Occurrence of filamentous fungi and mycotoxins in wrapped forages in Sweden and Norway and their relation to chemical composition and management

A study was conducted on 124 farms in Sweden and Norway where fungal (all farms) and mycotoxin (100 of the 124 farms) presence was examined in wrapped forage bales. Samples were also analysed for chemical composition, and data on the bale production and storage system on each farm were collected. Fungi, analysed by three common sampling methods, were found in bales from 89% of the visited farms (110 farms). The most frequently isolated fungal species from the bale surface was Penicillium roqueforti. Mycotoxins were present in 39% of the 100 samples analysed. The most common mycotoxins present were enniatin B (14 farms) followed by deoxynivalenol (12 farms). The risk of finding fungi in baled forage samples was higher with odds ratio (OR) of 5.1 when less than eight layers of stretch film were applied, low seal integrity of wrapping (OR 172 at <10 s of seal integrity), higher dry‐matter content (OR 1.17–1.56 per % unit DM) and higher concentrations of acetic acid (OR 47.5 per g DM) and ethanol (OR 3.4 per g DM). Mycotoxin presence was not found to be correlated with any of the chemical characteristics of the baled forage, or with any forage production and management factors. A positive correlation was present between total fungal counts and general mycotoxin presence, but not between specific mycotoxins and the toxin‐producing fungal species.     

Fungal contamination of big-bale grass silage on Irish farms: predominant mould and yeast species and features of bales and silage

The extent of visible fungal growth and the identity of the predominant fungi causing spoilage of baled grass silage were recorded on 180 farms in Ireland. Fungal growth was evident on bales on 174 of the 180 farms visited and on 331 of the 360 bales examined. The mean proportion of surface area of bale, that was affected, was 0·06. Silage‐making method, storage characteristics and geographical location were significantly associated with the level of fungal contamination on bales. Fungal contamination was higher (P < 0·001) in bales where the surrounding polythene stretch‐film was visibly damaged compared with bales where the film appeared intact. A strong positive relationship was found between polythene film damage and dry‐matter content of the silage. The predominant fungus affecting the largest numbers of bales was Penicillium roqueforti. Other fungi frequently isolated included Schizophyllum commune, Pichia fermentans and Penicillium paneum. The distribution of individual fungi on bales was associated with geographical location, weather at harvest, and lactic and butyric acid concentrations of the silage. Penicillium roqueforti and P. paneum were more common on bales harvested in dry weather and with higher concentrations of butyric and propionic acids in the silage. Overall, a high incidence of visible fungal growth was recorded on bales throughout the country and the extent of colonization and fungal species occurring were not random.     

Assessment of hygienic quality of haylage fed to healthy horses

Wrapped forages such as haylage and silage are increasing in popularity in equine feed rations, but knowledge of their microbial composition, especially of haylage, is scarce. Haylage may be more at risk of mould growth compared to silage, and methods for the assessment of hygienic quality of haylage are needed. Varying culturing conditions, including aerobic/anaerobic incubation, four substrates and three incubation temperatures were therefore evaluated for analysis of fungi in haylage samples from eighteen horse farms, taken on two occasions (autumn and the following spring). Average mould counts in forage samples were low, but fungi with the potential for producing mycotoxins, such as Aspergillus fumigatus and Penicillium spp., were present. The microbial composition and content of fermentation products were similar in haylage samples taken in autumn and in spring. The type of substrate used for cultivation did not influence mould or yeast counts, but not all mould species were present on all substrates. Incubation temperature influenced fungal counts and the presence of mould species. By using at least two substrates (malt extract agar and dichloran 18% glycerol agar) and two incubation temperatures (25 and 37°C), all mould species/genera that were identified in this study could be detected.     

Rebaling of silage and haylage and its effects on forage microbial and chemical composition—A pilot study

Use of big bale silage and haylage can be difficult on farms where daily forage consumption is comparatively low as speed of deterioration of forage after bale opening may be faster than feed-out rate. Production of smaller bales at harvest is possible, but expensive and work-intensive. Therefore, a pilot study of rebaling forage stored in big bales to smaller bales was conducted. Three separate experiments were included, where microbial and chemical composition of silage and haylage was studied before and after rebaling. In Experiment III, residual big bale forage stored and opened together with rebaled forage was included. Results showed that rebaled haylage and silage had higher yeast counts compared to initial forage; however, residual bales in Experiment III had yeast counts similar to rebaled forage, indicating an effect of storage time rather than of rebaling. In Experiment II, mould counts were higher in rebaled compared to initial silage, but not in haylage. Chemical composition was similar in initial and rebaled forage except for ammonia-N. In Experiment III, ammonia-N was higher in rebaled compared to initial and residual forage and was the only chemical variable affected by rebaling. Bale temperature during aerobic storage followed ambient temperature until day 6–8 in Experiment I and until day 14 in Experiment III where ambient temperature was lower. In conclusion, rebaling can be done without large changes in chemical composition of the forage, but yeast and mould counts may be higher in rebaled forage, and this risk should be considered when using this procedure.     

Gas composition of baled grass silage as influenced by the amount,stretch, colour and type of plastic stretch‐film used to wrap the bales,and by the frequency of bale handling

The effectiveness of the polyethylene stretch‐film barrier to air infiltration is the major factor affecting the preservation of silage in bales. Three separate experiments investigated the effects of the number of layers of stretch‐film cover, film colour, stretch extent, film type and frequency of bale handling on gas composition, surface mould growth and conservation characteristics of baled grass silages. Monitoring gas composition in bales during ensiling proved useful for assessing the success with which wrapped bales were stored anaerobically. Under good storage conditions the early stages of ensiling were characterized by the rapid reduction of O₂ concentration in the bale and the creation of a CO₂‐rich environment. However, wrapping bales in only two layers of stretch‐film failed to create the anaerobic conditions required for a successful fermentation and the inhibition of visible fungal growth. In contrast, a minimum of four layers of stretch‐film were required to achieve suitably anaerobic conditions, but the additional benefits of applying more layers were relatively small. Under temperate climatic conditions with moderate solar radiation, film colour had little effect on the gas composition in baled silage. Likewise, the extent of stretching applied to the film at wrapping and film type had no influence on gas composition, baled silage quality or mould development. However, frequent mechanical handling of bales after wrapping had a negative effect on gas composition and surface mould growth, and thus should be kept to a minimum.     

A technique of cotton bale laydown using clustering algorithm

A new technique of cotton bale management using clustering algorithm has been proposed. The method is based on the grouping cotton bales of similar kind into respective categories using k-mean square clustering algorithm. A set of 500 cotton bales were clustered into 5 categories by minimizing the total within-group squared Euclidean distance around the 5 centroids. In order to cluster bales of different categories, 8 fibre properties, viz., strength, elongation, upper half mean length, length uniformity, short fibre content, micronaire, reflectance and yellowness of each bale have been considered. Once the bales are clustered into different categories, it is possible to prepare consistent bale mix for consecutive laydowns on the basis of frequency relative picking method.     

普洱茶中真菌种群的分离与分子鉴定

采用平板稀释法以孟加拉红(DRBC)和18%的甘油琼脂(DG18)两种培养基对60个普洱茶样品中的真菌种群进行了分离,种群分离结果显示:样品中真菌种群数量变化值范围为1.6×103～1.16×105cfu/g;应用分子生物学的手段,对分离到的71株真菌做了分子鉴定,鉴定结果表明:这些真菌分别属于19个属,40个种,主要是曲霉属13种,青霉属7种,其他属20种。数量上占优势的真菌种群是酵母和曲霉属的不同种。这些真菌的安全性有待进一步评估。     

Storage of small bale silage and haylage – influence of storage period on fermentation variables and microbial composition

An experiment investigating changes in fermentation variables and microbial composition during storage of small‐bale silage and haylage was performed. Haylage was defined as silage with a dry‐matter (DM) content exceeding 500 g kg^?1. Grass was wilted to three different DM contents, and baled into silage (350 g DM kg^?1), haylage with a low DM content (550 g kg^?1) and haylage with high DM content (700 g kg^?1) in small rectangular‐shaped bales (0·80 m × 0·48 m × 0·36 m) that were individually wrapped. Bales were stored for short (2 months) or long (14 months) periods before opening and sampling. Silage had higher concentrations of fermentation products and a lower pH than either of the two haylage types. In general, long‐term storage influenced all fermentation variables except concentrations of butyric acid and succinic acid, and yeast counts were higher after 14 months than 2 months of storage. However, silage changed in more fermentation variables during storage than the two haylage types. Although differences between short‐ and long‐term stored silage were found, linear correlations between short‐ and long‐term stored bales were present for all chemical variables. Pearson's correlation coefficients were highest for lactic acid, followed by pH.     

Identification,ecological evaluation and phylogenetic analysis of non‐symbiotic endophytic fungi colonizing timothy grass and perennial ryegrass grown in adjacent plots

Non‐systemic endophytes coexist with grasses and produce positive or negative effects for the host. In agricultural grasses, endophytes such as Epichloë spp. (formerly: Neotyphodium spp.) enhance the biometric parameters and agricultural value of grass biomass and seeds. Some endophytic fungi produce active substances that exert a negative influence on grass‐fed livestock. There is a general scarcity of studies investigating other endophytic fungi, the species composition of fungal communities, fungal species capable of colonizing different grasses and endophyte transfer between grass taxa. This study aims to fill in the existing knowledge gap by describing the relationships between fungal species and grass species. Timothy grass (Phleum pratense L.) is more readily colonized by endophytic fungi than perennial ryegrass (Lolium perenne L.), and the ratio of fungi isolated from the above species was determined at 3:1. Ecological indicators, especially diversity, were also higher in the fungal community colonizing timothy grass. The vast majority of the isolated fungi were ascomycetes. In addition, two Basidiomycota isolates and three Oomycota isolates (Phythium acanthicum) were also obtained from timothy grass. The most prevalent fungal species were Alternaria alternata, Microdochium bolleyi and Epicoccum nigrum. An analysis of minisatellite DNA regions revealed high levels of genetic polymorphism in A. alternata, whereas the remaining isolates were characterized by low levels of genetic variation or genetic homogeneity. The transfer of endophytic fungi between grass species was determined, which was one of the most important observations made in the study. The Sørensen–Dice coefficient reached 50%, which indicates that all fungal species isolated from perennial ryegrass are capable of colonizing timothy grass.     

Effect of various bale treatments on physical quality and chemical composition of rhodes grass (Chloris gayana) hay

The effect of harvest season (winter vs. summer), moisture content at baling and bale mass on hay physical quality and chemical composition of two varieties of Rhodes grass ( Chloris gayana ) was studied during bale storage. Three moisture levels (15–20%, 20–25%, 25–30%) and three bale masses (13 kg, 18 kg, 24 kg, at an equal volume) were tested in varieties Pioneer and Alimba - the most common cultivars in the Arabian Gulf region. Variety Alimba has a rougher texture with more stems and fewer leaves. This caused significantly higher water retention and consequently higher bale temperatures. In summer, bale temperatures of Alimba stored at 25–30% moisture content and 24 kg bale mass averaged 37.7°C compared with 28·2°C in variety Pioneer. Lowest dry-matter (DM) content was 793 g kg⁻¹ and was recorded in the winter cut of variety Alimba baled at the upper moisture level (25–30%), whereas the highest was that of variety Pioneer. Lowest crude protein content was that of variety Pioneer (61 g kg DM⁻¹). Prolonged heat build-up of some bales caused dark-brown discoloration, and, although colour variations were significant, they were not large. There was no contribution of bale mass to changes in DM content, indicating that the selected levels of bale mass in the experiment were lower than those expected to cause significant effects on hay chemical composition and nutritive value. In general, it is recommended to store Rhodes grass hay at moistures up to 30% and even higher in the summer season in the case of variety Alimba. Higher moisture contents at baling could preserve hay quality by minimizing shattering of leaves excessively dried under the prevailing hay-making conditions, especially in the variety Pioneer.     

Characteristics of baled silage made from first and second harvests of wilted and severely wilted forages

First and second harvests of lucerne (Medicago sativa L.), perennial ryegrass (Lolium perenne L.) and a lucerne–perennial ryegrass mixture [80 or 144 g kg^?1 dry matter (DM) of ryegrass] at the first and second harvests were cut and conditioned, wilted to 500 or 700 g DM kg^?1 then baled and stretch‐wrapped for silage on the same dates. Lucerne bales were denser (411 kg m^?3) than bales of perennial ryegrass (331 kg m^?3) (P < 0·05). After an 8‐month storage period, silage made from high DM‐content forage had a higher concentration of neutral‐detergent fibre (NDF) and was less digestible than that made from low DM‐content forage. Daily DM intakes by beef steers, when the silages of the second harvest were fed ad libitum, were 31·2, 31·2 and 22·3 g kg^?1 live weight for lucerne, lucerne–perennial ryegrass mixture and perennial ryegrass silages, respectively (P < 0·01), when the herbage had been wilted to 500 g kg^?1. In vivo digestibility of NDF in the lucerne–perennial ryegrass mixture silage (0·587) was significantly lower than that of perennial ryegrass silage (0·763) but higher than lucerne silage (0·518). Higher intakes of baled lucerne silage tended to offset its lower digestibility values. Lucerne–perennial ryegrass mixture silage had a higher DM and NDF digestibility than lucerne silage, indicating perhaps the presence of associative effects.     

Intercropped wheat (Triticum aestivum L.) and bean (Vicia faba L.) as a whole-crop forage: effect of harvest time on forage yield and quality

Abstract Sole crops and intercrops of wheat (Triticum aestivum L.) and bean (Vicia faba L.), at three harvest dates, representing successive growth stages, were evaluated for biomass production of whole‐crop forage and quality characteristics of crude protein (CP), neutral‐detergent fibre (NDF), acid‐detergent fibre (ADF), water‐soluble carbohydrate (WSC) concentrations and ash content. These tests were carried out for two field experiments, respectively, drilled during the spring of 1997 and autumn of 1997 on Imperial College Farm, Wye, UK. Results indicated that optimum forage yield and quality were obtained from the second to third harvest dates for the spring‐drilled experiment and the second harvest for the autumn‐drilled experiment. Wheat and bean intercrops were higher in total forage dry matter (DM) yield than either wheat or bean grown as sole crops. Field bean intercropped with wheat led to increased forage quality (CP and NDF concentrations) compared with sole wheat, and higher WSC concentrations compared with sole bean. Intercrops also enhanced weed suppression compared with sole bean. It is suggested that winter wheat–bean intercrops may have considerable potential as a moderate‐yielding, relatively high‐quality, low‐input and environmentally benign forage crop with considerable potential with regard to yield and quality and warrant further study.     

丛枝菌根真菌与胡萝卜毛状根双重培养体系研究

以发根农杆菌（Agrobacterium rhizogenes）K599诱导胡萝卜产生毛状根,接种丛枝菌根（AM）真菌摩西斗管囊霉（Funneliformis mosseae）建立双重培养体系,研究不同消毒方法、超声波、低温预处理和培养基pH对摩西斗管囊霉孢子萌发的影响及其与胡萝卜毛状根建立双重培养体系的最佳条件。研究结果表明：消毒方法3孢子萌发率最高,孢子污染率最低,15 d孢子萌发率达48.88%,而污染率仅为9.98%;超声波处理能降低孢子污染率11.17%~14.53%;低温预处理可有效提高孢子的萌发率,4℃低温处理10 d和15 d效果较好,其萌发率分别为70%和65%;AM真菌孢子在水琼脂培养基萌发最佳pH为6.5,萌发率达到48.50%,pH< 5.5或pH>8.0均抑制孢子萌发,pH 5.5和pH 8.0的萌发率分别为15.43%和16.06%。消毒孢子先于水琼脂萌发后,再挑取萌发管多,菌丝较长的孢子并将菌丝生长方向正对毛状根方向进行转接,可以提高双重培养的成功率。MSR培养基为双重培养的最优培养基。胡萝卜毛状根与AM真菌双重培养可为菌根真菌繁殖及相关分子机理研究提供可行有效的途径。     

The herbage productivity of tall fescue in the Pampas region of Argentina is correlated to its ecological niche

Since its introduction in the 1950s, tall fescue has spread throughout the Pampas region of Argentina to become naturalized in much of this region. Its annual forage mass productivity shows significant differences among sites. In this work, we hypothesized that, under dryland conditions, the annual forage mass productivity is related to the probability that the corresponding site is within the ecological niche of the species. To test this hypothesis, the spontaneous occurrence of tall fescue was surveyed in an area of 440 000 km². The abundance of tall fescue was verified on roadsides of national and provincial roads, in systematic sampling points spaced every 50 km. Subsequently, the ecological niche of the species was estimated with the Maxent software, based on the environmental information available. Additionally, the bioclimatic variables with greatest influence in determining the ecological niche were identified. Based on the information of comparative yield trials of tall fescue cultivars, a correlation analysis between annual forage mass productivity and the likelihood of ecological niche was performed. We found that the realized ecological niche of tall fescue in the Pampas region covers an area of 237 000 km² where the average minimum temperature of the coldest month is between 2·6 and 3·2°C and the rainfall in the driest quarter is 100 mm or higher. We also found that there were significant correlations between annual forage mass productivity and the probability of realized ecological niche. Therefore, in areas with low probability of realized ecological niche, other forage species could be a better option than tall fescue to obtain a high and stable annual forage mass productivity.     

The effect of propionic acid on the storage losses of hay

Storage losses in moist hay treated with propionic acid were compared with those occurring in untreated moist hay in two experiments and with field-cured hay in three experiments. Dry matter losses in treated hays ranged from 41 to 8.6% and from 1.7 to 12.6% in untreated hays. Digestible organic matter losses in both treated and untreated hays were generally greater than dry matter losses. Only in one experiment did propionic acid application significantly reduce nutrient losses in moist hays. Nutrient losses, and water-soluble carbohydrate losses in particular, were shown to be correlated with maximum and cumulative bale temperatures during storage in two of the experiments. The rise in hale temperatures during storage was reduced in all three experiments, to a greater or lesser extent, by application of the additive. Loss of propionic acid from the hay during and after application was very large. In the three experiments 86.2, 85.3 and 85.6% of the acid applied was lost by the end of the storage period. Acid distribution studies indicated that variation in acid concentration within bales was as great as between bales. It was concluded that more research is needed into applicator design and position on the baler and into alternative application methods if the benefits of propionic acid as a moist hay preservative are to be fully exploited.     

Impact of non-corrosive forage stabilizer on chemical composition and storage characteristics of lucerne hay

Three trials examined the impact on chemical composition, leaf-stem ratio and bale temperature of applying a low-acid stabilizer and a Lactobacillus fermentation product at baling lo moist (20–25% moisture) lucerne Medicago saliva L.) hay. Treatments evaluated were lucerne baled at: 17–20% moisture (dry control); 20–25% moisture with addition of 200 g or 400 g 100kg^-1 of a low-acid stabilizer, with 4·1 ml or 8·1 ml 100kg^-1 of a Lactobacillus fermentation product; and 20–25% moisture with no treatment (wet control). In trial 1, low-concentration acid treatment was effective in limiting the increase in bale temperature of moist hay. In trials 2 and 3, bale temperature for low-concentration acid and Lactobacillus fermentation product-treated hay was similar to untreated moist hay In trial 3, higher application rates of either product were not effective in further reducing bale temperature. In trials 1 and 3, levels of neutral detergent fibre, acid detergent fibre, acid detergent lignin and acid detergent insoluble nitrogen were higher for moist hay than dry control. Nitrogen levels tended to be higher for moist hay. Leaf-stem data from trial 2 suggest that more leaves can be retained by baling relatively high-quality (late bud maturity) legumes at 20–25% moisture. In some circumstances use of a low-acid forage stabilizer for preservation of high-quality lucerne can minimize increases in temperature during storage of hay baled while moist (20–25%).     

Penicillium brasilianum as a novel pathogen of onion (Allium cepa L.) and other fungi predominant on market onion in Korea

Onion (Allium cepa L.) is an important vegetable crop in Korea, but its production is severely affected by fungal pathogens during plant growth and bulb storage. We investigated the occurrence of fungi on market onion bulbs; identified the predominant fungal species based on the internal transcribed spacer region, β-tubulin region, and elongation factor 1-α gene sequences; and tested the pathogenicity of each predominant fungal species in onion bulbs. The genera Aspergillus (63.9%), Penicillium (15.5%), Fusarium (6.4%), Rhizopus (5.2%), and others (9.0%) were detected in the samples. Among these genera, Aspergillus awamori, Fusarium oxysporum, Penicillium brasilianum, and Rhizopus oryzae were identified as the predominant species. All of the fungi tested could infect both the inner layers and outer surfaces of onion bulbs and be re-isolated from the infected tissues. To our knowledge, this is the first report that P. brasilianum is a fungal pathogen of onion bulbs.     

Separating the effects of forage source and field microbiota on silage fermentation quality and aerobic stability

This study attempted to separate the effects of forage source and field microbiota on silage fermentation quality and aerobic stability. Single samples of grass, red clover and maize were used. Field microbiota was obtained by centrifugation of microbial suspensions of the three samples. The intact forages were dried and sterilized by heating at 60°C for 3 h + 103°C for 15 h, inoculated in a 3 (forage) × 3 (inoculum) design and reconstituted to a dry‐matter level of 400 g kg^?1 before ensiling. After ensiling for 71 d, subsamples were subjected to an 8‐d aerobic stability test, which included temperature and pH measurements. Bacterial community analysis was performed on samples before and after ensiling by 16S rRNA gene amplicon sequencing. Forage source had a marked effect on the levels of lactic acid, acetic acid, ammonia‐N and 2,3‐butanediol, but microbiota source only affected the acetic acid concentration. The forage and microbiota as well as their interactions affected silage stability variables. The maize microbiota improved silage stability, whereas silages made from the maize forage had the poorest stability. Bacterial community analysis revealed higher abundance of lactic acid bacteria on the maize forage, with Lactococcus and Leuconostoc being the dominant genera. These preliminary results suggested that fermentation quality is mainly affected by forage source, whereas the aerobic stability is affected by both forage and field microbiota.     

广西百色市芒果树根际土壤丛枝菌根真菌资源初探

为探明广西百色市芒果根际土壤丛枝菌根（arbuscular mycorrhizal, AM）真菌的分布情况,本研究对广西芒果主产区的芒果根际土壤及根系样本进行AM真菌分离,并比较不同施肥制度下芒果根际土壤的AM真菌种类和根系菌根侵染情况。采集5个主施有机肥的芒果园（OT）和5个主施化肥的芒果园（CT）根际土壤,采用湿筛倾析法分离土壤中的AM真菌孢子,通过富集和诱导培养纯化其中的AM真菌,进行分子和形态鉴定。采用墨水醋染色法对根系样本进行染色及内生真菌侵染率的测定。共分离出6种AM真菌,OT处理分离出无梗囊霉属（Acaulospora sp.）1种,近明球囊霉属（Claroideoglomus sp.）1种,类球囊霉属（Paraglomus sp.）1种;CT处理分离出无梗囊霉属2种,近明球囊霉属1种。2种施肥制度分离出的AM真菌种类较少,且分离出的AM真菌种类均较常见,并无特有种。根系染色发现,OT处理菌丝分布较多,AM真菌结构丰富,可明显观察到丛枝和泡囊结构,还发现有少量的深色有隔真菌（dark septate endophytes, DSE）;CT处理的菌丝相对较少,泡囊结构和丛枝也较少,DSE相对较多。方差分析结果显示,施肥类型、芒果品种和树龄对AM真菌的根外菌丝、泡囊结构以及孢子密度均有不同程度的影响,其中施用有机肥较化肥对AM真菌的根外菌丝和泡囊结构均有显著的促进作用。综上,本研究筛选所得菌种丰富了我国AM真菌菌种库,并为筛选果树高效AM真菌菌剂奠定物质基础,也为果园管理提供了新方向。     

甘蔗根际土壤 AM 真菌群落季节性变化研究

为了探明甘蔗根际土壤 AM 真菌群落季节性变化规律及其影响因素，2016 年 4 月、8 月、10 月和 12 月在里建甘蔗试验基地，采集 4 个施肥水平（0%、25%、50%、100%）下的甘蔗根际土壤，采用高通量测序技术分析不同施肥水平下 AM 真菌群落季节变化规律。结果表明：4 个季节共检测到 10 属 AM 真菌，AM 真菌 Chaol、Shannon-Wiener 指数 Shannon-Wiener 和 Invsimpson index 指数从春季到冬季呈先降后升的趋势，夏季最低；4 个季节共检测出 281 个 AM 真菌 OTUs（operational taxonomic units），春季、夏季、秋季、冬季的 OTUs 数目分别为160、68、103、198 个。4 个季节甘蔗根际土壤中球囊霉属（Glomus）占有绝对的优势，之后是类球囊霉属（Paraglomus）和多样孢囊霉属（Diversispora）。此外，也有少量的原囊霉属（Archaeospora）、巨孢囊霉属（Gigaspora）、无梗囊霉属（Acaulospora）、盾巨孢囊霉属（Scutellospora）和两性球囊霉属（Ambispora）。不同季节 AM 真菌群落组成差异显著，但总体来说冬季和春季种群结构相似，夏季和秋季相似，而夏季和秋季的 AM 真菌种类比春季和冬季的 AM 真菌种类多。