元宝槭VA菌根的研究

自然状态下,球囊霉属(Glomus)的真菌为元宝械VA菌根菌优势种;在幼龄到壮龄期随树龄增加VA菌根感染强度增强,而后逐渐减弱;苗期接种VA菌根菌可提高菌根感染率,促进苗木生长。     

果树VA菌根研究进展

ＶＡ菌根是分布最广的内生菌根。ＶＡ菌根真菌能和多种果树的根系共生。本文了影响果树ＶＡ菌根自然侵染率的因素,ＶＡ菌根对果树矿质营养、水分状况、生长、抗病性及抗盐碱的效应,并对ＶＡ菌根在果树上的应用前景提出设想。     

VA菌根与植物病害

从VA菌根对真菌、细菌、线虫等引起的病害影响,VA菌根菌诱导寄主产生与抗病有关的次生代谢产物和酶类,VA菌根对根际微生物区系的影响以及少数VA菌根促进病害发生的原因等几方面,就近年来VA菌根对植物病害的影响及其机理进行了综述。     

VA菌根与果树矿质营养

对VA菌根的研究概况、VA菌根的形成的VA菌根与果树矿质营养的关系及其应用前景做一综述。     

苹果树VA菌根形态结构观察

研究了苹果树ＶＡ菌根在自然条件下的发育状况。观察结果表明：ＶＡ菌根结构主要位于各供试品种新生根的成熟区和伸长区，在根皮层细胞内具型的泡囊和丛枝。根内和根外菌丝的直径为２．１￣４．５μｍ，泡囊主要呈椭圆形和圆形。不同品种之间的泡囊数、丛枝百分率、根上菌丝着生位点数及侵染率存在显著差异。不同粗度的根系ＶＡ菌根真菌的侵染情况存在着差异，其中直径０．１－０．５ｍｍ的细根，ＶＡ菌根真菌的侵染率最高。不同土层     

园艺作物VA菌根研究进展

综述了近年来国内外有关VA菌根对园艺作物生长发育，矿质营养吸收，抗逆性（干旱，盐碱害，非节律性变温）及抗病性4个方面影响的研究现状，展望了VA菌根在园艺作物上的应用前景。     

Effects of vesicular-arbuscular mycorrhizae on the drought resistance of wild jujube (Zizyphs spinosus Hu) seedlings

The current study explored the effects of vesicular-arbuscular mycorrhizae (VAM) inoculation on the growth and water requirement of pot-grown wild jujube (Zizyphs spinosus Hu). Three water regimes (20%, 40% and 60% of soil water content) were conducted. The VAM inoculation could significantly increase plant growth (including plant height, leaf area, and fresh and dry mass), enhance relative leaf water content, photosynthetic rates, transpiration rates and stomatal conductance, and improve plant drought tolerance. The water consumption of the mycorrhizal plants producing 1 g of dry matter was 18.7%–26.6% lower than the consumption of non-mycorrhizal plants grown under the same soil water content conditions. __________ Part of the results was translated from Acta Horticulturae Sinica, 2003, 30(1): 29–33 [部分译自: 园艺学报]     

紫云英根瘤菌分子遗传学研究进展

总结了紫云英根瘤菌分子遗传学研究进展。这类根瘤菌的寄主范围较窄，早先根据互接种族概念将其定名为Rhizobium astragali。后来定名为Rhizobium huakuii。最近并入Mesorhizobium属，对大量菌株进行的16S和23SrDNAPCR-RFLP分析和代表菌株的部分16SrDNA碱基测序，揭示了7个不同基因型，表明这类菌具有遗传多样性。可以认为存在不同的种，它们都有质粒，数量1-5个，因菌株而异，可分为不同质粒型。共生基因常定位在最大的一个质粒上，即共生质粒，它们的结瘤基因具有独特结构。采用包括nodA,nodB。noC,nodD的苜蓿根瘤菌突变株进行基因互补，从紫云英根瘤蓖基因文库中获得了相应的转移接合子，这类结瘤基因的这种结构在7个基因型的菌株中都是一致的，说明结瘤基因的保守性。     

西北盐碱土主要植物丛枝菌根研究

对西北地区盐碱土主要植物的丛枝菌根真菌共生状况进行了调查与分析。结果表明,在14科29种植物中,除红砂(Reaumuria songarica Maxim.)外,其余植物均被菌根真菌侵染,侵染比例为96.55%;在过去认为不被侵染的莎草科(Cyperaceae)和藜科(Chenopodiaceae)植物中,发现寸草苔(Carex duriuscula C.A.Mey.)、筛草(Carex kobomugi Ohwi)、盐角草(Saliconia europaea L.)、碱蓬(Suaeda glauca Beg.)和盐爪爪(Kalidium foliatumMoq.)有侵染现象;所调查的乔木和草本类植物的菌根植物比例为100%,灌木植物为87.50%;丛枝菌根结构类型以A型为主,占65.52%,P型占27.59%;菌根侵染率和侵染强度与植物的种类、生活型、根系类型及土壤含水量的关系密切;菌根结构类型主要受植物种类及其根系类型的影响,与土壤含水量和植物的生活型无关。     

Breeding against mycorrhizal symbiosis: Modern cotton (Gossypium hirsutum L.) varieties perform more poorly than older varieties except at very high phosphorus supply levels

Cotton (Gossypium hirsutum L.) is an important fiber cash crop, but its root traits related to phosphorus (P) acquisition, including mycorrhizal root traits, are poorly understood.  Eight cotton varieties bred in northwestern China that were released between 1950 and 2013 were grown in pots with or without one arbuscular mycorrhizal fungal (AMF) species (Funneliformis mosseae) at three P supply levels (0, 50 and 300 mg P as KH₂PO₄ kg^–1).  Eleven root traits were measured and calculated after 7 wk of growth.  The more recent accessions had smaller root diameters, acquired less P and produced less biomass, indicating an (inadvertent) varietal selection for thinner roots that provided less cortical space for AMF, which then increased the need for a high P fertilizer level.  At the two lower P levels, the mycorrhizal plants acquired more P and produced more biomass than non-mycorrhizal plants (3.2 vs. 0.9 mg P per plant; 1.8 vs. 0.9 g biomass per plant at P₀; 14.5 vs. 1.7 mg P per plant; and 4.7 vs. 1.6 g biomass per plant at P₅₀).  At the highest P level, the mycorrhizal plants acquired more P than non-mycorrhizal plants (18.8 vs. 13.4 mg per P plant), but there was no difference in biomass (6.2 vs. 6.3 g per plant).  At the intermediate P level, root diameter was significantly positively correlated with shoot biomass, P concentration and the P content of mycorrhizal plants.  The results of our study support the importance of the outsourcing model of P acquisition in the root economics space framework.  Inadvertent varietal selection in the last decades, resulting in thinner roots and a lower benefit from AMF, has led to a lower productivity of cotton varieties at moderate P supply (i.e., when mycorrhizal, the average biomass of older varieties 5.0 g per plant vs. biomass of newer varieties 4.4 g per plant), indicating the need to rethink cotton breeding efforts in order to achieve high yields without very high P input.  One feasible way to solve the problem of inadvertent varietal selection for cotton is to be aware of the trade-offs between the root do-it-yourself strategy and the outsourcing towards AMF strategy, and to consider both morphological and mycorrhizal root traits when breeding cotton varieties.     

AFLP标记技术在甘薯育种中的应用进展

近年来,AFLP分子标记技术已经逐步应用于甘薯的遗传育种研究中。本文简要概述了AFLP技术在甘薯的起源、进化与亲缘关系研究、遗传多样性分析、连锁图谱构建及基因定位和分子标记辅助育种等的应用进展,并对其发展前景进行了展望。     

VA菌根真菌对植物养分吸收与传递的影响

VA菌根是泡囊-丛枝内生菌根菌与高等植物根系形成的共生体.VA菌丝增加根系的吸收面积,促进植物对矿质养分(尤其是磷和微量元素)的吸收,增强植物抵抗养分胁迫的能力,减少氮、磷肥的使用量和流失,从而避免水体富营养化.VA菌丝可以形成菌丝桥,在不同植株间传递养分,成为生态系统养分循环的重要通道.     

干旱胁迫下AM真菌对矿区土壤改良与玉米生长的影响

以神东矿区塌陷区退化土壤为供试基质,以玉米为宿主植物,研究在干旱胁迫下,丛枝菌根真菌(arbuscular mycorrhizal fungi)对玉米生长和养分吸收的影响,以及对矿区退化土壤的改良作用。结果表明:干旱胁迫下,接种AMF显著提高了玉米根系侵染率和生物量,玉米叶片相对含水量和叶色值明显高于对照组;接种组玉米地上部分磷、氮、钙和根系部分磷、钾、钙含量显著增加;接种AMF后,玉米根际土壤总球囊霉素和易提取球囊霉素含量分别增加了36.2%和33%,且根际土壤中有机质含量显著增加。由此可见,接种AMF促进了玉米对矿质养分的吸收,缓解了干旱造成的玉米生长的不利影响,提高了根际土壤中有机质含量,对矿区退化土壤改良有重要意义。     

植物病原真菌分子生物学研究进展

就近年来分子生物学技术在植物病原真菌研究中的进展进行了综述。内 容涉及植物病原真菌的种类鉴定、群体遗传、致病机理、发育调控及抗药性机制等方面，列举了代表性应用实例，并就植物病原真菌分子生物学研究的重要性及分子生物学技术在植物病原真菌研究中的广阔前景进行了展望。     

大气臭氧浓度升高对丛枝菌根(AM)及其功能的影响

通过模拟大气O₃浓度(0.02μL·L^-1、0.1μL·L^-1和0.2μL·L^-1)升高,观察其对丛枝菌根(AM)及功能的影响.结果表明,大气O₃浓度升高对菌根侵染率影响较小,但对孢子和外生菌丝影响显著,高浓度O₃时的孢子数比自然O₃浓度时增加1倍,低、高浓度O₃分别使AM外生菌丝量比自然浓度时下降48.7%和85.6%.随着O相似文献   

龙头山区野生花卉丛枝菌根调查及应用

采用热碱液透明根系后再以苯胺蓝染色的方法 ,调查了龙头山地区 4 2种有代表性的野生花卉的丛枝菌根(AM)状况 .结果表明 :在调查的 4 2种植物中 ,有 90 7%的种类根系不同程度地受到AM真菌侵染 ,仅糖芥、玉竹、沙葱根系中没有观察到AM真菌结构 .柳兰是调查区草甸群落中的优势种 ,在该次调查中表现出较高的侵染程度 .前期引种试验表明 ,柳兰幼苗成活率低、苗期生长缓慢 .将采自柳兰根系附近含有混合土著AM真菌的土壤和残根 ,在温室条件下以三叶草进行富集培养 ,3个月后用培养物接种柳兰 ,幼苗存活率得到大幅度提高 ;与对照相比 ,接种土著AM真菌可以显著地提高柳兰幼苗早期叶面积和株高 .