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21.
1 属的起源根据地质历史资料和形态、生态综合分析 ,我们认为在第三纪早期 ,泡桐属中还只有一种 ,到第三纪中新世时 ,才分化成华东泡桐 ( Paulownia kawakamii)和毛泡桐 ( P.tomentosa)两个种。在第三纪地层中 ,毛泡桐叶的化石在我国山东、法国、捷克和北美都有发现 ,特别是同一时期在日本歧阜县发现类似华东泡桐直径 1 55cm的矽化树干 ,这样的大树 ,在现存的华东泡桐中是从未见过的 ,这说明在当时的环境下 ,华东泡桐是适应生长的。另外 ,在形态上两种泡桐均为树形较小、叶宽有角、叶缘有锯齿、宽大圆锥花序、深裂的花萼、较小的果实和种… 相似文献
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Glacial survival and local adaptation in an alpine leaf beetle 总被引:1,自引:0,他引:1
The challenge in defining conservation units so that they represent evolutionary entities has been to combine both genetic properties and ecological significance. Here we make use of the complexity of the European Alps, with their genetic landscape shaped by geographical barriers and postglacial colonization, to examine the correlation between ecological and genetic divergence. Montane species, because of the fragmentation of their present habitat, constitute extreme cases in which to test if genetically distinct subgroups based on neutral markers are also ecologically differentiated and show local adaptation. In the leaf beetle Oreina elongata, populations show variation in host plant use and a patchy distribution throughout the Alps and Apennines. We demonstrate that despite very strong genetic isolation (F(ST) = 0.381), variation in host plant use has led to differences in larval life-history traits between populations only as a secondary effect of host defence chemistry, and not through physiological adaptation to plant nutritional value. We also establish that populations that are more ecologically different in terms of larval performance are also more genetically divergent. In addition, morphological variation used to define subspecies appears to be mirrored in the population genetics of this species, resulting in almost perfect clustering based on microsatellite data. Finally, we argue from their strong genetic structure and congruent distribution that the subspecies of O. elongata were divided among the same glacial refugia within the Alps that have been proposed for alpine plants. 相似文献
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根据采自贵州剑河辣子寨杷榔组的张氏虫Changaspis 296块标本,采用传统形态测量方法,对头部及躯干特征进行度量;结合散点图、简化主轴回归分析及线性拟合对比分析后,确认这些标本均为长形张氏虫Chang-aspis elongata的标本,厘定出从分节6期至成虫期共计12个连续个体发育序列,揭示其形态变化特点。从分节6期至10期,背壳长、头鞍长、头盖长和宽的增长幅度相对小;随着体节的增多,头盖长度与背壳长度的比值从50%减少至34%;随着头鞍长度的增长,头鞍前部及后部宽均呈线性关系的连续增长趋势;个体发育序列确认该种成虫期有17节胸节,不同以往认为的16节胸节。对比分析及线性拟合的数据比较论证,确认原为C.micropyge和C.placenta 2个种的特征应为C.elongata在个体发育变化中的种内差异,确认先前命名的这2种应为C.elongata的晚出同义名。 相似文献
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Accumulation and subcellular distribution of heavy metal in Paulownia fortunei cultivated in lead-zinc slag amended with peat 总被引:1,自引:0,他引:1
Qianni Zhang Mengying Zhang Liangze Han 《International journal of phytoremediation》2019,21(11):1153-1160
AbstractThe contamination of toxic heavy metals was a major issue of concern in the last century. A fast-growing metal-accumulating woody plant is a promising approach for the remediation of toxic heavy metal. In this study, the transportation of heavy metals (Pb, Zn, Cu, and Cd) in Paulownia fortunei cultivated in lead-zinc slag amended with different mass ratios of peat (CK: 0; T1: 10%; T2: 20%; T3: 30%) was investigated, as well as the subcellular distribution of Pb, Zn, Cu, and Cd in Paulownia fortunei. The results showed that the accumulation content of Pb, Zn, Cu, and Cd in Paulownia fortunei were increased with peat amendment, which was in the range of 4.216?~?6.853, 20.905?~?23.017, 1.898?~?2.572, and 0.530?~?0.616?mg/pot, respectivly. The experimental group with 30% dose of peat showed the best performance on the accumulation content of Pb, Zn, Cu, and Cd, with increase rates (compared to control) of 4.088, 10.573, 1.360, and 0.294?mg/pot, respectively. The bioconcentration, translocation and transfer quantity factor of Pb, Zn, Cu, and Cd were less than 1. Fixation of cell wall and compartmentalization of vacuolar appeared to play an important role in reducing the toxicity of Pb, Zn, Cu, and Cd. 相似文献
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TeaABC is a novel, osmoregulated secondary transport system for compatible solutes found in the halophilic proteobacterium Halomonas elongata DSM 2581(T). Sequence comparisons have confirmed that TeaABC belongs to the family of TRAP transporters and as such it consists of two putative transmembrane proteins (TeaB, TeaC) and a putative periplasmic substrate-binding protein (TeaA). TeaABC is the only osmoregulated transporter for ectoines found in H. elongata. By overexpressing TeaA-(6)His tag in Escherichia coli we demonstrated that TeaA is processed as predicted and exported to the periplasm. Furthermore, it was proven that TeaA is indeed a periplasmic ectoine-binding protein. The functionality of the purified protein as an ectoine-binding protein was tested employing a modified binding assay. 相似文献
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