 90 dph the realised heritability for BW was 0.13.Comparing with F_(1) generation,the growth performance of F_(2) fish was increased by 14.4%.Heritability of growth traits will be useful for future genetic improvement programmes of the Asian seabass.
基金The work was supported by the National Key Basic Research Program of China(973 Program)(2014CB239100).
文摘Through analysis of microscopic characteristics,mineral components,elements and isotopes,the genetic mechanism of carbonates in the deep lacustrine source rocks in the upper submember of Member 4 and lower submember of Member 3 of Shahejie Formation in Dongying sag,is well investigated.The results show that four types of carbonates in the deep lake,i.e.,lenticular coarse crystalline carbonate,lamellar micro-fine crystalline carbonate,lamellar cryptocrystalline carbonate and massive cryptocrystalline carbonate.Of which,the lenticular coarse crystalline carbonate is formed by diagenetic recrystallization.For the lamellar micro-fine crystalline carbonate and the lamellar cryptocrystalline carbonate,through the alga photosynthesis,the carbon dioxide(CO_(2))is constantly extracted from water,thus the concentration of CO_(3)^(-2) ion in water increases,and then the CO_(3)^(-2) ion reacts with Ca2+ ion in lake water surface to form the carbonates;the saline water environment is favorable for preservation of carbonate particles which mostly occur in lamellar micro-fine crystalline;in the brackish water environment,the water is deep,and the carbonate crystalline beneath the carbonate compensation depth surface is usually is dissolved,and most of lamellar cryptocrystalline are preserved.The massive cryptocrystalline carbonate is formed by the sedimentary carbonate which transport from shallow water to deep water by gravity flow.To some extent,the carbonates control reservoir property and compressibility of muddy shale in the upper submember of Member 4 and lower submember of Member 3 of Shahejie Formation in Dongying sag,and provide important information for reconstruction of sedimentary environment of the ancient lake.
基金supported by The Guangdong Province Agricultural Science and Technology Innovation and Promotion Project(No.2020KJ102,No.2021KJ102)Natural Science Foundation of Guangdong Province(2021A1515011643).
文摘Cultivated land quality(CLQ)is related to national food security.Rapid and high-precision monitoring of CLQ is crucial for the sustainable development of agriculture.However,current satellite image-based evaluation methods that only consider the crop's spatial spectrum characteristics in the key growth stages cannot accurately estimate CLQ.This study proposes a new method based on time-series spectral data of crop growth to improve the accuracy of CLQ estimation.This study was conducted in the Conghua District of Guangzhou,Guangdong Province,China.The results showed that seven spectral indicators were determined as the optimal indicators based on the gradient boosting decision tree(GBDT)and variance inflation factor(VIF).And the genetic algorithm-back propagation neural network(GA-BPNN)model provided more accurate CLQ estimates than the partial least squares regression(PLSR)model,indicating a nonlinear relationship between CLQ and the indicators.In addition,the GA-BPNN model with a normalized root mean square error(NRMSE)of 9.91%demonstrates the excellent potential for mapping CLQ over large areas.The model based on the seven optimal indicators of crop phenology provided higher accuracy than the GA-BPNN model based on the normalized difference vegetation index(NDVI)indicators in the spatial domain,significantly decreasing the NRMSE of the CLQ estimates by 3.17%.This further implied that the spectral indicators in the spatial frequency domain can improve the accuracy of estimating CLQ.
