菌根真菌菌种的更替与其可持续性的研究

巨尾桉菌根化组培苗试验林中所接种的彩色豆马勃,已持续生存达10a之久;而接种的西澳粘滑菇、漆蜡蘑仅生存2～6a,之后则被其它菌根菌种所更替。自然条件下未经接种的的蓝桉人工林,造林后2～4a的林中以硬皮马勃、漆蜡蘑等菌根真菌为主;之后则先后由鸡油菌和牛肝菌所取代。松茸菌在适合的自然条件下可在林中生存达数十年之久,其持续性十分明显;人工接种松茸菌的云南松幼苗上,经6a的连续观察,菌丝体仍然生长旺盛。菌根真菌的菌种更替现象及可持续性与菌种本身的生长特性有关。若菌种能适应其环境条件,则生长可持续下去;反之则可能被其它菌种所更替,因此,菌根技术的推广应用,应坚持“适地适菌”和“适树适菌”的原则,方可取得持久的接种效果。     

丛枝菌根真菌提高林木抗逆性机制研究进展

丛枝菌根（AM）真菌是存在于土壤中的重要真菌之一,它能够与宿主林木根系产生互利共生体,从而对林木的生长发育有着多种促进作用。文中综述了近10年来国内外关于AM真菌对林木影响的研究进展,包括AM真菌对林木的抗旱性、抗病性、抗盐性、耐热性、耐虫性及对有害重金属抗性的影响等,通过促进林木光合作用、营养吸收、新陈代谢等来增加林木生长量、生物量的积累,从而提高林木的抗逆性;对在AM真菌研究中存在的难题进行了分析,并对其在林木中的应用研究进行了展望,旨在为林木抗逆性机制研究、森林经营等提供科学参考。     

丛枝菌根真菌提高植物非生物胁迫耐受性研究进展

丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF或AM真菌)是一种在土壤中广泛存在的有益真菌,能与地球上80％左右陆生植物根系共生形成丛枝菌根结构.AM真菌能通过与宿主植物交换碳源,促进宿主植物对N和P等无机营养元素的吸收,提高植株生产力和抵抗非生物胁迫的能力.全球气候变化和化肥农药的使用...     

ADDRESS BY THE HON. W. A. MAREE,MINISTER OF FORESTRY,TO THE SOUTH AFRICAN LUMBER MILLERS ASSOCIATION

This article deals with statistical inference in forestry reasearch. After an introductory review of definitions, the applications, limitations and range of validity of statistical tests of significance and their use in the analysis of variance are discussed.

The basic principles of various experimental designs are briefly outlined.     

丛枝菌根对油桐幼苗生长和氮磷吸收的影响

通过非灭菌土盆栽接种试验,观察了Glomus mosseae(GM)、G.intraradices(GI)、G.aggregatum(GA)和G.atunicatum(GE)4种AM真菌对油桐幼苗生长和氮磷吸收的影响,结果表明接种GM、GI和GE后菌根侵染率显著提高,侵染率分别为77.4%、92.3%和96.7%,比对照分别提高20.4%、43.5%、50.4%。接种GA与对照无显著差异;接种GM和GI后植株的干质量增加,而接种GA和GE对全株及各器官干质量影响不明显;接种4种真菌对油桐幼苗的氮素营养影响不大;接种GM、GI和GE显著提高了根部磷含量。综合考虑,接种GM效果最好。     

黄芪幼苗丛枝菌根形成过程研究

盆栽灭菌条件下,研究了黄芪Astragalus membranaceus与摩西球囊霉Glomus mosseae形成丛枝菌根的过程及细胞结构变化情况。结果发现,黄芪接种34 d时,真菌菌丝开始侵染根表皮;44 d时菌丝在皮层细胞内逐渐增多,并且细胞间有极少量泡囊产生,形状为椭圆形;54 d时细胞内大量菌丝扩展;63 d时有大量真菌孢子萌发;84 d时细胞间有大量泡囊形成,呈圆形、近圆形或椭圆形,部分泡囊开始收缩衰老,同时皮层细胞内有少量丛枝并存。生长期间,菌根侵染率和孢子密度的变化与丛枝菌根的发育状况密切相关。     

Root-associated fungi of healthy-looking Pinus sylvestris and Picea abies seedlings in Swedish forest nurseries

The aim of this study was to assess fungal communities in roots of healthy-looking Pinus sylvestris L. and Picea abies (L.) Karst. seedlings in nine forest nurseries in Sweden using a combination of traditional culturing and direct sequencing of internal transcribed spacer of fungal ribosomal RNA (ITS rRNA) from the roots. Culturing from 1800 surface-sterilised root segments resulted in 2387 fungal cultures representing 42 different taxa. Direct sequencing from 180 root segments resulted in 119 ITS rRNA sequences representing 25 different taxa. In total, 55 different fungal taxa were detected using both methods. Although direct sequencing was more efficient than culturing in detecting different fungal taxa, both methods provided complementary information about fungal communities in roots since each detected rather different groups of fungi. The most dominant taxa detected by culturing were Trichoderma viride Pers. (19.5%), Phoma mucivora Davey & Currah (19.1%), Phialocephala fortinii Wang & Wilcox (17.4%) and Meliniomyces variabilis Hambl. & Sigler (10.2%), while Thelephora terrestris Ehrh. (26.1%), Unidentified sp. NS126 (25.2%) and Heliotales sp. C20 (10.1%) were most commonly detected by direct sequencing. In conclusion, results showed that forest nurseries in Sweden harbour diverse communities of fungi associated with the roots of healthy-looking P. sylvestris and P. abies seedlings. Although fungal communities were often dominated by saprotrophs and endophytes, several facultative pathogens were also detected indicating that under suitable conditions they may be a potential threat to the plants.     

马尾松共生菌根真菌调查研究

通过野外调查和室内鉴定,已查明与马尾松共生的菌根真菌27个种,其中有19个种是国内首次报道的。编制了马尾松菌根真菌名录(一)。马尾松隶属外生菌根树种,它可与多种菌根真菌共生形成典型的外生菌根的结构。     

Functional compatibility of two arbuscular mycorrhizae with thirteen fruit trees in Senegal

Functional compatibility between thirteen tropical fruit trees (Afzelia africana Smith., Adansonia digitata L., Aphania senegalensis Radlk., Anacardium occidentale L., Cordyla pinnata (Lepr. ex A. Rich.) Milne-Redhead, Dialium guineensis Wild., Landolphia heudelottii A.DC., Sclerocarya birrea (A.Roch.) Hochst., Saba senegalensis (A. DC.) Pichon and four reference hosts Balanites aegyptiaca (L.) Del., Parkia biglobosa (Jacq.), Tamarindus indica L. and Zizyphus mauritiana Lam.) and two arbuscular mycorrhizal fungi (AMF) (Glomus aggregatum Schenck and Smith emend. Schenck and Glomus intraradices Schenck and Smith), was investigated. Marked differences were found between them in terms of mycorrhizal formation, root colonization, relative mycorrhizal dependency (RMD) and phosphorus concentrations in shoot tissues. A. africana, L. heudelottii and S. senegalensis did not form symbiotic associations, and the growth of A. africana decreased following mycorrhizal inoculation, while L. heudelottii and S. senegalensis showed no dependency. In contrast, A. digitata, A. senegalensis, A. occidentale, B. aegyptiaca and S. birrea were well colonized with AMF, but did not significantly increase in biomass production. Five fruit trees did, however, show dependency by a positive interaction with G. aggregatum, the most effective AMF. Z. mauritiana was found to be very highly dependent (RMD > 75%), T. indica was highly dependent (50–75% RMD), and D. guineensis, P. biglobosa and C. pinnata were moderately dependent (25–50% RMD). Phosphorus absorption probably contributed to this dependency more than the absorption of potassium. These results indicate that some tropical fruit trees do derive benefits from AM inoculation, while others do not.This revised version was published online in November 2005 with corrections to the Cover Date.     

香格里拉亚高山两种植被类型主要植物的丛枝菌根研究

以滇西北香格里拉亚高山地区生态严重退化的荒草坡植被类型和基本实现恢复的近原生林地植被类型中主要植物的丛枝菌根真菌(AMF)作为研究对象,对这些植物根系的AMF感染率及其根际土壤中的AMF孢子密度进行了调查研究。结果表明,荒草坡的10种植物和近原生林地的9种植物,均形成典型的丛枝菌根(AM)。荒草坡和近原生林植物根际土壤中的平均孢子密度分别为674±221(SE)个/100g土和290±72个/100g土。单因素方差分析表明,两植被类型的主要植物在根系AMF菌丝感染率以及根际土壤中AMF孢子密度方面的差异都极显著。同种植物在近原生林地具有较高的AMF感染率,而根际土壤中的孢子密度则是在荒草坡为高。相关性分析表明,所调查植物的根系AMF菌丝感染率与根际土壤中的AMF孢子密度间不存在相关性。