森林生态系统铝毒危害研究进展

铝毒是酸性条件下抑制林木生长、造成森林大面积衰退的主要原因.近年来, 世界各国针对铝毒害机理及植物的耐铝机制进行了大量研究, 然而目前研究者对植物铝毒报道多限于农作物, 对林业铝毒的综述性报道还不多见.文中从森林土壤铝毒产生的原因、铝毒害机理、林木响应机制、铝毒对森林生态系统的危害以及防治措施等方面综述了森林生态系统铝毒的研究进展, 对我国森林资源保护和林木管理具有重要意义; 并提出林业铝毒研究存在的问题及今后的研究方向, 为进一步开展林业铝毒研究提供参考.     

酸性土壤植物锰毒与修复措施研究进展

指出了锰是植物必需微量元素,但过量的锰会对植物产生毒害。锰毒作为酸性土壤上主要的植物生长限制因子,已引起了越来越多的关注。综述了近年来有关土壤锰有效性、植物锰毒症状、锰毒害生理过程、植物耐锰机制和对应的锰毒修复措施等方面的研究进展。     

铝毒害与森林衰退研究评述

综述了国内外森林衰退与铝毒害研究现状.国外诸多研究表明,森林衰退与铝毒害有着紧密联系,但国内大面积多树种人工林衰退是否与铝毒害有关,尚未引起学术界的高度重视.     

植物铝毒害研究进展

综述了国内外有关植物铝毒害的研究进展 ,其中包括铝的形态及其植物毒性、植物铝毒害的症状、植物铝毒害的生理生化反应 (包括对养分、水分的吸收和运输、光合作用、呼吸作用、质膜透性、活性氧代谢、氮代谢、碳水化合物代谢、核酸代谢等的影响 )。     

林木低磷胁迫适应机制研究进展

土壤有效磷缺乏在自然环境中是一种非常普遍的现象,近年来世界各国针对植物的觅磷和耐磷机制进行了大量研究,然而目前相关的综述性报道多限于农作物,对林木低磷胁迫适应性的综述性报道尚不多见。在长期进化过程中,林木为利用土壤中现有的含量极低的有效磷,形成了各种适应低磷胁迫的机制。文中从林木根系的形态学变化、根系分泌物对土壤难溶性磷的活化作用、林木对土壤低浓度有效磷的吸收利用以及应对低磷胁迫的遗传调控等方面综述了低磷环境中林木的适应机制,为揭示林木对缺磷环境的适应机理、发掘林木自身对土壤有效磷高效率的吸收利用能力、以及进一步筛选林木的磷高效品种和合理经营管理人工林提供参考。     

林木抗虫机制研究进展

分别从林木对害虫的抗性防卫、林木抗虫的化学机制及遗传机制等方面 ,对国内外林木抗虫机制研究的现状与进展进行了综述。认为抗虫性不是单因素的 ,而是形态学、解剖学及生理生化因子和谐作用下对入侵昆虫产生的物理和化学影响能力     

土壤中铝对马尾松影响的试验研究

70年代以来,世界发生了大面积的森林衰退,给林业生产带来了不可估量的损失。从目前的研究情况看,土壤酸化引起的铝毒可能是森林衰退的原因之一。以Ulrich为首提出了铝毒假说,各国相继研究了铝对森林树种的影响,但大部分实验都限于室内模拟或现场类比调查,缺乏更直接的野外研究,为此,本文采用了一种新的方法——孔洞根系生长法,进行野外实验研究,测定了铝对森林马尾松的影响。     

铝处理对桉树幼苗抗氧化酶CAT和POD活性的影响

采用室内水培试验法,研究了铝处理对广西2个优良桉树无性系(Eucalyptus grandis×E.urophylla No.9和E.urophylla No.4,分别记为G9、G4)根系及叶片内CAT、POD的影响,为进一步揭示速生桉对铝毒害的响应机制及选育耐铝型速生桉优良无性系提供参考,结果表明:(1)桉树叶片中CAT、POD对活性氧的清除起主要作用,而POD对铝处理最为敏感,CAT对铝处理最不敏感,在根和叶中均有此规律。(2)铝处理下,2个桉树无性系根、叶内CAT、POD活性均发生变化,变化幅度差别较大,不同酶在不同部位对铝毒害的响应程度不一致,CAT在根内对铝处理响应较强,POD在G9叶内及G4根内对铝处理响应较强。     

不同铝毒害对毛竹笋营养品质影响的研究

铝毒害是酸性土壤中植物生长发育的一个主要限制因素,为了探讨不同铝毒害对毛竹笋营养品质的影响规律,试验采用二因素正交旋转回归设计,分析不同试验处理对笋品质的影响。     

细胞工程育种——林木耐盐体细胞突变体育种研究进展

本文综述了组织和细胞培养筛选林木耐盐体细胞突变体的研究进展,论述了确定耐盐体细胞突变体的生理生化研究工作,简单介绍了DNA分子遗传标记在这一领域的应用情况,并对林木耐盐突变体育种进行了展望。     

Root parameters of forest trees as sensitive indicators of acidifying pollutants: a review of research of Japanese forest trees

The root parameters of forest trees can be indicators of a changing environment. We summarize the results of root studies with regard to the effects of acidifying pollutants, especially soil acidification and aluminum toxicity, on various root parameters of Japanese forest trees under experimentally controlled conditions. All root parameters such as biomass, morphology, nutritional status, and physiology can be regarded as indicators, because, under laboratory conditions, root responses occur prior to the responses in the aboveground parts. However, considering the conditions of forest sites, the nutritional status and physiological changes are better indicators of soil acidification and Al stress than the biomass and morphological response. The currently available data suggest that the most important indicator is the Ca/Al molar ratio in roots of Japanese tree species. In order to predict and detect the initial effects of soil acidification, we postulate that the specific root response to the Ca/Al molar ratio of tree roots should be considered as a parameter for use in long-term forest monitoring sites.     

林木对低P胁迫的适应性机制和遗传学研究进展

土壤具有巨大P库,但有效P含量很低,培育有效利用土壤P素的林木基因型,可从根本上解决土壤有效P的缺乏。本文结合国内外植物营养遗传和改良研究成果,就林木有效利用土壤P素的基因型差异、对低P胁迫的适应机理、P效率的遗传控制、耐低P种质资源筛选和新品种培育等进行述评。基于资源与环境问题考虑,作者认为P效率应作为一个重要的林木育种目标,加强我国主要造林树种以P效率为主的营养利用效率遗传改良,以达到低投入、高产出、无污染的人工林可持续发展目标。     

成花调节在林木育种中的应用

花发育是一个复杂的形态建成过程,了解林木花发育分子机理对实现林木的遗传调控具有重要意义。本文综述林木成花的分子机制的研究进展和以转基因等技术定向调控林木及木本经济作物生殖生长的实践案例,并对成花调节在林木育种中的应用前景进行展望。     

Induction of callose in roots of Norway spruce seedlings after short-term exposure to aluminum

Callose (1,3-beta-glucan) is a suggested physiological indicator of aluminum (Al) toxicity in crop plants. It is not known if callose serves a similar function in forest trees, because quantitative data on callose formation in tree roots are limited, particularly under controlled conditions. To evaluate callose as a physiological indicator of Al toxicity in tree roots, we quantified callose formation in roots of Norway spruce (Picea abies (L.) Karst.) seedlings. Seedlings were grown in simulated soil solutions in the presence or absence (control) of Al under controlled conditions. In seedlings grown in solutions containing 280 microM Al, callose concentrations in roots were twice as high as control values after 6 h of Al treatment and 5 times higher than control values after 1 day. Thereafter, root callose concentrations gradually decreased and were only twice as high as control values after 7 days. The presence of various Al concentrations in the simulated soil solutions indicated that callose was induced by a relatively low Al concentration (84 microM). We conclude that callose in tree roots is an indicator of Al toxicity.     

林木成花分子基础研究进展

多数林木的幼年期长、始花期晚,为了探索林木早花的分子机制,克服经济林木育种周期长的难题,为进一步的林木童期调控和分子育种研究奠定基础,综述了高等植物的成花假说、成花诱导分子机理、林木成花相关基因的克隆及相关生理信号的研究进展．     

Accretion, partitioning and sequestration of calcium and aluminum in red spruce foliage: implications for tree health

Calcium (Ca) is an essential macronutrient in plants and is an important component of many cellular structures and physiological processes as well as overall forest function. Aluminum (Al) in soil solution can inhibit Ca uptake by plants and disrupt many Ca-dependent metabolic and physiological processes of plants. The ratio of Ca to Al in soil solution can be an important indicator of forest health, especially on acid soils. We used sequential chemical extractions (water, acetic acid and hydrochloric acid) to assess the chemical availability of Ca and Al in foliage from mature red spruce (Picea rubens Sarg.) trees growing under ambient environmental conditions. In plants deficient in Ca and with intermediate total foliar Ca concentration ([Ca]), Ca preferentially accrued in labile and physiologically available forms (water- and acetic acid-extractable). In plants with total foliar [Ca] above a "sufficiency" threshold, Ca also accrued in a chemically sequestered form with low solubility (HCl-extractable), suggesting that Ca sequestration is an inducible process in response to excess foliar Ca. Because it has low solubility, it is likely that sequestered Ca is unavailable for Ca-dependent physiological processes. Immobilization of Al in foliage was related to Ca sequestration, suggesting that Ca sequestration may provide a passive mechanism for Al tolerance in the foliage of these trees. Aluminum immobilization was evident based on the ratio of HCl-extractable Al to the more labile (water- and acetic acid-extractable) forms of Al. Sufficient labile Ca combined with Al sequestration was associated with plant health, including enhanced foliar accretion of Mg and Mn, greater tree growth, enhanced foliar cold hardiness and reduced winter injury. These findings demonstrate that not all chemical forms of foliar Ca and Al are of equal physiological significance and underscore the importance of assessing the biologically significant element forms in biogeochemical research.     

林火干扰对森林土壤活性有机碳影响的研究

土壤活性有机碳作为森林土壤有机碳的活跃成分，在凋落物分解和土壤碳循环中发挥着重要作用。林火干扰通过改变土壤底物的数量和理化性质进而影响土壤活性有机碳，因而阐明林火干扰对土壤活性有机碳的影响是开展森林碳循环研究的基础。文中以6种土壤活性有机碳为研究对象，分别阐述林火干扰对土壤活性有机碳影响的研究进展。针对目前研究现状及存在问题，认为应进一步深化探究林火干扰后土壤微生物活性变化机制对土壤活性有机碳的影响，揭示土壤碳库平衡的影响机理；加强林火干扰后C-N耦合循环特征的研究；深入研究林火干扰后影响土壤活性有机碳的内在因素和外在因素的相互作用，综合评价林火干扰对土壤活性有机碳的短期与长期影响；加强林火干扰—土壤碳库—全球气候变化的交互关系研究，深入探讨林火干扰与土壤活性有机碳的相互作用关系及影响机理。     

杉木人工林地力衰退研究进展

杉木作为我国重要速生树种,在我国林业生产中占据不可或缺的重要地位,但其地力衰退问题日益显露,已引起相关学者的高度重视。文中通过查阅大量文献,在前人研究的基础上,论述了杉木人工林地力衰退特征,如土壤酸化、缺磷、富铝和化感等;从不同角度论述了杉木人工林地力衰退的原因,如酸沉降加剧、不适宜的营林活动、肥料施用不当等;提出了一系列维护措施,如轮作、营造混交林、追肥等;概述了杉木人工林地力衰退的最新研究进展及今后的研究方向。