The chloroplast genes matK and rbcL, ribo- somal gene 18S and ITS regions of nuclear ribosomal DNA from Ephedra rhytidosperma, a species endemic to China, were sequenced and its phylogenetic position was investi- gate...The chloroplast genes matK and rbcL, ribo- somal gene 18S and ITS regions of nuclear ribosomal DNA from Ephedra rhytidosperma, a species endemic to China, were sequenced and its phylogenetic position was investi- gated. Independent and combined phylogenetic analyses for the DNA sequences from 16 taxa representing 15 species of the genus Ephedra were performed using the maximum par- simony (MP), neighbor-joining (NJ), minimum evolution (ME) and maximum likelihood (ML) methods. The results indicate that E. rhytidosperma is closely related to E. equiset- ina. The divergence time between them is estimated to be 10.85±2.44 Ma based on the results of the relative-rate tests and the evolutionary rate of rbcL gene.展开更多
A plant's adaptation to its environment is one of the most important issues in evolutionary biology. Mangroves are trees that inhabit the intertidal zones with high salinity, while salt tolerance competence of dif...A plant's adaptation to its environment is one of the most important issues in evolutionary biology. Mangroves are trees that inhabit the intertidal zones with high salinity, while salt tolerance competence of different species varies. Even congeneric species usually occupy distinct positions of intertidal zones due to differential ability of salt tolerance. Some species have different ecotypes that adapt well to littoral and terrestrial environments, respectively. These characteristics of mangroves make them ideal ecological models to study adaptation of mangroves to salinity. Here, we briefly depict adaptive traits of salt tolerance in mangroves with respect to anatomy, physiology and biochemistry, and review the major advances recently made on both the genetic and genomic levels. Results from studies on individual genes or whole genomes of mangroves have confirmed conclusions drawn from studies on anatomy, physiology and biochemistry, and have further indicated that specific patterns of gene ex-pression might contribute to adaptive evolution of mangroves under high salinity. By integrating all information from mangroves and performing comparisons among species of mangroves and non-mangroves, we could give a general picture of adaptation of mangroves to salinity, thus providing a new avenue for further studies on a molecular basis of adaptive evolution of mangroves.展开更多
基金supported by the Chinese National Key Project for Basic Research(“973"”)(2003CB715904)the National Natural Science Foundation of China(Grant Nos.30230030&30370105).
文摘The chloroplast genes matK and rbcL, ribo- somal gene 18S and ITS regions of nuclear ribosomal DNA from Ephedra rhytidosperma, a species endemic to China, were sequenced and its phylogenetic position was investi- gated. Independent and combined phylogenetic analyses for the DNA sequences from 16 taxa representing 15 species of the genus Ephedra were performed using the maximum par- simony (MP), neighbor-joining (NJ), minimum evolution (ME) and maximum likelihood (ML) methods. The results indicate that E. rhytidosperma is closely related to E. equiset- ina. The divergence time between them is estimated to be 10.85±2.44 Ma based on the results of the relative-rate tests and the evolutionary rate of rbcL gene.
基金the National Natural Science Foundation of China (Grant Nos. 30730008, 30470119, and 30500049)
文摘A plant's adaptation to its environment is one of the most important issues in evolutionary biology. Mangroves are trees that inhabit the intertidal zones with high salinity, while salt tolerance competence of different species varies. Even congeneric species usually occupy distinct positions of intertidal zones due to differential ability of salt tolerance. Some species have different ecotypes that adapt well to littoral and terrestrial environments, respectively. These characteristics of mangroves make them ideal ecological models to study adaptation of mangroves to salinity. Here, we briefly depict adaptive traits of salt tolerance in mangroves with respect to anatomy, physiology and biochemistry, and review the major advances recently made on both the genetic and genomic levels. Results from studies on individual genes or whole genomes of mangroves have confirmed conclusions drawn from studies on anatomy, physiology and biochemistry, and have further indicated that specific patterns of gene ex-pression might contribute to adaptive evolution of mangroves under high salinity. By integrating all information from mangroves and performing comparisons among species of mangroves and non-mangroves, we could give a general picture of adaptation of mangroves to salinity, thus providing a new avenue for further studies on a molecular basis of adaptive evolution of mangroves.
