The research history and new discoveries of the specific characteristics of Yulania Spach were reported, as to the specific characteristics, such as the terminal , axillary and fascicled similar flower buds,sometimes ...The research history and new discoveries of the specific characteristics of Yulania Spach were reported, as to the specific characteristics, such as the terminal , axillary and fascicled similar flower buds,sometimes polycymes; 2-4 flower types of a plant; two spathe-like stipoles of single flower; drape or overlap of tepals, deep split or shallow split on the edge of tepals. The discoveries could provide valuable information for the further studies on the taxonomic system, anthotaxical evolution, phylogenetic relationship and breeding.展开更多
Diacylglycerol acyltransferase （DGAT） is the key enzyme that catalyzes the triacylglycerol biosynthesis. The comparative analysis was performed on the DGAT1 genes of cotton and other model plants. Sequence analysis ...Diacylglycerol acyltransferase （DGAT） is the key enzyme that catalyzes the triacylglycerol biosynthesis. The comparative analysis was performed on the DGAT1 genes of cotton and other model plants. Sequence analysis showed that most of the DGAT1 genes,with high variation of intron length and high conservation of intron phrase,from the cotton and other model plants had 16 exons. Additionally, 7 conserved motifs were present in these DGAT1 proteins. The core motifs were overlapped with the functional domain of DGAT1 protein. Phylogenetic analysis demonstrated that gene tree was highly consistent to species tree,suggesting that the evolutionary history of species was revealed by gene tree. There was single copy of DGAT1 gene in cotton,but at least two duplicated DGAT1 genes were iden- tified in rice,maize,poplar and moss genomes. The selective pressure analysis showed that the PtDGATla/PtDGATlb was under positive selection,but other four pairs of homologous genes were under negative selection. 17 positively selected sites were identified at subgroup level （P〉0.05）,suggesting these subgroups under relaxed functional constraint. The findings provide a basis for further studying func- tion and evolution of DGAT1 genes in cotton and other model plants.展开更多
Inflorescences structures in context of their evolution have been conducted for 60 genera and 170 species of Celastrales （according to APG （Angiosperm Phylogeny Group） III 2009, almost 60% of genera and 15% of spec...Inflorescences structures in context of their evolution have been conducted for 60 genera and 170 species of Celastrales （according to APG （Angiosperm Phylogeny Group） III 2009, almost 60% of genera and 15% of species from this taxon of the world flora）. There are two big groups of inflorescences in Celastrales-intercalary （more often） and terminal. For many genera of Celastrales both types of inflorescences can be observed, although the frequency of their occurrence varies. There is an important difference between two types of inflorescences： character of completion of the main axis （the terminal flower present or absent）. Flower opening can be in basipetal （Celastraceae, Brexia） or acropetal （Stackhousiaceae） order. Partial inflorescence types included： simple, compound or umbrellate dichasia, spike, raceme, thyrse. Simple flowers of Parnassia are large, nested on long reproductive shoots, emerging from a rosette, with amplexicaule leaf.展开更多
基金Supported by Project of Doctor Fund of Henan University of Technology(2006BS015)~~
文摘The research history and new discoveries of the specific characteristics of Yulania Spach were reported, as to the specific characteristics, such as the terminal , axillary and fascicled similar flower buds,sometimes polycymes; 2-4 flower types of a plant; two spathe-like stipoles of single flower; drape or overlap of tepals, deep split or shallow split on the edge of tepals. The discoveries could provide valuable information for the further studies on the taxonomic system, anthotaxical evolution, phylogenetic relationship and breeding.
基金Supported by Youth Science Research Fund of Zhoukou Normal University in 2005(zknu B315213)
文摘Diacylglycerol acyltransferase （DGAT） is the key enzyme that catalyzes the triacylglycerol biosynthesis. The comparative analysis was performed on the DGAT1 genes of cotton and other model plants. Sequence analysis showed that most of the DGAT1 genes,with high variation of intron length and high conservation of intron phrase,from the cotton and other model plants had 16 exons. Additionally, 7 conserved motifs were present in these DGAT1 proteins. The core motifs were overlapped with the functional domain of DGAT1 protein. Phylogenetic analysis demonstrated that gene tree was highly consistent to species tree,suggesting that the evolutionary history of species was revealed by gene tree. There was single copy of DGAT1 gene in cotton,but at least two duplicated DGAT1 genes were iden- tified in rice,maize,poplar and moss genomes. The selective pressure analysis showed that the PtDGATla/PtDGATlb was under positive selection,but other four pairs of homologous genes were under negative selection. 17 positively selected sites were identified at subgroup level （P〉0.05）,suggesting these subgroups under relaxed functional constraint. The findings provide a basis for further studying func- tion and evolution of DGAT1 genes in cotton and other model plants.
文摘Inflorescences structures in context of their evolution have been conducted for 60 genera and 170 species of Celastrales （according to APG （Angiosperm Phylogeny Group） III 2009, almost 60% of genera and 15% of species from this taxon of the world flora）. There are two big groups of inflorescences in Celastrales-intercalary （more often） and terminal. For many genera of Celastrales both types of inflorescences can be observed, although the frequency of their occurrence varies. There is an important difference between two types of inflorescences： character of completion of the main axis （the terminal flower present or absent）. Flower opening can be in basipetal （Celastraceae, Brexia） or acropetal （Stackhousiaceae） order. Partial inflorescence types included： simple, compound or umbrellate dichasia, spike, raceme, thyrse. Simple flowers of Parnassia are large, nested on long reproductive shoots, emerging from a rosette, with amplexicaule leaf.
