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1.
纵坑切梢小蠹伴生菌危害机理的研究 总被引:4,自引:2,他引:4
该文对纵坑切梢小蠹伴生菌Leptographium yunnanense的危害机理作了初步研究,结果表明,L.yunnanense在与小伴随侵入后,产生致病毒素对寄主树林进行危害,从而辅助纵坑切梢小蠹成功定殖于寄主树木内,该毒素在低浓度条件下仍维持一定的致病力,进一步表明伴生菌在小蠹虫成功蛀害的过程中具有重要的作用。 相似文献
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[目的]探讨3株源于滨麦的内生镰刀菌对北美枫香幼苗生长和耐盐性的调控效应,为开发极端环境中内生菌资源应用于林木抗性育苗提供理论基础。[方法]结合形态学和分子系统学方法鉴定内生镰刀菌并体外检测其毒素种类及含量,建立内生镰刀菌与无菌北美枫香实生幼苗共培养体系;利用台盼蓝染色观察菌株在根系组织中形成的侵染结构;在正常和盐胁迫条件下,研究内生镰刀菌对幼苗生长和耐盐性的影响。[结果]3个菌株分别为黄色镰刀菌(Class2-1B)、假禾谷镰刀菌(Class2-1C)和1株未鉴定到种的镰刀菌(Class2-3)。与2株强毒力农作物病原镰刀菌相比,Class2-1B、Class2-1C产毒素类型和含量极少,而Class2-3能产生大量恩镰孢菌素。Class2-1B、Class2-1C菌丝能顺利进入根部皮层细胞并形成串珠状的膨大细胞,Class2-3菌丝几乎只在根表定殖。接种试验表明:Class2-1B、Class2-1C接种幼苗的生物量、株高、根长和叶片数等多数指标显著高于对照组(P 0. 05),而Class2-3对幼苗生长有明显的抑制和毒害作用。3个菌株孢子混合接种也对幼苗表现出一定的促生效应。在海盐溶液胁迫处理下,Class2-1B处理组幼苗盐害指数显著低于对照组(P 0. 05),但处理组幼苗叶绿素体色素含量与对照组相比并无显著差异。[结论]3株内生镰刀菌菌株对北美枫香幼苗生长和耐盐的调控存在显著差异,正负效应可能与镰刀菌产毒素类型及含量有密切关系。 相似文献
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体细胞离体培养筛选桉树抗青枯病新品种研究 总被引:1,自引:0,他引:1
以尾叶桉胚性愈伤组织为材料,采用病原菌活体接种与添加致病毒素二种方法进行了离体条件下抗青枯病细胞无性系筛选研究。结果表明:采用致病毒素为抗病愈伤无性系选择压力时,所需致病毒素提取液的加入最适浓度为130 m L/L培养基,最适选择时间为培养后15 天;三种活体接种法选择抗病愈伤无性系时,培养基混菌法较为切实可行,加入浓度为50 m L/L菌液培养基为宜,选择时期为培养后10~12 天。愈伤组织的继代年龄对选择剂的加入量与选择效果有较大的影响,以接种后培养3~5 天的材料作为选择对象较好。 相似文献
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通过对杨树感病寄主美×青Populus pyramidalis×P.cathayana分离培养冰核细菌,初步确定春优势种为欧文氏菌Erwinia sp.1个菌株,假单孢菌Pseudomonas spp.3个菌株,室外杨树幼苗接种试验结果表明,冰核细菌引起杨树冻在,诱发肿茎溃疡病,是病害发生的主导因素。 相似文献
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AM菌对桉树幼苗接种可提高对青枯病的抗性。在有AM菌存在的情况下,桉树幼苗不发病或发病较轻。对两种桉树幼苗进行青枯病菌的人工接种结果表明:菌根苗比无菌根苗的发病率降低10%~40%,而幼树的高生长可增加12%~39%;AM菌对青枯病的防治效果优于外生菌根(即ECM)的效果,其中以AM6008和AM9004菌株的效果最好,而AM3006的效果较差;大田试验结果表明;经AM菌根化的幼苗对青枯病的抗病作用较强,发病率可下降10.0%~17.5%。 相似文献
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《内蒙古林业调查设计》2016,(4):112-114
文章以9种当地阔叶树种为研究对象,挑选同一林分阔叶树种枝丫材,经劈切捆成直径15cm和高20cm的接菌培养木段,接种发菌后,扣塑料棚进行地栽出芝,结果表明9种不同树种的木段均能出芝,但产量表现出较大的差异,不同树种对灵芝子实体和孢子粉产量由高至低的排序为千金榆、蒙古栎、柠劲子槭、最高,色木槭、假色槭、白榆其次,紫椴、白桦、核桃楸最低。试验结果为从事灵芝栽培产业选择适宜的树种木段接菌料提供依据。 相似文献
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影响木麻黄青枯病抗性测定的几项因素的研究 总被引:4,自引:1,他引:4
木麻黄无性系对青枯假单胞杆菌的抗病性测试受到植物材料、接种条件及病级测定三方面因素的影响。研究表明在无根苗与有根苗上病害的发生具有一致性特征,并且与高度相关,但无根苗更为感病。在三种龄期的无根苗中,以木质化的褐梗最为感病,绿梗次之,嫩枝较为抗病。青枯菌在连续培养14天后接种致病力不减。病害的相对强度在直射光、散射光及灯光等三种光照条件下无明显区别。病害强度随着接种浓度的增加而增高,但当达到一定程度后便趋缓。研究认为在室内以中等浓度的青枯菌液接种木麻黄无根褐梗苗是快速测定其抗性的一个可靠方法,并就采用相对病害强度代替发病株率作为病级指标等问题进行了讨论。 相似文献
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《Southern Forests》2013,75(3):215-220
The infection and association between the wood wasp Sirex noctilio and the fungus Amylostereum areolatum is responsible for large-scale tree mortality in the Midlands of the KwaZulu-Natal province in South Africa. An exploratory investigation on the effect of the infestation of trees by the wood wasp and its associated fungus on the chemical composition of Pinus patula pulpwood was undertaken. Various tree classes representing different levels of physiological growth stress from this infestation were compared. Together with the above stress agents, fire damage to P. patula trees was also considered as a possible cause of changes in pulpwood chemical composition. Chemical analyses to determine the Seifert cellulose and Klason lignin contents as well as the levels of water- and solvent-soluble extractives were conducted using published Tappi standard methods. The results indicated only negligible differences between infestation levels (tree classes) with respect to Seifert cellulose and Klason lignin contents. In contrast, highly significant differences were observed for solvent- and water-borne extractives. It is evident from the results that P. patula trees engage a defence strategy to counter the effects of the infestation and the resulting physiological stress. The results of the chemical analyses suggest that trees should not be harvested any younger than the intended rotation age of 12 years and at the time of harvesting all the biomass, including the infected wood, should be sent to the pulp mill. Fire-damaged trees can be utilised in the same way as healthy trees when applying the TMP process provided the charcoal on the outer bark is removed. The usefulness of a biplot to simultaneously display the various tree classes and their chemical composition is illustrated. 相似文献
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In nature, only a minority of alder trees infected by the alder yellows phytoplasma develop symptoms. To elucidate the reason for this phenomenon, healthy alder seedlings were inoculated with scion wood from five infected but differently affected trees. The symptoms developed by the inoculated plants largely corresponded to disease severity of the inoculum sources. Inoculation with tissue from three of four severely affected trees resulted in severe disease of the recipient trees as expressed by reduced vigour, sparse foliage and little leaves. Inoculum from one of the severe sources caused milder symptoms. No symptoms were developed when the inoculum was collected from a vigorous, non-symptomatic tree. From these results it can be concluded that the alder yellows phytoplasma is pathogenic to alder but that avirulent and low virulent strains do occur. 相似文献
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山东省长清县36个8年生美洲黑杨无性的木材基本密度、纤维长度,树高和胸径在无性系间的变异达极显著水平,用选优法选出5个密度较高,纤维较生,生长较快的优良无性系,它们的引种号分别是13号,3号,34号,22号和8号,除22号起源于加拿大外,其余均起源于美国,木材基本密度,纤维长度,树高和胸径的广义遗传力分别为0.32、0.40、0.43和0.71,材性和生长性受中等或较强遗传控制。树木生长速度分别与 相似文献
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To determine if trees respond to dynamic and static loading in the same manner, 2-year-old maritime pine (Pinus pinaster Ait.) trees were subjected to different types of mechanical loading in the field. One block of trees (the control) were kept in pots and planted in the field at an angle of 0 or 45 degrees to the vertical. A similar block of leaning potted trees was planted nearby and subjected to frequent, unilateral wind loading for a period of 1 s every 2 min. Half the leaning trees were oriented toward the direction of wind loading and half were oriented along the axis of wind loading. The stem profile was measured three times during the growing season to quantify the rate of stem straightening. Compression wood formation and stem shape were measured in all plants. No differences in mean height or diameter were observed between blocks and all leaning trees straightened, but not at the same rate. Although no difference in the rate of apical straightening occurred between control and wind-treated trees, the righting response of the basal part of the stem of leaning trees subjected to wind was four times greater than that of leaning trees without wind. No differences in the righting response were observed between leaning trees growing toward and trees growing away from the source of wind. No significant differences in compression wood formation were found between control trees and wind-treated trees, indicating that other factors must determine the reorientation rate of leaning trees. Results are discussed with reference to the quality of compression wood in conifers and the mechanotransductive pathway in plants. 相似文献
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This study considered the effects of thinning on the development of compression wood in stems of 35-year-old stand of Corsican
pine (Pinus nigra L.). Part of the stand had been thinned at 5-yearly intervals and part left unthinned. Twenty trees each from the thinned
and unthinned stands were randomly selected and felled. Measurements were made on tree height, stem diameter, stem slenderness
and canopy depth. Wood samples were removed from the central part of the main log and cross-sectional measurements made on
ring width, basic density and compression wood content. Cross-sectional area of compression wood was found to be three time
higher in stems from the unthinned trees in comparison with those from the thinned trees. No significant differences in mean
radial ring width or basic density were found between treatments. Correlations indicated that, with increasing in stem diameter,
compression wood content increased in the unthinned trees, while a decline in compression was observed in the thinned trees.
Tree height was also positively correlated with compression wood content in unthinned trees, while no equivalent relationship
was observed in thinned trees. Observations from this study, while not conclusive, suggest that phototropic stimulus may be
producing stem inclinations in the unthinned stand as trees compete for space in the canopy, whereas crown competition has
been largely eliminated in the thinned stand; and that this is responsible for compression wood levels recorded in this study. 相似文献
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Shigeru Yamauchi Yoichi Sakai Yasuo Watanabe Michael Kenya Kubo Hideaki Matsue 《Journal of Wood Science》2007,53(4):324-331
The distributions of boron in Japanese cedar (Cryptomeria japonica D. Don) sapwood blocks treated with aqueous or methanolic boric acid [B(OH)3] solutions were explored through Raman spectroscopy and prompt gamma-ray analysis (PGA). B(OH)3 was the sole boron species observed in Raman spectra of the wood blocks treated with either solution. Plots of weight gain
of the treated wood blocks versus boron concentration in treatment solutions were found to be linear. The results indicated
that the methanolic solution makes it possible to impregnate wood with much larger amounts of boron than the aqueous solution.
PGA confirmed that B(OH)3 was highly enriched near the end grains of the treated wood blocks. Raman measurements suggested that boron content in the
bulk of the wood block is not as large as expected from the weight gain of the treated wood blocks when an ordinary air-drying
method is used. It was concluded that the aqueous solution impregnates the cell walls of wood with boron more easily than
the methanolic solution.
Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan
Wood Research Society. This article follows the previous rapid communication “Analysis of boron in wood treated with boric
acid solutions using Doppler broadening method of prompt gamma-rays.” J Wood Sci (2006) 52:279–281 相似文献
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K. Rykowski 《Forest Pathology》1981,11(3):178-186
The chemical analysis of needles and wood of roots of trees belonging to four stages of disease caused by A. mellea in fertilized (N, P, K, Ca, Mg) and non-fertilized three Scotch Pine plantations were made. The attack caused gradual interruption of absorption and resulted in the exhaustion of some elements (N, P) and concentration of other ones (K, Ca) in needles and in the decrease of P and transitional growth of Mg-level in wood of roots. Considerable growth of concentration of some chemical substances in wood of roots of dead trees was observed. This referred to the fertilized and nonfertilized trees as well. The rate of these changes, however, was different after treatment: fertilization had no effect on the concentration of K in needles of trees in intermediate stages of disease, but it influenced in the lower rate the exhaustion of Mg in wood of roots. The role of K and Mg in defensive reactions is discussed. 相似文献
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Mirela Tulik 《European Journal of Forest Research》2014,133(5):845-855
Oaks’ decline in vitality is attributed to a complex process that involves interactions of several factors leading to increased trees’ mortality. This study investigates the structure of trunk wood of oaks with reference to its physiological role in hydraulic conductivity. On the basis of the crown condition, the oaks were classified into three health groups: healthy trees, declining trees and dead trees. Anatomical traits of wood, such as annual ring width, vessel density, vessel diameter of earlywood and theoretical hydraulic conductivity, were measured and calculated. The narrowest annual rings formed by the cambium were observed in dead oaks. These trees were also characterized by the smallest diameter of earlywood vessels, not only in the period of occurrence of dieback symptoms, but also during their whole life. It is suggested that the formation of narrow annual rings and earlywood vessels of small diameter increases susceptibility of a tree to decay. A reduced vessel diameter implies changes in hydraulic conductivity of oak trunks and thus impairs the water transport, which affects the health of trees. The process of oak decline is considered to have characteristics of natural selection and leads to the elimination of the weakest trees. 相似文献
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马尾松无性系种子园半同胞子代变异分析和家系选择 总被引:13,自引:0,他引:13
以福建省漳平五一林场马尾松无性系种子园自由授粉子代半同胞家系为研究对象,分析其树高、胸径、材积、冠幅、通直度、高径比、冠径比、木材基本密度、管胞长度和宽度、管胞长宽比等性状,发现家系间除管胞长宽比性状差异显著,其余性状均达差异极显著,暗示着马尾松种子园半同胞家系间存在较为丰富的变异,具选育潜力。8年生林分内各性状的家系遗传力以树高性状为最高(0·691),其次是木材基本密度(0·640)。各性状间的相关性分析结果表明,生长量性状的改良可间接改善通直度,且生长量性状与木材基本密度存在显著正相关关系,木材基本密度与管胞长度和宽度不相关。采用10%入选率,发现5年生林分和8年生林分入选家系一致,材积遗传增益分别达19·74%和19·23%,且5年生林分和8年生林分生长量性状的遗传相关极显著,认为马尾松制浆造纸材短轮伐期的初选年龄可确定为5年生;根据性状遗传力的相对大小和典型相关分析的结果,认为马尾松家系选择可适当注重树高生长量指标。以树高和材积为选择指标,按照10%入选率,兼顾材性和种子园内无性系的开花结实情况,筛选出制浆造纸材短轮伐期优良家系12个。 相似文献