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排序方式: 共有203条查询结果,搜索用时 15 毫秒
91.
Albert Kollmann Isabelle Touton Agathe Brault Michel Alvinerie Pierre Galtier Christian Mougin 《Environmental Chemistry Letters》2003,1(4):215-218
We investigated the effect of ivermectin, at environmental concentrations and above, on several strains of filamentous fungi. Ivermectin did not show significant short-term effect on biomass production and germination rate of the spores. By contrast, the spore production was stimulated twofold in Phanerochaete chrysosporium and Mucor racemosus cultures, whereas that endpoint was reduced in Fusarium cultures. A long-term exposure of F. oxysporum to ivermectin reduced both production and germination of fungal spores. Ivermectin was not an inducer of exocellular oxidases. 相似文献
92.
Greenhouse experiments were conducted to determine the effects of sand burial on survival and growth of seedlings ofCirsium pitcheri. In 1992–1993, seedlings were buried to depths of 0, 25, 50, 75, and 100% of their height while in 1993–1994, the seedlings
were buried to depths of 0, 4 cm (single burial), 4 cm (repeated burial of 1 cm every 8 days), 8 cm (single burial) and 8
cm (repeated burial of 2 cm every 8 days). Several physiological traits, net photosynthetic rate, chlorophyll a∶b ratio, leaf
area, number and length of leaves, number of internodes, amount of tillering, and biomass, were measured. The results showed
that all seedlings died in the complete (100%) burial, 20% died in the 75% burial and none died in the 0, 25 and 50% burial
treatments. Burial of seedlings to a depth of 25% stimulated their growth but 75% burial significantly decreased the total
dry weight. Repeated burial treatments exhibited significantly greater stimulation of growth than single burial. Surviving
seedlings grew through the sand deposit by elongating the stem and leaf petioles, increasing the number of nodes and the length
of internodes. This elongation occurred at the expense of development of the root system indicating that available energy
was re-allocated to above-ground parts. 相似文献
93.
极低频电磁场对萌发期大豆的生物学效应 总被引:4,自引:2,他引:4
观察了50Hz.0.2mT或6.0mT的电磁场暴露对大豆的萌发过程,丙二醛(MDA)含量,超氧化物歧化酶(SOD),过氧化氢酶(CAT),过氧化物酶(POD),蛋白酶活性和可溶性蛋白含量以及幼苗根茎的组织形态学影响。结果表明:电磁场暴露下,大豆的开始萌发时间由32h提前到8h,萌发率到达50%的时间由72h分别提前到48h(0.2mT组)和40h(6.0mT组);MDA含量随磁场强度的增大而下降;SOD,POD活性随磁场强度的增大而升高,而CAT活性在0.2mT暴露组下降,在6.0mT暴露组升高;蛋白酶活性和可溶性蛋白含量分别随磁场强度的增大升高或降低。幼苗根茎细胞的大小和形态没有明显变化。结果提示,极低频电磁场可以改变抗氧化酶的活性,减缓脂质过氧化,增强蛋白酶的活性,促进大豆的萌发过程。图4参6。 相似文献
94.
分别以锯末、玉米芯、麦麸、稻壳和堆肥腐熟物作为调理剂,与水果、蔬菜垃圾进行好氧堆肥试验,分析了各处理堆肥过程中的温度、含水率、有机质、p H值、EC、全氮和GI的变化情况。结果表明:各处理组的含水率和有机质总体上呈下降的规律,且堆肥结束时EC都在适宜范围内,堆肥腐熟物处理的有机质下降最高,且全氮含量有所升高;其中,麦麸处理的堆肥升温最快,高温持续时间最长,种子发芽率也最高。综合来看,在本研究范围内,麦麸为水果蔬菜有机垃圾堆肥的最适宜调理剂。 相似文献
95.
96.
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%. 相似文献
97.
98.
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。 相似文献
99.
壳聚糖对小麦发芽及生根效应的研究 总被引:1,自引:0,他引:1
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. 相似文献
100.
Antoine Gardarin 《Ecological modelling》2011,222(3):626-636
In fields, the timing of weed emergence flushes is mostly related to the timing and rate of seed germination, which depend on seed dormancy level, soil temperature and water potential conditions as well as soil tillage and crop sowing date. Seed germination parameters are essential in weed dynamics models to account for the effects of soil conditions on weed demography. Since these parameters are difficult to measure, our objective was to test the possibility of estimating them from easily accessible information. Seed germination parameters (germination lag-time, time to mid-germination and mid-germination rate) were measured or collected from the literature for 25 weed species with contrasted seed characteristics. Correlations were then searched for between these parameters and morphological, chemical and physiological seed traits as well as seed dormancy level. The dormancy level was positively correlated with speed of germination parameters. Earliness of germination was positively correlated with seed lipid content and the seed area to mass ratio. Germination was also earlier and faster in species with a high base temperature for germination. These relationships explained about half the observed variability in germination speed parameters but should be further tested before being used to predict the germination behaviour of weed species in the field in different seasons. 相似文献