绿僵菌防治第1代马尾松毛虫的研究

供试的绿僵菌和白僵菌菌种在室内对马尾松毛虫2～3龄幼虫的毒力相当.在25℃条件下,绿僵菌的n (LC50)=1.06×107 L-1, t (LT50) = 7.95～12.04 d (n(spore)=1.0×1011～1.0×107 L-1);白僵菌的n( LC50) =1.37×106 L-1 ,t (LT50) = 7.48～11.27 d ( n(spore) = 1.0×1011～1.0×107 L-1).试验显示与白僵菌相比,绿僵菌具有较强的耐高温和耐旱特性.在高温、低湿的条件下绿僵菌的杀虫效果优于白僵菌.林间防治试验也表明,绿僵菌防治第1代马尾松毛虫的效果显著优于白僵菌,显示出较好的应用前景.表8 参14     

Allelopathic effects of extracts from Solidago canadensis L.against seed germination and seedling growth of some plants

To investigate the potential role of allelopathy in plant interference and in the successful invasion of alien species Solidago canadensis, aqueous and ethanolic extracts from rhizomes, stems and leaves of S. canadensis were prepared and used as treatment solutions to assess their effects on seed germination and seedling growth in four target species, mulberry （Morus alba）; morning glory （Pharbitis nil）, wheat （Triticum aestivum） and rape （Brassiea campestris）. Reduction and/or growth in germination and growth of the target plant species in the presence of both aqueous and ethanolic extracts at different concentrations indicated that the responses were species-specific and concentration-dependent. Generally, ethanolic extracts （especially from leaves） imposed stronger effects on both seed germination and seedling growth. Extracts with lower concentration at 0.001 g/ml dw could stimulate the seedling growth of rape and morning glory, whereas extracts at any given concentrations have inhibitory effects on wheat and mulberry. It is suggested that the aqueous and ethanolic extracts of all the three parts of S. canadensis have significant allelopathic effects. Although both inhibition and stimulation occurred in the germination and growth of the target species, extracts with higher concentrations definitely inhibit seed germination and seedling growth of all target plants. We suggest that allelopathy plays a more important role than other mechanisms do in the out-competition ofS. canadensis over other plants, and make it invasive in new habitats.     

苯酚对蔬菜幼苗生长及氧化酶同工酶的影响

含酚污水是当前世界上危害大,污染范围广的一种工业污染源.未经处理直接排放到市郊农村的工业污水严重污染农业生态环境.一些学者就其对鱼类、小麦的毒性影     

镉与除草剂草甘磷的交互作用对小麦的毒性

种子发芽试验、根伸长抑制试验及植物早期生长试验是目前所建立的3种高等植物毒性试验，这些试验通过研究植物在污染条件下根系发育状况、生物量减少程度或植物耐污特性等方面而对污染物的环境效应进行诊断。文章研究了镉与草甘磷交互作用对小麦发芽率以及发芽后小麦的根长和芽长的影响。结果发现，镉对小麦发芽率没有明显影响，而草甘磷对小麦发芽率、根长和芽长有明显抑制效应。镉在一定程度上降低了草甘磷对小麦发芽的毒性，但对小麦生长仍有明显毒害。当镉与草甘磷共同作用于小麦时，镉的存在增加了低浓度草甘磷的生物毒性，而降低了高浓度草甘磷的生物毒性或没有影响。但是，随着镉浓度增加它们的联合毒件又逐渐增加。     

紫花苜蓿在柴油污染土壤中的萌发状况

选择以柴油作为土壤污染物，以单-外源环境因子污染水平为主要调控因子，采用室内盆栽试验的方法并且以不同质量分数的柴油污染土壤，在此情况下观察不同土壤柴油污染质量分数控制下紫花苜蓿种子的萌发与生长情况。结果表明，紫花苜蓿种子发芽抑制率与土壤柴油污染质量分数呈现指数线性相关关系，并且发现苜蓿发芽之后，高质量分数柴油处理组的幼苗出现黄叶和干枯现象。文章最后从土壤内柴油和柴油在土壤-大气界面间的迁移对种子萌发的影响进行了探讨。     

Response of peroxidase and catalase to acid rain stress during seed germination of rice, wheat, and rape

Seed germination of plants with various acid-resistance display different responses to acid rain. To understand the reason why such differences occur, the effects of simulated acid rain (pH 2.5–5.0) on the activities of peroxidase (POD) and catalase (CAT) during seed germination of rice (O. sativa), wheat (T. aestivum), and rape (B. chinensis var. oleifera) were investigated. Results indicated that the maximum change in activities of CAT and POD by acid rain treatment with different acidity and time in relation to the referent treatment without acid rain, was in the order: rice (28.8%, 31.7%) < wheat (34.7%, 48.3%) < rape (79.3%, 50.0%). The pH level for which the treatment with acid rain did not cause significant difference (p < 0.05) was in the order: rice (3.5).wheat (4.0).rape (5.0). Moreover, the change in activity of POD was higher than that of CAT, which showed that POD was more sensitive to acid rain stress than CAT. The difference in the ability of POD and CAT in removing free radicals was one reason why the germination indexes of these three species behaved differently. __________ Translated from Environmental Science, 2005, 26(6): 123–125 [译自: 环境科学]     

川牛膝种子保存技术初探

对川牛膝种子开展室温常规贮藏、室温湿沙贮藏、室温超干燥贮藏、4℃低温贮藏、冷冻贮藏等5种贮藏试验,结果表明：①室温湿沙贮藏是川牛膝种子短期保存的最优方法,能显著提高种子发芽率,其值较常规保存高14.5％;其次为4℃低温贮藏.②冷冻贮藏是川牛膝种子长期保存的最佳方法,保存3年后当其他保存方式的种子寿命几乎丧失时,其生活力及发芽率仍保持在较高水平,分别为60.3％和49.9％;其次为超干燥贮藏,种子生活力和发芽率分别为51.3％和41.2％.     

Cr~(6+)污染对白菜的生态毒理效应研究

试验采用水培方法研究了白菜种子和幼苗对铬离子的富集能力与耐受性,铬离子对白菜叶绿素a、叶绿素b、类胡萝卜素浓度的影响。结果表明随Cr6+浓度梯度的变化,白菜种子萌发抑制率的差异不显著,而对白菜生长起到明显的抑制作用。随Cr6+浓度梯度的升高,Cr6+对叶绿素a和叶绿素b的抑制作用加剧,Cr6+对叶绿素a的抑制效果更明显。白菜根对铬离子的富集量大于茎,根的富集能力最强。铬离子影响白菜幼苗的正常生长,白菜对铬离子具有一定耐受性。     

乙酰甲胺磷和汞单一及复合污染对黄瓜发芽及幼苗生长的影响

有机磷农药和重金属是目前我国土壤中较常见的污染物。本文以黄瓜种子为供试作物,研究了重金属汞与农药乙酰甲胺磷单一污染及复合污染对其发芽率以及幼苗生长的毒害效应。结果表明,Hg2+与乙酰甲胺磷单一污染及复合污染对黄瓜种子的发芽率、芽长和根伸长的生态毒性敏感程度依次为:根伸长>芽长>发芽率,Hg2+与乙酰甲胺磷单一污染及复合污染对黄瓜幼苗的毒害效应均较明显。复合污染对黄瓜种子发芽指标和幼苗生长的抑制效应表现为协同作用,其结果是复合污染的整体生态毒性效应增强。研究结果为进一步研究农药和重金属复合污染的生态毒性提供基础资料。     

壳聚糖对小麦发芽及生根效应的研究

利用壳聚糖浸泡小麦种子,通过考察小麦的出芽率、发芽指数、活力指数、生根数量和根的长度等各项指标的变化,探讨壳聚糖对小麦发芽和生根生理效应的影响.结果表明,当pH值6.5、壳聚糖浓度为4-6mg/mL时能显著提高小麦种子活力,促进幼苗生长;当壳聚糖浓度低于8mg/mL时,小麦的出芽率、发芽指数、活力指数随壳聚糖处理浓度的增大而明显提高;当壳聚糖浓度为4mg/mL、浸泡时间为10h时,小麦种子生根效应最为明显.