Total mercury and methylmercury levels in commercially important fishes in Japan

ABSTRACT:   The distribution of mercury in the muscle and other tissues was determined in 23 species of fishes and invertebrates. This study reveals species-specific patterns of mercury accumulation in the muscle of tuna and alfonsino. Consistently high levels of total mercury were found in Beryx splendens (0.78 ± 0.56 µg/g), Atlantic Thunnus thynnus (0.42 ± 0.06 µg/g), Pacific T. thynnus (0.59 ± 0.34 µg/g), Thunnus obesus (0.98 ± 0.34 µg/g), Makaira nigricans (0.56 ± 0.05 µg/g), Tetraptrus audax (0.51 ± 0.08 µg/g), and Xiphias gladius (0.47 ± 0.24 µg/g). Other fish species had lower levels of total mercury or methylmercury in muscle than the maximum permitted level of mercury in fish in Japan (0.4 µg/g). Total mercury and methylmercury levels in the muscles of T. thynnus , T. obesus, and B. splendens were closely correlated with body weight.     

一串红新品种‘紫衣仙子’

‘紫衣仙子’是经实生苗系统选育得到的一串红新品种。株高55~62 cm,冠幅68~78 cm,花序长18~24 cm,花轮数14~21,花轮间距1.1~1.8 cm,整株花序67~110枝。花萼白色带淡紫色晕,花冠淡紫色。花期6—10月,盛花期8—9月。抗性强,具有一定的耐热性,不易发生疫病和花叶病。适宜在北京地区种植。     

一串红(Salvia splendens Ker-Gawl)花粉活性研究

[目的]探讨4种花色一串红花粉的生活力和在不同条件下的萌发率,为一串红育种提供理论依据。[方法]获取4种花色一串红花粉,采用TTC法和培养基法研究其生活力和萌发率。[结果]在TTC浓度为0.5%时活力测定效果最好,其中紫色和红白相间一串红达到94%。适宜一串红花粉萌发的培养条件为蔗糖浓度为10%,硼酸浓度为1.5%的液体培养条件下萌发率最高,达到83%(紫色一串红)。在常温贮藏条件下,6 h左右开始萌发,12 h的时候萌发率达到最高(紫色一串红为86%),48 h以后花粉几乎丧失了萌发力。[结论]花粉的生活力和萌发规律在一串红可育性上起关键作用。     

Copper Tolerance and Accumulation of Elsholtzia splendens Nakai in a Pot Environment

ABSTRACT

Elsholtzia splendens Naki has been identified as a copper (Cu) geobotanical indicator. In this study, the effects of Cu supply levels (control, 100, 200, 400, 600, 800, 1000, 1200 mg kg¹) on the growth and Cu accumulation in E. splendens were studied in one pot experiment. The results showed that no reduction in shoot height and dry weight was noted when the plants were grown at Cu supply levels up to 1000 mg kg^?1 in soil. Slight stimulation on shoot growth was noted at Cu levels ≥ 100 mg kg^?1. Copper concentration in shoots and roots increased with increasing Cu levels, and reached a maximum of 1751 and 9.45 mg kg^?1 (DW) at 1200 mg Cu kg^?1. The amount of Cu accumulated in the roots and shoots were 313 and 22 μ g plant^?1 at external Cu levels of 1000 and 800 mg kg^?1, respectively. The shoot/root Cu ratios ranged from 0.005 to 0.008 and more than 92% of the total Cu taken up by E. splendens was accumulated in roots. Furthermore, Cu concentrations in roots and shoots were significant and positively correlated with total soil Cu, water, ammonium nitrate (NH₄NO₃), ammonium (NH₄)-acetate, and ethylenediaminetetraacetic acid (EDTA) extractable Cu. These results indicate that E. splendens can considered as a Cu tolerant and accumulated plant, and root is the major part for accumulation of Cu in E. splendens.     

Economic weed control with grass carp

Abstract

Conventional methods of aquatic weed control meet increasing objections on economic and/or environmental grounds. An alternative approach is the use of grass carp (Ctenopharyngodon idella Val.), a herbivorous fish. This biological method has mainly been used in Europe and the USA, but since 1976 an Egyptian‐Dutch project has studied the potential of this approach for the Egyptian irrigation systems. All aspects of the production and use of grass carp have been studied and evaluated, Egyptian personnel have been trained, a large‐scale breeding station has been established and practical use of the technique has begun. The programme has shown that a stocked grass carp population not only provides effective weed control, but it also increases the protein production in Egyptian waterways substantially. If managed well, this production can provide continuous revenues that far outweigh the costs of weed control. The necessary management techniques developed are mainly based on yearly restocking with grass carp and cooperation between irrigation authorities and professional fishermen. The experience described in this paper will be of interest to many other countries.     

青海湖芨芨草干草原植被退化对土壤温湿特征的影响

芨芨草(Achnatherum splendens）干草原目前退化严重,但对土壤温湿特征的驱动机理仍不清楚。利用2011年连续观测资料分析环青海湖区域的芨芨草干草原原生植被和典型退化区域的0 cm、5 cm、10 cm、20 cm、40 cm和80 cm土壤温度和5 cm、10 cm、20 cm、40 cm和80 cm土壤容积含水量。结果表明:植被退化直接导致0 cm和5 cm表层土壤温度日极大值显著升高了39.04%和13.91%,温度日极小值显著降低,温度日较差升高;而10 cm以下温度日特征无显著响应。原生植被区0 cm逐日土壤温度在植物生长季（5-9月）极显著降低,非生长季5 cm和10 cm则略高。芨芨草植被改变了土壤年均温度垂向扩散特征。植被退化间接导致土壤5 cm土壤容积含水量升高了35.20%,10 cm无差别,20 cm以下显著降低,同时降低了系统土壤含水量的时间稳定性。特征聚类分析结果表明,芨芨草干草原土壤温湿特征对植被退化的综合响应主要表现在7-8月。     

一串红的引种筛选试验

以10个一串红品种为试材,在浙江省杭州市进行引种试验。结果表明,不同品种在生育期、植物学特性、观赏性状和耐热性等方面有明显的差异。总体来看,进口品种生长速度较快,但国产品种花期普遍较长,且耐热性略优于进口品种,综合各性状指标,认为国产品种神州红和塞诺尔、进口品种展望和帝王较适宜杭州市春季栽培。     

泰国斗鱼的胚胎发育及温度对胚胎发育的影响

观察了泰国斗鱼Betta splendens受精卵的形态和胚胎发育的过程,研究了温度对胚胎发育的影响。试验设置5个温度组（20、23、26、29、32℃）,记录各温度下胚胎发育历时、孵化率和畸形率,共重复5次。结果表明：水温为20～32℃时,泰国斗鱼受精卵均能孵化,最适孵化温度为26～29℃。孵化温度T与孵化时间t呈负相关,相关方程为t=18878T-1.8528（R2=0.9811）;泰国斗鱼胚胎发育的生物学零度为11.08℃,有效积温为659.39℃.h。     

Two New Jaspamide Derivatives from the Marine Sponge Jaspis splendens

Two new jaspamide derivatives 2 and 3, together with the parent compound jaspamide (1) have been isolated from the marine sponge Jaspis splendens collected in Kalimantan (Indonesia). The structures of the new compounds were unambiguously elucidated based on 1D and 2D NMR spectral data, mass spectrometry and comparison with jaspamide (1). The new derivatives inhibited the growth of mouse lymphoma (L5178Y) cell line in vitro with IC₅₀ values of <0.1 μg/mL.     

不同生态环境下一串红的结实规律

[目的]探索各生态环境下一串红单花序结实的构成及其各构成要素对结实的贡献,为确定不同生态环境下的最佳采种时间提供依据。[方法]以一串红皇帝系列品种为试材,将其分别定植于大棚、露地、阴棚、地膜覆盖4种生态环境．测定初花后不同时间主花、侧花及单花序的结实量。[结果]研究表明,露地、塑料大棚、地膜覆盖和阴棚采种的最佳时间分别为始花后15、25、25、30d以上。[结论]各生态环境下一串红主花、侧花和单花序表现出不同的结实规律,其中地膜覆盖是种子生产的最佳方法。