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排序方式: 共有86条查询结果,搜索用时 156 毫秒
21.
桃儿七光合生理特性的地理差异研究 总被引:7,自引:3,他引:4
对中国由南向北5个种源地桃儿七(Sinopodophyllum hexandrum)的光合生理生态特性进行了研究.结果表明:(1)北部宁夏六盘山地区植株的光饱和点(LSP)和光补偿点(LCP)最高,表观光量子效率(AQY)、瞬时光能利用效率(ILUE)和最大光合速率(Pmax)最低,光合能力最差;最南部云南纳帕海植株的LSP和LCP很低,但因其AQY和ILUE最高,故其Pmax最大,强光下的光合能力最高.(2)最南部云南纳帕海和最北部甘肃兴隆山个体的羧化效率(CE)最高,且CO2补偿点(CCP)较低,因此CO2利用率较高;而较南部四川刷经寺个体的CE最低,且CCP最高,故CO2利用效率最低.(3)各种源植株叶片的叶绿素总量及叶绿素a含量无显著差异,而不同地区个体的Chla/Chlb值差异显著,最北部甘肃兴隆山植株的Chla/Chlb值最大,而南部四川刷经寺的Chla/Chlb值最小.(4)各种源地植株的水分利用效率(WUE)和蒸腾速率(Tr)对光量子通量密度(PFD)与CO2浓度的响应过程也表现出显著的地理分异.总的来看,桃儿七是一种喜光但又较耐阴植物,但不同分布区桃儿七的光合生理生态特征已经出现了较显著的地理分化. 相似文献
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卤虫染色体倍性组成的研究 总被引:8,自引:1,他引:8
本文报道了我国4个地理品系卤虫的染色体倍性组成及卵径分布,分析了卤虫染色体的非整倍性,讨论了卤虫种的分布。 天津卤虫有2倍体(2n=42),占33.3%和5倍体,占16.2%;染色体数的波动为21—108;卵径为262±17μm。 海南卤虫有2倍体(2n=42),占8%;4倍体,占17.7%;5倍体,占18.3%;染色体数的波动为16—111;卵径为285±15μm。 新疆卤虫有2倍体(2n=42),占39.2%;染色体数的波动为17—106;卵径为269±15μm。 山西卤虫有2倍体(2n=42),占45.1%,染色体数的波动为17—84;卵径为234±13μm。 相似文献
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A G Basnak'ian L Z Topol' I D Kirsanova I I Votrin F L Kiselev 《Molekuliarnaia biologiia》1989,23(3):750-757
Activities of nuclear endonucleases and topoisomerase I were measured in rat fibroblasts which were at the stages of tumor transformation: control embryonal fibroblasts--CEF; cells immortalised by transfection of S1A segment of SA7 adenovirus--REF-1; intermedius cells transfected once by EJras oncogene--REF-1EJ; and cells transformed after the second transfection by the same oncogene--REF-2EJ. The topoisomerase I and Ca2+, Mg2+-dependent endonuclease was most decreased at the stage of immortalised cells, and the intermedius stage (REF-1EJ) was characterized by the lower activity of Ca2+, Mg2+-dependent endonuclease. The highest activity of Mn2+-dependent endonuclease is seen in REF-2EJ cells. In model experiments the ability of Ca2+, Mg2+-dependent endonuclease to split non-stochastically the EJras oncogene inserted into pBR322 plasmid was shown. The role of the investigated enzymes in the restriction of plasmid integration, cellular immortalisation and recombination of plasmids with chromosomes during cell transformation is discussed. 相似文献
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The modification of Prescott's (Prescott et al., 1972) method of enucleation in vitro was described. A special teflon chamber faciliatating the enucleation of monolayer cultured cells to produce cytoplasts and karyoplasts was constructed. Mouse L-cells were enucleated by exposing to cytochalasine B (10 gamma/ml) followed by centrifugation. The fraction of cells enucleated in the chamber was about 98%. The life time of cytoplasts in cultural medium after their enucleation was 48 hours (sometimes 56-72 hours) as tested by vital neutral red staining. The cytoplasts that survived were shown to accumulate large lysosomes, and the evidence of appearing ring-like fibrillar structures was provided using a simple technique of cytoskeleton observation under light microscope. 相似文献
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LÚCIA J. ROSADA CLAUDINÉIA C. S. FRANCO JULIANE R. SANT'ANNA EDILSON N. KANESHIMA MARIA CELESTE GONÇALVES‐VIDIGAL MARIALBA A. A. CASTRO‐PRADO 《The Journal of eukaryotic microbiology》2010,57(4):383-384
ABSTRACT. Heterokaryosis is the initial step of the parasexual cycle, a process that provides genetic variability in filamentous fungi through the production of heterozygous diploid nuclei. To characterize the parasexual cycle in Colletotrichum lindemuthianum, we evaluated the presence of heterokaryosis, vegetative compatibility reactions, and diploid formation among isolates of Race 65 collected from different Brazilian states. Vegetative compatibility groups were identified among the isolates according to their ability to form heterokaryons. Two heterozygous diploids were selected from compatible heterokaryons, which were characterized by the segregation of the parental auxotrophic markers and by RAPD profiles. 相似文献
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Ramadan B Sopi Syed IA Zaidi Mitko Mladenov Hazbije Sahiti Zahide Istrefi Icko Gjorgoski Azem Laj?i Muharrem Jakupaj 《Respiratory research》2012,13(1):68