Diversity of Arbuscular Mycorrhizal Fungi Associated with Six Rice Cultivars in Italian Agricultural Ecosystem Managed with Alternate Wetting and Drying

Alternate wetting and drying(AWD)system,in which water has been reduced by approximately 35%with an increased occurrence of beneficial arbuscular mycorrhizal(AM)symbiosis and no negative impact on rice yield,was proposed to utilize water and nutrients more sustainable.In this study,we selected six rice cultivars(Centauro,Loto,Selenio,Vialone nano,JSendra and Puntal)grown under AWD conditions,and investigated their responsiveness to AM colonization and how they select diverse AM taxa.In order to investigate root-associated AM fungus communities,molecular cloning-Sanger sequencing on small subunit rDNA data were obtained from five out of the six rice cultivars and compared with Next Generation Sequencing(NGS)data,which were previously obtained in Vialone nano.The results showed that all the cultivars were responsive to AM colonization with the development of AM symbiotic structures,even if with differences in the colonization and arbuscule abundance in the root systems.We identified 16 virtual taxa(VT)in the soil compartment and 7 VT in the root apparatus.We emphasized that the NGS analysis gives additional value to the results thanks to a more in-depth reading of the less represented AM fungus taxa.

Effects of Arbuscular Mycorrhizal Fungi(AMF) on Growth of Upland Rice under Soil Pb Contamination

[Objective] This study aimed to investigate the effects of arbuscular mycor-rhizal fungi （AMF） on growth of upland rice under soil Pb contamination. [Method] Using potting method, the effects of Glomus mosseae on the growth of Oryzal sati-va L. under different soil Pb concentrations （0, 300, 600 mg/kg） were investigated. [Result] According to the results, the mycorrhizal colonization rate of upland rice in-oculated with Glomus mosseae was significantly reduced （P〈0.05） with the increase of Pb concentration in soil. Compared with non-inoculation treatment, inoculation of arbuscular mycorrhizal fungi significantly improved the biomass of upland rice and Pb concentration of upland rice roots with addition of 300 mg/kg Pb but significantly reduced Pb concentration of upland rice shoots, which was consistent with the re-duced R/S （P〈0.05）; with addition of 600 mg/kg Pb, inoculation of arbuscular mycor-rhizal fungi significantly improved the biomass of upland rice roots （P〈0.05） but sig-nificantly reduced Pb concentration of upland rice shoots and roots （P〈0.05）; there was no significant difference in R/S between inoculation treatment and non-inocula-tion treatment. [Conclusion] This study indicated that inoculating Glomus mosseae under certain Pb concentrations could to some extent al eviate the toxic effects of Pb on Oryzal sativa L.

Effects of Arbuscular Mycorrhizal Fungi on Upland Rice Oxidative Stress Induced by Cu and Pb Contamination in Soil

[Objective] This study aimed to investigate the effect of arbuscular mycor-rhizal fungi on upland rice oxidative stress induced by Cu and Pb contamination in soil. [Method] The upland rice seeds were sowed in pots, in which the soil was previously mixed with a certain amount of Glomus mosseae and 0, 100 and 200 mg/kg Cu, or 0, 300 and 600 mg/kg Pb. In the control treatment, Glomus mosseae was inactivated before mixed into the soil. Then, the physiological and chemical properties of the aboveground parts of rice plants were measured at mature stage. [Result] Compared with the control treatment （NM）, Glomus mosseae （GM） treat-ment inhibited the POD, CAT and SOD activity while increased the soluble protein content under 100 mg/kg Cu and 300 mg/kg Pb treatment, improved the POD and CAT activity and soluble protein content while decreased SOD activity under 200 mg/kg Cu. SOD and POD activity showed no significant difference between NM and GM treatment under 600 mg/kg Pb, but the CAT activity was enhanced and soluble protein content was decreased. [Conclusion] This study wil provide theoretical refer-ence for bioremediation of soil heavy metal pol ution.

Effects of Arbuscular Mycorrhizal Fungi (AMF) on Distribution of Pb Forms in Rhizosphere of Upland Rice

[Objective] The aim was to study the effects of AMF on distribution of Pb in different chemical forms in rhizosphere soil of upland rice. [Method] A pot experiment was conducted to explore effects of AMF inoculation on distribution of Pb in different forms in rhizosphere of rice (Oryzal sativa L.) with Pb in different concentrations (0, 300 and 600 mg/kg). [Result] With inoculation adopted, mycorrzhial colonization rate of upland rice under Pb pdlution root declined substantially with Pb increasing in soils (P<0.05). Compared with non-inoculation, rhizosphere pH significantly enhanced by inoculation; when Pb was at 300 mg/kg, glomalin content in soils improved significantly by inoculation; when Pb was at 600 mg/kg, glomalin content in soils declined substantially (P<0.05). In addition, inoculation significantly improved contents of Pb in exchangeable and organic forms, but lowered Pb in carbonate bound and Fe-Mn oxides bound forms (P<0.05). [Conclusion] The research indicated that AMF inoculation would change distribution of Pb in different forms in rhizosphere soils of upland rice.

Arbuscular Mycorrhizal Fungi Colonization in Upland Rice as Influenced by Agrochemical Application

Mycorrhizal status of rice under upland conditions was studied using potted seedlings, Percentage of arbuscular mycorrhizal fungi （AMF） root colonization varied between 17.35% and 37.18% over an age series of 7 to 70 days old rice plants, AMF root colonization was increased up to 35-42 days, beyond which the root colonization steadily declined, The vesicles appeared after two weeks and reached their maximum intensity on the 35th day. The arbuscules were formed late on the 42^rd day （2.93%） and slightly varied up to the 70^th day （3.03%）. Higher dosage of urea application suppressed plant growth whereas the superphosphate treatment had no marked impact on plant growth. Generally, application of these agrochemicals registered less influence on the hyphal colonization of AMF in rice plants, whereas arbuscular colonization was adversely affected by higher dosages of fertilizers. There were pronounced decreases in both the plant growth and their AMF colonization due to the application of systemic fungicides, carbendazim and thiophanate methyl. The application of single sprays of fungicides was less deleterious over multiple sprays.

Studies on Growing Edible Fungi on Improved Straw from a Dual Use Rice Cultivar

Every year 500 million tons of rice (Oryza sativa L.) straw are generated worldwide, which was almost equal to the production of rice grain. Most straw is not recovered due to the poor quality, high cost or complicated treatment operations. Through genetic improvements, a rice cultivar '201' was developed with both high nutrient content in straw and high grain yield. The results of 15N tracer experiments showed thatls N of urea could be effectively transformed into straw protein of ' 201' and the recovery rate of 15N in the straw of '201' was 104% higher than that of the check 'TY 63'. The straw protein of '201' could be effectively transformed into mushroom protein and the recovery rate of 15N was 21.7% higher than that of 'TY 63'. Using the straw of ' 201' as material to cultivate straw-based edible fungi, improved the yield and protein content of mushrooms. A total of 7.5 mg·ha-1straw of '201' increased the yield and crude protein of the edible mushroom Volvariella volvacea 797 kg yield and 67.9 kg respectively, and increased the yield and crude protein of the edible mushroom Agaricus blazei Murrill 675 kg and 80 kg respectively. The straw powder of '201' could be used to substitute for the same weight of wheat bran to cultivate lignicolous edible fungi, with no significant difference in terms of mushroom yield or the crude protein content. Straw powder could substitute for 20% of total amount of material to grow Auricularia polytricha, Auricularia auricula, Hypsizygus tessulatus, Lentinula edodes and Hericium erinaceus, 8% of that to grow Agrocybe cylindracea and 7.5% of that to grow Flammulina velutipes respectively.

Antifungal Activity and Toxicity of Two New types of Polyene Antibiotics against Four Species of Rice Pathogenic Fungi

The antifungal activity and toxicity of new type polyene macrolide antibiotics-Antifungalmycin 702 and Fungichromin against Rhizoctonia solani, Hel- minthosporium sigmoideum Car. , Magnaporthe grisea and Ustilaginoidea virens were studied by mycelial growth rate method and mycelial dry weight method in vitro. The results showed that both of Antifungalmycin 702 and Fungichromin had strong antifungal activity against four speices of rice pathogenic fungi. Treated with 50 μmL Antifungalmycin 702 , the inhibitory rates of Antifungalmycin 702 agmnst R. solani, H. sigmoideum Cav., M. grisea and U. virens were 100%, 100%,91.20% and 68.10%, and EC50 and ECho were 7.00, 10.30, 14.41, 26.71 and 13.20, 17.66, 27.67,128.28 p.g/mL, respectively. Treated with 13 pg/mL Fungichremln, the inhibitory rates of Fungichromin against four speices of rice pathogenic fungi were 78.20%, 100%, 100% and 79.17%, and ECs0 and ECg0 were 1.47, 1.91, 2.37, 0. 20 and 41. （15, 3.92, 4.34, 135.54 gg/mL, respectively. The antifungal activity of Fungichromin was stronger than Antifungalmycin 702.

Evaluation of Antioxidants, Total Phenolics and Antimicrobial Activities of Ethyl Acetate Extracts From Fungi Grown on Rice Straw

Rice straw(RS)collected from Egyptian agricultural environment(Al-Masied village-Alsharqia Governorate-Egypt)was used as substrate for three fungal isolates namely:4b,1Asp,Pleurotus ostreatus NRRL 3501 and mixed culture of(4b,1Asp).Isolates number 4b and 1Asp were identified using the molecular technique(18S rRNA).Isolate 4b and 1Asp,were identified as Trichoderma saturnisporum MN1-EGY and Aspergillus niger MN2-EGY,respectively.Trichoderma saturnisporum MN1-EGY extract exhibited the highest antimicrobial activity compared to the other fungal extracts.Total phenolic,antimicrobial and antioxidant activities were also determined from the ethyl acetate extract of rice straw inoculated by these fungi.The antioxidant scavenging concentration(SC50)values of the tested samples were 88.84,91.45,94.65 and 100.0μg/ml,respectively for Pleurotus sp.,Aspergiluus niger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.,after 15 days incubation,compared to ascorbic acid as positive control with SC50 value equal to 8.0μg/ml.Total phenolic contents(TPCs)were maximum in Pleurotus sp.extract and found to be the most polyphenolic enriched sample(380.64 mg GAE/g dry extract)compared to extracts of Aspergiluusniger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.(261.89,198.52,and 119.80 mg GAE/g dry extract),respectively.The GC-MS analysis has been also performed for the promising extracts.

霉菌对优质籼稻黄变的影响

优质籼稻在储藏期间品质容易发生改变,色泽的变化更是明显,而发生黄变的两个主要因素是微生物和环境条件。通过设置不同的水分含量和储藏温度,考察灰绿曲霉、黄曲霉、白曲霉和黑曲霉4种主要霉菌对优质籼稻黄变的影响。研究结果表明:在不同水分含量和储藏温度条件下,优质籼稻的黄度指数发生了不同程度的改变,其中单一接种灰绿曲霉水分含量为17%的优质籼稻在30℃储藏温度下,黄度指数增加最快;由带菌量和黄度指数的相关性分析得出4种霉菌分别在适宜的生长环境中,对黄变影响程度最大的为灰绿曲霉,最弱的为白曲霉。研究结果为储藏过程中稻谷黄变及预防提供了理论依据。

Effect of Inoculation with Arbuscular Mycorrhizal Fungus on Nitrogen and Phosphorus Utilization in Upland Rice-Mungbean Intercropping System

The effect of arbuscular mycorrhiza fungi （AMF） on plant growth and nutrition utilization in upland rice and mungbean intercropping system was studied. A pot experiment was conducted in the greenhouse and AMF colonization rates of rice and mungbean roots, plant nutrient contents, the ability of nitrogen fixation, and nutrient contents changed in the soil were analyzed. The results were obtained as follows： the rates of AMF colonization of rice and mungbean roots were reached to 14.47 and 92.2% in intercopping system, and increased by 4.11 and 11.95% compared with that of in monocropping; the nirtrogen contents of mungbean and rice were increased by 83.72 and 64.83% in shoots, and 53.76 and 41.29% in roots, respectively, while the contents of iron in shoot and root of mungbean were increased by 223.08 and 60.19%, respectively. In the intercropping system with inoculation of AMF, the biomass of mungbean increased by 288.8%. However, the biomass of rice was not significantly changed among all treatments with or without inoculation of AMF recorded. The number and dry weight of nodules were significantly increased either when mungbean was intercropped with rice or inoculated with AMF. When compared with that of monocropping without AMF inoculation, the contents of nitrogen, phosphorus and iron in nodules of intercropping mungbean with inoculation increased by 80.14, 69.54 and 39.62%, respectively. Additionally, intercropping with AMF inoculation significantly increased soil nitrogen content, but reduced soil phosphorus content. We concluded that upland rice-mungbean intercropping system and inoculation with AMF improved the nutrient uptake, the ability of nitrogen fixation and the growth of mungbean.

Rice False Smut Fungus, <i>Ustilaginoidea virens</i>, Inhibits Pollen Germination and Degrades the Integuments of Rice Ovule

Ustilaginoidea virens is a flower-infecting fungus that forms false smut balls in rice panicle. Rice false smut has long been considered a minor disease, but recently it occurred frequently and emerged as a major disease in rice production. In vitro co-cultivation of U. virens strain with young rice panicles showed that U. virens enters inside of spikelets from the apex and then grows downward to infect floral organs. In response to U. virens infection, rice host exhibits elevated ROS accumulation and enhanced callose deposition. The secreted compounds of U. virens can suppress rice pollen germination. Examination of sectioning slides of freshly collected smut balls demonstrated that both pistil and stamens of rice flower are infected by U. virens, hyphae degraded the contents of the pollen cells, and also invaded the filaments. In addition, U. virens entered rice ovary through the thin-walled papillary cells of the stigma, then decomposed the integuments and infected the ovary. The invaded pathogen could not penetrate the epidermis and other layers of the ovary. Transverse section of the pedicel just below the smut balls showed that there were no fungal hyphae observed in the vascular bundles of the pedicel, implicating that U. virens is not a systemic flower-infecting fungus.

Clustering and Expression Analysis of Chitinases in Maize and Rice

Chitinases play an important role in regulating plant growth and development, especially defending themselves from fungal pathogens. It is important to do the biological analyses in crops. In this study, the result showed that the chitinases were distributed into the whole genome in rice, and nearly the whole genome in maize expect for Chromosome 9. The clustering results showed that one out of three chitinases from maize and rice belonged to new groups, which were separated from those in the conformed Classes I-VII. The identification of most amino acid sequences was very low among the chitinases from rice and/or maize. It was inferred that the chitinases with different functions were relatively stable during plant evolution. The relationship of chitinases expression between leaf blade and anther was positively significant in maize, but not significant in rice. Additionally, the ratio of chitinases with up- or down-regulated expression in sensitive maize under Fusarium moniliforme inoculation was different from that in sensitive rice under Magnaporthe grisea inoculation. It might be result from different tissues infected by different fungi. The number of chitinases from resistant maize was less than that from sensitive maize, which inferred that the resistant pathways on F. moniliforme should be not only chitin induced Pathogen-associated molecular PTI （patterns-triggered immunity） pathway, but also might include other PTI pathways that improve tolerance to F. moniliforme. The analysis of expression pattern of chitinases from maize and rice under fungi inoculation will be contributed into further research on the defense mechanism of fungi in crops.

Plant growth-promoting characteristics of root fungal endophytes isolated from a traditional Cordillera rice landrace

This study was conducted to isolate and characterize the plant growth-promoting potential of fungal endophytes from the roots of Diket red,a traditional rice plant from the Cordillera,Northern Luzon.Eighteen morphospecies of filamentous endophytes were isolated of which twelve isolates were successfully identified to the species level.These isolates were identified as Aspergillus versicolor,Aspergillus sp.,Chaetosphaeria sp.,Cladosporium cladosporioides,Hypocrea lixii,Microascus murinus,and Trichoderma harzianum.The identified twelve isolates were selected to screen in vitro for their plant growth-promoting characteristics,and evaluated in vivo for their beneficial effects on seedling vigor and early seedling growth.Isolate PPL14 produced the highest IAA at 55.5μg ml^(-1)and M.murinus PPL10 produced the highest amount of IAA at 3.73μg IAA mg^(-1)dry mycelia wt.The seedling vigor assay and in vivo plant growth promotion bioassay indicated overall positive effects of culture filtrate(CF)application of the endophyte isolates.Rice seeds and seedlings grown in aseptic condition and treated with endophyte CFs displayed significantly enhanced levels of germination,seedling vigor,shoot,root,and total plant growth,and biomass compared to non-treated control.Other plant growth-promoting characteristics were also studied including phosphate solubilization,siderophore production,ammonia production,and catalase activity.This study supports the potential use of fungal endophytes as bio-inoculants for plant growth promotion and enhancement of nutrient assimilation of agriculturally important crops.

乡村振兴战略背景下柳州市食用菌产业高质量发展对策初探

随着柳州螺蛳粉从广西地方小吃发展为享誉全国的特色大产业,作为螺蛳粉产业上游的食用菌产业迎来了新的发展契机。文章分析了柳州市食用菌产业现状、经验做法和存在问题,立足柳州市自身资源优势条件,针对性提出推动柳州市食用菌产业高质量发展的对策建议,旨在探讨乡村振兴战略背景下柳州市食用菌产业发展方向,以期为柳州市螺蛳粉全产业链贯彻新发展理念提供参考。

丛枝菌根真菌缓解水稻盐碱胁迫的生理特性研究

为探明丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)对盐碱胁迫下不同水稻品种生长和生理特性的影响,采用温室盆栽试验,在盐碱和非盐碱条件下设接种根内根孢囊霉(Rhizophagus intraradices)和不接种处理,研究了耐盐碱水稻品种津源85和盐碱敏感水稻品种辽粳763的根系菌根侵染率、生长特性、抗氧化系统及渗透调节物质的响应情况。结果表明,盐碱胁迫会显著抑制水稻的生长,接种AMF后可提高水稻株高和干物质量,且以津源85效果更好;盐碱胁迫会导致水稻植株MDA和H_(2)O_(2)含量增加,接种AMF后会显著提高SOD、POD、CAT和APX的活性,同时H_(2)O_(2)和MDA含量显著降低;此外,AMF还可以通过提高盐碱胁迫条件下植株的脯氨酸、可溶性糖和可溶性蛋白含量来缓解渗透胁迫。可见,AMF可在一定程度上缓解因盐碱胁迫造成的生理生长活性的抑制,通过调控抗氧化酶系统和渗透调节物质来提高水稻对盐碱胁迫适应性,且对不同品种所发挥的效果不完全相同。

丛枝菌根真菌和解磷细菌复合接种对水稻丛枝菌根真菌侵染率和肥料利用率的影响

为探究丛枝菌根真菌和解磷细菌复合接种对水稻肥料利用率的影响,本研究以金粳818为试验材料,以接种灭活复合菌剂为对照,分析2种丛枝菌根真菌[异形根孢囊霉(Rhizophagus irregularis,RI)和摩西管柄囊霉(Funneliformis mosseae,FM)]和3种解磷细菌[芽孢杆菌属细菌(Bacillus sp.,R1-3)、巨大芽孢杆菌(Bacillus megaterium,BM)、耐盐节杆菌(Arthrobacter pascens,AP)]单接种和两两组合接种对水稻丛枝菌根真菌侵染率和肥料利用率的影响。结果表明,与单接种丛枝菌根真菌处理相比,加入解磷细菌后大部分处理的水稻菌根侵染率降低,其中FM+BM处理的丛枝菌根真菌侵染率下降至7.54%,显著低于单接种丛枝菌根真菌处理。相较于对照和单接种丛枝菌根真菌或解磷细菌处理,复合接种处理在水稻生殖生长期末整体上提高了氮肥、钾肥利用率,其中FM+BM处理与对照相比分别提高了19.55个百分点、20.47个百分点。丛枝菌根真菌和解磷细菌复合接种有利于提高水稻生殖生长期末氮肥利用率和钾肥利用率,其中FM+BM为最优组合。

高地芽孢杆菌对水稻根际真菌群落的影响

为探究施用高地芽孢杆菌对水稻根际土壤真菌群落结构的影响,通过盆栽实验进行水稻根际土壤取样,基于真菌ITS高通量测序技术,分析比较高地芽孢杆菌B.altitudinis LZP02(LZP02)处理组与对照组水稻(Oryzasativa)根际土壤中真菌群落多样性.结果表明,LZP02并未显著提高水稻根际土壤真菌群落OTU数量及Sobs指数、Shannon指数、Chao指数和Ace指数,但PCo A分析显示对水稻根际土壤真菌群落结构具有显著影响.提高了根际土壤中未分类真菌门(unclassified_k__Fungi)相对丰度,促使土壤中新赤壳属(Neocosmospora)、未被分类真菌(unclassified_k__Fungi)、尾孢菌属(Cercophora)等一些有益真菌的相对丰度增加.高地芽孢杆菌LZP02可显著改变水稻根际真菌群落结构,为进一步揭示微生物接种与水稻的互作机制研究奠定了基础.

鄂西南羊肚菌+有机稻轮作种植模式

结合鄂西南当地条件,探索出一种食用菌高效轮作种植模式,该技术的推广对农业可持续发展、乡村振兴具有一定积极意义。文章对羊肚菌+有机稻种植要点进行了总结,对该种技术的效益进行了分析,以期为当地农民及农业工作者的种植提供理论基础。

磷水平对内生真菌枫香拟茎点霉与水稻互作平衡的调控作用

内生真菌枫香拟茎点霉(Phomopsis liquidambaris,B3)能够与水稻建立互惠互利关系,但是两者之间的互作关系是否会受到土壤中有效磷含量的影响尚不清楚。本研究以水稻-B3共生体系为研究对象,在低磷(LP)、中磷(MP)、高磷(HP)三个磷水平中分别设置未接菌组(E-)、接菌组(E+),共六个处理,探讨在室外盆栽试验与温室试验下,不同磷水平对植物-内生真菌互作关系的影响。室外盆栽试验表明,在低磷水平下,接种B3显著促进水稻生长,水稻产量提高7.05%;在中高磷水平下B3对水稻生长的作用减弱。为排除土壤中复杂环境的影响,设计温室试验,结果表明,在低磷水平下,与未接种处理相比,接种B3的水稻根冠比提高22.48%,磷含量增加39.98%,同时,B3显著增强叶绿素的含量以及水稻根部蔗糖、葡萄糖、果糖积累量,然而,低磷环境会限制B3在水稻根部的定殖量;在中磷和高磷水平下,B3定殖量高但对水稻的促生作用减弱。以上结果表明,在低磷水平下,B3与水稻之间是低丰度互作平衡关系,在该条件下,B3在水稻根部的定殖量低但能显著促进水稻生长;而在中高磷水平下,B3与水稻是高丰度互作平衡关系,B3在水稻根部定殖量高,虽然没有促生作用但可能具有其他优势。本研究有利于解释磷是否以及如何影响内生真菌与水稻的互作关系。

仓储稻米中产柄曲霉素菌的分离鉴定及其产毒条件研究

目的 获得产柄曲霉素(sterigmatocystin,STC)的菌株并研究其最适产毒条件。方法 将1份来自广东省韶关市仓储霉变稻米的稀释液接种至马铃薯葡萄糖琼脂(potato dextrose agar,PDA)培养基上,利用平板划线法分离获得菌株,通过高效液相色谱-串联质谱法对获得菌株的产STC能力进行检测,结合形态学观察和rDNA-ITS序列分析对产毒素菌鉴定,并对其产STC菌株的产毒条件(培养基、培养天数、培养温度)进行考察。结果 该稻米中共分离到9种菌,其中詹森曲霉(Aspergillus jensenii)可代谢合成STC,其最佳产毒培养基为大米培养基,最适温度为28℃,且在培养的第28 d含量达到最大。结论 该研究从发霉稻米中分离获得1株可代谢产生STC的菌株,可为我国针对性地防控粮食中产毒性真菌污染提供基础性实验菌株,同时也有利于STC生物合成、代谢等工作的开展。