Preparation and assessment of alginate-microencapsulated Trichoderma harzianum for controlling Sclerotinia sclerotiorum and Rhizoctonia solani on tomato.

This study aimed to develop microencapsulation technology using alginate to improve the viability and performance of Trichoderma harzianum. The method of ionic gelation was used to prepare the microparticles, and the efficiency of encapsulation was estimated to be 99%. The average size of the prepared microspheres was 2600 µm (wet) and 1000 µm (dry). Scanning electron microscopy revealed that the microspheres were approximately spherical. Fourier transform infrared spectrophotometer analysis indicated an interaction between T. harzianum and the microspheres. The results of temperature resistance and light stability against ultraviolet radiation emphasized the positive impact of microencapsulation in improving the viability and resistance of T. harzianum compared to the non-microencapsulated state. The disease percentage of Rhizoctonia solani and Sclerotinia sclerotiorum in plants treated with microencapsulated T. harzianum microcapsules was 8.88 % and 20 % respectively, but in the control group was 73.33 % (p ≤ 0.05).

Transcriptomic characterization of Trichoderma harzianum T34 primed tomato plants: assessment of biocontrol agent induced host specific gene expression and plant growth promotion.

In this study, we investigated the intricate interplay between Trichoderma and the tomato genome, focusing on the transcriptional and metabolic changes triggered during the late colonization event. Microarray probe set (GSE76332) was utilized to analyze the gene expression profiles changes of the un-inoculated control (tomato) and Trichoderma-tomato interactions for identification of the differentially expressed significant genes. Based on principal component analysis and R-based correlation, we observed a positive correlation between the two cross-comaparable groups, corroborating the existence of transcriptional responses in the host triggered by Trichoderma priming. The statistically significant genes based on different p-value cut-off scores [(padj-values or q-value); padj-value < 0.05], [(pcal-values); pcal-value < 0.05; pcal < 0.01; pcal < 0.001)] were cross compared. Through cross-comparison, we identified 156 common genes that were consistently significant across all probability thresholds, and showing a strong positive corelation between p-value and q-value in the selected probe sets. We reported TD2, CPT1, pectin synthase, EXT-3 (extensin-3), Lox C, and pyruvate kinase (PK), which exhibited upregulated expression, and Glb1 and nitrate reductase (nii), which demonstrated downregulated expression during Trichoderma-tomato interaction. In addition, microbial priming with Trichoderma resulted into differential expression of transcription factors related to systemic defense and flowering including MYB13, MYB78, ERF2, ERF3, ERF5, ERF-1B, NAC, MADS box, ZF3, ZAT10, A20/AN1, polyol sugar transporter like zinc finger proteins, and a novel plant defensin protein. The potential bottleneck and hub genes involved in this dynamic response were also identified. The protein-protein interaction (PPI) network analysis based on 25 topmost DEGS (pcal-value < 0.05) and the Weighted Correlation Gene Network Analysis (WGCNA) of the 1786 significant DEGs (pcal-value < 0.05) we reported the hits associated with carbohydrate metabolism, secondary metabolite biosynthesis, and the nitrogen metabolism. We conclude that the Trichoderma-induced microbial priming re-programmed the host genome for transcriptional response during the late colonization event and were characterized by metabolic shifting and biochemical changes specific to plant growth and development. The work also highlights the relevance of statistical parameters in understanding the gene regulatory dynamics and complex regulatory networks based on differential expression, co-expression, and protein interaction networks orchestrating the host responses to beneficial microbial interactions.

High-Quality Genome and Annotation Resource of Orange Pink Rot Pathogen Trichothecium roseum Strain YXFP-22015 Isolated from Hubei, China.

Trichothecium roseum is widely distributed throughout the world and forms pink powdery molds on various fruits and vegetables, lowering their quality and leading to great economic losses. Due to the limited availability of high-quality genomic and annotation resources, little is known about the pathogenesis of T. roseum at the molecular level. In this study, we reported a high-quality genome assembly of strain YXFP-22015 using Oxford Nanopore Technologies (ONT) for long read sequencing and MGISEQ-2000 for short read sequencing. The genome was also well-annotated based on the combination of RNA-seq by MGISEQ-2000 and in silico prediction. Further analysis on this will contribute to a better understanding of T. roseum infection mechanisms.

Controlling insecticide resistant clones of the aphid, Myzus persicae, using the entomopathogenic fungus Akanthomyces muscarius: fitness cost of resistance under pathogen challenge.

BACKGROUND: Biological control is a cornerstone of integrated pest management and could also play a key role in managing the evolution of insecticide resistance. Ecological theory predicts that the fitness cost of insecticide resistance can be increased under exposure to invertebrate natural enemies or pathogens, and can therefore increase the value of integrating biological control into pest management. In this study of the peach potato aphid, Myzus persicae, we aimed to identify whether insecticide resistance affected fitness and vulnerability of different aphid clones to the entomopathogenic fungus Akanthomyces muscarius. RESULTS: Insecticide resistant clones were found to be slightly less susceptible to the pathogen than susceptible clones. However, this pattern could also be explained by the influence of length of laboratory culture, which was longer in susceptible clones and was positively correlated with susceptibility to fungi. Furthermore, resistance status did not affect aphid development time or intrinsic rate of increase of aphids. Finally, in a cage trial the application of fungus did not increase the competitive fitness of insecticide resistant clone 'O'. CONCLUSION: We found no fitness cost in reproductive rate or pathogen susceptibility associated with chemical resistance in M. persicae. In contrast, some susceptible clones, particularly those subject to decades of laboratory rearing, showed enhanced susceptibility to a fungal pathogen, but not reduced reproductive fitness, an observation consistent with down-regulation of costly immune functions in culture. Overall, fungal pathogen control is compatible with insecticides and should not increase the selection pressure for resistance of M. persicae to chemical insecticides.

Draft Genome Resources for Plant-Beneficial Fungi Clonostachys rosea Strains ACM941 and 88-710.

Clonostachys rosea strains ACM941 and 88-710 are beneficial microbes recognized for their plant disease control and growth promotion properties, respectively, when applied to economically important crops. In addition to their geographical and functional overlap, the two strains also share a high degree of genetic similarity. In an effort to identify the subtleties that underlie their strain-specific applications, their genomic sequence is reported here. The genome size of ACM941 was estimated to be 56.9 Mb, encoding 17,585 putative genes, while strain 88-710 was estimated to have a 55.5 Mb genome size, containing 17,188 predicted genes. Overall, ACM941 and 88-710 share >96% of their encoded genomes, such that their strain-specific characteristics are likely encoded in either the remaining variable 4% or differentially regulated shared genes or both. These genomic sequences form a foundation for future studies aimed at identifying the genomic and metabolic machinery driving their respective beneficial properties.

Harvest and trade of caterpillar mushroom (Ophiocordyceps sinensis) and the implications for sustainable use in the Tibet Region of Southwest China.

ETHNOPHARMACOLOGICAL RELEVANCE: Caterpillar mushroom (Ophiocordyceps sinensis) is a unique medicinal fungi which is only found in alpine grasslands in Himalayan mountain regions and the Tibetan Plateau. Known locally as Yartsa Gunbu, it has been widely used in Tibetan and Chinese Medicine for centuries. It is crucial to understand local commercial harvest and trade practices of caterpillar mushroom to support the sustainable management of this valuable resource. However, data derived from empirically grounded research is currently limited, particularly in China. AIM OF THIS STUDY: The research aims to provide the most up-to-date insights into caterpillar mushroom harvest and trade in the main production area of the Tibet Region in Southwest China and to generate policy recommendations for sustainable use. MATERIALS AND METHODS: The research was conducted in 2015-2016 in six Tibetan communities located in two counties in Diqing Tibetan Autonomous Prefecture, Southwest China. Quantitative and qualitative data were collected from in-depth interviews with local households engaged in caterpillar mushroom harvesting (n = 157), local caterpillar mushroom traders (n = 14), and from focus groups discussions (n = 5) with regional caterpillar mushroom industry stakeholders. RESULTS: The research found large regional- and community-level differences in caterpillar mushroom harvest practices. The harvest practices of communities involved in the co-management of a Nature Reserve were more sustainable than those communities not involved in such a scheme, and this was due to the external support and training provided via the co-management scheme. Moreover, a customary tenure system was proving effective for avoiding competition over caterpillar mushroom collection. However, in both counties, narrow marketing channel and non-grading system in trade limits the possibility of improving the local benefits generated from the commercial harvest of caterpillar mushroom. Meanwhile, the local traders play an important bridging role in the value chain and generate greater benefits from product grading. CONCLUSION: To support the sustainable management of the caterpillar mushroom industry in Southwest China, the prefectural governments should invest in training on appropriate harvesting techniques and the dissemination of market information. It is also critical that prefectural governments recognize and support the customary tenure system of mushroom collection to avoid competition between collectors.

Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes): A Potential Bioresource for Commercialization in Sikkim Himalaya, India.

Ophiocordyceps sinensis has a long history of use in Tibetan traditional medicine and traditional Chinese medicine as a powerful tonic and aphrodisiac. The species is inextricably linked to the trade of medicinal and aromatic plants in East Asia. Its demand has increased substantially in the international market, and its collection and trade have significantly improved the socioeconomic status of the people in some regions. Nonetheless, in Sikkim this resource is still untapped formally, but it is traded illegally. Formal legalization and the community's involvement will ensure the conservation and sustainability of the species, as well as proper management of harvesting areas and monitoring of pressure on Yartsa Gunbu to exploit it.

Assessment of diversity and genetic relationships of Neonectria ditissima: the causal agent of fruit tree canker.

BACKGROUND: Neonectria ditissima is one of the most important fungal pathogens of apple trees, where it causes fruit tree canker. Information about the amount and partitioning of genetic variation of this fungus could be helpful for improving orchard management strategies and for breeding apple cultivars with high levels of genetically determined resistance. In this study single-spore Neonectria isolates originating from both the same and from different perithecia, apple cultivars and apple orchards in Sweden and Belgium, were evaluated for AFLP- and SSR-based genetic similarity and for mating system. RESULTS: Seven SSR loci produced a total of 31 alleles with an average of 4 alleles per locus, while 11 AFLP primer combinations produced an average of 35 fragments per primer combination and 71 % polymorphic fragments. An AFLP-based analysis of molecular variance (AMOVA) revealed that 89 % of the variation was found within orchards and 11 % between orchards. Genetic similarity among the studied isolates was illustrated with a principal coordinate analyseis (PCoA) and a dendrogram. AFLP-based Jaccard's similarity coefficients were the highest when single-ascospore isolates obtained from the same perithecium were compared, medium-high for isolates from different perithecia on the same tree, and lowest when isolates from different trees were compared. CONCLUSIONS: Based on the results of PCoA and AMOVA analysis, isolates from the same or geographically close orchards did not group together. Since AFLP profiles differed also when single-ascospore isolates from the same perithecium were compared, the mating system of N. ditissima is most likely heterothallic.

Review on Natural Enemies and Diseases in the Artificial Cultivation of Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes).

Ophiocordyceps sinensis (syn. Cordyceps sinensis), well known as DongChongXiaCao (DCXC), is one of the most valuable traditional Chinese medicinal species. In this article, we provide a systematic review of natural enemies and diseases encountered in artificial cultivation of DCXC. Unfortunately, DCXC has been endangered over the past decades due to overharvesting and a worsening ecological environment. Therefore, the artificial cultivation of DCXC has been extensively investigated in recent years. Complete indoor artificial cultivation and semi-field cultivation are the two most common strategies used to cultivate DCXC. However, cultured DCXCs are often attacked by various natural enemies and diseases, which have resulted in substantial loss of the valuable medicinal resource. In this study, we have summarized the species of natural enemies and types of diseases confronted by DCXC. Twenty reported natural enemy species are categorized into four classes, one of which is reported for the first time in this study. Moreover, six microbial pathogens are also discussed. The recapitulation of the natural enemies and diseases in DCXC artificial cultivation not only promote the development of integrated pest management of DCXC cultivation but also provide important information to help preserve and develop this valuable resource.

The UHPLC-DAD fingerprinting method for analysis of extracellular metabolites of fungi of the genus Geosmithia (Acomycota: Hypocreales).

A new simple ultra-high-performance liquid chromatography method with diode array detection (UHPLC-DAD) was developed for chemical fingerprinting analysis of extracellular metabolites in fermentation broth of Geosmithia spp. The SPE method employing Oasis MCX strong cation-exchange mixed-mode polymeric sorbent was chosen for extraction of the metabolites. The analyses were performed on an Acquity UPLC BEH C18 column (100 × 2.1 mm i.d.; particle size, 1.7 µm; Waters) using a gradient elution program with an aqueous solution of trifluoroacetic acid and acetonitrile as the mobile phase. The applicability of the method was proved by analysis of 38 strains produced by different species and isolated from different sources (hosts). The results revealed the correlation of obtained UHPLC-DAD fingerprints with taxonomical identity.

Influence of the carbon and nitrogen sources on keratinase production by Myrothecium verrucaria in submerged and solid state cultures.

Myrothecium verrucaria is a nondermatophytic filamentous fungus able to grow and to produce keratinase in submerged (93.0 +/- 19 U/ml) and solid state (98.8 +/- 7.9 U/ml) cultures in which poultry feather powder (PFP) is the only substrate. The purpose of the present work was to verify how different carbon and nitrogen sources can influence the production of keratinase by this fungus. Addition of carbohydrates, such as glucose and sucrose, caused only slight improvements in keratinase production, but the addition of starch caused a significant improvement (135.0 +/- 25 U/ml). The highest levels of keratinase activity, however, were obtained by supplementing the PFP cultures with cassava bagasse, 168.0 +/- 28 U/ml and 189.0 +/- 26 U/ml in submerged and solid state cultures, respectively. Contrarily, the supplementation of PFP medium with organic or inorganic nitrogen sources, such as casein, soy bean protein, gelatin, ammonium nitrate and alanine, decreased the production of keratinase in both types of cultures (around 20 U/ml), showing that the production of keratinase by M. verrucaria is repressed by nitrogen sources. The results obtained in this work suggest that the association of the two residues PFP plus cassava bagasse could be an excellent option as a cheap culture medium for the production of keratinase in submerged and solid state cultures.

A novel test for host-symbiont codivergence indicates ancient origin of fungal endophytes in grasses.

Significant phylogenetic codivergence between plant or animal hosts (H) and their symbionts or parasites (P) indicates the importance of their interactions on evolutionary time scales. However, valid and realistic methods to test for codivergence are not fully developed. One of the systems where possible codivergence has been of interest involves the large subfamily of temperate grasses (Pooideae) and their endophytic fungi (epichloae). These widespread symbioses often help protect host plants from herbivory and stresses and affect species diversity and food web structures. Here we introduce the MRCALink (most-recent-common-ancestor link) method and use it to investigate the possibility of grass-epichloë codivergence. MRCALink applied to ultrametric H and P trees identifies all corresponding nodes for pairwise comparisons of MRCA ages. The result is compared to the space of random H and P tree pairs estimated by a Monte Carlo method. Compared to tree reconciliation, the method is less dependent on tree topologies (which often can be misleading), and it crucially improves on phylogeny-independent methods such as ParaFit or the Mantel test by eliminating an extreme (but previously unrecognized) distortion of node-pair sampling. Analysis of 26 grass species-epichloë species symbioses did not reject random association of H and P MRCA ages. However, when five obvious host jumps were removed, the analysis significantly rejected random association and supported grass-endophyte codivergence. Interestingly, early cladogenesis events in the Pooideae corresponded to early cladogenesis events in epichloae, suggesting concomitant origins of this grass subfamily and its remarkable group of symbionts. We also applied our method to the well-known gopher-louse data set.

Animal performance and economic comparison of novel and toxic endophyte tall fescues to cool-season annuals.

Increased costs of annual establishment of small grain pasture associated with fuel, machinery, and labor are eroding the profitability of stocker cattle enterprises. Interest has therefore increased in development of cool-season perennial grasses that are persistent and high quality. This study occurred on 24 ha (divided into thirty 0.81-ha paddocks) located at the University of Arkansas Division of Agriculture Livestock and Forestry Branch Station, near Batesville. Two tall fescue (Festuca arundinacea Schreb.) cultivars infected with novel endophytes (NE), Jesup infected with AR542 endophyte (Jesup AR542), and HiMag infected with Number 11 endophyte (HM11) were established in September 2002. Jesup AR542 and HM11 were compared with endemic endophyte Kentucky 31 (KY-31) tall fescue; wheat (Triticum aestivum L.) and cereal rye (WR, Secale cereale L.) planted in September 2003, 2004, and 2005; and annual ryegrass [RG, Lolium perenne L. ssp. multiflorum (Lam.) Husnot] planted in September 2004 and 2005. Each year, 3 steers (3.7 steers/ha) were placed on each pasture for fall and winter grazing, and 5 steers (6.2 steers/ha) were placed on each pasture for spring grazing. Animal performance is presented by year in the presence of a year x treatment interaction (P < 0.01). Body weight gain per hectare of steers grazing NE tall fescue was greater (P < 0.01) than those of KY-31 and WR during 2003 to 2004, whereas in 2004 to 2005, BW gain per hectare of steers grazing NE and RG did not differ (P < or = 0.29) and was greater (P < 0.01) than that of WR, which was greater (P < 0.01) than that of KY-31. During 2005 to 2006, BW gain per hectare was greater (P < 0.01) for steers grazing RG than those of NE and WR, which did not differ (P > or = 0.14). Body weight gain per hectare was least (P < 0.01) for steers grazing KY-31. Average net return of NE tall fescue was greater (P < 0.01) than KY-31, but profitability of NE did not consistently differ from cool-season annuals. Across the 3-yr study, NE tall fescue produced net returns per hectare of $219; this level of profitability would require 4 yr for a new planting of NE tall fescue to break even. Novel endophyte tall fescues offer potential benefits related to decreased risk of stand establishment of annual forage crops, longer growing season, and acceptable animal performance.