[Objectives] This study was conducted to better understand the variation law of sugarcane clones during tissue culture process,and to provide a reference for rapid propagation and detection of healthy sugarcane seedli...[Objectives] This study was conducted to better understand the variation law of sugarcane clones during tissue culture process,and to provide a reference for rapid propagation and detection of healthy sugarcane seedlings.[Methods] The genetic stability of tissue culture clones of three sugarcane varieties was analyzed using the AFLP molecular marker technique.[Results]The average number of polymorphic loci was 19. 58 for each primer pair,and the percentage of polymorphic loci was 41. 74%. Compared with the donor varieties,all tissue culture materials were mutated. There were 3-16 missing bands,with an average of 5. 2 bands,and there were 0-17 increased bands,with an average of 3. 3 bands. The total number of missing and increased bands was 4-33,with an average of 8. 5. The band difference rates were in the range of 0. 009 4%-0. 077 6%,with an average of 0. 020 6%. The genetic similarity coefficients between materials ranged from 0. 685 6 to 0. 998 2,with an average of 0. 818 4. The three sugarcane varieties and their tissue culture clones were clustered into three groups.[Conclusions] Although variations occur in tissue culture,the variations are not too obvious,and the genetic stability is relatively high. It is recommended to minimize the number of subculture generations and cultivation time to reduce the occurrence of variation during tissue culture for rapid propagation of sugarcane seedlings.展开更多
The root system is fundamental for maize growth and yield.Characterizing its heterogeneity and cell type-specific response to nitrate at the single-cell level will shed light on root development and nutrient uptake.We...The root system is fundamental for maize growth and yield.Characterizing its heterogeneity and cell type-specific response to nitrate at the single-cell level will shed light on root development and nutrient uptake.We profiled the transcriptomes of>7000 cells derived from root tips of maize seedlings grown on media with or without nitrate,and identified 11 major cell types or tissues and 85 cell type-specific nitrate-response genes,including several known nitrate metabolic genes.A pseudotime analysis showed a continuous pseudotime series with the beginning at meristematic zone cells and showed that the root hair cell was derived by differentiation of a subset of epidermal cells.Interspecies comparison of root cells between maize and rice revealed the conservation and divergence of the root cell types and identified 57,216,and 80 conserved orthologous genes in root hair,endodermis,and phloem cells respectively.This study provides a global view of maize root tip developmental processes and responses to nitrate at the single-cell level.The genes described in the present work could serve as targets for further genetic analyses and accurate regulation of gene expression and phenotypic variation in specific cell types or tissues.展开更多
[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgen...[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgenic plants, thereby improving breeding efficiency of insect-resistant sugarcane cultivars in China. [ Method] Approximately 1 mg of root tips and other materials were crushed, placed in the bottom of PCR tubes, added successively with solution I and mineral oil, headed at 95 ℃ for 15 rain, added with solution Ⅱ, and finally added with solution III containing GBt primer for PCR. After separated by using electrophoresis on agarese gel, amplification products were observed and photographed under a gel imaging system. [ Result] Various materials treated with different concentrations of solution led to different amplification results. Specifically, the appropriate concentration of NaOH in solution I was 0.1 -0.2 mol/L; the appropriate pH value of solution II was 2. No bands were amplified from mature leaves, tender leaves and old roots of Bt transgenic sugarcane, while root tips successfully amplified 545 bp target bands. The established method was used to identify and analyze 63 hybrid seedlings of YT 91 -976 × SBR216, results showed that a total of 17 samples exhibited 545 bp bands, accounting for approximately 27% of the total number of hybrid seedlings, indicating that these 17 seedlings were Bt transgenic sugarcane plants. [ Conclusion] The rapid detection method established in this study is conducive to identifying Bt transgenic sugarcane and improving breeding efficiency of insect-resistant sugarcane lines, which provides basis for screening of other transgenic materials.展开更多
To assess the indica-japonica differentiation of improved rice varieties, a total of 512 modem varieties including 301 indica and 211 japonica accessions were analyzed using 36 microsatellites. The Fst coefficients ra...To assess the indica-japonica differentiation of improved rice varieties, a total of 512 modem varieties including 301 indica and 211 japonica accessions were analyzed using 36 microsatellites. The Fst coefficients ranged from 0.002 to 0.730 among the loci with an average of 0.315. Significant differentiation was detected at 94.4% of the loci studied （P 〈 0.05, pairwise Fst tests）, indicating that there was a high level of indica-japonica differentiation within the improved varieties. At 18 loci, about 74%-98% of the alleles of indica and japonica accessions were distributed in two ranges of amplicon length. Linkage disequilibrium analysis showed that the distribution trends were significantly nonrandomly associated. Using the differentiation trends at the 18 loci, microsatellite index （MI） was proposed for discrimination of the two subspecies. When rice accessions with MI value greater than zero were classified as indica, and those with MI value smaller than zero were classified as japonica, about 96.1% of the accessions could be classified. This result agrees with the classification based on morphological-physiological characters, indicating that this method is feasible and effective.展开更多
基金Supported by Action Fund for the Guangdong Academy of Sciences Special Funds for Building Top-ranking Research Institutions in China(2019GDASYL-0104013)Science and Technology Program of Guangzhou(201804010418)+1 种基金National Key R&D Program of China(2018YFD1000503)China Agriculture Research System of Sugar(CARS201707)
文摘[Objectives] This study was conducted to better understand the variation law of sugarcane clones during tissue culture process,and to provide a reference for rapid propagation and detection of healthy sugarcane seedlings.[Methods] The genetic stability of tissue culture clones of three sugarcane varieties was analyzed using the AFLP molecular marker technique.[Results]The average number of polymorphic loci was 19. 58 for each primer pair,and the percentage of polymorphic loci was 41. 74%. Compared with the donor varieties,all tissue culture materials were mutated. There were 3-16 missing bands,with an average of 5. 2 bands,and there were 0-17 increased bands,with an average of 3. 3 bands. The total number of missing and increased bands was 4-33,with an average of 8. 5. The band difference rates were in the range of 0. 009 4%-0. 077 6%,with an average of 0. 020 6%. The genetic similarity coefficients between materials ranged from 0. 685 6 to 0. 998 2,with an average of 0. 818 4. The three sugarcane varieties and their tissue culture clones were clustered into three groups.[Conclusions] Although variations occur in tissue culture,the variations are not too obvious,and the genetic stability is relatively high. It is recommended to minimize the number of subculture generations and cultivation time to reduce the occurrence of variation during tissue culture for rapid propagation of sugarcane seedlings.
基金financially supported by the Special Project of Guangdong Academy of Sciences,China(2020GDASYL-20200103073)the Special Project for Research and Development in Key areas of Guangdong Province(2019B020238001)the National Natural Science Foundation of China(32072027)。
文摘The root system is fundamental for maize growth and yield.Characterizing its heterogeneity and cell type-specific response to nitrate at the single-cell level will shed light on root development and nutrient uptake.We profiled the transcriptomes of>7000 cells derived from root tips of maize seedlings grown on media with or without nitrate,and identified 11 major cell types or tissues and 85 cell type-specific nitrate-response genes,including several known nitrate metabolic genes.A pseudotime analysis showed a continuous pseudotime series with the beginning at meristematic zone cells and showed that the root hair cell was derived by differentiation of a subset of epidermal cells.Interspecies comparison of root cells between maize and rice revealed the conservation and divergence of the root cell types and identified 57,216,and 80 conserved orthologous genes in root hair,endodermis,and phloem cells respectively.This study provides a global view of maize root tip developmental processes and responses to nitrate at the single-cell level.The genes described in the present work could serve as targets for further genetic analyses and accurate regulation of gene expression and phenotypic variation in specific cell types or tissues.
基金Supported by Modern Agricultural Industry Technology System (CARS-2004B)
文摘[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgenic plants, thereby improving breeding efficiency of insect-resistant sugarcane cultivars in China. [ Method] Approximately 1 mg of root tips and other materials were crushed, placed in the bottom of PCR tubes, added successively with solution I and mineral oil, headed at 95 ℃ for 15 rain, added with solution Ⅱ, and finally added with solution III containing GBt primer for PCR. After separated by using electrophoresis on agarese gel, amplification products were observed and photographed under a gel imaging system. [ Result] Various materials treated with different concentrations of solution led to different amplification results. Specifically, the appropriate concentration of NaOH in solution I was 0.1 -0.2 mol/L; the appropriate pH value of solution II was 2. No bands were amplified from mature leaves, tender leaves and old roots of Bt transgenic sugarcane, while root tips successfully amplified 545 bp target bands. The established method was used to identify and analyze 63 hybrid seedlings of YT 91 -976 × SBR216, results showed that a total of 17 samples exhibited 545 bp bands, accounting for approximately 27% of the total number of hybrid seedlings, indicating that these 17 seedlings were Bt transgenic sugarcane plants. [ Conclusion] The rapid detection method established in this study is conducive to identifying Bt transgenic sugarcane and improving breeding efficiency of insect-resistant sugarcane lines, which provides basis for screening of other transgenic materials.
基金supported by the National Basic Research Program of China (No.2004CB117201)National Natural Science Foundation of China (No.30600388)the Key Technologies Research and Development Program of China (No.2006BAD13B01)
文摘To assess the indica-japonica differentiation of improved rice varieties, a total of 512 modem varieties including 301 indica and 211 japonica accessions were analyzed using 36 microsatellites. The Fst coefficients ranged from 0.002 to 0.730 among the loci with an average of 0.315. Significant differentiation was detected at 94.4% of the loci studied （P 〈 0.05, pairwise Fst tests）, indicating that there was a high level of indica-japonica differentiation within the improved varieties. At 18 loci, about 74%-98% of the alleles of indica and japonica accessions were distributed in two ranges of amplicon length. Linkage disequilibrium analysis showed that the distribution trends were significantly nonrandomly associated. Using the differentiation trends at the 18 loci, microsatellite index （MI） was proposed for discrimination of the two subspecies. When rice accessions with MI value greater than zero were classified as indica, and those with MI value smaller than zero were classified as japonica, about 96.1% of the accessions could be classified. This result agrees with the classification based on morphological-physiological characters, indicating that this method is feasible and effective.
