Using drift nets to capture early life stages and monitor spawning of the Yangtze River Chinese sturgeon (Acipenser sinensis)

P>A sampling system for capturing sturgeon eggs using a D-shaped bottom anchored drift net was used to capture early life stages (ELS) of Chinese sturgeon, Acipenser sinensis, and monitor annual spawning success at Yichang on the Yangtze River, 1996-2004, before and just after the Three Gorges Dam began operation. Captured were 96 875 ELS (early life stages: eggs, yolk-sac larvae = eleuthero embryos, and larvae); most were eggs and only 2477 were yolk-sac larvae. Most ELS were captured in the main river channel and inside the bend at the Yichang spawning reach. Yolk-sac larvae were captured for a maximum of 3 days after hatching began, indicating quick dispersal downstream. The back-calculated day of egg fertilization over the eight years indicated a maximum spawning window of 23 days (20 October-10 November). Spawning in all years was restricted temporally, occurred mostly at night and during one or two spawning periods, each lasting several days. The brief temporal spawning window may reduce egg predation by opportunistic predators by flooding the river bottom with millions of eggs. During 1996-2002, the percentage of fertilized eggs in an annual 20-egg sample was between 63.5 to 94.1%; however, in 2003 the percentage fertilized was only 23.8%. This sudden decline may be related to the altered environmental conditions at Yichang caused by operation of the Three Gorges Dam. Further studies are needed to monitor spawning and changes in egg fertilization in this threatened population.

Seeding nets with neutral spores of the red alga Porphyra umbilicalis (L.) Kutzing for use in integrated multi-trophic aquaculture (IMTA)

Nets in traditional Porphyra mariculture are seeded with conchospores derived from the conchocelis phase, and spend a nursery period in culture tanks or calm coastal waters until they reach several centimeters in length. Some species of Porphyra can regenerate the foliose phase directly through asexual reproduction, which suggests that the time, infrastructure, and costs associated with conchocelis culture might be avoided by seeding nets with asexual spores. Here, we present work from a short-term mariculture study using nets seeded with asexual spores (neutral spores) of a native Maine species of Porphyra. Porphyra umbilicalis (L.) Kutzing was selected for this proof of concept research because of its reproductive biology, abundance across seasons in Maine, and evidence of its promise as a mariculture crop. We studied the maturation, release, and germination of the neutral spores to develop an appropriate seeding protocol for nets, followed by development of a nursery raceway to provide an easily manipulated environment for the seeded nets. Neutral spores were produced throughout the year on the central Maine coast,however, there was a temporal variability in the number and survival of released neutral spores, depending upon thallus position in the intertidal zone. Small thalli were strictly vegetative, but most thalli reproduced by neutral spores- sexual reproduction was absent. Neutral spores germinated quickly at 10 and 15 'C, but germination was delayed at 5 degrees C. Unlike some algal zygotes and spores, neutral spores of R umbilicalis required light to germinate; however, irradiances of 25 and 100 mu mol photons M-2 S-1 were equally sufficient for germination. Rafts of seeded nets were deployed in Cobscook Bay, Maine, at two distances from salmon aquaculture pens and at a control site on a nearby, fallow aquaculture site (no salmon). There was no difference in nitrogen content of harvested thalli; however, both the density and the surface area of harvested thalli were different among the sites. The possible causes of these differences are discussed in the context of potential use of P umbilicalis in IMTA. (C) 2007 Elsevier B.V. All rights reserved.

Feeding and growth on bivalve biodeposits by the deposit feeder Stichopus japonicus Selenka (Echinodennata : Holothuroidea) co-cultured in lantern nets

Suspension aquaculture of filter-feeding bivalves has been developing rapidly in coastal waters in the world, especially in China. Previous studies have demonstrated that dense populations of filter-feeding bivalves in shallow water can produce a large amount of faeces and pseudofaeces (biodeposits) that may lead to negative impacts on the benthic environment. To determine whether the deposit feeder Stichopus (Apostichopus) japonicus Selenka can feed on bivalve biodeposits and whether the sea cucumber can be co-cultured with bivalves in suspended lantern nets, three experiments were conducted, two in tanks in the laboratory and one in the field. In a 3-month flow-through experiment, results showed that sea cucumbers grew well with specific growth rate (SGR) reaching 1.38% d(-1), when cultured in the bottom of tanks (10 m(3) water volume) where scallops were cultured in suspension in lantern nets. Moreover, results of another laboratory experiment demonstrated that sea cucumbers could survive well on bivalve biodeposits, with a feeding rate of 1.82 +/- 0.13 g dry biodeposits ind(-1) d(-1), absorption efficiency of organic matter in biodeposits of 17.2% +/- 5.5%, and average SGR of 1.60% d(-1). Our longer-term field experiments in two coastal bays (Sishili Bay and Jiaozhou Bay, northern China) showed that S. japonicus co-cultured with bivalves also grew well at growth rates (0.09-0.31 g wet weight ind(-1) d(-1)) depending on individual size. The results suggest that bivalve lantern nets can provide a good habitat for sea cucumbers; and the co-culture of bivalve molluscs with sea cucumbers may provide an additional valuable crop with no additional inputs. (c) 2006 Elsevier B.V. All rights reserved.

Insecticidal activity of proteinous venom from tentacle of jellyfish Rhopilema esculentum Kishinouye

Insecticidal activity of proteinous venom from tentacle of jellyfish Rhopilema esculentum Kishinouye was determined against three pest species, Stephanitis pyri Fabriciusa, Aphis medicaginis Koch, and Myzus persicae Sulzer. R. esculentum full proteinous venom had different insecticidal activity against S. pyri Fabriciusa, A. niedicaginis Koch, and M. persicae Sulzer. The 48 It LC50 values were 123.1, 581.6, and 716.3 mu g/mL, respectively. Of the three pests, R. esculentuin full proteinous venom had the most potent toxicity against S. pyri Fabriciusa, and the corrected mortality recorded at 48 It was 97.86%. So, S. pyri Fabriciusa could be a potential target pest of R. esculentum full proteinous venom. (c) 2005 Elsevier Ltd. All rights reserved.

棉花抗虫基因工程研究

本文通过根农杆菌（Agrobacterium tumfaciens）介导法分别将Signal和KDEL修饰的豇豆胰蛋白酶抑制剂（Cowpea trypsin inhibitor, CpTI）基因、豌豆外源凝集素（Pea lectin, P-Lec）和大豆Kunitz型胰蛋白酶抑制剂（Soybean Kunitz typsin inhibitor, SKTI）双价抗虫基因、雪花莲外源凝集素（Galanthus nivals agglutinin, GNA）基因以及高效复合启动子OM控制的苏云金杆菌（Bacillus thuringiensis, B.t.）杀虫毒蛋白基因导入了陆地棉（Gossypium hirsutum L.）栽培品种新陆早1号、新陆中2号、晋棉7号、冀合321、辽9和晋棉12号，并获得了大批转基因再生植株。 实验中对影响棉花转化和再生的一些条件进行了研究，从根农杆菌培养、棉花无菌苗的制备、转化操作和共培养等方面对转化条件进行了探讨;从激素配化、植物表达载体、外植体类型、基因型等方面对抗性愈伤组织的诱导进行了摸索;从激素、从碳源、培养容器、pH值、抗褐化剂及固化剂的选择等方面对影响植株再生的条件进行了优化。 本文开创性地采用嫁接代替移栽，从而极大地提高了转化植株定植成活率，缩短了缓苗时间并增加了转化植株当代的繁殖系数。 在建立了一套较为高效的陆地棉转化及再生系统基础上，本文还进行了其它转化方式和转化体系的初步探讨。利用棉花幼嫩种子无菌苗下胚轴作为外植体，通过改变愈伤组织诱导培养基配方面提高胚性愈伤组织的诱导频率，进而得到更多的体细胞胚状和再生植株，缩短再生周期;尝试用胚性愈伤组织作为外植体的根农杆菌介导法转化，确定了一些与转化有关的条件;建立了一套棉花茎尖培养程序，为运用基因枪法轰击棉花茎尖分生组织或用根农杆菌直接转化茎尖分生组织，以克服根农杆菌转化棉花时体胚发生的基因型局限开辟了一条新途径。 本文还建立了一种快速鉴定转化植株后代的方法。这一简便方法还有助于进行转基因棉纯合系的筛选以及外源基因的遗传稳定性研究。 转基因植株经Npt-II ELISA、PCR、PCR Southern 检测证明外源抗虫基因CpTI、SKTI、P-lec、GNA以及B.t.基因已存在于转化植株基因组内。修饰的CpTI转基因植株抗棉铃虫（Heliothis armigera Hubner）试验结果表明，其杀虫效果显著优于前期未修饰的CpTI转化植株。P－lec和SKTI双价转基因植株抗棉铃虫试验结果表明，转基因植株对棉铃虫幼虫具有较强的杀虫活力。 目前，已获得转以上抗虫基因棉花T1代植株。为今后进一步将植物基因工程技术应用于棉花遗传改良打下了基础。

Effects of human activities on migratory waterbirds at Lashihai Lake, China

Surveys on migratory waterbirds and their habitats at Lashihai Lake, China, were conducted from October 1999 to April 2000. Five fixed points, representing different degrees of habitat disturbance and quality, were selected around the lake. We used counts (n = 30) to compare diversity and abundance of waterbirds at each point and evaluate the effects of habitat disturbance. The distribution of waterbirds was affected by disturbance, with snore than one-third of the total species and nearly half of the total individuals occurring at the least disturbed point. Species richness was weakly and abundance was strongly correlated to habitat disturbance, but not to habitat quality. Habitat destruction and use of canoes were prominent at the lake. Naxi ethnic fishermen (n = 37) were interviewed. They caught 570 waterbirds between October 1999 and March 2000 in fishing nets. An estimation of the total number of waterbirds been trapped on the lake is 6164. Diving species were most susceptible. Conservation measures that should implement immediately include the cessation of habitat destruction, better plan for the development of tourism, a reduction in the number of canoes and zoning of the non-fishing area. (C) 2002 Elsevier Science Ltd. All rights reserved.

黄花蒿提取物的杀虫活性

黄花蒿精油对米象、玉米象、绿豆象和蚕豆象等 4种仓库害虫具有很强的熏杀活性 ,其甲醇和乙醇提取物对小菜蛾、菜青虫、大菜粉蝶、银纹夜蛾和斜纹夜蛾幼虫也具有一定的杀虫活性。