Infrageneric variation of the low molecular weight carbohydrate composition of the seeds of the genusVicia (Leguminosae)

The low molecular weight carbohydrate compositions of the seeds of 29 species ofVicia, namelyV. amoena, V. amurensis, V. bifolia, V. dumetorum, V. fauriei, V. japonica, V. nipponica, V. pisiformis, V. pseudo-orobus, V. sylvatica, V. unijuga, V. venosa, V. cassubica, V. orobus, V. cracca agg.,V. hirsuta, V. villosa agg.,V. tetrasperma,V. oroboides, V. sepium, V. cuspidata, V. grandiflora, V. lathyloides, V. sativa agg.,V. bithynica, V. faba, V. narbonensis, V. hybrida andV. lutea were determined by gas liquid chromatography. The carbohydrate compositions were found to be species-specific. Principal component analysis of the carbohydrate composition data showed that these species can be divided into three groups. Although, as far as the examined species were concerned, these groups were not correlated with the known subgenera, significant correlation between the groups and the known sections was detected in the subgenusVicia. The carbohydrate composition character would be important to clarify the relationships among closely related taxa of the genusVicia.     

黄皮种子发育过程中脱水敏感性与细胞膜透性的关系

黄皮（Ｃｌａｕｓｅｎａ ｌａｎｓｉｕｍ （Ｌｏｕｒ．） Ｓｋｅｅｌｓ）胚轴与完整种子的发育模式以及发育中电解质渗漏率变化有些不同． 种子生理成熟前、后的胚轴对脱水的反应也不同,前者经轻微脱水可提高萌发率和活力指数,后者不耐任何程度的脱水．活力指数的急剧下降伴随着电解质渗漏率的迅速上升．实验表明,黄皮种子在发育过程中没有形成耐脱水性． 细胞膜透性变化可反映脱水对种子的伤害程度     

Genetically stable cell lines of cucumber for the large-scale production of diploid somatic embryos

For the initiation of embryogenic cucumber ( Cucumis sativus L.) cell lines, from excised radicles, directly in liquid medium, the culture regime, explant density and type and concentration of hormones were adjusted so that pro-embryogenic masses (PEMs) were formed within about 8 weeks. The established cucumber cell lines were maintained tor several years without loss of embryogenic and genetic stability. The ploidy level of somatic embryos from different cucumber eell lines was either diploid or tetraploid and depended on the ploidy level of Ihe cell line. Cucumber cell lines that produced only diploid embryos were obtained by selecting completely diploid explant material and growing it in the dark during the initiation phase. Mixoploid explains could lead to tetraploid or mixoploid ceil lines. Isolation and additional selection and subculturing of single PEMs resulted in either completely diploid or tetraploid cell lines, indicating that all cells of individual PEMs are either diploid or tetraploid. The ernbryogenic cucumber cell Imes, differing only in ploidy level, were indistinguishable in growth rate and embryogetiic potential and were genetically stable over several years.     

Removal of seeds from Neotropical frugivore droppings

In a Costa Rican rain forest, the majority of tree and shrub species have their seeds dispersed by vertebrates. Over a third of the species' seeds are of a size accessible to, and primarily carried away by, ants. Frugivorous bird droppings come in sizes from a few seeds to over a thousand, with number of seeds isometric with bird body mass. Dropping size decreases as seeds are scattered by rain. Larger droppings produced from fruits ofMiconia affinis (Melastomataceae) are discovered and recruited to more by ants, with a diverse guild of 22 ant species carrying away the seeds. Droppings with 64 and 16 seeds were used by a subset of the ant community exploiting 4-seed droppings, likely due to resource defense by aggressive species. Seeds in the smallest droppings stood the smallest chance of being removed. Although soil-nesting ants of the tribe Attini were the primary removers of seeds in this forest, a third of removal was by ants living in ephemeral litter nests. Seeds ofM. affinis were found in litter ant nests in 8 of 28 1-m² plots, suggesting that seed rain was not highly localized. Since litter nests are common, contain few seeds/nest and are often abandoned by their ants, litter ants may be the best candidates for ant-plant dispersal mutualisms.     

模拟四季温度层积对南方红豆杉种子生理性状的影响

为了解濒危物种南方红豆杉(Taxus chinensis var. mairei)种子内含物含量受温度和湿度层积的影响,设置4个季节、2种湿度(16%和24%)基质层积处理,对种子的可溶性糖、淀粉、可溶性蛋白和脂肪等内含物质的变化进行研究。结果表明,不同层积处理下种子贮藏物质的含量有显著变化,春季层积9个月后,可溶性蛋白含量达到最高值;可溶性糖含量呈现降低-升高-降低的变化趋势;淀粉和脂肪含量均随层积逐渐减少。秋季层积9个月后,淀粉含量降至最低。相比于24%湿度,16%湿度的春季、秋季、冬季层积9个月后,脂肪含量均减少较多,说明16%湿度下种子代谢活动更强。春季和秋季的暖温更能促进种子代谢,促进种子形态后熟。夏季温度过高,导致种子生活力下降,夏季层积处理3个月后,种子已经发霉和腐烂。层积过程中,种子内含物在相关酶的作用下,降解为可溶性蛋白、可溶性糖等,为种子萌发提供物质与能量。种子层积时间、温度和湿度及交互作用可作为种子内含物的调控因子。     

Gathered fruits and cultivated plants at Bercy (Paris), a Neolithic village in a fluvial context

Recent rescue excavations at Bercy (Paris), a site on the alluvial plain of the Seine valley, yielded plant remains which are associated with the recent occupation phase dating from the middle Neolithic II (Chasséen), when a village was established on the former channel of the river Seine. Various contexts (the channel, the flat lower part of the bank, and several archaeological features) have been studied and 84 taxa have been identified. Cultivated plants are represented by Triticum aestivum/durum, T. dicoccum, T. monococcum and Hordeum vulgare. Among the wild plants with potentially edible fruits or seeds, only very few satisfy the various criteria for association with human activities: Corylus avellana, Vitis sylvestris, Cornus sanguinea, Quercus sp. and Prunus spinosa of which carbonized fruits were also present, were found in archaeological features and were very abundant. Though not found in archaeological features, we consider that Crataegus monogyna (carbonized and well represented) and Rubus spp. (especially abundant) were not deposited there naturally and had also been intentionally collected. Finally, it is suggested that the allochthonous (varied) origin of these taxa is the reason why there are no concentrations of their fruits in the channel. The exploitation of wild seeds and fruits appears to have been very selective. All other wild taxa can be attributed to natural deposition.     

花生种子高纯度DNA的提取（简报）

花生种子高纯度ＤＮＡ的提取（简报）王艳,何军贤,傅家瑞（中山大学生命科学学院,广州５０２７５）关键词花生;种子;ＤＮＡ;十六烷基三甲基溴化铵ＲＡＰＩＤＡＮＤＥＦＦＩＣＩＥＮＴＰＵＲＩＦＩＣＡＴＩＯＮＯＦＤＮＡＦＲＯＭＰＥＡＮＵＴ（ＡＲＡＣＨＩＳＨＹＰ...     

D-Amino-acid-stimulated ethylene production in seed tissues

Ethylene production by axial and cotyledonary tissues excised from Xanthium pennsylvanicum Wallr. seeds was markedly (up to 5-fold) stimulated by the D-isomers of phenylalanine, valine, leucine, threonine, methionine and eithionine while the L-isomers caused no such effect. Responsiveness of these seed tissues to D-methionine appeared soon after the beginning of imbibition, reached a maximum after 6–12 and 12–24 h for the axial and cotyledonary tissues, respectively, and then decreased sharply. D-Phenylalanine and D-methionine also stimulated ethylene production in seed tissues of X. canadense Mill. and in cotyledonary segments from seeds of Helianthus annuus L., Cucurbita moschata Duch. and Vigna radiata (L.) Wilczek. The endogeneous ethylene production and the D-amino-acid-stimulated ethylene production by the seed segments was strongly inhibited by aminoethoxyvinyl glycine, a potent inhibitor of ethylene synthesis from L-methionine.     

Isozymes of the glycolytic and pentose-phosphate pathways in storage tissues of different oilseeds

Isozymes of hexose-phosphate isomerase (HPI; EC 5.3.1.9), pyruvate kinase (PK; EC 2.7.1.40) and 6-phosphogluconate dehydrogenase (6PGDH; EC 1.1.1.44) have been detected in the developing cotyledons of soybean (Glycine max (L.) Merr.), safflower (Carthamnus tinctorius L.) and sunflower (Helianthus annuus L.). In each seed there are two isozymes each of PK and HPI. The isozyme patterns of 6PGDH are more complex: soybean has two forms of the enzyme, safflower three, and sunflower six. In each tissue, at least 25% of the activity of each of the three enzymes is in the plastids. This supports the proposal that the glycolytic and pentose-phosphate pathways are operating in the plastids and that the plastids are the site of long-chain fatty-acid biosynthesis in developing oilseeds.Abbreviations HPI hexose-phosphate isomerase - 6PGDH 6-phosphogluconate dehydrogenase - PK pyruvate kinase     

The control of food mobilisation in seeds of Cucumis sativus L.

The development of maximal rates of lipid and protein hydrolysis in cucumber cotyledons depends upon the removal of the testa and the presence of the embryonic axis. The testa appears to exert at least part of its inhibitory influence by suppressing the development of enzyme activity associated with lipolysis and proteolysis. There is, however, no evidence to suggest that the presence of the embryonic axis is a pre-requisite for the development of optimal enzyme activity.Abbreviations TLC thin layer chromatography - GC-MS gas chromatography-mass spectrometry - GLC gas-liquid chromatography - TCA trichloroacetic acid