黄土高原的VA菌根真菌IV.

红色盾巨孢囊霉和珊瑚囊盾巨孢囊霉为中国新记录种。考察过的样片保存在山西农科院棉花研究所。     

VA菌根真菌与植物相互选择性的研究

采用土培试验了灭菌条件下同一菌种对不同植物和不同菌咱对同一植物的接种效应。试验结果表明,供试植物都能与ＶＡ菌根真菌形成共生体系,接种ＶＡ菌根真菌促进了植物的生长,植株干物质量显著是否 同ＶＡ菌根真菌与宿主植物形成共生体的能力及对植物的接种疚差异明显,由此可见,选择优势菌咱和宿主植物组合,对于ＶＡ菌根真菌的广泛应用及农业生产具有重要的实践作用。     

龙胆VA菌根真菌的分离和鉴定

采用湿筛法和单孢接种技术,从东北龙胆根际土壤中分离到能在东北龙胆组培苗上形成VA菌根的真菌孢子和孢子果呆,依其显微形态特征对部分菌株进行鉴定,大多属于球囊霉属（Glomus）中的漏斗孢球囊霉（Glomusmosseae）和地球囊霉（G．geosporum）     

刺槐接种VA菌根真菌与环境条件的关系

1 引言 国内外众多的试验表明,VA菌根真菌侵染植物根系后,促进植物对养分吸收和物质转化,从而大幅度增加寄主生物量,但也有试验表明,接种VAMF后,寄主生物量并无明显增加,这可能与菌根接种物本身的特点及外界条件有关,其中土壤中磷的含量是重要因素之一。据报道,土壤P过高,对菌根的形成有影响。本文就刺槐接种VAMF,在不同立地环境下寄主生长变化及不同施磷量对VAMF侵染能力、孢子产生量、植株生物量等进行了研究。     

保藏条件对丛枝菌根真菌Glomus mosseae侵染的影响

以高粱为宿主植物,接种丛枝菌根真菌Glomus mosseae,测定了经不同保藏温度(18~20,4,-20,-80℃)处理,在不同保藏时间(3,6,12,18,24,30个月)下丛枝菌根真菌G.mosseae对根系的侵染率。结果表明:丛枝菌根真菌G.mosseae在18~20,4,-20℃温度下保藏12~18个月时,需进行转接,用高粱为宿主植物进行更新复壮培养,以保持菌种活力。     

土壤中镉对丛枝菌根真菌Glomus mosseae生长的效应

采用分室培养法,在同一宿主植物生长的土壤中设含有0、5、25、50mg/kg4个不同浓度重金属镉的菌丝生长室(用30μm尼龙网与根系隔开)以期建立在宿主植物生长状况完全相同的条件下研究环境因素对AM真菌直接影响的新方法,并在此基础上探讨不同浓度的重金属镉对丛枝菌根真菌Glomus mosseae(BEG167)生长的直接影响。结果表明,与不施加镉的处理相比,土壤中施加低浓度镉(5mg/kg)刺激了G.mosseae的生长,其菌丝总长度最大;高浓度镉(大于25mg/kg)抑制了G.mosseae的生长,其菌丝总长度较小。AM真菌的代谢活性与土壤镉浓度的关系也表现出与菌丝生物量相同的规律。以上结果表明:G.mosseae在镉污染环境中有应激反应的特征,即:当G.mosseae受到轻微毒害时,为了适应其生存条件的改变而不断增加其代谢活性和生长量来降低镉的毒害。此外,本方法用于研究宿主植物生长状况相同的条件下,重金属毒害或其他环境因素对AM真菌生长代谢的直接影响是可行的。     

Surface-sterilization of Glomus mosseae sporocarps for studying endomycorrhization in vitro

 The effects of sterilization time, sterilizing agents (ethanol, Chloramine T, calcium hypochlorite) and antibiotics (streptomycin and gentamycin) on Glomus mosseae (BEG 12) sporocarp germination and contamination were evaluated. Incubation for 10 s in 96 % ethanol, followed by 10 min in a solution of 2% Chloramine T, 0.02% streptomycin, 0.01% gentamycin and Tween 20, and then 6 min in 6% calcium hypochlorite greatly reduced fungal and bacterial contamination from sporocarps and caused little change in germination rate in water agar medium. Accepted: 4 March 1999     

不同生态型摩西球囊霉菌株对棉花耐盐性的影响

在盆栽条件下研究了4个NaCl水平下(0、1、2和3g／kg)接种丛枝菌根真菌Glomus mosseae的2个菌株M1和M2对棉花耐盐性的影响。M1自非盐渍土壤分离,M2自盐渍土壤分离。结果表明,不同盐水平下2个菌株对棉花根系的侵染率为20％～40％,M2的侵染率高于M1;这两个菌株对棉花在盐胁迫环境下的生长状况都有一定的促进,其中Ml的促进作用明显大于M2的,并且在NaCl水平为2和3g／kg时,两菌株对棉花生长的效应之间的差异达到极显著水平。进一步的分析表明两菌株对植株吸收矿质元素的作用方面存在一定差异。接种M1的植株含磷量在4个盐水平下均显著高于对照,而接种M2处理的植株含磷量只是在0和1g／kg NaCl时显著高于对照。在2和3g／kg NaCl时略低于对照,并显著低于接种M1处理的。在4个NaCl水平下,接种M1的植株钠和氯含量与对照没有显著差异;接种M2的植株氯含量在1～3g／kg 3个NaCl水平下、钠含量在2和3g／kg 2个NaCl水平下不仅显著高于对照,同时也显著高于接种M1的植株氯和钠含量。这些差异是M1和M2两菌株对提高棉花耐盐性作用大小不同的主要原因。上述结果说明不同生态型AM真菌菌株对植物的耐盐性的影响力不同,这与真菌自身的生物学特性有关。     

Influence of soil impoverishment on the interaction between Glomus mosseae and saprobe fungi

 The effect of the saprobe fungi Wardomyces inflatus (Marchal) Hennebert, Paecilomyces farinosus (Holm & Gray) A. H. S. Brown & G. Sm., Gliocladium roseum Bain., Trichoderma pseudokoningii Rifai and T. harzianum Rifai, isolated from sporocarps of Glomus mosseae, on arbuscular mycorrhizal (AM) colonisation and plant dry matter of soybean was studied in 2/3 and 1/5 diluted soils in a greenhouse trial. Soil dilution to 1/5 had no effect on shoot dry matter of soybean but decreased AM colonisation and root dry weight of plants. CFU of saprobe fungi, except T. harzianum, were higher in 1/5 than in 2/3 diluted soils. W. inflatus and Gliocladium roseum decreased the shoot dry weight of soybean plant when inoculated together with Glomus mosseae. The saprobe fungi P. farinosus and T. pseudokoningii increased the shoot dry weights of plants grown in 1/5 diluted soil. The shoot dry weight and AM colonisation in 1/5 diluted soil were also increased when T. harzianum was inoculated together with Glomus mosseae. Thus, saprobe fungi increased AM colonisation of soybean plants by indigenous endophytes. The AM colonisation of plants at both soil dilutions was increased by Glomus mosseae. The highest level of AM colonisation was observed when P. farinosus and T. pseudokoningii were inoculated together Glomus mosseae. The dilution of soils influenced the interaction between inoculated microorganisms and their effect on plant growth. Accepted: 7 June 1999     

Interactions between the root-knot nematode Meloidogyne incognita and Glomus mosseae in banana

The effects of the interaction between the arbuscular mycorrhizal fungus Glomus mosseae and the root-knot nematode Meloidogyne incognita on growth and nutrition of micropropagated ;Grand Naine banana (Musa AAA) cultivar was studied under greenhouse conditions. Inoculation with two G. mosseae isolates significantly increased growth of plants in relation to non-mycorrhizal plants. Response to mycorrhizae was as effective as with an optimum P fertilization in promoting plant development for most growth parameters. Meloidogyne incognita had no apparent effect on the percentage of root colonization in mycorrhizal plants. In contrast, G. mosseae suppressed root galling and nematode buildup in the roots. The percentage of mycorrhizal colonization was high (over 80%) in low P fertilized plants, but optimum P rates for bananas (four times higher than low P) significantly reduced mycorrhizal colonization. Most elements were within sufficiency levels for banana with exception of N which was low for all treatments. Mycorrhizal plants fertilized with a low P rate showed higher N, P, K, Ca, and Mg contents as compared to non-mycorrhizal plants low in P with or without the nematode. Inoculation with G. mosseae favours growth of banana plants by enhancing plant nutrition and by suppressing nematode reproduction and galling during the early stages of plant development.     

Root colonization by the arbuscular mycorrhizal fungus Glomus mosseae and enhanced phosphorous levels in cucumber do not affect host acceptance and development of Frankliniella occidentalis

Abstract

We tested the effect of root colonization of cucumber (Cucumis sativus L.) by the arbuscular mycorrhizal fungus (AMF) Glomus mosseae on different parameters of a plant-thrips (Frankliniella occidentalis Pergande) interaction. In leaf disc bioassays, the feeding activity, the oviposition rate, the settling preference of adult females and the developmental time (first instar larva to adult) on leaves of mycorrhizal and non-mycorrhizal plants were studied. To distinguish between a nutritional effect through an improved phosphorous (P) status of the mycorrhizal plant and other effects caused by mycorrhization, non-mycorrhizal plants watered with a nutrient solution with (+P) or without P (?P) were included in the study. Mycorrhization did not affect any of the parameters on host acceptance tested, whereas on plants with a higher P-level the duration of the non-feeding stages (pronymphae, nymphae) of F. occidentalis was shortened, but all other developmental parameters were similar as in the control and the mycorrhizal plants. Our data indicate that the polyphagous thrips F. occidentalis is neither affected by mycorrhization of cucumber plants nor by enhanced P-levels.     

Influence of the endomycorrhizal fungus Glomus mosseae on the development of peanut pod rot disease in Egypt

Glomus mosseae and the two pod rot pathogens Fusarium solani and Rhizoctonia solani and subsequent effects on growth and yield of peanut (Arachis hypogaea L.) plants were investigated in a greenhouse over a 5-month period. At plant maturity, inoculation with F. solani and/or R. solani significantly reduced shoot and root dry weights, pegs and pod number and seed weight of peanut plants. In contrast, the growth response and biomass of peanut plants inoculated with G. mosseae was significantly higher than that of non-mycorrhizal plants, both in the presence and absence of the pathogens. Plants inoculated with G. mosseae had a lower incidence of root rot, decayed pods, and death than non-mycorrhizal ones. The pathogens either alone or in combination reduced root colonization by the mycorrhizal fungus. Propagule numbers of each pathogen isolated from pod shell, seed, carpophore, lower stem and root were significantly lower in mycorrhizal plants than in the non-mycorrhizal plants. Thus, G. mosseae protected peanut plants from infection by pod rot fungal pathogens. Accepted: 10 February 2000     

Growth and gas exchange responses of Hevea brasiliensis seedlings to inoculation with Glomus mosseae

 The beneficial effect of arbuscular mycorrhizal (AM) fungi on plant growth is well known, but the physiological processes involved are still discussed. The purpose of this study was to determine if Glomus mosseae affects the growth of Hevea brasiliensis seedlings and, if it is the case, if it could be associated with variations in leaf CO₂ and H₂O gas exchange. H. brasiliensis rubber trees were grown for 9 months in a medium containing either propagules of G. mosseae or sterilized inoculum. Plant size, root collar diameter and leaf area, as well as net CO₂ assimilation, stomatal conductance (g_s) and water-use efficiency of photosynthesis were evaluated during the first 5 stages of growth. At stage 2, a growth depression occurred in the mycorrhizal seedlings coincident with the first AM infections. Then, at stage 5, Glomus mosseae-inoculated plants had moderate colonization (47% of root length) and were taller than control plants with a larger root collar diameter and an enhanced leaf organogenesis. This enhanced growth was accompanied by increased photosynthesis, transpiration, and stomatal conductance. After 9 months, dry weights of shoots and roots of inoculated plants were greater than those of controls by 27 and 17%, respectively. Received: 10 May 1997 / Accepted: 9 September 1997