Fungi Associated with Sand and Plants from Marine Coastlines: Potential Relevance for Human Health

The fungal community associated with beach sand and plants located along marine coasts are an under-studied area of research despite its potential relevance to human health. In this study, we isolated and identified the cultivable mycobiota associated with sand and plants collected along the coast of Gran Canaria (Spain) using culture-dependent and -independent methods. Clinically relevant species belonging to Cryptococcus spp. and related genera such as Naganishia and Papilotrema were isolated and identified from shoreline plants. Moreover, Candida tropicalis was isolated from beach sand, and Aspergillus fumigatus and Aspergillus terreus strains were associated with both types of samples (i.e., plants and beach sand). We conclude that beach sand and shoreline plants are potential reservoirs of fungi of high clinical interest. We recommend including beach sand and plants from the environment when assessing the quality of marine coastal systems. Our results open a framework for studying the natural marine environment and its role in the epidemiology of infectious diseases in order to more accurately manage public health.

Inventory and Management of Fungi Associated with Banana Plant through the Use of Allium ampeloprasum and Cymbopogon citratus Extracts

Despite the nutritional, economic and medicinal values of banana plant, independent of the region and production system is confronted with some diseases such as the fungi disease. These fungal diseases are responsible for the low yields. The objective of this study was to improve the sanitary state of banana plant. To achieve this objective, fungi associated with banana leaves were isolated on Potato Dextrose Agar (PDA) culture medium and their identification was done on the basis of morphological and microscopic characteristics using reference documents. Antifungal activity of Allium ampeloprasum and Cymbopogon citratus extracts were evaluated in vitro on agar medium on the development of Pseudocercospora fijiensis, P. musicola and Pestalopsis sp. The results showed that banana plant harbours a diversity of fungal species, the most frequent being P. fijiensis (51.58%), Pestalopsis sp. (15.47%) and P. musicola (12.03%). Aqueous extracts of C. citratus at the concentration of 15 mg/ml, inhibited 100% of the radial growth of P. fijiensis and Pestalopsis sp with a fungitoxic activity. Similarly, ethanolic extract A. ampeloprasum inhibited at 100% the radial growth of Pestalopsis sp. This antifungal activity was fungistatic. These results suggest that the aqueous and ethanol extracts of the tested plants could be used as alternatives to chemical products in the fight against banana diseases especially Sigatoka. Hence further studies need to be undertaken to isolate the active compounds from these extracts with fungicidal potential.

In Vitro Antifungal Activity of the Extract and Compound from Acorus tatarinowii Against Seven Plant Pathogenic Fungi

Acorus tatarinowii Schott is a traditional Chinese medicine plant and has multiple bioactivities in medicine and pesticide field. In this study, the antifungal compound 1,2-dimethoxy-4（2-propenyl） benzene was isolated from A. tatarinowii Schott by activity-directed isolation method, and the inhibitory activity of the extract and 1,2-dimethoxy-4（2-propenyl） benzene against seven plant pathogenic fungi was evaluated. The results showed that the extract and 1,2-dimethoxy-4（2- propenyl） benzene had high inhibitory activity against hyphal growth of Thielaviopsis paradoxa （de Seynes） V. Hohnel, Pestalotia mangiferae P. Henn., Fusarium oxysporum f. sp. niveum （E. F. Smith） Syn. et Hans., Alternaria alternate Tanaka, Colletotrichum musae （Berk et Curt） V. Arx, Sphaceloma fawcettii Jenk., and Mycosphaerella sentina （Fr.） Schroter. The EC50 values of extract were 1.6162, 1.6811, 1.1253, 3.5771, 1.7024, 2.2284, and 2.2221 g L^-1, respectively, and the EC50 values of 1,2-dimethoxy-4（2-propenyl） benzene were 0.1021, 0.0997, 0.0805, 0.1742, 0.1503, 0.1853, and 0.1924 g L^-1, respectively. 1,2-Dimethoxy-4（2-propenyl） benzene also inhibited spores germination of T. paradoxa （de Seynes） V. Hohnel and F. oxysporum f. sp. niveum （E. F. Smith） Syn. et Hans., with the inhibitory rates of 98.81 and 100% at a concentration of 0.4 g L^-1 after 8 h, respectively. 1,2-Dimethoxy-4（2-propenyl） benzene is a potential botanical antifungal agent for controling of plant fungal diseases.

Uniform categorization of biocommunication in bacteria,fungi and plants

This article describes a coherent biocommunication categorization for the kingdoms of bacteria,fungi and plants. The investigation further shows that,besides biotic sign use in trans-,inter-and intraorganismic communication processes,a common trait is interpretation of abiotic influences as indicators to generate an appropriate adaptive behaviour.Far from being mechanistic interactions,communication processes within organisms and between organisms are sign-mediated interactions.Sign-mediated interactions are the precondition for every cooperation and coordination between at least two biological agents such as cells,tissues,organs and organisms.Signs of biocommunicative processes are chemical molecules in most cases.The signs that are used in a great variety of signaling processes follow syntactic(combinatorial) ,pragmatic(context-dependent) and semantic(contentspecific) rules.These three levels of semiotic rules are helpful tools to investigate communication processes throughout all organismic kingdoms.It is not the aim to present the latest empirical data concerning communication in these three kingdoms but to present a unifying perspective that is able to interconnect transdisciplinary research on bacteria,fungi and plants.

Biodegradation and Sugar Release from Canola Plant Biomass by Selected White Rot Fungi

Canola crop is rich in plant biomass. It is considered a major cash crop in North America and a potential source for biofuel. We evaluated six strains of white rot basidiomycetes under solid state fermentation (SSF) for their potentials to secrete oxidative and hydrolytic enzymes to biodegrade canola plant biomass (CPB), and release sugars. Fuscoporia gilva and Pleurotus tuberregium produced high amount of laccase (440.86 U/L and 480.63 U/L at day 7), as well as carboxylmethylcellulase (CMCase) (4.78 U/mL at day 21 and 3.13 U/mL at day 14) and xylanase (4.48 U/mL and 7.8 U/mL at day 21), respectively. Bjerkandera adusta showed high amount of MnP (50.4 U/L) and peroxidase (64.5 U/L), relative to the other strains. Loss of organic matter peaked after 21 days of incubation in all the tested strains;however, the best result (34.0%) was shown in P. tuberregium. The highest lignin loss was observed in Coriolopsis caperata strains. Among the sugar polymers, hemicellulose was highly degraded by P. tuberregium and P. pulmonarius (4.1% - 4.6%), while cellulose (3.3% - 4.3%) was mainly degraded by F. gilva and B. adusta. Glucose was the dominant sugar released by all the fungi tested, with the highest concentration of 1.25 mg/mL produced by B. adusta at day 14 of incubation. Results indicate that selected white rot fungi can achieve significant delignification of CPB within 14 days of solid state fermentation. Their importance in low cost pretreatment of lignocellulosic biomass prior to conversion into biofuels and bio-products of economic importance is discussed.

Identification of Plant-Pathogenic Fungi Using Fourier Transform Infrared Spectroscopy Combined with Chemometric Analyses

Identification of plant-pathogenic fungi is time-consuming due to cultivation and microscopic examination and can be influenced by the interpretation of the micro-morphological characters observed.The present investigation aimed to create a simple but sophisticated method for the identification of plant-pathogenic fungi by Fourier transform infrared(FTIR)spectroscopy.In this study,FTIR-attenuated total reflectance(ATR)spectroscopy was used in combination with chemometric analysis for identification of important pathogenic fungi of horticultural plants.Mixtures of mycelia and spores from 27fungal strains belonging to nine different families were collected from liquid PD or solid PDA media cultures and subjected to FTIR-ATR spectroscopy measurements.The FTIR-ATR spectra ranging from 4 000to 400cm-1 were obtained.To classify the FTIRATR spectra,cluster analysis was compared with canonical vitiate analysis(CVA)in the spectral regions of3 050~2 800and 1 800~900cm-1.Results showed that the identification accuracies achieved 97.53%and99.18%for the cluster analysis and CVA analysis,respectively,demonstrating the high potential of this technique for fungal strain identification.

Effectiveness of Ringworm Cassia and Turmeric Plant Extracts on Growth Inhibition against Some Important Plant Pathogenic Fungi

Crude plant extracts of ringworm cassia, Cassia alata L. and turmeric, Curcuma longa L. were prepared by either hot water or organic solvents such as ethanol and ether. Various concentrations of the crude extract were then subjected to an in vitro test for their effectiveness on mycelia growth inhibition against some important plant pathogenic fungi such as Alternaria alternata, Colletotrichum gloeosporioides, Fusarium oxysporum fsp. lycopersici, Sclerotium rolfsii, Phytophthora infestans and Pythium sp. in comparison to commercial fungicides such as copper oxychloride and mancozeb. Reduction of the fungal growth was significantly obtained with C. longa extracts and the best median effective inhibitory concentration (IC50) value of 6.07, 6.50 and 7.13 mg/ml was from the ethanol extract for S. rolfsii, C. gloeosporioides and F. oxysporum fsp. lycopersici respectively. While all extracts from C. alata were almost the least effective against these fungi. The efficacy of C. longa extracts therefore, provided an alternative regime for the control of the fungal diseases and a promising appreciable choice for a replacement of chemical fungicides.

Dynamics of arbuscular mycorrhizal fungi associated with desert ephemeral plants in Gurbantunggut Desert

Previous studies documented that most desert plants can be colonized by arbuscular mycorrhizal （AM） fungi, however, little is known about how the dynamics of AM fungi are related to ephemerals in desert ecosystems. The dynamics of AM fungi with desert ephemerals were examined to determine the effects of host plant life stages on the development of AM fungi. Mean colonization of ephemeral annual plants was 45% lower than that of ephemeral perennial plants. The colonizations were much higher in the early part of the growing season than in later parts, peaking at flowering times. The phenology of AM fungi in root systems varied among different ephem- erals. The density of AM fungal spores increased with the development of ephemeral annual plants, reached its maximum at flowering times, and then plateaued about 20 days after the aboveground senescence. A significant positive correlation was found between AM fungi spore density and biomass of ephemeral annual plants. The life cycles of AM fungi associated with desert ephemerals were very shod, being about 60-70 days. Soil temperature and water content had no direct influence on the development of AM fungal spores. We concluded that the development of AM fungi was in response to desert ephemeral phenology and life history strategy.

Endophytic Fungi Associated with a Holoparasitic Plant, Balanophora japonica (Balanophoraceae)

Holoparasitism is a special life cycle of flowering plants. All carbon resources are provided by photosynthetic host plants. A recent study revealed the presence of endophytic fungi in holoparasitic plants, but their ecological and evolutionary roles are still unknown. In this study, we examined endophytic fungi isolated from the holoparasitic plant Balanophora japonica (Balanophoraceae), collected from Kochi, Shikoku in western Japan. We isolated 23 fungal strains on inflorescences and tubers from three B. japonica plants at two locations and on one sample of the host plant (Symplocos lancifolia, Symplocaceae). Predominant isolates were Trichoderma-Hypocrea, Penicillium and Phialemonium. The first group was also predominant in the host plant. Fungal composition revealed in this study differed from the composition on B. harlandii or other root holoparasites with endophytic fungal (Rafflesia cantleyi) data. Those differences might be caused by various factors, including growth habits, location, phylogenetic position or host-parasite relationship.

石榕树中补骨脂素分离鉴定及其抗真菌活性

[目的]分离出石榕树中能够有效抑制植物病原真菌的活性单体化合物并探索其抗真菌活性。[方法]采用生物活性追踪和化学分离相结合的方法对石榕树甲醇提取物进行分离,运用质谱、核磁共振氢谱和碳谱并结合相关文献数据鉴定活性单体化合物。采用菌丝生长速率法测定活性单体化合物对7种植物病原真菌的抑菌活性。[结果]石榕树(叶)甲醇提取物对甘蔗凤梨病菌具有良好抑菌活性,在10 mg·mL^(-1)浓度下,抑菌率为100%。在浓度为1.5 mg·mL^(-1)时,石榕树(叶)石油醚、乙酸乙酯、正丁醇萃取物和水层萃余物对甘蔗凤梨病菌的抑菌率分别为58.73%、100.00%、39.49%和6.63%。表明石榕树(叶)乙酸乙酯层萃取物对甘蔗凤梨病菌的抑制作用最高,其EC_(50)值为0.430 7 mg·mL^(-1)。石榕树(叶)乙酸乙酯层萃取物进行柱色谱分离后得到对甘蔗凤梨病菌有较高抑菌活性的是LMNO1bc1a活性组分,0.1 mg·mL^(-1)的LMNO1bc1a活性组分对甘蔗凤梨病菌的抑菌率为100.00%。LMNO1bc1a组分经结晶、重结晶纯化后命名为SRS-1,SRS-1经NMR和MS技术鉴定为补骨脂素(psoralen)。SRS-1对甘蔗凤梨病菌、甘蓝黑斑病菌、玉米大斑病菌、罗汉果白绢病菌、柑橘砂皮病菌、茶轮斑病菌、烟草黑胫病菌这7种植物病原真菌都有一定的抑菌活性,其EC_(50)值分别为0.018 2、0.038 8、0.040 9、0.051 2、0.080 7、0.092 7、0.115 4 mg·mL^(-1)。[结论]从石榕树中分离出抑菌活性单体化合物SRS-1,鉴定为补骨脂素,其对甘蔗凤梨病菌、甘蓝黑斑病菌、玉米大斑病菌、罗汉果白绢病菌、柑橘砂皮病菌、茶轮斑病菌、烟草黑胫病菌这7种植物病原真菌都有一定的抑菌活性。

AMF和PGPR联合芦苇修复重金属污染河道底泥的效应

研究旨在探究河道底泥重金属污染下丛枝菌根真菌(Arbuscular Mycorrhizal Fungi,AMF)与植物根际促生菌(Plant Growth-Promoting Rhizobacteria,PGPR)对芦苇生长、磷吸收以及重金属去除的效应。以沈阳市浑河河道底泥为研究对象,对芦苇接种AMF双网无梗囊霉(Acaulospora bireticulata,AM1)、摩西斗管囊霉(Funneliformis mosseae,AM2)、PGPR黏质沙雷氏菌(Serratia marcescens,PG)、双网无梗囊霉+黏质沙雷氏菌(APG1)、摩西斗管囊霉+黏质沙雷氏菌(APG2)和不接种对照(CK)共6个处理。结果显示,AMF能够促进PGPR在芦苇根区土壤以及根内的定殖数量,而PGPR能够促进AMF侵染发育,增加其侵染率、泡囊数以及孢子数。AMF、PGPR或AMF+PGPR处理均显著增加了芦苇生物量以及地上部和根系磷质量比,促进了植物对底泥中重金属(Cd、Zn、Pb、Cu)的吸收,降低了土壤中重金属含量。在各处理下,APG2处理对底泥中重金属的去除率最高,达33.24%~55.51%,土壤中过氧化氢酶、蔗糖酶、脲酶和碱性磷酸酶活性也显著高于AM1、AM2、PG和CK处理。此外,底泥重金属在芦苇内的分布均为根系大于地上部,可见芦苇根系对重金属的吸收和富集能力较强,且以APG2处理下对Cd、Zn、Pb的吸收效果最好,分别是CK处理的2.4倍、2.0倍以及1.7倍。因此,AMF和PGPR双接种可提高芦苇P吸收量以及土壤酶活性,促进芦苇生长,而AMF和PGPR能够相互促进,增加对底泥重金属的去除效率,其中APG2是最佳组合。

激光农业研究进展和展望

激光作为一种新兴的人造光源,是20世纪以来最伟大的发明之一,具有功率密度高、方向性好和优良的单色性等优点,在农业领域得到了广泛的应用。激光技术在植物生产、动物管理和菌物研究方面展现了显著优势。文章主要对激光技术在农业领域的研究进展和发展动态进行深入剖析。在植物生产方面,介绍了激光技术在植物诱变育种、促进植物生长发育、提高产量和品质、植物保护、植物检测和植物表型中的应用情况。在动物管理方面,主要分析了激光技术在动物遗传育种、动物生长、动物医疗和动物产品检测方面的研究。在菌物研究方面,重点总结激光技术在菌物育种、菌物生长发育及菌物检测和鉴定中的应用详情。最后,针对激光技术与农业生产研究相结合所面临的困难和挑战,从提升激光技术在农业生产管理中的精度和扩展其适用范围角度出发,提出了激光技术在植物生产精准化、动物生产管理优化和菌物生产科学化的发展方向。虽然激光技术在农业领域已经取得了一系列的成果,但在未来的研究中,应探索更多创新应用,并与人工智能和大数据技术相结合,进一步推进激光技术与农业产业的深度融合,以实现更高效、更智能的农业生产管理模式,为现代农业的发展带来更多机遇和突破。

丛枝菌根真菌对实葶葱生长及化感作用的影响

【目的】探究丛枝菌根真菌(AMF)对实葶葱生长发育、生理活动以及化感作用的影响,为实葶葱驯化利用和AMF种质资源开发提供参考。【方法】采用盆栽试验,将分离自实葶葱栽培田土壤中的AMF(优势属为球囊霉属和无梗囊霉属)孢子接种于人工栽培的实葶葱根际(AM处理),以未接种AMF的实葶葱为对照(N-AM处理),测定实葶葱植株生长和生理特征的变化;取实葶葱地上部和地下部,分别制备0(对照),0.25,0.5和1 mg/mL的水浸提液,以叶用莴苣种子为受体材料,采用卷纸发芽法进行发芽试验,测定叶用莴苣幼苗生长指标,以衡量实葶葱化感作用的变化。【结果】接种AMF后实葶葱生长受到显著促进,植株表型得到调控。出苗后150 d,AM处理的株高、全株鲜质量、地上部鲜质量、地下部鲜质量、根长、根体积、须根数、侧根分支数分别为15.00 cm、0.87 g/株、0.46 g/株、0.42 g/株、21.17 cm、2.24 cm 3、8.83个/株、13.92个/株,较N-AM处理分别增加了36.74%,182.87%,251.42%,132.18%,23.83%,116.23%,14.23%,169.25%;菌根生长效应随实葶葱生长而增强,于出苗后120 d达到最高值1.33;AM处理实葶葱的全株、地上部和地下部干质量分别为127.60,90.20,37.40 mg/株,较N-AM处理分别显著增加了188.04%,290.48%和76.42%,根冠比则显著降低了54.84%。AM处理实葶葱叶片叶绿素a、鳞茎可溶性糖和EPY含量较N-AM处理分别显著提高了130.25%,58.33%和41.18%,叶片叶绿素b和可溶性糖含量比N-AM处理略降低但差异不显著。AM处理根系中独脚金内酯素含量在出苗后呈增高-降低-增高的变化趋势,于出苗后60 d达到最高值(2.86 ng/g),根系活力始终高于N-AM处理,盆栽实葶葱根系AMF侵染率最终为31.55%。当实葶葱地上部浸提液质量浓度为0.5 mg/mL、地下部浸提液质量浓度为0.25 mg/mL时,AM处理的综合化感效应指数分别比N-AM处理分别提高了112.12%和66.67%;当地上部浸提液质量浓度为0.25和1 mg/mL、地下部浸提液质量浓度为0.5和1 mg/mL时,AM处理的综合化感效应指数分别比N-AM处理降低了50.94%和4.69%及18.52%和35.19%。不同质量浓度实葶葱水浸提液对叶用莴苣幼苗生长均表现出促进作用,各处理的综合化感隶属函数值均高于对照(4.06),其中以0.5 mg/mL AM处理地上部水浸提液最高(15.49),0.25 mg/mL N-AM处理地下部水浸提液最低(6.89)。【结论】实葶葱的生长发育与生理活动均受到AMF强烈的正向作用,实葶葱对受体植物的化感作用效果也受到AMF的调节。

纤维素-聚乙烯亚胺水凝胶的制备及其抑菌性

纤维素是地球上存量最大的生物质,为了将其功能化并开拓新的用途,制备了一种纤维素基的抗菌水凝胶,并利用平板抑菌实验证明了其对两种常见植物病害真菌有良好的抑制效果。首先,采用高碘酸钠将纤维素氧化,测定其氧化度,并得到最适氧化条件;然后将氧化纤维素与聚乙烯亚胺反应生成水凝胶,并通过高速匀浆得到质量分数为1.0%的水凝胶悬浮液;最后,评价纤维素-聚乙烯亚胺水凝胶(PEI/OC-gel)对水稻稻瘟病菌和尖孢镰刀菌(西瓜专化型)的抑菌效果。结果表明,质量浓度高于0.75 mg·mL^(-1)的PEI/OC-gel可有效抑制稻瘟病菌和尖孢镰刀菌(西瓜专化型)的生长,因此有望将其用于防治水稻稻瘟病和西瓜蔓枯病等常见的植物真菌性感染。

独蒜兰提取物对植物病原真菌的抑菌活性

【目的】研究独蒜兰假鳞茎乙醇提取物对植物病原真菌的抑菌作用,为植物源杀菌剂的开发提供依据。【方法】采用菌丝生长速率法,研究独蒜兰假鳞茎乙醇提取物对15种植物病原菌的抑制活性;以西瓜尖孢镰刀菌作为供试菌,进一步研究该提取物对病原真菌的菌丝干重、细胞膜、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)等的影响。【结果】独蒜兰假鳞茎提取物对辣椒疫霉病菌、西瓜尖孢镰刀菌、番茄灰霉病菌和非洲隐地疫霉菌的抑菌效果明显,其EC_(50)值分别为0.849、0.782、0.813和1.161 mg·mL^(-1);经独蒜兰提取物处理后的西瓜尖孢镰刀菌菌丝干重随着药剂浓度的增加而减少;细胞膜丙二醛含量和相对电导率增加;菌丝体细胞内CAT、POD和SOD 3种保护酶活性增加。【结论】独蒜兰假鳞茎提取物对植物病原真菌具有较好的抑菌活性,其抑菌作用可能与其干扰菌丝生长、使菌丝细胞膜正常功能受损等有关。

板栗花抑制植物病原真菌成分提取及活性研究

为促进板栗花资源的充分利用,本研究优化了板栗花中有效成分的提取条件,并评价了其对植物病原真菌的抑制活性。采用菌丝生长速率法比较板栗花提取物对3种不同植物病原体的作用,包括小麦赤霉病菌(FG)、油菜菌核病菌(SS)和黄瓜枯萎病菌(FO),结合单因素试验和响应面曲线法优化板栗花抑菌活性成分的提取工艺,并通过萃取分相探究不同相的抑菌活性成分含量及抑菌活性。结果表明,板栗花抑菌活性成分对3种植物病原真菌均有明显的抑制作用,其中对FG的抑制作用最为明显。经过严格的试验和优化,确定最佳提取条件为乙醇体积分数55.00%(V/V)、提取时间50.00 min、提取温度65.00℃、液料比15.00∶1 mL·g^(-1),该优化条件下提取物中的活性成分抑菌率达到了45.27%。乙酸乙酯相总酚、总黄酮含量最高,其抑制中浓度值(EC50)为2.51 mg·mL^(-1)。本研究结果可为开发新型植物源抗菌剂提供理论依据。

圆叶青藤内生真菌Phlebiopsis crassa次生代谢产物研究

本文对分离自圆叶青藤(Illigera orbiculata C.Y.Wu)的一株内生真菌Phlebiopsis crassa MYYJ-5-1的次生代谢产物进行了研究,从其土豆固体发酵物中分离得到9个化合物,分别鉴定为:benzophenone(1)、p-hydroxybenzoic acid(2)、p-hydroxybenzaldehyde(3)、indole-3-carboxaldehyde(4)、indole-3-carboxylic acid(5)、thymidine(6)、uracil(7)、thymine(8)、mono-methyl succinate(9)。同时采用二倍稀释法对化合物进行体外抗植物病原菌活性测定,结果显示:化合物1和3对黄瓜萎蔫球菌具有中等抑制活性,MIC值均为32μg·mL^(-1);化合物5对人参链格孢菌具有中等抑制活性,MIC值为32μg·mL^(-1);化合物6对黑曲霉菌具有显著抑制活性,活性等同于阳性对照制霉素,MIC值均为16μg·mL^(-1)。

植物覆盖对香蕉园土壤真菌多样性及群落结构的影响

高度集约化的农业措施致使蕉园土壤退化日趋严重,制约了中国香蕉产业的健康可持续发展。植物覆盖能够改善土壤理化性质,优化土壤微生物群落结构,是一种重要的改善农业生态系统土壤退化的耕作措施。本研究通过宽窄行种植方式,以传统的裸露土壤种植方式为对照,在宽行中人工种植大翼豆[Macroptilium atropurpureum(DC.)Urb.]和自然生杂草为植物覆盖处理,通过连续定位试验,采集土壤样品并进行高通量测序,分析蕉园在植物覆盖下的土壤真菌多样性及群落结构的差异特征,以期探索蕉园土壤可持续利用种植模式。结果表明:蕉园植物覆盖处理下真菌群落组成差异显著,并随着覆盖年限增加呈现加强的趋势。根据FUNguild功能预测,与对照相比,大翼豆覆盖处理2019年和2020年Saprotroph_Symbiotroph真菌种群显著地(P≤0.05)增加,2020年Pathogen_Saprotroph真菌种落显著(P≤0.05)降低。共线性网络分析结果表明大翼豆覆盖处理与对照相比,群落复杂性无差异,但群落稳定性更高。同时核心物种无镰刀菌属ASVs,这可能反映了大翼豆覆盖可以减少镰刀属ASVs在群落中主导力,降低土传病害香蕉枯萎病的潜在发生风险。大翼豆处理有效提高了共生有益真菌群,减少了潜在的致病真菌群,有利于保持香蕉种植中的土壤健康。宽窄行与行间覆盖植物相结合的种植技术可有效改善土壤微生物多样性,有利于香蕉产业的可持续发展。

AMF和PGPR单独或“跨界”互作促进植物耐盐性的研究进展

盐碱地改良和利用对拓展我国后备耕地资源及保障国家粮食安全具有重要意义。根际微生物作为植物的“第二基因组”,在提高作物抗盐碱胁迫能力,促进作物“以种适地”方面具有巨大潜力。其中,丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和植物根际促生细菌(plant growth promoting rhizobacteria,PGPR)均为重要的根际有益微生物,能显著提高植物耐盐性。本文分别总结了AMF和PGPR提高植物抗盐能力的相关研究进展,并进一步梳理了两者协同提高植物耐盐的机制,包括提高养分效率、调节激素内稳态、提高植物诱导抗性以及调控转录因子表达等,最后提出了基于两者跨界组合的改良方向。旨在充分理解盐胁迫条件下微生物耐盐促生的作用机制,为充分挖掘微生物资源潜力和发展生物技术治理盐碱地提供重要的科学支撑。

无子刺梨内生真菌拮抗活性菌株筛选及分子鉴定

为进一步开发利用无子刺梨枝条和叶片中具有生物防治潜力的内生真菌,以2种木腐菌和4种植物病原真菌为靶标,采用五点对峙法筛选对病原真菌具有拮抗活性的内生真菌菌株,并探讨活性菌株的分类地位。结果显示,菌株RSZF 36、RSZF 39和RSYF 34对2种木腐菌的抑制率均达80%以上,菌株RSZF 34和RSZF 36对4种植物病原真菌的抑制率均大于75%,菌株RSZF 36对6种病原菌的抑制率均高于75%,呈现强抑制能力。84株内生真菌中有12株对6种病原菌抑制率均在70%以上,属于活性菌株,其中9株来自枝条,3株来自叶片。对12株活性菌株进行分子生物学鉴定,将其归属为1门2纲3目3科4属,拟盘多毛孢属(Pestalotiopsis)为优势菌属,占活性菌株的41.67%。综上,无子刺梨内生真菌中广泛分布着抑菌活性菌株,且不同内生菌株对不同病原菌的拮抗能力表现出一定的选择性或专一性。本研究结果可为无子刺梨内生真菌资源的开发利用提供理论参考。