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光肩星天牛对干旱胁迫下复叶槭挥发物的嗅觉反应   总被引:2,自引:0,他引:2  
对干旱胁迫下3a生复叶槭的挥发物进行了鉴定。当复叶槭受到干旱胁迫时,9种化合物释放量升高(包括:丁醇、戊醇、反—2—己烯—1—醛、顺—3—己烯—1—醇、戊醛、戊酸、己醛、己酸、苯乙酮),而长叶烯释放量降低:复叶槭复水后苯乙酮升高,但其他挥发物释放量降低。通过GC—EAD检测了光肩星天牛对其中某些化合物的触角电位反应,并使用诱捕器和人工合成单体进行了田间生测实验。丁醇、戊醇和顺—3—己烯—1—醇能引起光肩星天牛的触角反应,这一结果在田间实验中得到了证实。这表明干旱胁迫在光肩星天牛选择寄主植物方面起着重要作用。  相似文献   
3.
土壤含水量对三种阔叶树苗光合作用的影响   总被引:1,自引:0,他引:1  
研究了在温室内用盆栽法,其土壤含水量对茶条槭、山梨和山桃三种阔叶树苗光合作用的影响,以及各树种在土壤相对含水量为75.0%时光合作用的日变化.  相似文献   
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We assessed the effects of a prescribed fire on the phytochemical characteristics and vigor of overstory chestnut oak, scarlet oak, and red maple, and measured the impact of potential changes on herbivore fitness. We compared foliar carbohydrates, tannins, nutrients, and fiber concentrations in foliage from burned and non-burned forest canopies. There were significant differences in most foliar characteristics between tree species. Total non-structural carbohydrate concentrations in scarlet oak and red maple foliage, and calcium levels in red maple foliage, were significantly lower in burned plots, but other phytochemical characteristics were largely unaffected by burning. Tree growth also varied with species. Burning increased chestnut oak relative growth, decreased scarlet oak growth, and had no affect on red maple growth. Scarlet oak and red maple foliage from burned and non-burned forest canopies were assayed for gypsy moth performance. Caterpillars fed foliage from scarlet oak, the preferred host, grew larger and developed more rapidly than did those fed red maple foliage. There were no significant burn treatment differences in caterpillar development within either tree species, suggesting that managers using prescribed fire to promote oak regeneration need not worry about enhancing forest stand susceptibility to gypsy moth. However, the fire in this study was of low to moderate intensity; more intense fires may alter foliar palatability.  相似文献   
6.
申世杰  沈隽 《林业科技》1995,20(6):41-44
本文描述了利用山杨材制和复合胶合板的研究,研究结果表明,以其优质材料旋切的单板为表层材料,以劣质木材制作的刨花板为芯层材料制作和复合胶合板的主要物理力学性能指标与传统的胶合板板基本相同。  相似文献   
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莫梅英  冷扬  张志 《湛江医学院学报》2007,25(3):250-251,260
目的利用微核试验了解松木刨花和枫木刨花的遗传毒性。方法80只NIH种小白鼠随机分为8组,每组10只。其中3组分别以100、50、12.5g/kg剂量的松木刨花水提取物染毒,另3组分别以100、50、12.5g/kg剂量的枫木刨花水提取物染毒,1组(阳性对照组)以环磷酰胺50mg/kg染毒,1组((阴性对照组)以生理盐水染毒。染毒方法均是先经口染毒,24h后以同样剂量再次灌胃。6h后颈椎脱臼处死动物,制片,观察并计数嗜多染红细胞的微核率。结果以松木刨花及枫木刨花水提取物染毒的各组小白鼠的微核率与阳性对照组比较差异有统计学意义(P<0.01),与阴性对照组比较差异无统计学意义(P>0.05)。结论松木刨花和枫木刨花的水提取物对小鼠的骨髓细胞未见有何致突变性。  相似文献   
8.
The experiment was designed to study the histology of reproductive organ of Rana temporaria chensinesis David in reproductive season and dereproductive season, The results displayed that the sexual gland weight and oviduct weight of the Rana temporaria chensinesis David were significantly different between reproductive season and dereproductive season.  相似文献   
9.
本文从山杨小径材的材性与成熟材材性的差异,对干燥时易皱缩的原因作了研究和分析,并指出汽蒸两段式干燥基准可有效地减少皱缩。  相似文献   
10.
Community structures of Collembola and their seasonal fluctuations were studied in eight southern Quebec sugar maple (Acer saccharum Marsh.) forests growing on mull, moder and mor humus types. Endogeic species were extracted from soil cores using Berlese-Tullgren funnels while epigeic species were collected using pit-light traps (Luminoc®). Comparisons of species presence, abundance, and dominance among sites and seasons were done using Sorensen's similarity coefficients and CANOCO. A total of 92 species from 7 families and 35 genera were identified. Species dominance and community structure differed according to humus types. Two groups of endogeic species were identified. The mor/mor-moder type group included Folsomia penicula, Hypogastrura (Ceratophysella) spp. Que., Micrisotoma achromata, Onychiurus (Protaphorura)? parvicornis, Onychiurus (Onychiurus) sp. A Que. And Onychiurus (Onychiurus) sp. B Que. The mull/mull-moder type group included Isotoma (Desoria) notabilis, Tullbergia (Tullbergia) silvicola, Tullbergia (Tullbergia) clavata, and Pseudosinella alba. Such clear humus type relationships were not found among the epigeic species, but important seasonal changes in community structures were found for these species. Spring species were Sminthurinus (Katiannina) macgillivrayi, Hypogastrura (Ceratophysella) maheuxi, Hypogastrura (Hypogastrura) sp. A Que. and Sminthurinus (Sminthurinus) latimaculosus. Tomocerus (Pogonognathellus) flavescens, Sminthurinus (Sminthurinus) henshawi, and Orchesella hexfasciata appeared in the summer samples while Dicyrtoma (Dicyrtoma) aurata was found only in fall samples where it was dominant in most sites along with either Sminthurides (Sminthurides) lepus or Sminthurinus (Sminthurinus) quadrimaculatus. No strong seasonal trends were found among the dominant endogeic species.  相似文献   
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