974 resultados para Camellia sinensis Teses
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PCRDNA,(Acipenser sinensis)DNA(mtDNA)(D-loop),,,(Psephurus gladius)(A. dabryanus)(A. schrenckii)
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Random amplified polymorphic DNA (RAPD) markers are used to investigate genetic variation and evolutionary relationships of 29 samples of Cordyceps sinensis from different geographical populations on the Qinghai-Tibet plateau. Out of 137 RAPD bands scored, 100 are polymorphic. A correlation is revealed between geographical distance and genetic distance. The molecular phylogenetic tree suggests that the 29 samples are divided into three notable clusters, corresponding to the geographical populations, i.e., the north population (NP), middle population (MP), and south population (SP). The NP consists of 7 northern samples from Menyuan, Maqu, and Luqu, the MP consists of 8 samples from Yushu and Chengduo, and the SP consists of 14 samples from Byma Snow Mountain, Renzhi Snow Moutain, Chongcaoxiwa, and Dacaodi. It is demonstrated that extensive genetic diversity is found among different geographical populations of C. sinensis. The genetic diversity pattern of C. sinensis may be caused by the founder effects. The taxonomic status of NP, MP, and SP populations should be that they are different subspecies rather than different species.
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The anadromous Chinese sturgeon (Acipenser sinensis), mainly endemic to the Yangtze River in China, is an endangered fish species. The natural population has declined since the Gezhouba Dam blocked its migratory route to the spawning grounds in 1981. In the near future, the completion of the Three Gorges Dam, the world's largest hydroelectric project, may further impact this species by altering the water flow of the Yangtze River. Little is currently known about the population genetic structure of the Chinese sturgeon. In this study, DNA sequence data were determined from the control region (D-loop) of the mitochondrial genome of adult sturgeons (n = 106) that were collected between 1995-2000. The molecular data were used to investigate genetic variation, effective female population size and population history of the Chinese sturgeon in the Yangtze River. Our results indicate that the reduction in abundance did not change genetic variation of the Chinese sturgeon, and that the population underwent an expansion in the past. AMOVA analysis indicated that 98.7% of the genetic variability occurred within each year's spawning populations, the year of collection had little influence on the diversity of annual temporary samples. The relative large effective female population size (N-ef) indicates that good potential exists for the recovery of this species in the future. Strikingly, the ratio of N-ef to the census female population size (N-f) is unusually high (0.77-0.93). This may be the result of a current bottleneck in the population of the Chinese sturgeon that is likely caused by human intervention.
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The phylogenetic position of Diplura within Hexapoda has been controversial. There are three major lineages in Diplura: Campodeoidea, Projapygoidea, and Japygoidea. However, most of the previous studies were restricted to Campodeoidea and Japygoidea. Unti
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Fourteen new lignans, tiegusanins A-N (1-14), together with 13 known compounds were isolated from the aerial parts of Schisandra propinqua var. sinensis. The structures and absolute configurations of 1-13 were established using a combination of spectrosco
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PCR DNA , ( Acipensersinensis) DNA( mt DNA) ( D- loop) , . , , ( Psephurus gladius) ( A.dabryanus) ( A.schrenckii) .
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PCRAcipensersinensisDNAmtDNADloopmtDNADNAmtDNArylooptRANpro82bpmtDNA57.4426mtDNA2345
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The numbers of spawning sites for Chinese sturgeon have been drastically reduced since the construction of the Gezhouba Dam across the Yangtze River. This dam has blocked migration of Chinese sturgeon to their historic spawning ground causing a significant decline of the Chinese sturgeon population. We conducted a VORTEX population viability analysis to estimate the sustainability of the population and to quantify the efficiency of current and alternative conservation procedures. The model predicted the observed decline of Chinese sturgeon, resulting from the effect of the Gezhouba Dam. These simulations demonstrated the potential interest of two conservation measures: increasing spawning area and reducing predation on sturgeon eggs. The simulations also demonstrated that the actual restocking program is not sufficient to sustain sturgeon population as the artificial reproduction program induce the loss of more wild mature adults that the recruitment expected by the artificial reproduction.
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Crocodilians are quite vocal relative to other reptile groups, and the alligators are among the most vocal of the crocodilians. The Chinese alligator, Alligator sinensis, is usually solitary but engages in bellowing choruses in certain waters during the mating season. This paper reports the organization of Chinese alligator's bellowing choruses based upon field observations and playback experiments. Alligators of both genders engaged in the choruses, remaining immobile throughout and inclining toward bellowing synchronously (i.e., starting and finishing at about the same time). The choruses lasted about 10 min with abrupt onset and offset. Moreover, playback experiments revealed that both male and female alligators responded equally to bellowing stimuli from the same and opposite sexes and that none of the tested alligators approached the loudspeaker in spite of playback of male or female stimuli. These suggest that Chinese alligators. may not bellow to compete for or attract mates during the choruses. Instead, when their ecological behaviors, namely, dispersed inhabitation, multi-copulation, restricted mating season, etc., are considered, we hypothesize that they may synchronize bellows to enhance group detectability for assembling individuals into certain waters for subsequent copulations. (C) 2009 Acoustical Society of America. [DOI: 10.1121/1.3203667]
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The immunoglobulin (Ig) joining (J) chain plays an important role in the formation of polymeric Igs and their transport into secretions. In the present study, the cDNA sequence of J chain has been cloned from the Chinese soft-shelled turtle (Pelodiscus sinensis) by reverse transcription (RT)-PCR and rapid amplification of cDNA ends (RACE). The cDNA sequence is 2347 bp in length and contains an open reading frame of 480 bp encoding 160 aa including the signal sequence. The deduced amino acid sequence has a high degree of homology with that of an already reported turtle J chain (80.7%), and of chicken (71.3%). By using real-time quantitative RT-PCR analysis, a significant up-regulation of J-chain transcripts was observed in spleen, kidney and blood of turtles injected with inactivated Aeromonas hydrophila, indicating the immune role of J chain in response to bacterial infection. (C) 2009 Elsevier B.V. All rights reserved.
