主养河蟹池塘套混养名优品种技术试验报告

近年来，河蟹池塘养殖已积累了一些成熟的经验，但从目前河蟹池塘养殖技术水平来看，还存在一些问题。譬如，河蟹商品规格偏小；池塘的空间、水体及饵料资源未充分利用；病虫害防治方法不当；成活率不高等等。因此，需要我们水产工作者进一步去研究、探索。为使主养河蟹池塘获得优质高产高效，并促进池塘河蟹养殖业的可持续发展，我们于１９９９～２０００年进行了《主养河蟹池塘套混养名优品种技术试验》，取得了显著的经济效益和社会效益。现将２０００年的试验情况报告如下： 一、试验条件 １．试验地点位于上虞市９６丘围涂地区，１９９…     

不同复合肥在辣椒上的肥效试验

为了筛选出成本低、肥效高的复合肥,本研究以辣椒为试验材料,进行了5种复合肥田间试验。试验结果表明:澳特尔复合肥(N、P、K配比为25∶10∶16)和洋洋复合肥(N、P、K配比为20∶10∶10)对辣椒生长效果最好,产量最高,比对照处理1分别增产14.6%和11.2%,达到极显著水平。此两种复合肥可以在同等肥力条件下大面积推广使用。     

施肥对多盐水池塘浮游植物演替的影响

选择辽宁盘锦光合水产有限公司养殖基地为试验场所,于2002年春季4~5月进行试验。选择5个具有代表性的土池作为试验池,同时另选一土池作为对照池。研究相同N/P比值下不同施肥量对室外土池多盐水体的水化学和浮游植物群落、叶绿素a含量和初级生产力的影响,以及浮游动物对浮游植物的下行效应。共检出浮游生物42种。其中,浮游植物33种,浮游动物9种。浮游植物生物量高达288.2 mg.L-1,优势种为蛋白核小球藻(Chlorella pyrenoidesa)。叶绿素a含量为5.89~325.44μg.L-1。各池在第2次施肥后5~6天,叶绿素a含量达到高值,之后开始下降,8~9 d后恢复到原来水平。初级生产力均值为4.40 g(O2).m-2.d-1,呈低-高-低的变化,极值为1.25 g(O2).m-2.d-1和10.92 g(O2).m-2.d-1。以施N 2.0 mg.L-1、P 0.3 mg.L-1的4#池高峰期维持最长,施肥量的不同对浮游植物的生物量、种类数和种类组成影响较大。在北方地区的多盐水池塘,施氮磷混合肥能有效促进小球藻等藻类增长,达到定向培育的目的。     

增产素在亚心形扁藻生产上的应用

亚心形扁藻是鱼、虾、贝幼体最为常用的活饵料。如何提高它的产量和质量问题,正引起各方面的关注。水稻生产中应用增产灵,使稻谷每公顷增产4.46％;海带、紫菜的生产中,应用外源激素,产量提高了3～5倍。一些研究还表明,激素在不同的环境条件下,对不同部分和不同年龄的植物体所起的生理作用不同,其生长结果也不一样。我们在已有工作的基础上,进行了增产素处理亚心形扁藻的生产性试验、不同培养因素试验及生理效应、产品质量分析和投喂海水动物的试验,现报导如下。     

Algal-oligosaccharide-lysates prepared by two bacterial agarases stepwise hydrolyzed and their anti-oxidative properties

Twenty algal-oligosaccharide-lysates (AOLs), derived from six agars and four algal polysaccharide extracts (APEs), were treated first with agarases with 250 or 500 agarase activity units (AU), which were produced from the agar-liquefying bacterial strain Pseudomonas vesicularis MA103, named MA103-agarases. The AOLs were then treated with agarases (250 or 500 AU) derived from the agar-softening bacterial strain Aeromonas salmonicida MAEF 108, named MAEF 108-agarases. Anti-oxidative properties of the AOLs were evaluated by five in vitro methods. The AOL obtained from the APE of Porphyra dentate, digested by 250 AU of MA 103-agarases, and by 250 AU of MAEF 108-agarases, designated as A₂₅₀-Por, showed better results than the 19 other AOLs. This result is in accordance with the level of soluble total polyphenols (STP) of A₂₅₀-Por, which was also higher than the remainder of the AOLs tested. The AOL derived from the APE of P. dentate, digested by 500 AU of MA103-agarases and then 500 AU of MAEF108-agarases, and designated as B₅₀₀-Por, displayed the second highest data in four potential evaluation methods, except in H₂O₂ scavenging capacity. In this study, certain agars or APEs digested by specific agarases can present an increasing antioxidative capacity. These agars include Bitek agar, Agar powder, Bacteriological, Agar Bacteriological, and Guanghui agar, plus APEs of Gracilaria sp. and Monostroma nitidum decomposed stepwise by two agarases. The fraction of polyphenols (<1 kDa) that were derived from A₂₅₀-Por showed anti-oxidative activities on α, α-diphenyl-β-picrylhydrazyl (DPPH) assay and reducing power determination, while the remaining four agar-lytic fractions obtained from A₂₅₀-Por did not exhibit anti-oxidative activity. This phenomenon may suggest that anti-oxidative properties of AOLs originate in polyphenols. Algal-oligosaccharide-lysates may have potential use as a health food.     

种植方式和密度对夏玉米子粒灌浆特征的影响

以郑单958为材料,在67 500株/hm²和82 500株/hm²两个种植密度水平下,以常规等行距种植方式为对照,设置3种不同缩行宽带种植方式（3行一带、4行一带、5行一带）,进行连续两年比较研究。结果表明,缩行宽带种植方式增产显著,其中,3行一带种植方式高密度水平下产量最高。通过Logistic方程拟合,缩行宽带各种植方式中,高密度下灌浆时间持续期均值较对照等行距方式增加1.2～10.2 d。无论是高密度还是中等密度条件下,3行一带种植方式平均灌浆速率（R）、最大灌浆速率（R_max）、最终百粒重及渐增期灌浆速率（R₁）均较高。因此,3行一带缩行宽带种植方式子粒灌浆特性较优。     

Interface behavior of quaternized chitosan on cellulosic substrates

Quaternized chitosan (QCS) was prepared and its interface behavior on cellulosic substrates was investigated. FT-IR result indicated that quaternary ammonium groups were connected to -NH₂ in chitosan, and the highest degree of substitution (DS) of QCS was 80.0 %. The adsorption behavior of QCS was well performed on cellulosic substrates. The initial critical concentrations of QCS were between 10 mg/l and 20 mg/l, which were related to its DS and the weight average molecular weight (M _w ): the critical concentration decreased with the increasing DS of QCS, and the concentration increased when M _w increased. The results from SEM and particle size revealed that the flocculation took place mainly because the electrostatic interaction between cellulosic substrates and QCS, which can be accelerated by forming a charge patch. At last, QCS displayed high efficiency as a retention and drainage-aid agent through a Schopper-Riegler beating degrees tester.