库布齐沙漠穿沙公路路域封育效益研究

库布齐沙漠穿沙公路按地表状况划分为3个路段,通过对这3个路段的封育效果的不同层次的对比,得出了不同条件下的封育结果,并由该结果分析提出几点建议,为类似自然条件下实施封育措施提供参考。     

Improvement of Plant Regeneration from Immature Embryos of Wheat Infected by Agrobacterium tumefaciens

Wheat, one of the most important food crops, has been extensively studied with respects to plant regeneration and transformation employing the immature embryos as recipient tissues. However, the transformed tissues often become severely necrotic after co-cultivation with Agrobacterium, which is one of the major obstacles in gone delivery. In this study, wheat varieties CB037, Kenong 199, Xinchun 9, Lunxuan 987, and Shi 4185 showed desirable culture potential or high infection ability in Agrobacterium-mediated transformation. Similarly, optimal regeneration conditions were determined by testing their ability to inhibit the cell necrosis and cell death phenotype. Two auxins of 2,4-dichlorophenoxyacetic acid(2,4-D) and 3,6-dichloro-o-anisic acid (dicamba) were evaluated for highly significant effect on both callus and plantlet production, although they were genotype-dependent in wheat. Substitution of 2,4-D by dicamba enhanced the growth and regeneration ability of callus from the immature embryos of most genotypes tested. The callus growth state couldn't be modified by adding antioxidants such as ascorbic acid, cysteine, and silver nitrate or organic additives such as thiamine HCl and asparagine to the media. On the contrary, the best tissue statement and plant regeneration was achieved by employing the media containing the simplest MS (Murashige and Skoog) components and dicamba without organic components and vitamins. Thereby, our results are thought to inhibit wheat cell necrosis effectively and suggested to be used for more wheat genotypes.     

青花菜高频再生体系建立及芽再生机理的研究

以青花菜无菌苗的不同部位为外植体,研究了青花菜离体再生体系的建立以及芽形态建成过程中其组织内部生理生化的变化。结果表明:在所选用的外植体中,萌发10d的无菌苗下胚轴和生根15d的试管苗茎段为再生的最适外植体;在研究所涉及的生长调节剂中以6-BA/IBA对芽分化最有效,当培养基中6-BA/IBA为4.0/0.3mg/L时,下胚轴和茎段外植体芽分化率均高达96.67%。愈伤组织形成、不定芽分化均与其组织内部大分子变化有关,在整个芽再生过程中可溶性蛋白质含量呈增加趋势,过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、多酚氧化酶(PPO)活性也随着芽的形态发生呈现相应的变化。     

Assessing the potential for ash canopy tree replacement via current regeneration following emerald ash borer-caused mortality on southeastern Michigan landscapes

The emerald ash borer (EAB) has killed millions of ash trees in Michigan and at least fourteen other states since its first detection near its introduction point in metropolitan Detroit in 2002. Despite overstory ash mortality near 100% in many areas, ash seedling and saplings remain unaffected and provide the potential for ash re-establishment into the canopy of deciduous forests of the region. We examined the potential for ash re-establishment in areas of heavy mortality by measuring the status and change of ash regeneration at 45 sites across southeastern Lower Michigan in 2007 and 2009. Ash regeneration was found to be abundant in all forest types, particularly in the smallest height classes, though it was more abundant in ash species of upland forests compared to those of lowland forests. New seedlings 1-2 years old were less common than other regeneration size classes, and declined substantially between 2007 and 2009, suggesting a depletion of the ash seed bank in these forests. Regeneration density was not explained well by the presence of overstory ash prior to EAB introduction, suggesting that competitive interaction with other tree species in higher canopy strata is an important driver of ash regeneration density. Regeneration is sufficient to replenish overstory ash to pre-EAB levels in upland forests, though ecological changes caused by overstory ash mortality in lowland areas may affect local hydrology in a way that reduces opportunities for tree regeneration. Despite abundant ash regeneration, it remains unclear whether ash will recover to the overstory of forests in southeastern Michigan because of uncertainties in the future dynamics of EAB in the region.     

桃胚培养及子叶再生的研究进展

以国内外桃胚培养和子叶再生研究的相关文献为基础,综述了桃胚培养和子叶再生的研究进展,分析并讨论了影响桃胚培养和子叶再生的相关因子,并总结了桃胚培养和子叶再生的最佳培养条件。     

严格执行更新造林技术规程确保造林成活

介绍了保证造林成活率的技术要求、质量要求、管护要求,对提高造林成活率具有一定指导意义。     

间伐对辽东山区长白落叶松人工林生境和更新的影响

为弄清间伐对落叶松人工林内环境因子,进而对落叶松林内天然更新的影响,在辽东山区对40年生落叶松人工林进行了5种不同强度的间伐试验(分别为0%、10%、20%、30%和40%)。间伐后,对环境因子和更新状况进行了观测。结果表明,林冠开阔度随间伐强度增大而增加,间伐后其林冠下光量子数量、地表平均温度、不同层次土壤平均含水量与空隙度大小成线形关系;落叶松人工林间伐一年内,更新树种丰富度没有显著变化,而更新密度和更新频度都明显增加(p<0.05)。更新树种数量增加与树种特性有关,增长幅度为阳性树种>耐荫树种。所有的更新树种中,对林冠开阔度变化响应最大的是黄波罗(Phellodendronamurense)。实验结果证实了辽东地区落叶松人工林间伐后,更新数量变化与周围保留的树种分布、树种特性和立地条件有关。图9表2参43。     

江西德兴天然次生林林下幼苗更新特征

为了解实生和萌生幼苗个体数量及比例在各类植被中的变化情况,本文以江西德兴常绿阔叶林不同林分为研究对象,对各林型中幼苗的种类组成、数量、多样性与更新方式进行调查研究。结果表明：7种林分类型的乔木更新情况不同,德兴常绿阔叶林更新幼苗共35种,分属17科23属。更新苗数量最低的是拟赤杨＋马尾松林,仅为1 250株/hm^2,更新苗最多的林分类型为米槠＋甜槠林,为6 500株/hm^2;甜槠＋木荷林更新幼苗种类高达25种,居7种林分之首,马尾松＋木荷林下幼苗仅有10种;从演替更新年龄结构来看,马尾松＋木荷林和丝栗栲＋木荷林所在的群落,林下更新苗属于增长型锥体。其它5种林型属于下降型锥体。     

船舶柴油机尾气中 PM 颗粒的控制技术研究

根据研究前期内容系统介绍了减少柴油机颗粒物（PM ,particulate matter）排放的后处理技术,从实船应用等方面分析了各处理技术的优缺点,结合研究内容对PM 及其他有害物质的综合处理技术进行了探讨。     

人工促进天然更新的技术措施

延平区林木采伐后多数以营造人工林为主,现残存天然阔叶林比例逐年减少,加上人为破坏严重,取而代之的是大面积人工针叶林,使得森林结构分布极度不均衡,生态环境不断恶化。因此,需要转变传统人工造林更新观念,通过提高人工促进天然更新技术恢复森林,以扩大阔叶林资源,促进森林群落演替以及物种多样性,这对于保持森林的生态平衡,保护地力,减少森林病虫害,充分利用自然力,节约劳动力,降低造林成本,提高经济效益等方面都具有重要意义。