Long-term responses of Melilotus segetalis to salinity. I. Growth and partitioning

Annual sweetclover plants [Melilotus segetalis (Brot) Ser.] were grown for a complete life cycle with and without saline (NaCl treatment of CE=15 dS m⁻¹). Growth and partitioning analyses were performed. Sequential harvests (every 15 d) during the life cycle, and separation of plant material into roots, stems, petioles, leaves and reproductive structures were carried out Salt treatment reduced growth during the early and middle stages of the life of the plant, but did not significantly affect RGR in the reproductive phase. The root–shoot allometric coefficient of salinized plants in the generative phase decreased more than in control plants. We suggest that salinity-induced growth reduction in M. segetalis was primarily a result of a lower unit leaf rate (ULR) despite an increased leaf area ratio (LAR). Earlier flowering, higher biomass allocation to shoot and greater reproductive investment, but similar relative growth rate (RGR), were some of the main characteristics of salt-stressed plants compared to controls during the reproductive phase, these apparently being associated with increased sink strength caused by developing flowers and fruits.     

广西植物小资料

<正> 近年来,我们在中草药资源调查工作中,发现有一些广西未曾记录过的植物,现在整理出来,以供有关部门参考。本文引用的标本,除圆叶西番莲外,其余均收藏在广西中医药研究所植物标本室(GXMI)。     

中药王不留行化学成分的研究Ⅲ

从经产麦蓝菜（Ｖａｃｃａｒｉａ ｓｅｇｅｔａｌｉｓ（Ｎｅｃｋ）Ｇａｒｃｈｅ．）的种子王不留行中分离得到５个化合物,经波谱分析和化学方法分别鉴定为化学方法分别鉴定为：ＶａｃｃａｒｏｓｉｄｅＢ（１）、Ｃ（２）、Ｄ、（３）,６－Ｎ－ｍｅｔｈｙｌａｄｅｎｏｓｉｎｅ（４）和Ｎ,Ｎ－ｄｉｍｅｔｈｙｌ－Ｌ－ｔｒｙｐｔｏｐｈａｎ（５）。其中化合物４和５为首次从该植物中分得。     

麦蓝菜的花粉母细胞减数分裂及核型分析

采用压片法,对麦蓝菜的花粉母细胞减数分裂及体细胞核型进行了研究。结果表明,麦蓝菜的绝大多数花粉母细胞减数分裂中染色体的行为正常,在终变期同源染色体配对后可形成15个二价体;在少数花粉母细胞减数分裂中观察到落后染色体、染色体桥等异常行为;其减数分裂为同时型,其花粉粒育性为88.04%。麦蓝菜的染色体数目为2n=2X=30,核型公式为K(2n)=2X=30=22m(2SAT)+8 sm,染色体相对长度组成为2n=16M2+14M1,其核型为"1A"型。     

王不留行环肽研究

从中药王不留行（Ｖａｃａｒｉａｓｅｇｅｔａｌｉｓ）种子中分离并鉴定了４个环肽化合物,分别命名为王不留行环肽Ａ,Ｂ,Ｃ,Ｄ（ｖａｃｃａｒｉｎｓＡ,Ｂ,Ｃ,Ｄ）,其中王不留行环肽Ａ为新环肽化合物。其结构通过光谱和化学方法分别确定为：ｖａｃｃａｒｉｎＡ——ｃｙｃｌｏ－（Ｔｒｐ－Ａｌａ１－Ｇｌｙ－Ｖａｌ－Ａｌａ２）,ｖａｃｃａｒｉｎＢ———ｃｙｃｌｏ－（Ｐｒｏ－Ｇｌｙ－Ｌｅｕ－Ｓｅｒ－Ｐｈｅ１－Ａｌａ－Ｐｈｅ２）,ｖａｃｃａｒｉｎＣ———ｃｙｃｌｏ－（Ｐｒｏ１－Ｇｌｙ－Ｔｙｒ－Ｖａｌ－Ｐｒｏ２－Ｌｅｕ－Ｔｒｐ）,ｖａｃａｒｉｎＤ———ｃｙｃｌｏ－（Ｐｒｏ－Ｖａｌ１－Ｔｒｐ－Ａｌａ－Ｇｌｙ－Ｖａｌ２）．     

Nutrition, aspects of land use and environment in medieval times in southern Germany: plant macro-remain analysis from latrines (late 11th–13th century a.d.) at the town of Überlingen, Lake Constance

From high medieval courtyards at überlingen, Lake Constance (Bodensee), 17 archaeobotanical samples from seven latrines (11th–13th century) were analysed for plant macrofossils. They contained small amounts of cultivated plants and many well preserved seeds and fruits of wild plants. The most numerous cereal finds were of Triticum spelta followed by Secale cereale. Recorded oil plants were Papaver somniferum and Linum usitatissimum. Cultivated and gathered fruits such as various Prunus species, Pyrus communis and Malus domestica, Rubus sp. and Fragaria vesca were eaten by the people of überlingen. Only one seed of Ficus carica was found which may have been imported; no other imported plants could be recognised. Agrostemma githago and Vaccaria hispanica were prevalent weeds. The presence of the latter probably indicates the cultivation of cereals on the steeper slopes above überlingen. It is shown that in central Europe, V. hispanica became a troublesome weed only around the 12th/13th century A.D. Grassland species—mainly from more or less wet locations—and ruderal plants of nitrogen-rich soils were well represented in the samples and characterize the surrounding area. Electronic Supplementary Material Supplementary material is available in the online version of this article at     

Long-term responses of Melilotus segetalis to salinity. II. Nutrient absorption and utilization

Specific absorption rates (SAR) and specific utilization rates (SUR) of sodium, chloride, potassium, calcium, magnesium and phosphate ions were determined for Melilotus segetalis (Brot.) Ser. (annual sweetclover) grown under both control and salinized conditions (NaCl treatment of CE=15 dS m⁻¹) for a complete life cycle with sequential harvests. The behaviour over time of the SARs and SURs of the mineral elements was in general correlated with relative growth rate (RGR) kinetics, with a parabolic trend during the vegetative phase and a progressive linear decrease during the reproductive stage. Salinity significantly reduced the SARs of K and Mg but did not affect the SARs of Ca and P during the vegetative phase. During the reproductive stage, however, the SARs of K, Ca and P of salt-stressed plants were higher than in control plants. The similar SARs of total cations (TC) found in control and salt-stressed plants may indicate compensatory mechanisms to maintain a constant total cation content. Salt-stressed plants showed lower SURs of K, Ca and P during the vegetative phase, and lower SURs of K and P but a higher SUR of Mg during the reproductive stage. A nutrient imbalance, caused by a lower root efficiency in absorbing K and Mg and a lower leaf efficiency in producing biomass per unit of K, Ca and P, apparently contributed to the salt-induced reduction in growth during the vegetative phase of M. segetalis. The switch to non-reduced, compensated growth during the reproductive phase may have been caused by a higher nutrient demand which increased the root efficiency in absorbing K, Ca and P and the leaf efficiency in utilizing Mg.