孢粉-植被-气候关系研究进展

随着全球变化研究的不断深入 ,第四纪孢粉学研究已取得了长足的进步 ,特别是近些年来 ,孢粉 植被 气候关系研究已成为世界孢粉学界的热点之一。空气孢粉学的研究在大气环境污染监测、花粉过敏症、农业收成预报和第四纪植被与环境重建等方面得到了广泛应用 ,并不断发展 ;近年来 ,为开展全球范围的古环境研究 ,各大洲相继建立了孢粉数据库 ,大量开展表土孢粉研究。中国第四纪孢粉数据库的建立 ,汇集了我国近半个世纪积累的孢粉资料 ,并利用中国第四纪孢粉数据 ,系统开展了中国现代表土孢粉、6kaBP(中全新世 )及 1 8kaBP(末次盛冰期 )的生物群区模拟及重建 ,建立了花粉 气候转换函数和响应面模型 ,并取得了良好的结果 ;冲积物孢粉学和环境考古孢粉学研究 ,也取得了一定成果 ,但研究还有待于深入 ;特征指示种花粉雨研究 ,对古生态环境重建也具有重要的意义。     

Early markers of in vitro microspore reprogramming to embryogenesis in olive (Olea europaea L.)

Microspore embryogenesis to form haploid and double-haploid embryos and regenerated plants is an efficient method of producing homozygous lines for crop breeding. In trees, the process is of special interest since classical methods are impractical in many cases, as in Olea europaea L. Recently, a convenient method has been developed for microspore embryogenesis induction by stress in olive isolated microspores in vitro cultures. In the present work, the switch of the microspore developmental pathway and the formation of microspore-derived multicellular proembryos have been achieved and a cytochemical and immunocytochemical analysis was performed in the early stages. The young microspore proembryos displayed defined features different to both, the in vivo gametophytic, and the in vitro non-responsive microspores. Reprogrammed microspores showed an absence of starch, the occurrence of a first symmetrical division and cytokinesis, the presence of an abundant ribosomal population, and changes in cellulosic and pectic cell wall components which constituted early markers of the embryogenic microspore process. They provided new insights on the molecular and cellular events associated with the microspore reprogramming of woody plants, and specifically in olive, providing interesting knowledge which could guide future selection and regeneration strategies in this fruit tree of high economic interest.     

MAU-8 is a Phosducin-like Protein required for G protein signaling in C. elegans

The mau-8(qm57) mutation inhibits the function of GPB-2, a heterotrimeric G protein beta subunit, and profoundly affects behavior through the Galphaq/Galphao signaling network in C. elegans. mau-8 encodes a nematode Phosducin-like Protein (PhLP), and the qm57 mutation leads to the loss of a predicted phosphorylation site in the C-terminal domain of PhLP that binds the Gbetagamma surface implicated in membrane interactions. In developing embryos, MAU-8/PhLP localizes to the cortical region, concentrates at the centrosomes of mitotic cells and remains associated with the germline blastomere. In adult animals, MAU-8/PhLP is ubiquitously expressed in somatic tissues and germline cells. MAU-8/PhLP interacts with the PAR-5/14.3.3 protein and with the Gbeta subunit GPB-1. In mau-8 mutants, the disruption of MAU-8/PhLP stabilizes the association of GPB-1 with the microtubules of centrosomes. Our results indicate that MAU-8/PhLP modulates G protein signaling, stability and subcellular location to regulate various physiological functions, and they suggest that MAU-8 might not be limited to the Galphaq/Galphao network.     

几种含笑属(木兰科)植物的花粉形态

含笑属 ( Michelia) 4种花粉光镜下形态相似。SEM下观察 ,黄兰 ( M.champaca)和金叶含笑 ( M.foveolata)表面雕纹为小穿孔 ,苦梓含笑 ( M.balansae)为小穴 ,野含笑 ( M.skinner-iana)为细皱纹 ,较粗糙。 TEM下观察 ,4种花粉外壁均可分为覆盖层、柱状层和基层。其中黄兰的柱状层结构较原始 ,金叶含笑的较进化。花粉形态在一定程度上可反映类群的系统演化。     

Zinc is critically required for pollen function and fertilisation in lentil

The role of zinc (Zn) in reproduction of lentil (Lens culinaris Medik. cv. DPL 15) and the extent to which the Zn requirement for reproduction can be met through supplementation of Zn at the time of initiation of the reproductive phase have been investigated. Low supply (0.1micromol/L) of Zn reduced the size of anthers, the pollen producing capacity and the size and viability of the pollen grains. Scanning electron microscopy (SEM) of pollen grains of Zn deficient plants showed enhanced thickening of exine and wide and raised muri. In vitro germination of pollen grains was reduced by >50% and growth of pollen tubes was retarded. Unlike Zn sufficient plants, the cuticle around the stigmatic papillae of Zn deficient plants remained intact, preventing the interaction between pollen grains and stigmatic exudates that provides the polarity for the growth of pollen tubes through the stylar tract. Zn deficiency increased the activity of acid phosphatase and peroxidase in extracts of pollen grains. Histochemical localisation on the stigmatic surface and native PAGE of the enzyme extracts of pollen grain and stigma exudates showed enhanced expression of acid phosphatase and peroxidase and suppressed expression of esterase in response to Zn deficiency. Zn deficiency reduced the setting of seeds and also their viability. The effect on seed setting was more marked than on in vitro germination of pollen grains, suggesting that the latter was not the exclusive cause of inhibition of fertility. Possibly, loss of fertility was also caused by impairment in pollen-pistil interaction conducive to pollen tube growth and fertilisation. Impairment in pollen structure and function and seed setting was observed even when plants were deprived of Zn at the time of flowering, but to a lesser extent than in plants maintained with low Zn supply from the beginning. Increasing the Zn supply from deficient to sufficient at the initiation of flowering decreased the severity of Zn deficiency effects on pollen and stigma morphology, pollen fertility and seed yield. In conclusion, structural and functional changes induced in pollen grains and stigma of Zn deficient plants and associated decrease in seed setting of lentil indicate a critical requirement of Zn for pollen function and fertilisation that can be partially met by supplementing Zn at the onset of the reproductive phase.     

钙和硼对蓝猪耳花粉萌发及花粉管生长的影响

研究了钙(Ca^2 )和硼(H3BO3)对蓝猪耳花粉萌发和花粉管生长的影响。结果表明：(1)在一定范围内Ca^2 几乎不影响花粉萌发频率,而主要影响花粉萌发速度和花粉管生长速度;低Ca^2 不利于花粉管生长,而高Ca^2 抑制花粉萌发速度和花粉管生长;在稍高于最适Ca^2 浓度的条件下,花粉管生长早期呈现波浪形。(2)硼明显影响花粉萌发频率及花粉管形态;花粉管生长必需硼,但不同浓度的硼对花粉管生长速度影响不明显;在高浓度硼条件下,较长时间内花粉管均呈现出波浪形。(3)Cooled-CCD动态跟踪观察进一步证实Ca^2 影响花粉管生长速度,而硼则不明显。     

胞松素B对洋葱根尖细胞分裂及亚显微结构的影响

洋葱鳞茎被培养在含不同浓度胞松素B的自来水中时,根尖伸长的速度减慢,间期细胞的比例上升,前、中、后和末各期的细胞的比例相应下降。在超显微结构水平上,内质网和高尔基体小泡的内腔膨大,线粒体的结构和分布改变,细胞核表面突起或内陷,部分细胞器解体,文章讨论了胞松素B可能的作用机制。     

小尺度海域空间评价单元划分技术研究——以福建省东山湾为例

科学合理的海域空间评价单元划分是各类海洋空间监测、评价、规划和管理的基础工作,对于保护海洋生态环境,实现海洋资源的可持续开发利用具有重大现实意义。然而,海洋的流动性、开放性、边界模糊性等特征,导致海洋空间评价单元划分较陆地而言更为复杂、困难。以福建省东山湾为例,提出一种适用于小尺度海域的空间评价单元划分技术方案,通过从化学属性、物理属性、生物学属性三个方面构建海域空间生态属性划分指标体系,进行空间分类评价,运用插值、叠加分析等GIS技术将东山湾划分为67个基本空间评价单元。研究结果不仅能为进一步划定东山湾海洋空间规划提供技术支持,同时为其他小尺度海域生态监测、评价、规划和管理提供科学参考。     

Ultrastructural and Cytochemical Study on Mature Pollen of Pinus tabulaeformis

The pollen of Pinus tabulaeformis Cart. comprised two prothallial cells, a generative cell and a tube cell which degenerated at pollen maturation. The generative cell had its own cell wall, seperating from the intine of pollen, but with its side wall attached to the infine. Cytoplasmic channels were present on the side of the generative cell wall, which faced to the tube cell cytoplasm. The generative cell differed conspicuously from the tube cell. The main differences include: ( 1 ) The chromatin in the generative cell nucleus was condensed, but was dispersed and had numerous nueleare pores in the tube cell nucleus; (2)There was no microbody in the generative cell but many microbodies were present in the tube cell cytoplasm; (3)More inclusions were present in the tube cell than in the generative cell. Both the generative cell and the tube cells contained lipid bodies and amyloplasts in the cytoplasm, but there were more amyloplasts in the former. The tube cell also contained a few proteins which was absent in the generative cell. In addition, there were numerous mitochondria, polyribosomes, and a few endoplasmic reticulums and dictyosomes in the generative and tube cells. DAPI staining demonstrated numerous cytoplasmic DNA in both generative cell and tube cell. The mode of cytoplasmic inheritance, and the composition, structure and the nature of the pollen wall of P. tabulaefonnis are also discussed in this paper.     

食管癌细胞病理变化数学模型

本文研究食管癌细胞的增殖控制机理,建立了食管癌细胞病理变化的数学描述,并形成其数学模型,给出食管癌细胞分裂以及逆转可能性若干观点。