Twenty-three isolates of soft rot bacteria from konjac corms were examined for their diversity using 16S rDNAs and AFLP technology. Both methods clustered two groups, dependent on their biotype characterization of Pec...Twenty-three isolates of soft rot bacteria from konjac corms were examined for their diversity using 16S rDNAs and AFLP technology. Both methods clustered two groups, dependent on their biotype characterization of Pectobacterium carotovora subsp. carotovora (P.c.c) and Pectobacterium chrysanthemi (P.ch), respectively. Of all isolates, 17 (73.9%) belonged to P. ch, indicated as the main pathogenic bacteria of konjac producing areas in China. The genetic variation among isolates from the same biotype was also rich, not consistent with the distances of the geographic sources.展开更多
Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.Howe...Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.However,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely revealed.Herein,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room temperature.Photoluminescence(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE properties.And their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence method.The stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) NCs.With large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon excitations.These results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers.展开更多
扩增片断长度多态性（Amplified fragment lengthpolymorphism，AFLP）标记技术是一种新的DNA指纹技术主要用于检测DNA多态性。AFLP技术是根据基因组DNA水平的差异进行检测，不受组织和器官、发育阶段、生理条件等诸多因素影响，因此在...扩增片断长度多态性（Amplified fragment lengthpolymorphism，AFLP）标记技术是一种新的DNA指纹技术主要用于检测DNA多态性。AFLP技术是根据基因组DNA水平的差异进行检测，不受组织和器官、发育阶段、生理条件等诸多因素影响，因此在水产动物中应用AFLP技术具有广阔的前景，可作为水产动物种质鉴定、亲缘关系及种质分类研究的理想标记。展开更多
本刊讯：扩增片段长度多态性（Amplified Fragment Length Polymorphism，AFLP）技术，该技术是由Vos等1995年建立的一项分子标记技术，其基本原理是选择性扩增带有人工接头的DNA酶切片段。因不同个体的DNA的酶切片段存在差异，从而产...本刊讯：扩增片段长度多态性（Amplified Fragment Length Polymorphism，AFLP）技术，该技术是由Vos等1995年建立的一项分子标记技术，其基本原理是选择性扩增带有人工接头的DNA酶切片段。因不同个体的DNA的酶切片段存在差异，从而产生扩增片段的长度多态性。AFLP技术具有不需要预先知道被研究物种的基因组DNA序列信息，展开更多
Genetic profiling of environmentally important organisms is very essential for easy identification of biodegrading bacteria. In the previous study, we have reported the perchlorate biodegrading bacteria and characteri...Genetic profiling of environmentally important organisms is very essential for easy identification of biodegrading bacteria. In the previous study, we have reported the perchlorate biodegrading bacteria and characterized them by biochemical analysis and 16 S sequencing. We have observed a very similar isolates of Arthrobacter (Actinobacteria) degrading 4.1 mM and 4.7 mM of ammonium perchlorate [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300390038003100390037003300340037000000 . In this study, we report PCR based DNA fingerprinting technique to generate the genomic signature of these closely related group of Arthrobacter species. This study also effectively generates unique genomic signature for each of these isolates that has potential for use in molecular monitoring as well as for tracking genomic variation and rearrangements.展开更多
The genetic diversity of the populations for 14 wild green peafowls (Pavo muticus) and 18 captive green pea-fowls was investigated by using the technology of random amplified polymorphic DNA (RAPD). Totally 161 and 16...The genetic diversity of the populations for 14 wild green peafowls (Pavo muticus) and 18 captive green pea-fowls was investigated by using the technology of random amplified polymorphic DNA (RAPD). Totally 161 and 166 ampli-fied bands were obtained by using 23 arbitrary primers to amplify the genomic DNA of wild and captive green peafowls re-spectively. The results showed that the average relative genetic distance of the wild and captive green peafowls popula-tions was 0.0555 and 0.1355, respectively, and difference of the average relative genetic distances between the two popu-lations was 0.1635. The Shannon diversity index for the wild and captive green peafowl populations was 0.4348 and 1.0163, respectively, which means that there exists significant difference in genetic diversity between the two populations, and the genetic diversity of wild green peafowl was low. The two populations originated from two different families according to analysis by the UPGMA method. This research can provide the theoretical basis for supervising genealogies management of peafowl populations.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
The translucent endosperm trait in a japonica rice variety ＇Kantou 194＇ is controlled by a Wx-mq gene which is allelic to Wx locus by genetic analysis and allelic test. The amylose content analysis showed that an in...The translucent endosperm trait in a japonica rice variety ＇Kantou 194＇ is controlled by a Wx-mq gene which is allelic to Wx locus by genetic analysis and allelic test. The amylose content analysis showed that an intermediate amylose content between those of glutinous and non-glutinous rice existed in endosperm of homozygous Wx-mq genotype. The slight changes of amylose content in different varieties and F1 grains with an identical Wx-mq genotype might be influenced by dissimilar genetic background. To identify the Wx-mq genotype simply and rapidly, a cleaved amplified polymorphic sequence （CAPS） marker was designed. The result from the molecular detection indicated that it could be used for marker-assisted selection for low amylose content varieties in rice breeding.展开更多
Lablab purpureus (L.) Sweet is a multipurpose legume that combines use as human food and animal feed in addition to serving as a cover crop for soil conservation. In this work, molecular diversity in Lablab purpureus ...Lablab purpureus (L.) Sweet is a multipurpose legume that combines use as human food and animal feed in addition to serving as a cover crop for soil conservation. In this work, molecular diversity in Lablab purpureus was assessed using amplified fragment length polymorphism markers on fifty Kenyan lablab accessions obtained from farmers’ fields and the Kenya National gene bank. One hundred and eighty polymorphic bands were revealed using fifteen selective primer pairs. The overall mean expected heterozygosity (He) for the five populations was 0.189. Estimates of components of molecular variance revealed that most of the genetic variation resided within populations (99%) and only 1% variance was among the populations, while Principal Coordinate Analysis showed an overlap between accessions from different geographic origins. The UPGMA cluster analysis generated from the distance matrix of the 50 assayed accessions, revealed low diversity among most of the accessions. The low diversity observed may be due to the narrow genetic base for breeding stocks, and extensive exchange of germplasm among smallholder farmers across the country. Results obtained from this study are discussed in light of the need to enhance the genetic management and improvement of this multipurpose crop species.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
This paper reports on the fabrication and characterization of a newly erbium-doped single-mode tellurite glass-fibre applicable for 1.5-μm optical amplifiers. A very broad erbium amplified spontaneous emission in the...This paper reports on the fabrication and characterization of a newly erbium-doped single-mode tellurite glass-fibre applicable for 1.5-μm optical amplifiers. A very broad erbium amplified spontaneous emission in the range 1450-1650 nm from erbium-doped single-mode tellurite glass-fibre is obtained upon excitation of a 980-nm laser diode. The effects of the length of glass-fibre and the pumping power of laser diode on the amplified spontaneous emission are discussed. The result indicates that the tellurite glass-fibre is a promising candidate for designing fibre-optic amplifiers and lasers.展开更多
An effective PCR protocol for detecting the sequence related amplified polymorphism （SRAP） in rice was developed. One hundred and ten pairs of SRAP primers were used for segregation analysis in an F2 population deri...An effective PCR protocol for detecting the sequence related amplified polymorphism （SRAP） in rice was developed. One hundred and ten pairs of SRAP primers were used for segregation analysis in an F2 population derived from a cross between Shennong 606 and Lijiangxintuanheigu. Among the 110 primer pairs, 35 pairs generated 143 polymorphic bands with an average of 4.09 polymorphic bands per primer pair, and 24 pairs （16.78%） showed the genetic distortion （P〈0.05）. Of the 24 primer pairs, 12 pairs deviated toward the male parent Shennong 606 and 11 pairs toward the female parent Lijiangxintuanheigu, only one toward heterozygote. It was found that the segregation distortion might be caused by the joint gametic and zygotic effects.展开更多
We present an all-fiber 1.94μm nanosecond pulse laser in master oscillation-power amplifier configuration.A dual-FBGs gain-switched Tm^(3+)-doped fiber laser is built and is used as the seed laser.The output characte...We present an all-fiber 1.94μm nanosecond pulse laser in master oscillation-power amplifier configuration.A dual-FBGs gain-switched Tm^(3+)-doped fiber laser is built and is used as the seed laser.The output characteristics of the amplifier are studied at different pulse repetition rates,and the maximum output energy of 500μJ is achieved under incident pump power of 39 W.The emitting spectra are checked at 5 and 10 kHz,and no obvious nonlinear effects are observed in the spectrum of the amplified laser.The beam quality factor is M^(2)=2.1±0.03 measured by the traveling knife-edge method,and the laser beam spot is also monitored by an infrared vidicon camera.展开更多
To obtain a stable amplified spontaneous emission（ASE） source for complex environment applications, we design an ASE source and study the output power and spectral characteristics under different ambient temperature...To obtain a stable amplified spontaneous emission（ASE） source for complex environment applications, we design an ASE source and study the output power and spectral characteristics under different ambient temperatures.We optimize the structure of the ASE source to flatten the ASE spectrum, and study the output characteristics in terms of output power and optical spectrum under different pump powers. Then the performance of the ASE source is investigated in the temperature range from-18.9°C to 50°C. A stable-power and flat-spectrum ASE source can be obtained by structural optimization and pump control.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
Restriction site amplified polymorphism (RSAP) was used, for the first time, to analyze the genetic structure and diversity of four, mainly cultivated, varieties of the brown alga, Saccharina japonica. Eighty-eight sa...Restriction site amplified polymorphism (RSAP) was used, for the first time, to analyze the genetic structure and diversity of four, mainly cultivated, varieties of the brown alga, Saccharina japonica. Eighty-eight samples from varieties "Rongfu", "Fujian", "Ailunwan" and "Shengchanzhong" were used for the genetic analyses. One hundred and ninety-eight bands were obtained using eight combinations of primers. One hundred and ninety-one (96.46%) were polymorphic bands. Nei's genetic diversity was 0.360, and the coefficient of genetic differentiation was 0.357. No inbreeding-type recession was found in the four brown alga varieties and the results of the "Ailunwan" variety using samples from 2 years showed that the variety was becoming less diverse during the selection inherent in the breeding program. Genetic diversity and cluster analyses results were consistent with these genetic relationships. The results show the RSAP method is suitable for genetic analysis. Continuous inbreeding and selection could reduce the genetic diversity effectively; therefore periodical supervision is required.展开更多
The purpose of the present study was to examine the genetic variation in Salamandra infraimmaculata from different breeding site habitats using the Amplified Fragment Length Polymorphism (AFLP) method. The results of ...The purpose of the present study was to examine the genetic variation in Salamandra infraimmaculata from different breeding site habitats using the Amplified Fragment Length Polymorphism (AFLP) method. The results of the dendogram from a hierarchical cluster analysis show that the grouping of S. infraimmaculata as cluster 5 differs from all the other clusters, including the St1 (Tel-Dan stream) population, which was the most predictable. Five Haplogroups (Hg) were characterized. The mean number of alleles per locus in each population (Ne) ranged from 10.566 (Sp1) to 2.720 (Po6). An average estimated heterozygosity (He) by population ranged from 0.100 (Po6) to 0.186 (St1). Population St1, a permanent breeding site where water was available all year round, exhibited the highest level of polymorphism, while population Po6, from the ephemeral breeding site, exhibited the lowest level of polymorphism. Gene flow between clusters showed that clusters 3 and 4 are sources of migrants and also receive gene flow, while clusters 1 and 2 may be a source of migrants but may not receive much gene flow. A phylogenetic analysis, based on clustering using Nei’s genetic distance, demonstrated that the Tel-Dan population is located on a separate branch within its sub-population. The conclusion of the present study shows that the genetic divergence among isolated populations is not correlated to distance but is affected by the variation of habitats.展开更多
The transition of a plant from vegetative to reproductive stage is controlled by a large group of genes, which respond to environmental and endogenous stimuli. Application of methyl jasmonate （MeJA） and gibberellins...The transition of a plant from vegetative to reproductive stage is controlled by a large group of genes, which respond to environmental and endogenous stimuli. Application of methyl jasmonate （MeJA） and gibberellins （GA3） to oilseed plants （Brassica napus L.） interrupts the delicate endogenous balance and results in various floral organ abnormalities. Exogenous MeJA or GA3 influences the transcriptome at the initial fiowenng stage in Arabidopsis, but the corresponding changes of transcriptome in floral tissues of oilseed rape remain unknown. In this study, cDNA-amplified fragment length polymorphism （cDNA-AFLP） was analyzed to identify genes whose expression was modulated by application of MeJA and GA3 to flower buds. A total of 2 787 cDNA fragments were counted using 64 primer pair combinations, and bands larger than 50 bp were compared among four treatments, namely, water control, MeJA （50 μmol L-1）, MeJA （100 μmol L-1）, and GA3 （50 μmol L-1）. Overall, 168 transcript-derived fragments （TDFs） were differentially expressed among the treatments. The expression pattern of some TDFs was confirmed by semi-quantitative RT-PCR analysis, and a group of 106 differentially displayed TDFs was cloned and sequenced. Homologs of Arabidopsis genes were identified and classified into 12 functional categories. A total of 34, 39, and 24 TDFs were responsive to GA3, MeJA, and both GA3 and MeJA, respectively. This finding indicated that cross-talk between these two hormones may be involved in regulating flower development. This study provides potential target genes for manipulation in terms of flowering time and floral organ initiation, important agronomic traits of oilseed rape.展开更多
文摘Twenty-three isolates of soft rot bacteria from konjac corms were examined for their diversity using 16S rDNAs and AFLP technology. Both methods clustered two groups, dependent on their biotype characterization of Pectobacterium carotovora subsp. carotovora (P.c.c) and Pectobacterium chrysanthemi (P.ch), respectively. Of all isolates, 17 (73.9%) belonged to P. ch, indicated as the main pathogenic bacteria of konjac producing areas in China. The genetic variation among isolates from the same biotype was also rich, not consistent with the distances of the geographic sources.
文摘Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.However,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely revealed.Herein,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room temperature.Photoluminescence(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE properties.And their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence method.The stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) NCs.With large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon excitations.These results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers.
文摘扩增片断长度多态性（Amplified fragment lengthpolymorphism，AFLP）标记技术是一种新的DNA指纹技术主要用于检测DNA多态性。AFLP技术是根据基因组DNA水平的差异进行检测，不受组织和器官、发育阶段、生理条件等诸多因素影响，因此在水产动物中应用AFLP技术具有广阔的前景，可作为水产动物种质鉴定、亲缘关系及种质分类研究的理想标记。
文摘本刊讯：扩增片段长度多态性（Amplified Fragment Length Polymorphism，AFLP）技术，该技术是由Vos等1995年建立的一项分子标记技术，其基本原理是选择性扩增带有人工接头的DNA酶切片段。因不同个体的DNA的酶切片段存在差异，从而产生扩增片段的长度多态性。AFLP技术具有不需要预先知道被研究物种的基因组DNA序列信息，
文摘Genetic profiling of environmentally important organisms is very essential for easy identification of biodegrading bacteria. In the previous study, we have reported the perchlorate biodegrading bacteria and characterized them by biochemical analysis and 16 S sequencing. We have observed a very similar isolates of Arthrobacter (Actinobacteria) degrading 4.1 mM and 4.7 mM of ammonium perchlorate [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300390038003100390037003300340037000000 . In this study, we report PCR based DNA fingerprinting technique to generate the genomic signature of these closely related group of Arthrobacter species. This study also effectively generates unique genomic signature for each of these isolates that has potential for use in molecular monitoring as well as for tracking genomic variation and rearrangements.
文摘The genetic diversity of the populations for 14 wild green peafowls (Pavo muticus) and 18 captive green pea-fowls was investigated by using the technology of random amplified polymorphic DNA (RAPD). Totally 161 and 166 ampli-fied bands were obtained by using 23 arbitrary primers to amplify the genomic DNA of wild and captive green peafowls re-spectively. The results showed that the average relative genetic distance of the wild and captive green peafowls popula-tions was 0.0555 and 0.1355, respectively, and difference of the average relative genetic distances between the two popu-lations was 0.1635. The Shannon diversity index for the wild and captive green peafowl populations was 0.4348 and 1.0163, respectively, which means that there exists significant difference in genetic diversity between the two populations, and the genetic diversity of wild green peafowl was low. The two populations originated from two different families according to analysis by the UPGMA method. This research can provide the theoretical basis for supervising genealogies management of peafowl populations.
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.
基金supported by the National High Technology Research and Development Program of China(Grant No.2006AA100101)National Science and Technology Support Program of China(Grant No. 2006BAD01A01-5)+1 种基金Special Program for Rice Scientific Research,Ministry of Agriculture,China(Grant No. nyhyzx 07-001-006)Super Rice Breeding and Demonstration Program,Ministry of Agriculture,China and Jiangsu Agricultural Scientific Self-innovation Fund,China(Grant No.CX[07]603)
文摘The translucent endosperm trait in a japonica rice variety ＇Kantou 194＇ is controlled by a Wx-mq gene which is allelic to Wx locus by genetic analysis and allelic test. The amylose content analysis showed that an intermediate amylose content between those of glutinous and non-glutinous rice existed in endosperm of homozygous Wx-mq genotype. The slight changes of amylose content in different varieties and F1 grains with an identical Wx-mq genotype might be influenced by dissimilar genetic background. To identify the Wx-mq genotype simply and rapidly, a cleaved amplified polymorphic sequence （CAPS） marker was designed. The result from the molecular detection indicated that it could be used for marker-assisted selection for low amylose content varieties in rice breeding.
文摘Lablab purpureus (L.) Sweet is a multipurpose legume that combines use as human food and animal feed in addition to serving as a cover crop for soil conservation. In this work, molecular diversity in Lablab purpureus was assessed using amplified fragment length polymorphism markers on fifty Kenyan lablab accessions obtained from farmers’ fields and the Kenya National gene bank. One hundred and eighty polymorphic bands were revealed using fifteen selective primer pairs. The overall mean expected heterozygosity (He) for the five populations was 0.189. Estimates of components of molecular variance revealed that most of the genetic variation resided within populations (99%) and only 1% variance was among the populations, while Principal Coordinate Analysis showed an overlap between accessions from different geographic origins. The UPGMA cluster analysis generated from the distance matrix of the 50 assayed accessions, revealed low diversity among most of the accessions. The low diversity observed may be due to the narrow genetic base for breeding stocks, and extensive exchange of germplasm among smallholder farmers across the country. Results obtained from this study are discussed in light of the need to enhance the genetic management and improvement of this multipurpose crop species.
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 supported by the National Natural Science Foundation 0f China （Grant Nos 50472053 and 60307004）, National Century Elitist Table （Grant Nos 04-0821 and 04-0823） and Natural Science Foundation of Guangdong Province. （Grant Nos 04020036 and 2004A10602002）.Acknowledgments We are grateful to Mrs Zhang W N, Feng Z M, Chen H and Chen B Y for their technical assistance.
文摘This paper reports on the fabrication and characterization of a newly erbium-doped single-mode tellurite glass-fibre applicable for 1.5-μm optical amplifiers. A very broad erbium amplified spontaneous emission in the range 1450-1650 nm from erbium-doped single-mode tellurite glass-fibre is obtained upon excitation of a 980-nm laser diode. The effects of the length of glass-fibre and the pumping power of laser diode on the amplified spontaneous emission are discussed. The result indicates that the tellurite glass-fibre is a promising candidate for designing fibre-optic amplifiers and lasers.
文摘An effective PCR protocol for detecting the sequence related amplified polymorphism （SRAP） in rice was developed. One hundred and ten pairs of SRAP primers were used for segregation analysis in an F2 population derived from a cross between Shennong 606 and Lijiangxintuanheigu. Among the 110 primer pairs, 35 pairs generated 143 polymorphic bands with an average of 4.09 polymorphic bands per primer pair, and 24 pairs （16.78%） showed the genetic distortion （P〈0.05）. Of the 24 primer pairs, 12 pairs deviated toward the male parent Shennong 606 and 11 pairs toward the female parent Lijiangxintuanheigu, only one toward heterozygote. It was found that the segregation distortion might be caused by the joint gametic and zygotic effects.
基金the National Natural Science Foundation of China under Grant Nos 60878011 and 61078008the Program for New Century Excellent Talents in University under Grant No NCET-10-0067.
文摘We present an all-fiber 1.94μm nanosecond pulse laser in master oscillation-power amplifier configuration.A dual-FBGs gain-switched Tm^(3+)-doped fiber laser is built and is used as the seed laser.The output characteristics of the amplifier are studied at different pulse repetition rates,and the maximum output energy of 500μJ is achieved under incident pump power of 39 W.The emitting spectra are checked at 5 and 10 kHz,and no obvious nonlinear effects are observed in the spectrum of the amplified laser.The beam quality factor is M^(2)=2.1±0.03 measured by the traveling knife-edge method,and the laser beam spot is also monitored by an infrared vidicon camera.
基金Supported by the National Natural Science Foundation of China under Grant No 11504320
文摘To obtain a stable amplified spontaneous emission（ASE） source for complex environment applications, we design an ASE source and study the output power and spectral characteristics under different ambient temperatures.We optimize the structure of the ASE source to flatten the ASE spectrum, and study the output characteristics in terms of output power and optical spectrum under different pump powers. Then the performance of the ASE source is investigated in the temperature range from-18.9°C to 50°C. A stable-power and flat-spectrum ASE source can be obtained by structural optimization and pump control.
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.
基金Supported by the National Special Research Fund for Non-Profit Sector(No.200805075)the Shandong Foundation for Development of Scienceand Technology, China (No.2007GG10005018)+2 种基金the Genetically Modified Organism Technology Major Project (No.2009ZX08009-100B)the National High Technology Research and Development Program of China(863 Program) (Nos.2010AA10A401,2012AA10A406)the National Agricultural Transformation (No.2010GB23600666)
文摘Restriction site amplified polymorphism (RSAP) was used, for the first time, to analyze the genetic structure and diversity of four, mainly cultivated, varieties of the brown alga, Saccharina japonica. Eighty-eight samples from varieties "Rongfu", "Fujian", "Ailunwan" and "Shengchanzhong" were used for the genetic analyses. One hundred and ninety-eight bands were obtained using eight combinations of primers. One hundred and ninety-one (96.46%) were polymorphic bands. Nei's genetic diversity was 0.360, and the coefficient of genetic differentiation was 0.357. No inbreeding-type recession was found in the four brown alga varieties and the results of the "Ailunwan" variety using samples from 2 years showed that the variety was becoming less diverse during the selection inherent in the breeding program. Genetic diversity and cluster analyses results were consistent with these genetic relationships. The results show the RSAP method is suitable for genetic analysis. Continuous inbreeding and selection could reduce the genetic diversity effectively; therefore periodical supervision is required.
文摘The purpose of the present study was to examine the genetic variation in Salamandra infraimmaculata from different breeding site habitats using the Amplified Fragment Length Polymorphism (AFLP) method. The results of the dendogram from a hierarchical cluster analysis show that the grouping of S. infraimmaculata as cluster 5 differs from all the other clusters, including the St1 (Tel-Dan stream) population, which was the most predictable. Five Haplogroups (Hg) were characterized. The mean number of alleles per locus in each population (Ne) ranged from 10.566 (Sp1) to 2.720 (Po6). An average estimated heterozygosity (He) by population ranged from 0.100 (Po6) to 0.186 (St1). Population St1, a permanent breeding site where water was available all year round, exhibited the highest level of polymorphism, while population Po6, from the ephemeral breeding site, exhibited the lowest level of polymorphism. Gene flow between clusters showed that clusters 3 and 4 are sources of migrants and also receive gene flow, while clusters 1 and 2 may be a source of migrants but may not receive much gene flow. A phylogenetic analysis, based on clustering using Nei’s genetic distance, demonstrated that the Tel-Dan population is located on a separate branch within its sub-population. The conclusion of the present study shows that the genetic divergence among isolated populations is not correlated to distance but is affected by the variation of habitats.
基金sponsored by the National Basic Research Program of China(2015CB150205)the National Natural Science Foundation of China(31371542)the Jiangsu Collaborative Innovation Center for Modern Crop Production(JCIC-MCP),China
文摘The transition of a plant from vegetative to reproductive stage is controlled by a large group of genes, which respond to environmental and endogenous stimuli. Application of methyl jasmonate （MeJA） and gibberellins （GA3） to oilseed plants （Brassica napus L.） interrupts the delicate endogenous balance and results in various floral organ abnormalities. Exogenous MeJA or GA3 influences the transcriptome at the initial fiowenng stage in Arabidopsis, but the corresponding changes of transcriptome in floral tissues of oilseed rape remain unknown. In this study, cDNA-amplified fragment length polymorphism （cDNA-AFLP） was analyzed to identify genes whose expression was modulated by application of MeJA and GA3 to flower buds. A total of 2 787 cDNA fragments were counted using 64 primer pair combinations, and bands larger than 50 bp were compared among four treatments, namely, water control, MeJA （50 μmol L-1）, MeJA （100 μmol L-1）, and GA3 （50 μmol L-1）. Overall, 168 transcript-derived fragments （TDFs） were differentially expressed among the treatments. The expression pattern of some TDFs was confirmed by semi-quantitative RT-PCR analysis, and a group of 106 differentially displayed TDFs was cloned and sequenced. Homologs of Arabidopsis genes were identified and classified into 12 functional categories. A total of 34, 39, and 24 TDFs were responsive to GA3, MeJA, and both GA3 and MeJA, respectively. This finding indicated that cross-talk between these two hormones may be involved in regulating flower development. This study provides potential target genes for manipulation in terms of flowering time and floral organ initiation, important agronomic traits of oilseed rape.
