The lake groups in the Songnen Plain are low plain lake groups, which are located in the temperate semihumid area in China. They are characterized by small area, shallow basin, thick density and various types. In the ...The lake groups in the Songnen Plain are low plain lake groups, which are located in the temperate semihumid area in China. They are characterized by small area, shallow basin, thick density and various types. In the try for classifying comprehensively the lake groups, a classification system is developed based on three main factors, i.e. forming cause, water quantity and water quality. The most internal character can be concisely grasped through three principal indexes and three auxiliary indexes of three main factors. A sample of complicated changeable path is put forward for further analyzing and outlining these basic types, in the meantime, it’s linking up easily with the classification system of the single factor. According to the regional environment, the regional differences of the type composition and the principal types, the lake groups in the Songnen Plain can be divided into 6 sub-regions.展开更多
Head smut of maize (Zea mays L.), which was caused by Sporisorium reiliana, occurred in most of the maize growing areas of the world. The purpose of this study was to develop SCAR markers for map-based cloning of re...Head smut of maize (Zea mays L.), which was caused by Sporisorium reiliana, occurred in most of the maize growing areas of the world. The purpose of this study was to develop SCAR markers for map-based cloning of resistance genes and MAS. Two sets of BC3 progenies, one (BC3Q) derived from the cross Qi319 (resistance)×Huangzao 4 (susceptible), the other (BC3M) from Mol7 (resistance)× Huangzao 4 (susceptible), were generated. Huangzao 4 was the recurrent parent in both progenies. A combination of BSA (bulked segregant analysis) with AFLP (amplified fragment length polymorphism) method was applied to map the genes involving the resistance to S. reiliana, and corresponding resistant and susceptible bulks and their parental lines were used for screening polymorphic AFLP primer pairs. One fragment of PI3M61-152 was converted into SCAR (sequence charactered amplified fragment) marker S130. The marker was mapped at chromosome bin 2.09, the interval of a major QTL region previously reported to contribute to S. reiliana resistance. Furthermore, S130 was highly and facilitate map-based cloni associated with resistance to S. reiliana, and could be useful for marker-assisted selection ng of resistance genes.展开更多
Self-biting disease occurred in most farmed fur animals in the world. The mechanism and rapid detection method of this disease has not been reported. We applied bulked sergeant analysis (BSA) in combination with RAP...Self-biting disease occurred in most farmed fur animals in the world. The mechanism and rapid detection method of this disease has not been reported. We applied bulked sergeant analysis (BSA) in combination with RAPD method to analyze a molecular genetic marker linked with self-biting trait in mink group. The molecular marker was converted into sequence-characterized amplified regions (SCAR) marker for rapid detection of this disease. A single RAPD marker A8 amplified a specific band of 263bp in self-biting minks, which was designated as SRA8-250, and non-specific band of 315bp in both self-biting and healthy minks. The sequences of the bands exhibited 75% and 88% similarity to Canis familiarizes major histocompatibility complex (MHC) class II region and Macaca mulatta MHC class I region, respectively. A SCAR marker SCAR-A8 was designed for the specific fragment SRA8-250 and validated in 30 self-biting minks and 30 healthy minks. Positive amplification of SCAR-A8 was detected in 24 self-biting minks and 12 healthy minks. χ2 test showed significant difference (p〈0.01) in the detection rate between the two groups. This indicated that SRA8-250 can be used as a positive marker to detect self-biting disease in minks. Furthermore, the finding that self-biting disease links with MHC genes has significant implications for the mechanism of the disease.展开更多
To screen genetic polymorphisms of Panax ginseng, as well as those of Panax quinquefolium and Panax notoginseng, analysis of random amplified polymorphic DNA (RAPD) was performed using 120 random primers. Of the suc...To screen genetic polymorphisms of Panax ginseng, as well as those of Panax quinquefolium and Panax notoginseng, analysis of random amplified polymorphic DNA (RAPD) was performed using 120 random primers. Of the successful amplicons obtained, the Panax ginseng-specific RAPD marker C-12 was cloned into a TA vector and sequenced (Genl3ank access number KU553472). Based on the sequence analysis results, a pair of primers specific to C-12 was designed. Finally, a SCAR marker-based identification system for Panax ginseng was developed after optimization of the reaction conditions. Using this method, two positive bands were stably observed at 300 bp and 130 bp in 33 batches of Panax ginseng samples tested, while negative results were obtained for another 101 batches of samples, including Panax quinquefolium, Panax notoginseng, adulterants, and other medicinal herbs. Thus, we successfully developed a PCR-based method for rapid and effective identification of Panax ginseng, which can be effectively used for the protection and utilization of germplasm resources and identification of the origins of Panax ginseng samples.展开更多
Alien chromosomes of twelve giant spike wheat germplasm lines were identified by C-banding, genomic in situ hybridization (GISH), sequence characterized amplified region (SCAR), and random amplified polymorphic DNA (R...Alien chromosomes of twelve giant spike wheat germplasm lines were identified by C-banding, genomic in situ hybridization (GISH), sequence characterized amplified region (SCAR), and random amplified polymorphic DNA (RAPD). All lines showed a chromosome number of 2n = 42, five of them carried both a pair of wheat-rye (Triticum aestivum-Secale cereal) 1BL/1RS translocation chromosomes and a pair of Agropyron intermedium (Ai) chromosomes, three carried a pair of Ai chromosomes only, three others carried a pair of 1BL/1RS chromosomes only, and one carried neither 1BL/1BS nor Ai chromosome. Further identification revealed that the identical Ai chromosome in these germplasm lines substituted the chromosome 2D of common wheat (T aestivum L.), designated as 2Ai. The genetic implication and further utilization of 2Ai in wheat improvement were also discussed.展开更多
The fiber length trait (FLT) of 538 individuals from nature birch population in Maorshan region, Heilongjang, China were measured, of which 100 individuals were selected as representative variety of correlated fragm...The fiber length trait (FLT) of 538 individuals from nature birch population in Maorshan region, Heilongjang, China were measured, of which 100 individuals were selected as representative variety of correlated fragments screening with random amplified polymorphism DNA (RAPD) technique. In total of 20 RAPD primers were tested through multiple regression analysis between amplified strip and the character behaviors, and a correlative segment BFLR-16 was obtained. The correlation coefficient between BFLI-16 and FLT was 0.6144, with the significant level of 1%. BFLI-16 was then cloned, sequenced and transformed into SCAR marker. The percentage of identifying long fiber birches by this SCAR was more than 92. The result indicates that the SCAR markers has high specificity for the long fiber individuals and is highly linked with the gene controlling the character of fiber length, and its existence is significantly correlative with the increase in the fiber length.展开更多
Molecular markers have been widely used in crop genetic improvement, seed test and genetic mapping. Of which, sequence characterized amplified region (SCAR) markers are particularly popular for its diversity, stable...Molecular markers have been widely used in crop genetic improvement, seed test and genetic mapping. Of which, sequence characterized amplified region (SCAR) markers are particularly popular for its diversity, stable reproducibility, and suitability for analyzing large number of samples. In this study, 500 random amplified polymorphic DNA (RAPD) primers were tested, and a set of SCAR markers comprising 37 pairs of loci-specific primers were developed from the DNA fragments ranging from 300 to 1000 bp which correspond to the stable, distinctive RAPD banding patterns. Using these SCAR markers, 59 hybrid rice combinations were assessed and distinguished into 58 subgroups at the similarity coefficient of 0.97 in a genetic clustering tree based on the allele diversities of the SCAR markers. Furthermore, 13 hybrid rice combinations were reassayed with 40 randomly selected simple sequence repeat (SSR) markers to evaluate the effectiveness of these SCAR markers. SSR markers produced similar results to SCAR markers as the 13 hybrid rice combinations were completely separated at the similarity coefficient of 0.91 in the clustering tree established from SSR patterns. Taken together, SCAR markers prove to be effective tools for identifying and differentiating hybrid rice combinations.展开更多
A fast knowledge based recognition method of the harbor target in large gray remote-sensing image is presented. First, the distributed features and the inherent feature are analyzed according to the knowledge of harbo...A fast knowledge based recognition method of the harbor target in large gray remote-sensing image is presented. First, the distributed features and the inherent feature are analyzed according to the knowledge of harbor targets; then, two methods for extracting the candidate region of harbor are devised in accordance with different sizes of the harbors; after that, thresholds are used to segment the land and the sea with strategies of the segmentation error control; finally, harbor recognition is implemented according to its inherent character (semi-closed region of seawater).展开更多
The DNAfragments about 1 600 bp were amplified using random amplified polymorphism DNA (RAPD) primer OPAl2 with the templates of mitochondrial DNA of Zhenshan 97A and Zhenshan 97B, and were sequenced. The nucleotide...The DNAfragments about 1 600 bp were amplified using random amplified polymorphism DNA (RAPD) primer OPAl2 with the templates of mitochondrial DNA of Zhenshan 97A and Zhenshan 97B, and were sequenced. The nucleotide sequences and lengths of the fragments from Zhenshan 97A and Zhenshan 97B showed no difference. The precise length of the fragment was 1 588 bp. Sequence characterized amplification region (SCAR) primers were then developed to discriminate the cytoplasmic male sterile (CMS) lines and their maintainer lines. A specific 1 588 bp fragment could be amplified with SCAR primers, CHI19F2/CHI19R2 and CHI20F3/CHI23R3, in the mitochondrial DNA of Zhenshan 97A, but not Zhenshan 97B. Furthermore, the specific fragment could be also amplified from the total DNA from green leaf tissues of Zhenshan 97A with SCAR primers, but not Zhenshan 97B. With the corresponding primers, the specific fragment could also be amplified from the total DNA of green leaves of other two CMS lines with wild abortive type cytoplasm (CMS-WA), namely Zhenpin A and Tianfeng A, but not in their maintainer lines. Moreover, using total DNA as template, each of the four pairs of SCAR primers could also be used to amplify the 1 588 bp fragment in CMS-ID (Indonesia paddy type) line 11-32A but not in 11-32B, and the specific fragment was amplified from the DNA of both F1 and F2 seedlings of Shanyou 63. The results of detecting the genetic purity of a man-made mixture of the seeds of Zhenshan 97A using CHI20F3/CHI23R3 were completely consistent with the phenotypes. Taken together, these results indicated that the specific 1 588 bp-fragment amplified by CHI20F3/CHI23R3 was the unique amplification products of CMS mitochondrial DNA, and could be used to distinguish CMS-WA and CMS-ID lines from their corresponding maintainer lines at the seedling stage.展开更多
The red alga Gracilariopsis lemaneiformis(Bory) is an economically valuable macroalgae. As a means to identify the sex of immature Gracilariopsis lemaneiformis, the amplifi ed fragment length polymorphism(AFLP) techni...The red alga Gracilariopsis lemaneiformis(Bory) is an economically valuable macroalgae. As a means to identify the sex of immature Gracilariopsis lemaneiformis, the amplifi ed fragment length polymorphism(AFLP) technique was used to search for possible sex- or phase-related markers in male gametophytes, female gametophytes, and tetrasporophytes, respectively. Seven AFLP selective amplifi cation primers were used in this study. The primer combination E-TG/M-CCA detected a specifi c band linked to male gametophytes. The DNA fragment was recovered and a 402-bp fragment was sequenced. However, no DNA sequence match was found in public databases. Sequence characterized amplifi ed region(SCAR) primers were designed from the sequence to test the repeatability of the relationship to the sex, using 69 male gametophytes, 139 female gametophytes, and 47 tetrasporophytes. The test results demonstrate a good linkage and repeatability of the SCAR marker to sex. The SCAR primers developed in this study could reduce the time required for sex identifi cation of Gracilariopsis lemaneiformis by four to six months. This can reduce both the time investment and number of specimens required in breeding experiments.展开更多
Dear Editor,The brain experiences ongoing changes across different ages to support brain development and functional reorganization.During the span of adulthood,although the brain has matured from a neurobiological per...Dear Editor,The brain experiences ongoing changes across different ages to support brain development and functional reorganization.During the span of adulthood,although the brain has matured from a neurobiological perspective,it is still continuously shaped by external factors such as habits,the family setting,socioeconomic status,and the work environment [1].In contrast to chronological age (CA),brain(or biological) age (BA) is conceptualized as an important index for characterizing the aging process and neuropsychological state,as well as individual cognitiveperformance.Growing evidence indicates that BA can be assessed by neuroimaging techniques,including MRI [2].展开更多
In this paper, the theory and method of the fuzzy mathematics areused to probe the connection between the activity of the active region and characterizat ion of the sunspot groups, to build the subordinating function ...In this paper, the theory and method of the fuzzy mathematics areused to probe the connection between the activity of the active region and characterizat ion of the sunspot groups, to build the subordinating function according to the rela tionship between them and to evaluate comprehensively the activity of the active region on t he solar disk. The precise prediction of activity of the active regions has been obta ined by data reduction and analysis. The predicting accuracy is higher th an 95% . Forecast results indicate that the method of the fuzzy comprehensive evaluatio n is a good one for the solar activity prediction.展开更多
The effects of development states on the artemisinin content of clone S1 of Artemisia anuua L. grown in a greenhouse were investigated in the present study. The artemisinin content increased gradually during the phase...The effects of development states on the artemisinin content of clone S1 of Artemisia anuua L. grown in a greenhouse were investigated in the present study. The artemisinin content increased gradually during the phase of vegetative growth and reached its highest level at 8-9 mg/g dry weight (DW) when the S1 was 6 months old on a long day (LD) photoperiod. Treatment with 9-18 d of short day (SD) photoperiod resulted in the artemisinin content reaching and being maintained at a higher level (2.059-2.289 mg/g DW), twofold that of control plants and plants of S1 presented at the pro-flower budding and flower-budding stages. The artemisinin content varied in different parts of the plant. The artemisinin content of leaves was higher than that of florets and branches. The artemisinin content in middle leaves was higher than that of bottom leaves, and then top leaves. Different densities of capitate glands (the storage organ of artemisinin) located on the surface of leaves, florets, and branches explained the variations in artemisinin content in these parts of the plant. The correlation coefficient between artemisinin content and density of capitate glands on the surface of different organs was 0.987. The genetic marker for artemisinin content was screened using random amplified polymorphic DNA (RAPD) and sequence characterized amplified region (SCAR) techniques. The random primer OPAl5 (5'-TTCCGAACCC-3') could amplify a specific band of approximately 1 000 bp that was present in all high-artemisinin yielding strains, but absent in all low-yielding strains in three independent replications. This specific band was cloned and its sequence was analyzed. This RAPD marker was converted into a SCAR marker to obtain a more stable marker.展开更多
Abstract: Inter-simple sequence repeat (ISSR) analysis was used to assess genetic diversity among 10 pairs of male and female Laminaria gametophytes. A total of 58 amplification loci was obtained from 10 selected ISSR...Abstract: Inter-simple sequence repeat (ISSR) analysis was used to assess genetic diversity among 10 pairs of male and female Laminaria gametophytes. A total of 58 amplification loci was obtained from 10 selected ISSR primers, of which 34 revealed polymorphism among the gametophytes. Genetic distances were calculated with the Dice coefficient ranging from 0.006 to 0.223. A dendrogram based on the unweighted pair-group method arithmetic (UPGMA) average showed that most male and female gametophytes of the same species were clustered together and that 10 pairs of gametophytes were divided into four groups. This was generally consistent with the taxonomic categories. The main group consisted of six pairs of gametophytes, which were selected from Laminaria japonica Aresch. by intensive inbreeding through artificial hybridization. One specific marker was cloned, but was not converted successfully into a sequence characterized amplified region (SCAR) marker. Our results demonstrate the feasibility of applying ISSR markers to evaluate Laminaria germplasm diversities.展开更多
Scrophularia ningpoensis has long been used in the Chinese Materia Medica for inflammation.Like other herbal medicines,S.ningpoensis collected from different localities may considerably differ in their therapeutic eff...Scrophularia ningpoensis has long been used in the Chinese Materia Medica for inflammation.Like other herbal medicines,S.ningpoensis collected from different localities may considerably differ in their therapeutic efficacy,and the one grown in Zhejiang Province is recognized as geo-authentic.However,it is difficult to confirm the geo-graphical authenticity by similar morphological characteristics.In the present study,inter-simple sequence repeat(ISSR) markers were conducted to detect S.ningpoensis from different origins.A 1 259-bp fragment amplified by primer UBC874 was found only in geo-authentic ones.By cloning and sequencing that specific band,sequence characterized amplified region(SCAR) markers were designed to distinguish geo-authentic S.ningpoensis from others.This is a rapid and easy method that can be used to identify the geographical authenticity of S.ningpoensis.展开更多
基金Under the auspices of the National Natural Science Foundation of China(49671077).
文摘The lake groups in the Songnen Plain are low plain lake groups, which are located in the temperate semihumid area in China. They are characterized by small area, shallow basin, thick density and various types. In the try for classifying comprehensively the lake groups, a classification system is developed based on three main factors, i.e. forming cause, water quantity and water quality. The most internal character can be concisely grasped through three principal indexes and three auxiliary indexes of three main factors. A sample of complicated changeable path is put forward for further analyzing and outlining these basic types, in the meantime, it’s linking up easily with the classification system of the single factor. According to the regional environment, the regional differences of the type composition and the principal types, the lake groups in the Songnen Plain can be divided into 6 sub-regions.
基金funded by the National Hi-Tech R&D Program,China(863Program,2006AA100103,2007AA10Z172)the International Cooperation Project for Science and Technology(2007DFA31010)
文摘Head smut of maize (Zea mays L.), which was caused by Sporisorium reiliana, occurred in most of the maize growing areas of the world. The purpose of this study was to develop SCAR markers for map-based cloning of resistance genes and MAS. Two sets of BC3 progenies, one (BC3Q) derived from the cross Qi319 (resistance)×Huangzao 4 (susceptible), the other (BC3M) from Mol7 (resistance)× Huangzao 4 (susceptible), were generated. Huangzao 4 was the recurrent parent in both progenies. A combination of BSA (bulked segregant analysis) with AFLP (amplified fragment length polymorphism) method was applied to map the genes involving the resistance to S. reiliana, and corresponding resistant and susceptible bulks and their parental lines were used for screening polymorphic AFLP primer pairs. One fragment of PI3M61-152 was converted into SCAR (sequence charactered amplified fragment) marker S130. The marker was mapped at chromosome bin 2.09, the interval of a major QTL region previously reported to contribute to S. reiliana resistance. Furthermore, S130 was highly and facilitate map-based cloni associated with resistance to S. reiliana, and could be useful for marker-assisted selection ng of resistance genes.
文摘Self-biting disease occurred in most farmed fur animals in the world. The mechanism and rapid detection method of this disease has not been reported. We applied bulked sergeant analysis (BSA) in combination with RAPD method to analyze a molecular genetic marker linked with self-biting trait in mink group. The molecular marker was converted into sequence-characterized amplified regions (SCAR) marker for rapid detection of this disease. A single RAPD marker A8 amplified a specific band of 263bp in self-biting minks, which was designated as SRA8-250, and non-specific band of 315bp in both self-biting and healthy minks. The sequences of the bands exhibited 75% and 88% similarity to Canis familiarizes major histocompatibility complex (MHC) class II region and Macaca mulatta MHC class I region, respectively. A SCAR marker SCAR-A8 was designed for the specific fragment SRA8-250 and validated in 30 self-biting minks and 30 healthy minks. Positive amplification of SCAR-A8 was detected in 24 self-biting minks and 12 healthy minks. χ2 test showed significant difference (p〈0.01) in the detection rate between the two groups. This indicated that SRA8-250 can be used as a positive marker to detect self-biting disease in minks. Furthermore, the finding that self-biting disease links with MHC genes has significant implications for the mechanism of the disease.
基金Project(2014ZX09304307-002)supported by the Major Program of Science and Technology Foundation of ChinaProject supported by Technology Platform for Quality/Safety Inspection and Risk Management of Traditional Chinese Medicine,China+1 种基金Project(2014SK2001)supported by the Key Program Foundation of Hunan Provincial Science&Technology Department,ChinaProject(XSYK-R201502)supported by the Hunan Provincial Food and Drug Administration under Key Project of Science and Technology for Food and Drug Safety,China
文摘To screen genetic polymorphisms of Panax ginseng, as well as those of Panax quinquefolium and Panax notoginseng, analysis of random amplified polymorphic DNA (RAPD) was performed using 120 random primers. Of the successful amplicons obtained, the Panax ginseng-specific RAPD marker C-12 was cloned into a TA vector and sequenced (Genl3ank access number KU553472). Based on the sequence analysis results, a pair of primers specific to C-12 was designed. Finally, a SCAR marker-based identification system for Panax ginseng was developed after optimization of the reaction conditions. Using this method, two positive bands were stably observed at 300 bp and 130 bp in 33 batches of Panax ginseng samples tested, while negative results were obtained for another 101 batches of samples, including Panax quinquefolium, Panax notoginseng, adulterants, and other medicinal herbs. Thus, we successfully developed a PCR-based method for rapid and effective identification of Panax ginseng, which can be effectively used for the protection and utilization of germplasm resources and identification of the origins of Panax ginseng samples.
文摘Alien chromosomes of twelve giant spike wheat germplasm lines were identified by C-banding, genomic in situ hybridization (GISH), sequence characterized amplified region (SCAR), and random amplified polymorphic DNA (RAPD). All lines showed a chromosome number of 2n = 42, five of them carried both a pair of wheat-rye (Triticum aestivum-Secale cereal) 1BL/1RS translocation chromosomes and a pair of Agropyron intermedium (Ai) chromosomes, three carried a pair of Ai chromosomes only, three others carried a pair of 1BL/1RS chromosomes only, and one carried neither 1BL/1BS nor Ai chromosome. Further identification revealed that the identical Ai chromosome in these germplasm lines substituted the chromosome 2D of common wheat (T aestivum L.), designated as 2Ai. The genetic implication and further utilization of 2Ai in wheat improvement were also discussed.
基金supported by the National 863 Program (2002BA515B0401)National Natural Science Foundation of China (30571513)Foundation of Heilongjiang Province (GA06B301)
文摘The fiber length trait (FLT) of 538 individuals from nature birch population in Maorshan region, Heilongjang, China were measured, of which 100 individuals were selected as representative variety of correlated fragments screening with random amplified polymorphism DNA (RAPD) technique. In total of 20 RAPD primers were tested through multiple regression analysis between amplified strip and the character behaviors, and a correlative segment BFLR-16 was obtained. The correlation coefficient between BFLI-16 and FLT was 0.6144, with the significant level of 1%. BFLI-16 was then cloned, sequenced and transformed into SCAR marker. The percentage of identifying long fiber birches by this SCAR was more than 92. The result indicates that the SCAR markers has high specificity for the long fiber individuals and is highly linked with the gene controlling the character of fiber length, and its existence is significantly correlative with the increase in the fiber length.
基金the National High Technology Research and Development Program of China (Grant Nos. 2010AA101304 and 2008ZX08001-004)
文摘Molecular markers have been widely used in crop genetic improvement, seed test and genetic mapping. Of which, sequence characterized amplified region (SCAR) markers are particularly popular for its diversity, stable reproducibility, and suitability for analyzing large number of samples. In this study, 500 random amplified polymorphic DNA (RAPD) primers were tested, and a set of SCAR markers comprising 37 pairs of loci-specific primers were developed from the DNA fragments ranging from 300 to 1000 bp which correspond to the stable, distinctive RAPD banding patterns. Using these SCAR markers, 59 hybrid rice combinations were assessed and distinguished into 58 subgroups at the similarity coefficient of 0.97 in a genetic clustering tree based on the allele diversities of the SCAR markers. Furthermore, 13 hybrid rice combinations were reassayed with 40 randomly selected simple sequence repeat (SSR) markers to evaluate the effectiveness of these SCAR markers. SSR markers produced similar results to SCAR markers as the 13 hybrid rice combinations were completely separated at the similarity coefficient of 0.91 in the clustering tree established from SSR patterns. Taken together, SCAR markers prove to be effective tools for identifying and differentiating hybrid rice combinations.
文摘A fast knowledge based recognition method of the harbor target in large gray remote-sensing image is presented. First, the distributed features and the inherent feature are analyzed according to the knowledge of harbor targets; then, two methods for extracting the candidate region of harbor are devised in accordance with different sizes of the harbors; after that, thresholds are used to segment the land and the sea with strategies of the segmentation error control; finally, harbor recognition is implemented according to its inherent character (semi-closed region of seawater).
基金financially supported by the National High-Tech Research and Development Program of China(Grant No.2010AA101301)the Program of Introducing Talents of Discipline to Universities(Grant No.B08025)+1 种基金the '948' Program of Ministry of Agriculture,China(Grant No.2006-G8[4]-31-1)the Key Project of Scientific Base Qualification Platform of Ministry of Education,China(Grant No.505005)
文摘The DNAfragments about 1 600 bp were amplified using random amplified polymorphism DNA (RAPD) primer OPAl2 with the templates of mitochondrial DNA of Zhenshan 97A and Zhenshan 97B, and were sequenced. The nucleotide sequences and lengths of the fragments from Zhenshan 97A and Zhenshan 97B showed no difference. The precise length of the fragment was 1 588 bp. Sequence characterized amplification region (SCAR) primers were then developed to discriminate the cytoplasmic male sterile (CMS) lines and their maintainer lines. A specific 1 588 bp fragment could be amplified with SCAR primers, CHI19F2/CHI19R2 and CHI20F3/CHI23R3, in the mitochondrial DNA of Zhenshan 97A, but not Zhenshan 97B. Furthermore, the specific fragment could be also amplified from the total DNA from green leaf tissues of Zhenshan 97A with SCAR primers, but not Zhenshan 97B. With the corresponding primers, the specific fragment could also be amplified from the total DNA of green leaves of other two CMS lines with wild abortive type cytoplasm (CMS-WA), namely Zhenpin A and Tianfeng A, but not in their maintainer lines. Moreover, using total DNA as template, each of the four pairs of SCAR primers could also be used to amplify the 1 588 bp fragment in CMS-ID (Indonesia paddy type) line 11-32A but not in 11-32B, and the specific fragment was amplified from the DNA of both F1 and F2 seedlings of Shanyou 63. The results of detecting the genetic purity of a man-made mixture of the seeds of Zhenshan 97A using CHI20F3/CHI23R3 were completely consistent with the phenotypes. Taken together, these results indicated that the specific 1 588 bp-fragment amplified by CHI20F3/CHI23R3 was the unique amplification products of CMS mitochondrial DNA, and could be used to distinguish CMS-WA and CMS-ID lines from their corresponding maintainer lines at the seedling stage.
基金Supported by the"Twelfth Five-Year-Plan"of National Science and Technology for the Rural Development in China(No.2012AA10A411)the Public Welfare Project of the Ministry of Agriculture of China(No.200903030)
文摘The red alga Gracilariopsis lemaneiformis(Bory) is an economically valuable macroalgae. As a means to identify the sex of immature Gracilariopsis lemaneiformis, the amplifi ed fragment length polymorphism(AFLP) technique was used to search for possible sex- or phase-related markers in male gametophytes, female gametophytes, and tetrasporophytes, respectively. Seven AFLP selective amplifi cation primers were used in this study. The primer combination E-TG/M-CCA detected a specifi c band linked to male gametophytes. The DNA fragment was recovered and a 402-bp fragment was sequenced. However, no DNA sequence match was found in public databases. Sequence characterized amplifi ed region(SCAR) primers were designed from the sequence to test the repeatability of the relationship to the sex, using 69 male gametophytes, 139 female gametophytes, and 47 tetrasporophytes. The test results demonstrate a good linkage and repeatability of the SCAR marker to sex. The SCAR primers developed in this study could reduce the time required for sex identifi cation of Gracilariopsis lemaneiformis by four to six months. This can reduce both the time investment and number of specimens required in breeding experiments.
基金supported by the National Natural Science Foundation of China(61971420)the Beijing Brain Initiative of the Beijing Municipal Science and Technology Commission(Z181100001518003)+1 种基金Special Projects of Brain Science of the Beijing Municipal Science and Technology Commission(Z161100000216139 and Z171100000117002)the International Cooperation and Exchange of the National Natural Science Foundation of China(31620103905)。
文摘Dear Editor,The brain experiences ongoing changes across different ages to support brain development and functional reorganization.During the span of adulthood,although the brain has matured from a neurobiological perspective,it is still continuously shaped by external factors such as habits,the family setting,socioeconomic status,and the work environment [1].In contrast to chronological age (CA),brain(or biological) age (BA) is conceptualized as an important index for characterizing the aging process and neuropsychological state,as well as individual cognitiveperformance.Growing evidence indicates that BA can be assessed by neuroimaging techniques,including MRI [2].
基金This work was supported by the National Weighty Natural Science Foundation of China (Grant No. 49990451).
文摘In this paper, the theory and method of the fuzzy mathematics areused to probe the connection between the activity of the active region and characterizat ion of the sunspot groups, to build the subordinating function according to the rela tionship between them and to evaluate comprehensively the activity of the active region on t he solar disk. The precise prediction of activity of the active regions has been obta ined by data reduction and analysis. The predicting accuracy is higher th an 95% . Forecast results indicate that the method of the fuzzy comprehensive evaluatio n is a good one for the solar activity prediction.
文摘The effects of development states on the artemisinin content of clone S1 of Artemisia anuua L. grown in a greenhouse were investigated in the present study. The artemisinin content increased gradually during the phase of vegetative growth and reached its highest level at 8-9 mg/g dry weight (DW) when the S1 was 6 months old on a long day (LD) photoperiod. Treatment with 9-18 d of short day (SD) photoperiod resulted in the artemisinin content reaching and being maintained at a higher level (2.059-2.289 mg/g DW), twofold that of control plants and plants of S1 presented at the pro-flower budding and flower-budding stages. The artemisinin content varied in different parts of the plant. The artemisinin content of leaves was higher than that of florets and branches. The artemisinin content in middle leaves was higher than that of bottom leaves, and then top leaves. Different densities of capitate glands (the storage organ of artemisinin) located on the surface of leaves, florets, and branches explained the variations in artemisinin content in these parts of the plant. The correlation coefficient between artemisinin content and density of capitate glands on the surface of different organs was 0.987. The genetic marker for artemisinin content was screened using random amplified polymorphic DNA (RAPD) and sequence characterized amplified region (SCAR) techniques. The random primer OPAl5 (5'-TTCCGAACCC-3') could amplify a specific band of approximately 1 000 bp that was present in all high-artemisinin yielding strains, but absent in all low-yielding strains in three independent replications. This specific band was cloned and its sequence was analyzed. This RAPD marker was converted into a SCAR marker to obtain a more stable marker.
文摘Abstract: Inter-simple sequence repeat (ISSR) analysis was used to assess genetic diversity among 10 pairs of male and female Laminaria gametophytes. A total of 58 amplification loci was obtained from 10 selected ISSR primers, of which 34 revealed polymorphism among the gametophytes. Genetic distances were calculated with the Dice coefficient ranging from 0.006 to 0.223. A dendrogram based on the unweighted pair-group method arithmetic (UPGMA) average showed that most male and female gametophytes of the same species were clustered together and that 10 pairs of gametophytes were divided into four groups. This was generally consistent with the taxonomic categories. The main group consisted of six pairs of gametophytes, which were selected from Laminaria japonica Aresch. by intensive inbreeding through artificial hybridization. One specific marker was cloned, but was not converted successfully into a sequence characterized amplified region (SCAR) marker. Our results demonstrate the feasibility of applying ISSR markers to evaluate Laminaria germplasm diversities.
基金Project supported by the National Basic Research Program (973) of China(No.2007CB411600)the National Natural Science Foundation of China(No.31070205)the Key Agricultural Program of Pan’an County of Zhejiang Province,China(No.2005ZB01)
文摘Scrophularia ningpoensis has long been used in the Chinese Materia Medica for inflammation.Like other herbal medicines,S.ningpoensis collected from different localities may considerably differ in their therapeutic efficacy,and the one grown in Zhejiang Province is recognized as geo-authentic.However,it is difficult to confirm the geo-graphical authenticity by similar morphological characteristics.In the present study,inter-simple sequence repeat(ISSR) markers were conducted to detect S.ningpoensis from different origins.A 1 259-bp fragment amplified by primer UBC874 was found only in geo-authentic ones.By cloning and sequencing that specific band,sequence characterized amplified region(SCAR) markers were designed to distinguish geo-authentic S.ningpoensis from others.This is a rapid and easy method that can be used to identify the geographical authenticity of S.ningpoensis.