Morphology of tube-like threads related to Limnochares aquatica (L., 1758) (Acariformes: Hydrachnidia: Limnocharidae) in the laboratory

Water mites Limnochares aquatica (L., 1758) during maintenance in the laboratory for a long period of time in constant conditions periodically produced certain whitish flocculent material consisting of long rigid unbranched tube-like threads 1.3 ± 0.3 µm in diameter crossing freely. These threads were studied using light-optical as well as transmission electron microscopical and scanning electron microscopical methods. Microbiological staining was also applied to the threads to exclude their bacterial or fungal origin. The thread wall is built of fine fibrils arranged at different angles to the long axis of threads that is reflected in a certain stratification of the wall. Threads are mostly hollow or may contain electron-dense homogeneous material. No cell components are present in the thread composition. Numerous dermal glands with their small slit-like orifice scattered throughout the mite body surface are thought to produce these threads. Most probably the thread formation is a reaction of mites to stress under laboratory conditions, and this is expected to be a type of defensive reaction.     

蕹菜营养器官的解剖

初生根具5—6原型初生木质部,韧皮部与之交互排列。根表皮层具一层细胞,壁薄,无根毛。皮层有多层薄壁细胞,内皮层无卡氏带加厚。茎的表皮层有大量腺毛,气孔从表皮层向上拱,皮层内有乳汁分泌道。中柱鞘具1—3层薄壁细胞。形成层成环状,具双韧维管束。每一维管束的内外韧皮部均由筛管,伴胞组成。髓部细胞在生长中部分或全部破坏。叶表皮层上有腺鳞。栅栏组织薄壁细胞1—3层,海绵组织中空腔发达。下表皮的气孔多于上表皮。主脉亦为双韧维管束。     

镉对不同品种空心菜种子萌发的初步研究

土壤中的高镉对农作物有重要影响,而关注镉对种子发芽作用的研究较少.本试验模拟了9个不同镉（Cd2＋）离子浓度对6种不同空心菜品种的种子发芽的影响.结果表明：6个空心菜品种中,台湾白骨柳叶空心菜的发芽情况最好,并在加入重金属Cd2＋之后仍有95%以上的发芽率、发芽势和发芽指数,可以用来作为受镉污染土壤修复的备选品种;另外,低浓度Cd2＋对大部分空心菜品种的种子发芽有促进作用,而高浓度则有一定的抑制作用.     

黑凹胫跳甲发生情况的调查观察与药剂防治试验

本文对海口郊区蕹菜上发生的黑凹胫跳甲[Chaetocnema baslis(Baly)]的生活史、生活习性和为害情况,进行了调查观察;同时对该虫进行了化学防治试验。结果表明:该虫在海口郊区一年可发生4个世代,具世代重叠,而无越冬现象;成虫群集性强,性喜干燥,畏忌潮湿;为害蕹菜损失率一般为12％左右。药剂防治以50％的巴丹可湿性粉500倍液喷雾效果较好,药后24小时防效达100％。     

水生经济植物净化受污染水体研究

在富营养化水体中,利用人工基质无土栽培水生经济净化水质的静态试验结果表明,在５月～１０月间,水蕹菜对ＴＮ、ＴＰ的去除率分别为８１．３２％和７１．３４％;在１１月～３月间,水芹菜对ＴＮ、ＴＰ的去除率分别为８２．７７％和９４．７７％。经重金属检测分析,水蕹舸和水芹菜茎叶部分的Ｃｕ、Ｃｄ、Ｐｂ和Ｚn含量均处于可食用范围内。结 果现场试验结果,轮种上述两种经济植物,每m＾２水面每年可自水中移除ＴＮ２０４．８     

水面栽培蕹菜-多花黑麦草净化浸出油厂废水初步研究

在进行植物选择性试验后，借助于人工基质，将陆生植物蕹菜、多花黑麦草进行水面栽培，漂浮于浸出油厂排放的废水中．通过中试研究后应用于大塘试验，以ＣＯＤｃｒ、ＤＯＤ５为指标，观察蕹菜对废水的净化效果．本文提出了蕹菜－多花黑麦草轮作治理浸出油厂废水的植物净化塘模式，讨论了本方法的可行性、效益及特点．     

赤泥治理重金属污染土壤对通菜生长的影响

赤泥作化学改良剂能有效降低土壤重金属对通菜生长的抑制作用,增加植株生物量,显著增加通菜地上部鲜重与干重.重金属污染的土壤经过赤泥处理还能使通菜中Cd的含量显著降低,表明赤泥可以有效减少通菜对重金属Cd的吸收.经赤泥处理后,重金属污染土壤的pH值显著上升,从而降低土壤中重金属含量.