6种外生菌根真菌对西南桦幼苗的接种效应

【背景】西南桦是兼具内生、外生菌根的典型菌根营养型树种,菌根化育苗是其壮苗培育的有效措施。【目的】揭示外生菌根真菌对西南桦无性系幼苗生长和养分含量的影响,为其菌根化育苗筛选优良外生菌根真菌提供科学依据。【方法】以BY1、FB4、FB4+和A5等4个西南桦优良无性系为研究对象,选用土生空团菌(Cenococcumgeophilum)、松乳菇(Lactariusdeliciosus)、黄硬皮马勃(Scleroderma flavidum)、多根硬皮马勃(S. polyrhizum)、褐环乳牛肝菌(Suillus luteus)和红绒盖牛肝菌(Xerocomuschrysenteron)6个外生菌根真菌进行盆栽接种试验,分析接种处理间及无性系间苗高、地径、生物量以及养分含量差异。【结果】6个菌种均能与西南桦无性系幼苗形成外生菌根共生体,接种多根硬皮马勃与黄硬皮马勃显著促进了幼苗生长和养分吸收(P0.05),说明其与幼苗的亲和力明显优于其它菌种。尽管菌根侵染率在4个无性系之间无显著差异(P≥0.05),但各菌种对FB4、BY1幼苗生长的促进作用显著强于其它2个无性系。【结论】多根硬皮马勃和黄硬皮马勃可作为西南桦菌根化育苗的优选菌种。     

辽东栎幼苗的外生菌根合成

 在温室花盆中播种辽东栎（Quercus liaotungensis）种子获得辽东栎幼苗,并对幼苗接种外生菌根真菌进行菌根合成试验。所用的外生菌根真菌有：铆钉菇（Gomphidius viscidus）、臭红菇（Russula foetens）、厚环乳牛肝菌（Suillus grevillei）、褐环乳牛肝菌（S. luteus）、彩色豆马勃（Pisolithus tinctorius）、美味牛肝菌（Boletus edulis）、赭丝膜菌（Cortinarius russus）、土生空团菌（Cenococ     

外生菌根菌对油松幼苗抗氧化酶活性及根系构型的影响

研究盆栽条件下,接种褐环乳牛肝菌(Suillus luteus)和红汁乳菇(Lactarius hatsudake)对油松(Pinus tabulaeformis)苗木生长,抗氧化酶活性和根系构型的影响。结果表明:(1)褐环乳牛肝菌和红汁乳菇均可与油松合成外生菌根,并显著提高苗木的苗高、地径、鲜重和干重。(2)接种褐环乳牛肝菌苗木针叶抗氧化酶(SOD、CAT、POD)活性分别比接种红汁乳菇苗木高14.77%、20.77%、34.68%;接种褐环乳牛肝菌苗木根系抗氧化酶(SOD、CAT、POD)活性分别比接种红汁乳菇苗木高8.54%,4.34%,33.31%;接种处理苗木抗氧化酶活性均显著高于不接种处理。接种处理苗木根长、表面积、体积、平均直径、根尖数、分叉数显著高于不接种处理;接种处理间苗木只有根尖数存在显著差异;接种褐环乳牛肝菌的油松根系分支成80°—90°的一级侧根数占23.81%,显著多于接种红汁乳菇和对照苗木。研究表明,接种褐环乳牛肝菌和红汁乳菇均能促进油松苗木生长,提高油松体内抗氧化酶活性,扩大苗木根系的吸收范围,其中褐环乳牛肝菌各方面的促进效果要优于红汁乳菇。     

外生菌根菌丝桥在板栗幼苗间传递磷的效应

采用^32P示踪和4室根箱方法研究了外生菌根菌丝桥对板栗磷营养和植株间磷素传递作用的效应。给一株板栗幼苗(供体)接种外生菌根真菌美味牛肝菌(Boletus edulis)、褐环乳牛肝菌(Suillus luteus),菌根真菌在侵染供体植物以后其根外菌丝继续生长并侵染邻近的另外一株板栗植株(受体)。同位素示踪试验表明,供体板栗体内的^32P可通过菌丝桥传递给受体板栗,受体植株不仅根中^32P放射性强度高于对照,而且茎中^32P强度也显著高于对照。说明外生菌根真菌在不同板栗植株间形成了菌丝桥,但是菌丝桥传递的磷的数量很有限,仅占供体植株体内总磷量的5％-8％。美味牛肝菌和褐环乳牛肝菌侵染供体板栗植株以后,使植株含磷量、总吸磷量和生物量较对照明显增加。受体板栗幼苗在菌丝桥建立以后其植株含磷量和总吸磷量显著高于对照,但生物量与对照没有显著差别。     

早期真菌与本土和外来松的菌根合成

为探讨早期真菌与本土和外来松树的共生特性,选用3种早期外生菌根真菌(环褐乳牛肝菌Suillus luteus、虎皮乳牛肝菌S. phylopictus和酒红蜡蘑Laccaria vinaceoavellanea)接种2种本地松(云南松Pinus yunnanensis、华山松P. armandii)和2种外来松(P. greggii、P. maximartinensis),并对接种后的侵染率、菌根特征和松苗株高等进行测量和分析,结果显示：6个月后,2种乳牛肝菌与4种松均能形成菌根,华山松与2种乳牛肝菌的亲和性最好,酒红蜡蘑仅能与2种外来松P. greggii和P. maximartinensis形成菌根,且菌根合成成功率仅为14.3%。此次合成的10种菌根组合均为首次报道,其中同一种真菌与不同松形成的菌根在形态和解剖特征上较为接近。3种真菌对宿主生长的促进作用因树种而异,整体上外来松苗的生长速率要快于本土松苗;华山松苗虽然菌根感染率最高,但生长效应却均不明显。研究认为：孢子接种对乳牛肝菌、蜡蘑等早期真菌的菌根合成研究是一种经济有效的手段;外生菌根真菌可能对外来树种具有更为重要的作用,与本土树种相比,外来树种与外生菌根真菌在能否形成菌根、菌根形成时间以及对宿主的生长效应等方面存在差异,需要开展进一步深入的相关研究。     

铝对外生菌根真菌营养元素吸收和酶活性的影响

以褐环乳牛肝菌Suillus luteus (Sl)、乳牛肝菌Suillus bovines (Sb)、琥珀乳牛肝菌Suillus placidus (Sp)为供试菌株,采用液体培养法,分析不同浓度Al³⁺ (0、0.2、0.4、0.8、1.2和1.6 mmol·L^–1)处理对3种外生菌根真菌生物量、pH、养分吸收、抗氧化酶活性、MDA含量的影响,探讨外生菌根真菌耐铝机制。结果表明,铝处理显著增加3种菌株生物量、P含量和Al含量,降低培养液中pH。当Al³⁺浓度为0.8 mmol·L^–1时,菌株生物量增幅最大,各浓度Al³⁺处理的3种菌株Al含量为Sp＞Sb＞Sl;K含量随Al³⁺浓度增加呈先上升后下降的趋势,低浓度Al³⁺(≤0.4 mmol·L^–1)显著促进Sl菌株中N元素的积累,0.4 mmol·L^–1 Al³⁺处理菌株N含量较无铝处理增加42.65%。铝处理还显著降低菌株POD和SOD活性,增加菌株MDA含量。菌株生物量与菌丝N、P、K含量呈极显著正相关(P＜0.01),其中与P含量相关性最高(r=0.635)。综上,环境中Al³⁺浓度是影响外生菌根真菌吸收铝的关键因素,在一定Al³⁺浓度下,外生菌根真菌通过增加对营养元素N、P、K的吸收,提高菌丝酶活性,降低MDA含量以缓解铝毒害,增强其在铝胁迫下的生存能力。该研究为筛选抗(耐)铝性强的优良菌株提供理论依据。     

4种外生菌根真菌对难溶性磷酸盐的溶解能力

以红绒盖牛肝菌(Xerocomus chrysenteron)、美味牛肝菌(Boletus edulis)、黄须腹(Rhizopogen luteous)和劣味乳菇(Lactarius insulsus)4种外生菌根真菌为对象,在纯培养条件下比较它们对4种难溶性磷酸盐[Ca_3(PO_4)_2、Ca_(10)(PO_4)_6(OH)_2、FePO_4·4H_2O和AlPO_4]的溶解能力,以探讨外生菌根真菌对难溶性磷酸盐的溶解作用及其影响因素.结果表明:(1)4种外生菌根真菌均能在Ca_3(PO_4)_2为唯一磷源的NBRIP平板上生长,但生长速率明显不同,且红绒盖牛肝菌生长速率最快.(2) 4种菌根真菌对4种磷酸盐的溶解能力存在显著差异,红绒盖牛肝菌发酵液可溶性磷含量大多显著高于对照和其他菌根真菌,对磷酸盐的溶解能力最强.(3)4种菌根真菌发酵液可滴定酸度(2.30～46.00 mmol·L~(-1))和pH(4.57～6.99)与其溶磷量分别呈极显著正相关(r=0.991**)和极显著负相关(r=-0.939**).(4)4种外生菌根真菌均能分泌乙酸、柠檬酸和反丁烯二酸,且它们分泌有机酸总量(14.14～1 537.46 mg·L~(-1))与其溶磷量呈显著正相关(r=0.998*).研究发现, 4种外生菌根真菌发酵液可滴定酸度、pH和有机酸的种类与含量是影响其溶解Ca_3(PO_4)_2能力的主要因素;红绒盖牛肝菌的溶磷能力较强,具有应用于中国土壤缺磷地区造林的潜力.     

油松菌根促生细菌——荧光假单胞菌的分离与鉴定

为了探讨菌根促生细菌荧光假单胞菌(Pseudomonas fluorescens)与菌根真菌的互作关系,本实验从油松菌根上分离得到36株在紫外灯下产荧光的细菌菌株,以荧光假单胞菌9702作为标准菌株,对分离菌株进行显微观察、生物学鉴定和16S rDNA序列分析,结果确定HDY-8、HDY-9、HDY-20、HDY-35共 4株菌株为荧光假单胞菌,并分别命名为P.fluorescens HDY-8、P.fluorescens HDY-9、P.fluorescens HDY-20、P.fluorescens HDY-35.用这4株细菌菌株分别与外生菌根真菌(ECMF)粘盖牛肝菌(Suillus bovinus)、褐环粘盖牛肝菌(Suillus luteus)和褐黄牛肝菌(Boletus luridus)进行纯培养互作研究.结果表明,只有P.fluorescens HDY-20对3种外生菌根真菌有不同程度的促生作用,并对S.luteus促进效果最好,S.bovinus次之,B.luridus最差;P.fluorescens HDY-20促进S.bovinus、S.luteus和B.luridus菌丝生长的最佳浓度分别为2.4×109 cfu/mL、0.8×109～2.4×109 cfu/mL和0.8×109 cfu/mL,与对照相比S.bovinus和S.luteus的生物量达到极显著差异(P<0.01),B.luridus的达到显著差异(P<0.05),且分别比对照增加6.5%、9.1%和4.3%.     

Cd胁迫下外生菌根菌对樟子松生理指标和根际土壤酶的影响

本研究采用盆栽试验法,研究了不同浓度Cd胁迫下,接种外生菌根菌——褐环乳牛肝菌(Suillus luteus)对樟子松(Pinus sylvestris var.mongolica)苗期植株的生长及叶绿素含量、抗氧化酶(CAT、POD和SOD)活性、细胞渗透调节物质(可溶性糖、MDA和游离脯氨酸)含量和根际土壤酶(过氧化氢酶、脲酶和碱性磷酸酶)活性的变化。结果表明:1年生樟子松苗木在Cd胁迫1个月后,接菌处理组无论在苗木生长、抗氧化酶活性方面均高于对照组,且大部分指标达到显著差异水平(P0.05)。各接菌处理组菌根侵染率达48.0%以上。抗氧化酶活性方面,CAT和POD活性呈现出随着胁迫程度的加深,先下降后上升的变化趋势,SOD活性则呈现出地上与地下部分"上下对称"的变化趋势。同时,通过对各处理组苗木细胞渗透调节物质的定量测定,接菌处理组的细胞受破坏程度显著低于不接菌处理组。对苗木根际土壤酶分析结果表明,Cd胁迫下,施加外生菌根菌可以有效提高樟子松根际土壤酶的活性(尤其是脲酶),进而起到增加樟子松根际土壤生物活性作用。综上,接种外生菌根真菌对樟子松缓解重金属Cd胁迫具有明显的促进作用。Cd胁迫下,外生菌根可以有效正向调节樟子松的生长、抗氧化胁迫能力并提高苗木细胞渗透调节作用,进而提高苗木对重金属的耐受性和提高苗木根际土壤生物活性。本研究可以为重金属污染土地的有效治理和利用木本植物修复改良重金属污染土壤提供参考。     

青蒿素对外生菌根真菌化感效应

青蒿素是治疗疟疾的首选药物,主要从黄花蒿(Artemisia annua L.)中提取,然而黄花蒿在生长过程中会向周围环境分泌青蒿素。为正确评估青蒿素对森林生态系统中的重要成分""外生菌根真菌的影响,试验以重庆地区有代表性的两株外生菌根真菌——褐环乳牛肝菌(Suillus luteus)Sl 8和松乳菇(Lactarius delicious)Ld 3为材料,研究了青蒿素对菌丝生长,H+和有机酸分泌,以及养分吸收的影响。结果表明,在液体培养基中加入青蒿素,外生菌根真菌的生长受到明显抑制,菌丝生物量降幅高达26.89%(Ld 3)和89.13%(Sl 8);Ld 3分泌H+和草酸的能力增强,而Sl 8分泌量下降。随着青蒿素浓度的增加,菌丝的N、P、K含量及吸收量显著减少。当培养基中青蒿素达到80 mg/L时,Ld 3的N、P、K吸收量比不加青蒿素的处理分别降低了50.55%、46.30%和42.28%;Sl 8几乎丧失对N、P、K的吸收能力。说明青蒿素不同程度地抑制了外生菌根真菌的生长和养分吸收,但对H+和草酸的分泌作用因菌株不同而异。     

七株外生菌根真菌与三种松苗菌根的形成能力

松树外生菌根菌资源丰富,但实际应用的种类不多。为筛选出与松苗形成菌根能力较强的菌种,采用播种接菌和芽苗截根移栽接菌两种方法,对7株外生菌根真菌与马尾松、湿地松和黑松3种松苗的菌根合成进行了研究。结果表明：形成的菌根以二叉分枝状为主,棒状菌根相对较少,多叉状菌根以马尾松较多。PC2形成的菌根表面菌丝厚且紧密,504、EG、Pt,形成的菌根表面菌丝紧密程度中等,而505、ZJ和HX形成的菌根其表面菌丝则比较稀疏;Pt1、Pt2、EG形成的菌根外延菌丝较长,而505、HX形成的菌根外延菌丝极短。截根接菌时的感染率和感染指数要高于播种接菌。504形成菌根的能力最强,在3种松苗上的菌根感染率都达100％,感染指数最高可达90,最低也达70;Pt2和EG与马尾松和黑松形成菌根的能力较强;而505和HX仅与马尾松形成菌根的能力较强;Pt1形成菌根的能力较差,在3种松苗上菌根感染率和感染指数都较低。在3种松苗中,马尾松的菌根化状况最好,其次为黑松,湿地松的菌根化状况较差。     

The number of nuclei in basidiospores of 63 species of ectomycorrhizal Homobasidiomycetes

The production of even a limited number of heterokaryotic spores would be advantageous for establishing new individuals after long distance dispersal. While Suillus and Laccaria species are known to produce binucleate, heterokaryotic spores, this condition is poorly studied for most ectomycorrhizal fungi. To begin addressing this matter the number of nuclei in basidiospores was recorded from 142 sporocarps in 63 species and 20 genera of ectomycorrhizal (EM) fungi. The mean proportion of binucleate basidiospores produced by sporocarps within a species ranged from 0.00 to 1.00, with most genera within a family showing similar patterns. Basidiospores from fungi in Amanita, Cortinariaceae and Laccaria were primarily binucleate but were likely still homokaryotic. Basidiospores from fungi in Boletaceae, Cantharellus, Rhizopogonaceae, Russulaceae, Thelephorales and Tricholoma were primarily uninucleate, but binucleate basidiospores were observed in many genera and in high levels in Boletus. Further research is needed to relate basidiospore nuclear number to reproductive potential in ectomycorrhizal species.     

Diversity of ectomycorrhizal fungi naturally established on containerised Pinus seedlings in nursery conditions

The study examined the diversity of ectomycorrhizal fungi, naturally established on roots of containerised Pinus seedlings in a nursery, using PCR-RFLP and sequencing of the nuclear ribosomal internal transcribed spacer. Seventy-two samples, including ectomycorrhizae and fruit bodies, were examined. Molecular typing assigned the fungal symbionts to four ectomycorrhizal Boletales: Rhizopogon rubescens, Suillus bovinus, S. variegatus, and R. luteolus. R. rubescens was abundant (37.5%), while Suillus and R. luteolus species were moderately established (25-26%) and rare (2.8%), respectively. In addition, Rhizopogon species colonised P. nigra ssp. salzmannii seedlings, whereas Suillus species were identified on Pinus nigra ssp. nigra seedlings. The diversity and the ability of these naturally established symbionts under artificial nursery conditions were discussed. The molecular survey investigated here should contribute to successful monitoring of mycorrhizal application under both nursery and plantation conditions.     

Influence of ectomycorrhizal inoculation on Pinus wallichiana and Cedrus deodara seedlings under nursery conditions

A study was undertaken to examine the extent of root colonization by four locally isolated ectomycorrhizal （ECM） fungi （Hebeloma theobrominum, Boletus dryophilus, Scleroderma citrinum and Suillus luteus） and their effects on seedling growth in Pinus wallichiana and Cedrus deodara under nursery conditions. Seedlings of the two conifers were inoculated with mycelium of ECM fungi and were grown in pots containing sterilized forest soil for six months. The percentage of ECM colonization of roots was 38%-52% in Pinus wallichiana and 33%-48~ in Cedrus deodara. ECM colonization increased shoot height, needle number, shoot and root biomass and survival of inoculated seedlings. Among the four ECM fungi Hebeloma theobrominum was more effective with Pinus wallichiana and Scleroderma citrinum with Cedrus deodara in promoting seedling survival and overall growth. All the four ECM fungi used enhanced growth of inoculated seedlings and thus can be used in afforestation and regeneration programmes in degraded forests ecosystems.     

Ectomycorrhizal ecology under primary succession on coastal sand dunes: interactions involving Pinus contorta, suilloid fungi and deer

Ectomycorrhizal fungi (EMF) are critical for pine establishment under primary succession. The species of EMF supporting primary successional pine seedlings on coastal sand dunes and mechanisms for their establishment were investigated. Fungi were identified from ectomycorrhizal roots using molecular techniques. Field seedlings were collected from forested and nonforested zones. Laboratory seedlings were grown in soils collected from the same zones, and in sterile soils inoculated with fresh and 1-yr-old dry deer fecal pellets. Suilloid fungi were frequently observed on all seedlings. A diverse group of fungi was available to seedlings in forested zones. A less diverse group of fungi was available to field seedlings in nonforested zones and all laboratory bioassay seedlings. Deer fecal inoculant yielded an average of two EMF per seedling. Both Suillus and Rhizopogon species dominated seedlings inoculated with fresh deer feces, but only Rhizopogon species dominated seedlings inoculated with 1-yr-old feces. Suilloid fungi are dispersed by deer, produce resistant spore banks and are the principle fungi supporting seedlings on the sand dunes.     

Response of ectomycorrhizalPinus banksiana andPicea glauca to heavy metals in soil

Pinus banksiana andPicea glauca inoculated or not with the ectomycorrhizal fungusSuillus luteus were grown in a sandy loam soil containing a range of Cd, Cu, Ni, Pb and Zn concentrations. Ectomycorrhizal colonization rates were significantly reduced on Pinus and Picea seedlings by the heavy metals, particularly Cd and Ni. Needle tissue metal concentrations were lower in ectomycorrhizal seedlings at low soil metal concentrations. However, at higher soil concentrations, heavy metal concentrations of needle tissue were similar in ectomycorrhizal and nonmycorrhizal plants. The growth of nonmycorrhizal seedlings exposed to heavy metals was reduced compared to those inoculated withSuillus luteus. Apparently ectomycorrhizal colonization can protect Pinus and Picea seedlings from heavy metal toxicity at low or intermediate soil concentrations of Cd, Cu, Ni, Pb and Zn.     

VA菌根化杉树苗抗酚能力的研究

利用 Ｖ Ａ 菌根化杉树苗进行了加酚水培和土培,试验结果表明, Ｖ Ａ 菌根化杉树苗对邻香草醛,对羟基苯甲酸、阿魏酸等酚类物质有明显的耐受性     

Apatite as a P source in mycorrhizal and non-mycorrhizal Pinus sylvestris seedlings

The objectives of the study are firstly to test the ability of ectomycorrhizal pine seedlings to use apatite as a P source in comparison with non-mycorrhizal pine seedlings and secondly, to determine if there is a relation between exudation of organic acids and the ability to use apatite as a P source. Non-mycorrhizal Pinus sylvestris (L.) seedlings and seedlings ectomycorrhizal with 4 different isolates of ectomycorrhizal fungi were grown for 220 days in sand/peat filled pots with apatite (Ca₅(F,OH)(PO₄)₃) as the sole P source. In an additional experiment, non-mycorrhizal Pinus sylvestris (L.) seedlings and seedlings ectomycorrhizal with 2 different isolates of ectomycorrhizal fungi were grown without any P source for 250 days. All other nutrients were supplied in a balanced nutrient solution.Ectomycorrhizal seedlings grew less than non-mycorrhizal seedlings but ectomycorrhizal seedlings produced a large external mycelium not included in the biomass estimates. All seedlings in the present study had low shoot:root ratios compared to seedlings growing under optimal conditions. All seedlings grown with apatite as P source had higher foliar P concentrations (0.71–2.11 mg/g) than seedlings growing without any P source (0.57–0.75 mg/g) indicating a significant ability to use apatite as a P source. Seedlings colonized by Suillus variegatus and Paxillus involutus had higher concentrations and total contents of P in shoots compared with non-mycorrhizal seedlings, indicating significant improvement of P uptake by these fungi in comparison with non-mycorrhizal seedlings or seedlings colonized Piloderma croceum.No clear relationship between exudation of organic acids and uptake of P was found. Seedlings colonized by S. variegatus reduced the pH of the soil more than seedlings colonized by P. involutus or non-mycorrhizal seedlings. It is suggested that S. variegatus colonization improves the P uptake by reducing the pH of the soil while P. involutus improves P uptake by having a greater ability to absorb dissolved phosphate than non-mycorrhizal roots or roots colonized by the other fungi used in the study.