To investigate chromosome differentiation of genome A and B between common wheat and wild emmer wheat (Triticum turgidum var. dicoccoides (Koern.) Bowden), the authors conducted a RFLP analysis of the two species usin...To investigate chromosome differentiation of genome A and B between common wheat and wild emmer wheat (Triticum turgidum var. dicoccoides (Koern.) Bowden), the authors conducted a RFLP analysis of the two species using 153 genomic, cDNA and chromosome_specific probes. 75.8% of the probes had detected hybridization polymorphism in at least one of the five restriction enzymes. However, the polymorphic probes were unevenly distributed among different homoeologous groups, between different genomes and in different regions of a single chromosome. Homoeologous group 1 possessed the highest level of polymorphism (96.2%), followed by group 6 and 2 (84.6% and 82.1% respectively). In contrast, only 60%-67% of probes of the other four groups was polymorphic. In most groups the number of probes capable of detecting B chromosome polymorphism was slightly higher than that revealing A chromosome difference (totally 51.8% vs 43.1%). In a single chromosome, RFLP was predominant in the distal region (65.1%) and showed a decreasing trend from the proximal (46.2%) to the pericentric (42.4%) regions. The results suggest that there exists a substantial amount of DNA polymorphism between the A and B chromosomes of common wheat and those of wild emmer wheat, indicating that a considerable degree of genetic differentiation has taken place in the A and B genoms of two species during evolution from wild emmer to common wheat. The extent of the genetic differentiation may vary among different homoeologous groups, between A and B chromosomes and in different regions of individual chromosome.展开更多
[Objective]To study the effects of homologous chromosomes 7 （7A,7B and 7D） on wheat photosynthesis and provide theoretical basis for breeding high photosynthetic efficiency wheat by genetic,physiological and biochem...[Objective]To study the effects of homologous chromosomes 7 （7A,7B and 7D） on wheat photosynthesis and provide theoretical basis for breeding high photosynthetic efficiency wheat by genetic,physiological and biochemical means. [Method]The Triticum asetivum cultivar Chinese Spring wheat and nullisomic wheat （N7A,N7B and N7D） were planted in greenhouse. The photosynthetic indexes were determined at early filling stage. [Result]The photosynthetic rate （Pn）,stomatal conductance （Gs）,primary photochemical efficiency （Fv/Fm）,actual chemical efficiency of photosystem II （ФPS II） and apparent electron transfer rate of photosystem II （ETR） were significantly lower in the N7A and N7B than in the Chinese Spring （P0.05）. The photosynthetic rate and stomatal conductance was significantly lower in the N7D than in the Chinese Spring （P0.05）. The Fv/Fm,ФPS II,ETR of N7D were higher than that of the Chinese Spring without significant difference. [Conclusion]The homologous chromosomes 7A and 7B have positive effects on photosynthetic rate and have relationship with stomatal conductance and photoreaction （chlorophyll fluorescence parameters）. The homologous chromosome 7D has negative effects on photosynthetic rate,which is mainly related to stomatal conductance rather than photoreaction.展开更多
Karyotype of 3 species of the genus Orius Wolff were firstly studied using the Giemsa staining and squashing slides method in male germ cell. It is reported that number of chromosome and system of sex chromosome of ha...Karyotype of 3 species of the genus Orius Wolff were firstly studied using the Giemsa staining and squashing slides method in male germ cell. It is reported that number of chromosome and system of sex chromosome of haploid chromosome complement of these species is n=11A＋X （Y） in the first meiotic stage. However, the behavior of chromosomes among the species are different distinctly, thus cytotaxonomic character can be adopted to the identification among the three species.展开更多
A small town is ＂the end of a city＂, but ＂the start of countryside＂. It is a main point of urban-rural dual structure and an intermediate from countryside to city. Therefore, it is key for the issue concerning ＂a...A small town is ＂the end of a city＂, but ＂the start of countryside＂. It is a main point of urban-rural dual structure and an intermediate from countryside to city. Therefore, it is key for the issue concerning ＂agriculture, countryside and farmers＂. In the research, the definition of small towns, the connotation and features of characteristic economy were discussed and the importance of small town characteristic economy and the approaches were proposed.展开更多
The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops ...The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops variabilis Eig. (or rye), a significant increase in the chiasmata of homoeologous pairing was shown by the phKL+Ph2(-) plants with respect to their phKL+Ph2 sibs, which indicates that Ph2-deficiency and phKL showed an additive effect on promoting pairing. The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents, of which, reduction of univalents was mainly due to the increment of rod bivalents. The combined lines are probably more desirable materials for alien gene transferring than phKL or Ph2(-) lines alone. In comparison with that of ph1b X Ae. variabilis (or rye), phKL+Ph2(-) X Ae. variabilis (or rye) show higher (or similar) numbers of rod bivalents, while the total chromosome pairing level significantly reduced that ascribed to the decrement in ring bivalents and multivalents. These results probably indicate the different genetic mechanisms for Ph1 and Ph2 or phKL on controlling homoeologous pairing.展开更多
文摘To investigate chromosome differentiation of genome A and B between common wheat and wild emmer wheat (Triticum turgidum var. dicoccoides (Koern.) Bowden), the authors conducted a RFLP analysis of the two species using 153 genomic, cDNA and chromosome_specific probes. 75.8% of the probes had detected hybridization polymorphism in at least one of the five restriction enzymes. However, the polymorphic probes were unevenly distributed among different homoeologous groups, between different genomes and in different regions of a single chromosome. Homoeologous group 1 possessed the highest level of polymorphism (96.2%), followed by group 6 and 2 (84.6% and 82.1% respectively). In contrast, only 60%-67% of probes of the other four groups was polymorphic. In most groups the number of probes capable of detecting B chromosome polymorphism was slightly higher than that revealing A chromosome difference (totally 51.8% vs 43.1%). In a single chromosome, RFLP was predominant in the distal region (65.1%) and showed a decreasing trend from the proximal (46.2%) to the pericentric (42.4%) regions. The results suggest that there exists a substantial amount of DNA polymorphism between the A and B chromosomes of common wheat and those of wild emmer wheat, indicating that a considerable degree of genetic differentiation has taken place in the A and B genoms of two species during evolution from wild emmer to common wheat. The extent of the genetic differentiation may vary among different homoeologous groups, between A and B chromosomes and in different regions of individual chromosome.
基金Supported by Excellent Young Academic Leaders Project of Shanxi Province~~
文摘[Objective]To study the effects of homologous chromosomes 7 （7A,7B and 7D） on wheat photosynthesis and provide theoretical basis for breeding high photosynthetic efficiency wheat by genetic,physiological and biochemical means. [Method]The Triticum asetivum cultivar Chinese Spring wheat and nullisomic wheat （N7A,N7B and N7D） were planted in greenhouse. The photosynthetic indexes were determined at early filling stage. [Result]The photosynthetic rate （Pn）,stomatal conductance （Gs）,primary photochemical efficiency （Fv/Fm）,actual chemical efficiency of photosystem II （ФPS II） and apparent electron transfer rate of photosystem II （ETR） were significantly lower in the N7A and N7B than in the Chinese Spring （P0.05）. The photosynthetic rate and stomatal conductance was significantly lower in the N7D than in the Chinese Spring （P0.05）. The Fv/Fm,ФPS II,ETR of N7D were higher than that of the Chinese Spring without significant difference. [Conclusion]The homologous chromosomes 7A and 7B have positive effects on photosynthetic rate and have relationship with stomatal conductance and photoreaction （chlorophyll fluorescence parameters）. The homologous chromosome 7D has negative effects on photosynthetic rate,which is mainly related to stomatal conductance rather than photoreaction.
基金The work was supported by Zhejiang Forestry College Science Foundation
文摘Karyotype of 3 species of the genus Orius Wolff were firstly studied using the Giemsa staining and squashing slides method in male germ cell. It is reported that number of chromosome and system of sex chromosome of haploid chromosome complement of these species is n=11A＋X （Y） in the first meiotic stage. However, the behavior of chromosomes among the species are different distinctly, thus cytotaxonomic character can be adopted to the identification among the three species.
基金Supported by Research Program of Humanities and Social Sciences of Hubei Provincial Department of Education[2011jyte269]~~
文摘A small town is ＂the end of a city＂, but ＂the start of countryside＂. It is a main point of urban-rural dual structure and an intermediate from countryside to city. Therefore, it is key for the issue concerning ＂agriculture, countryside and farmers＂. In the research, the definition of small towns, the connotation and features of characteristic economy were discussed and the importance of small town characteristic economy and the approaches were proposed.
文摘The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops variabilis Eig. (or rye), a significant increase in the chiasmata of homoeologous pairing was shown by the phKL+Ph2(-) plants with respect to their phKL+Ph2 sibs, which indicates that Ph2-deficiency and phKL showed an additive effect on promoting pairing. The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents, of which, reduction of univalents was mainly due to the increment of rod bivalents. The combined lines are probably more desirable materials for alien gene transferring than phKL or Ph2(-) lines alone. In comparison with that of ph1b X Ae. variabilis (or rye), phKL+Ph2(-) X Ae. variabilis (or rye) show higher (or similar) numbers of rod bivalents, while the total chromosome pairing level significantly reduced that ascribed to the decrement in ring bivalents and multivalents. These results probably indicate the different genetic mechanisms for Ph1 and Ph2 or phKL on controlling homoeologous pairing.
