Root Rot

The strawberry, or Fragaria x ananassa Duch., is a crop grown extensively around the world, including Kurdistan.
However, the crop is frequently compromised by soil-borne pathogens, particularly the fungal pathogen Fusarium
solani, which causes considerable damage and economic losses. The devastating nature of this disease has not been
adequately controlled by traditional techniques of disease management. This study aimed to integrate multiple control
strategies to mitigate the impact of F. solani on strawberry production. Strawberry samples were collected from the
region, and after the pathogen was isolated, investigations revealed that F. solani was the main culprit causing crown
and root rot of the crop. In a controlled greenhouse environment, eleven individual and combinatory control methods
were tested on potted strawberry plants. Disease severity was assessed and analyzed statistically. The findings revealed a
significant difference in the efficacy of the treatments, with treatments T3 (sumac extract), T4 (Pristine fungicide), and T9
(Gathering Trichoderma harzianum and Pristine) demonstrating superior disease prevention capabilities. Moderate
control was observed with treatments T2 (Trichoderma harzianum) and T5 (Gathering Pseudomonas flaorescens and
Trichoderma harzianum), while T6 (Gathering Pseudomonas flaorescens and sumac extract), T10 (Gathering sumac extract
and Pristine), and T8 (Gathering Pseudomonas flaorescens and Pristine) exhibited minimal effectiveness. These results
are fundamental for developing integrated pest management (IPM) strategies that optimize disease control in strawberry
cultivation, emphasizing sustainable practices that reduce reliance on fungicides. By adopting these integrated methods,
strawberry producers in Kurdistan can enhance crop resilience and sustainability.

Lentil (Lens culinaris Medik.), an important pulse crop in India, experiences significant losses due to Fusarium wilt caused by Fusarium oxysporum f. sp. lentis. In a laboratory investigation conducted at AMU, Aligarh, the efficacy of synthetic fungicides and biocontrol agents was evaluated against this pathogen. Among the Trichoderma isolates tested, AMUTV-3 exhibited the highest inhibition of mycelial growth, followed by AMUTV-1, AMUTH-1 and AMUTS-1. At a concentration of 100 ppm, carbendazim demonstrated the greatest effectiveness among the fungicides, surpassing thiophanate methyl, azoxystrobin, hexaconazole, mancozeb, and metalaxyl. The results indicate that carbendazim and AMUTV-3 are promising candidates for managing Fusarium wilt in lentil. These in vitro findings provide a basis for future studies aimed at integrating these agents into sustainable lentil production systems.

Onion (Allium cepa L.) is one of the most widely used vegetable due to its flavouring and seasoning the underground vegetable, both at mature and immature bulb stage in tropical and sub tropical countries. The foliar blight complex of onion resulted due to combined infection of Alternaria porri and Stemphylium vesicarium. Narrow spectrum fungicides viz., tebuconazole 25.9 EC and propiconazole 25 EC proved superior (84.07 and 81.94 % growth inhibition, respectively) against the combined radial growth of A. porri and S. vesicarium under laboratory condition. Rests of the fungicides were also found effective to inhibit the growth of the fungus. Among broad spectrum non-systemic fungicides, propineb 70 WP resulted in 79.07 % growth inhibition and among compound fungicides, highest growth inhibition was recorded in tebuconazole 50 WG + trifloxystrobin 75 WG followed by carboxin 37.5 DS + thiram 37.5 DS, carbendazim 12 WP + mancozeb 63 WP.

Macrophomina phaseolina (Tassi) Goidanich, the charcoal rot fungus, occurs worldwide and is one of the most economically important fungal pathogens reported to infect about 500 plant species in more than 100 families, including many important crops such as alfalfa, chickpea, maize, sorghum, soybean and sunflower . Charcoal rot disease can be controlled by soil fumigation with methyl

Background: Chickpeas are a prevalent and significant crop in the agricultural sectors of northern Iraq. In recent years, production has significantly declined due to diseases affecting chickpea plants. Investigating the pathogenic f ungi responsible for these diseases is essential to restore production levels to their prior and improved states. Methods: Samples of diseased chickpea plants were collected from fields in the Erbil, Sulaymaniyah and Salah al-Din governorates in northern Iraq. Isolated associated fungi led to the identification of the dominant pathogenic species. A pathogenicity test was performed on the fungal isolates, showing the most aggressive strain for subsequent antagonism testing against three rhizobacterial isolates: Azotobacter chroococcum, Bacillus cereus and B. pumilus. This testing was conducted both in vitro and in a greenhouse setting, using single treatments and combinations. Result: The results showed that the pathogenic fungus Rhizoctonia solani was predominant, with the strain Srs-21 exhibiting the highest virulence in vitro. The three rhizobacterial isolates, A. chroococcum, B. cereus and B. pumilus, showed high efficacy in inhibiting the pathogenic fungus in vitro on potato dextrose agar (PDA) medium. In the greenhouse, the triple bacterial interaction treatment showed a seed germination rate of 100% and diminished disease incidence and severity to 0%, in contrast to the positive control treatment, which recorded 90% and 70%, respectively. It also showed the highest rate of rise in the dry weight of plants, signifying enhanced growth metrics.

Background: Rhizobacteria are essential for plant health by offering natural antagonism to soil-borne fungi. Rhizobacteria are regarded as an alternative to chemical agents for the integrated control of plant diseases and for enhancing yield in an ecologically sustainable way. Nonetheless, there is a limited comprehension of the precise processes via which rhizobacteria suppress these diseases and the variety of rhizobacterial species implicated. Methods: Through experiments conducted in 2022-2024, the efficiency of 12 rhizobacterial isolates of Alloiococcus otitis BRE6, Aneurinibacillus thermoaerophilus SDV1, Aeribacillus pallidus ECC4, A. thermoaerophilus ECL1, Bacillus megaterium SKE2, Staphylococcus lentus BZD2, Enterobacter cloacae complex BZD3, B. megaterium TNK1, Leclercia adecarboxylata DKS3, B. halotolerans DMC8, B. subtilis NAS1 and Paenibacillus polymyxa TRS4, in controlling soilborne pathogenic fungi of Rhizoctonia solani, Macrophomina phaseolina and Pythium aphanidermatum, the causal agents of tomato root rot disease was evaluated under greenhouse conditions and plant growth parameters were evaluated. Result: The results indicated that the combination treatment of 12 rhizobacterial isolates (COR12) achieved the highest germination rate of tomato seeds in the presence of pathogenic fungi, reaching 100% and the lowest rate of disease incidence and severity, reached 5% and 1%, respectively, compared to the positive control treatment, which reached 82% and 53%, respectively. Representing control disease value of 98% compared to the single bacteria treatments. The COR12 treatment achieved a significant increase in the growth parameters represented by plant height and fresh and dry weight of the shoot and root system in the presence of pathogenic fungi compared to the individual bacterial treatments.

Cooking time of the common bean is an important trait for consumer preference, with implications for nutrition, health, and environment. For efficient germplasm improvement, breeders need more information on the genetics to identify fast cooking sources with good agronomic properties and molecular breeding tools. In this study, we investigated a broad genetic variation among tropical germplasm from both Andean and Mesoamerican genepools. Four populations were evaluated for cooking time (CKT), water absorption capacity (WAC), and seed weight (SdW): a bi-parental RIL population (DxG), an eight-parental Mesoamerican MAGIC population, an Andean (VEF), and a Mesoamerican (MIP) breeding line panel. A total of 922 lines were evaluated in this study. Significant genetic variation was found in all populations with high heritabilities, ranging from 0.64 to 0.89 for CKT. CKT was related to the color of the seed coat, with the white colored seeds being the ones that cooked the fastest. Marker t...

Background: Phytopathogens cause severe diseases on crop plants and pose a significant threat to agricultural industry by causing substantial economic losses. The excessive use of synthetic pesticides to combat phytopathogens has raised environmental and human health concerns.
Materials and methods: Rhizobacterial isolates were obtained from the rhizosphere soil of wheat after plating serial dilutions on King’s B media and screened for their antagonistic interactions under cultural conditions against Tilletia indica Mitra (earlier termed as Nevossia indica Mundkur), which causes Karnal bunt disease in wheat.
Results: Seventeen rhizobacterial isolates caused inhibition of Tilletia indica on PDA medium plates and inhibition zone varied from 5-17 mm. The culture supernatants of selected antagonistic bacterial isolates also showed growth inhibition of the pathogenic fungi under cultural conditions. The protein estimation of the culture supernatants showed that the amount of protein excreted in different rhizobacterial isolates varied from 3.6 to 33.0 mg/ml of the supernatant. SDS-PAGE analysis of the total protein followed by Coomassie blue staining showed the presence of four common protein bands, i.e., 22, 25, 45 and 86 kDa in different rhizobacterial isolates. Inoculation of wheat with T. indica caused 92% disease incidence at 135 days of plant growth (at maturity stage). Coinoculation of Pseudomonas culture WPS3 with T. indica spores reduced the disease incidence upto 96.4% under pot house conditions. Results suggested that the rhizobacterial isolate WPS3 could be further exploited for disease control and plant growth improvement under field conditions.
Conclusions: Recognizing the critical role of the rhizobacterial isolates in sustainable biocontrol, this study explores the growth inhibition of the pathogenic fungus T. indica. SDS-PAGE analysis of the total protein showed the presence of four common protein bands, i.e., 22, 25, 45 and 86 kDa in different rhizobacterial isolates. Inoculation of Pseudomonas cultures in wheat reduced the disease incidence and improved plant growth under pot house conditions.

Macrophomina phaseolina (Tassi) Goidanich, the charcoal rot fungus, occurs worldwide and is one of the most economically important fungal pathogens reported to infect about 500 plant species in more than 100 families, including many important crops such as alfalfa, chickpea, maize, sorghum, soybean and sunflower . Charcoal rot disease can be controlled by soil fumigation with methyl

Root rot is a serious disease of tomato (Solanum lycopersicum L.). It caused by the soil-borne fungus Rhizoctonia solani. This disease leads to major yield losses in tomato production worldwide. The aim of the present study was to isolate and identify the most virulent isolate of R. solani. Moreover, we aimed to evaluate the biocontrol ability of Trichoderma harzianum and aqueous clove (Syzygium aromaticum) extract. The aim was to evaluate both individually and in combination against tomato root rot under laboratory and greenhouse conditions. Several isolates of R. solani were obtained and tested for pathogenicity. Among them, isolate R4 showed the highest virulence. It has 100% disease incidence and 98.67% disease severity. So, it was selected for further experiments. Aqueous clove extract was prepared at concentrations of 5% and 10%. Trichoderma harzianum was cultured and applied as a spore suspension. Dual culture assays in vitro were used to evaluate the antifungal effects of these agents firstly. After that, greenhouse experiments were conducted to assess their effects on disease incidence, disease severity, and plant growth parameters. LSD test at a 5% significance level was statistically used to analyze data.

Muestra un archivo XML con los metadatos del artículo basados en el formato que maneja OAI - PMH (open archives initiative - Protocol for Metadata Harvesting) facilitando así la diseminación eficiente del contenido. ... Díaz-Celaya, MarleneRodríguez-Alvarado, Gerardo; ...

Phellinus weirii, the cause of laminated root rot, is considered the most destructive root rot of Douglas-fir, but little is known about the damage it causes, to a forest. The objective of this study was to determine silvicultural impacts of P. weirii on a managed forest. A survey ...

This research was aimed to identify the causal agent of the root rot disease of cucumber in some provinces of Iraq, and evaluate its pathogenicity and control it using beneficial bacteria of Serratia odorifera (So) and Enterobacter cloacae (Ec) which isolated from the rhizosphere of healthy cucumber plants, and using silicon (Si) and copper (Cu). The fungus Fusarium solani was predominant, while its percentage of appearance was 80.0% with frequency of 46.2%, Isolate Bfs- 1 was most virulent which prevent germination of the cucumber's seed overall in vitro compared to the control. The bacterial isolates D6 and Q10 exhibited 100% percentage of inhibition against the pathogen in vitro. Results of bacterial isolates identification using Vitiq2 Compact System showed that they belong to S. odorifera and E. cloacae respectively. Under greenhouse conditions the quadrant treatment (So+Ec+Si+Cu) was superior in controlling the disease, while it exhibited 100% percentage of seed germinatio...

To isolate rhizobacteria exhibiting antifungal activities for for five pathogenic fungi (Sclerotinia sclerotiorum, Fusarium solani, Collectotricum gloeosporides, Fusarium oxysporum, and Botrytis cinerea) which cause damage to Ginseng root in Ginseng grown fields, four soils were collected from Cheorlwon gun, in Korea. From 4 soils, a total of 160 bacterial strains were isolated by dilution plate method. Among 160 strains, 32 strains showed antifungal activities for one or more pathogens. From 32 strains, three strains exhibited antifungal activities for all pathogens. These are two Burkholderia cepacia (ATCC 25416 and ET 13) and one Paenibacillus polymyxa (ATCC 842). These potent antifungal strains showed high identities (99% using 16S-rRNA sequencing).

Background: Different strategies (genetics, biochemistry, and proteomics) can be used to study proteins involved in cell biogenesis. The availability of the complete sequences of several plant genomes allowed the development of transcriptomic studies. Although the expression patterns of some Arabidopsis thaliana genes involved in cell wall biogenesis were identified at different physiological stages, detailed microarray analysis of plant cell wall genes has not been performed on any plant tissues. Using transcriptomic and bioinformatic tools, we studied the regulation of cell wall genes in Arabidopsis stems, i.e. genes encoding proteins involved in cell wall biogenesis and genes encoding secreted proteins. Results: Transcriptomic analyses of stems were performed at three different developmental stages, i.e., young stems, intermediate stage, and mature stems. Many genes involved in the synthesis of cell wall components such as polysaccharides and

This study was conducted in Bekilli (Merkez), Buldan (Çamköy), Çal (Kabalar), Güney (Aydoğdu, Eziler and Adıgüzel) and Central (Gözler) towns of Denizli province in 2013-2014. Surveys were carried out in total of 29 thyme fields in Denizli and Manisa provinces. Plants in the surveyed fields were examined by walking diagonally and counting of infected or healthy plants. Infected plants were recorded and samples from symptomatic plants were collected. In addition, the prevalence rate of the disease at the province and distric level were determined. A total of 50 isolates were recovered from plants showing root and stem rot symptoms. These isolates were identified as Aspergillus niger Tiegh. Alternaria spp., Rhizoctonia solani J.G.Kühn. and Macrophomina phaseolina (Tassi) Goid. according to their morphological structure under microscope. In pathogenicity tests, thyme plants were inoculated with all isolates. Alternaria spp. and Aspergillus niger were not able to cause any symptoms. However Rhizoctonia solani and Macrophomina phaseolina caused root rot on plants, so these isolates were considered to be pathogen on thyme.

This study was conducted in Bekilli (Merkez), Buldan (Çamköy), Çal (Kabalar), Güney (Aydoğdu, Eziler and Adıgüzel) and Central (Gözler) towns of Denizli province in 2013-2014. Surveys were carried out in total of 29 thyme fields in Denizli and Manisa provinces. Plants in the surveyed fields were examined by walking diagonally and counting of infected or healthy plants. Infected plants were recorded and samples from symptomatic plants were collected. In addition, the prevalence rate of the disease at the province and distric level were determined. A total of 50 isolates were recovered from plants showing root and stem rot symptoms. These isolates were identified as Aspergillus niger Tiegh. Alternaria spp., Rhizoctonia solani J.G.Kühn. and Macrophomina phaseolina (Tassi) Goid. according to their morphological structure under microscope. In pathogenicity tests, thyme plants were inoculated with all isolates. Alternaria spp. and Aspergillus niger were not able to cause any symptoms. However Rhizoctonia solani and Macrophomina phaseolina caused root rot on plants, so these isolates were considered to be pathogen on thyme.

Onion is an important vegetable in Senegal horticulture, where it occupies the first place. However in the greatest areas production like the Gandiolais, in the North of Senegal, Pink root disease caused by a soil born fungus Pyrenochaeta terrestris (Hansen) Gorentz, Walker and Larson affects its productivity especially in nursery. On soil sterilized and inoculated by the fungus, we tested 5 natural fungicides and 2 synthetic fungicides, to measure their effectiveness on the Pink root disease on onion, in nursery. The device used is a split plot with 4 repetitions and 8 treatments. The measured variables are the emergence rates, the survival rates and the infestation rates. Our experimentations have shown that, for the emergence rates, there is no significant difference between thiophanate-methyl (Pelt 44), Carbendazim (Bavistine), Azadirachta indica A. Juss and Carica papaya L. It is the same between C. papaya and Moringa oleifera Lam, between M. oleifera and Cassia alata L. It is also the same between C. alata and Crotolaria retusa L. Regarding the survival rates, there is no significant difference between thiophanate-methyl, Azadirachta indica, Carbendazim, C. papaya and M. oleifera. The same is true between M. oleifera and Cassia alata, and between C. alata and C. retusa. Concerning the infestation rates, apart from the control check, all other treatments show no difference.

White root rot (WRR) disease, caused by Rigidoporus microporus, is one of the major constraints causing the economic loss to rubber plantation worldwide including in Malaysia. This glasshouse study was conducted to evaluate the efficacy of a peat-based bioformulation of Enterobacter sp. UPMSSB7 and an arbuscular mycorrhizal fungus (AMF, Glomus mosseae) with silicon (Si) for WRR suppression and plant growth promotion of rubber seedlings. Results revealed that the tested bioformulation significantly (P < 0.0001) reduced the disease compared to positive control while, was not significantly different than the propiconazole, a triazole fungicide. The lower values of disease incidence, disease severity of foliar and root rot symptoms, area under disease progress curve, pathogen colonization and higher value of disease reduction were recorded in both bioformulation and the triazole fungicide treated seedlings than positive control treatment 24 weeks after inoculation with R. microporus. Results indicated that pathogen-inoculated seedlings treated with bioformulation had significantly (P < 0.0001) increased stem height, girth size, chlorophyll content, leaf area, shoot and root dry weight, total root length, root volume and root surface area (103.8 cm, 8.08 mm, 56.62 SPAD value, 3534.8 cm2, 37.04 g and 36.76 g, 1617.7 cm, 24.15 cm3 and 402.97 cm2, respectively) as compared to fungicide and control treatments. The tested bioformulation also significantly (P < 0.0001) increased silicon content in root and shoot (18.56 g kg-1 and 27.61 g kg-1, respectively) as well as leaf nutrient (N, P, K and Ca) contents (3.89%, 0.19%, 1.06% and 0.57%, respectively) as compared to the triazole fungicide and control treatments. The population of Enterobacter sp. (1.1 × 108 cfu g-1 soil) recorded in pathogen-inoculated seedlings treated with bioformulation was not significantly different than non-inoculated seedlings treated with bioformulation. AMF spore density and root colonization were recorded higher in bioformulation treated seedlings with or without pathogen inoculation than the triazole fungicide and control treatments. From this study, it was concluded that the peat-based bioformulation of Enterobacter sp. and an AMF (Glomus mosseae) with Si could be a potential approach to suppress WRR and improve growth of rubber seedlings.

Utilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-tr...

Background The pathogens from Fusarium species can cause Fusarium root rot (RR) and other diseases in plant species including sugar beet ( Beta vulgaris L.), and they have a strong negative impact on sugar beet yield and quality. Methods A total of 22 sugar beet breeding lines were evaluated for the symptoms of RR after inoculation with Fusarium oxysporum Sch., isolate No. 5, and growth in a field trial. Two candidate genes for RR resistance, BvSP2 and BvSE2 , encoding chitinases Class IV and III, respectively, were previously identified in sugar beet, and used for genotyping using modern Amplifluor-like single nucleotide polymorphism (SNP) genotyping approach. The qPCR expression analysis was used to verify responses of the candidate genes for RR infections. Results A strong association of two SNP markers for BvSP2 and BvSE2 with resistance to RR in sugar beet was found in our study. Very high BvSP2 expression (100-fold compared to Controls) was observed in three RR resistant acces...

BackgroundThe pathogens fromFusariumspecies can cause Fusarium root rot (RR) and other diseases in plant species including sugar beet (Beta vulgarisL.), and they have a strong negative impact on sugar beet yield and quality.MethodsA total of 22 sugar beet breeding lines were evaluated for the symptoms of RR after inoculation withFusarium oxysporumSch., isolate No. 5, and growth in a field trial. Two candidate genes for RR resistance,BvSP2andBvSE2, encoding chitinases Class IV and III, respectively, were previously identified in sugar beet, and used for genotyping using modern Amplifluor-like single nucleotide polymorphism (SNP) genotyping approach. The qPCR expression analysis was used to verify responses of the candidate genes for RR infections.ResultsA strong association of two SNP markers forBvSP2andBvSE2with resistance to RR in sugar beet was found in our study. Very highBvSP2expression (100-fold compared to Controls) was observed in three RR resistant accessions (2182, 2236 and...

Background: Tomato (Solanum lycopersicum L.) is an important vegetable crop not only for its economic importance but also for its nutritional value. It remained prone to various diseases and amongst them, root rot disease complex caused by concomitant occurrence of R. solani and M. javanica has been key problem in Haryana resultantly reduces yield and production to great extent. Methods: Present study was carried out with the aim to evaluate the effect of organic amendments and biocontrol agents on root rot disease complex in tomato cv. Hisar Arun (Selection 7). Tomato seeds were sown @ 10 seeds/pot filled with sterilized sandy loam soil having 1000 mg/kg soil (Rhizoctonia solani inoculum level) and 1000 J2/kg soil (M. javanica inoculum level). Result: The minimum mortality of 33.3 and 36.6 per cent was observed when the soils were incorporated with mustard cake @ 2 g/kg soil followed by cotton cake @ 2 g/kg soil in comparison to total mortality of 63.3 per cent in control pots and the soil application of mustard cake protected 47.4 per cent plants from mortality. The application of Glomus mosseae (VAM) at 200, 150, 100 sporocarps/kg soil managed disease to the extent of 36.8% 21.0% and 10.4% respectively. Incorporation of T. harzianum@ 5 g/kg soil and 10 g/kg soil managed the disease to the extent of 21% and 42% respectively. The minimum mortality of 33.3% was recorded when seeds were dressed with Carbendazim 50WP whereas 36.6 per cent with Carboxin 37.5WP + Thiram 37.5W P in comparison to 63.3 per cent in control pots. Systemic approach to manage the root-rot disease complex with the help of organic amendments, bioagents and fungicides can prevent the losses caused to the crop.

Soy is an important oilseed crop in Kazakhstan. However, its yield is significantly reduced due to an increase in the development of fungal diseases with soil infection. This study aims to identify the root rot pathogen in soybean varieties in Western Kazakhstan and assess its pathogenicity. Samples of soybean roots to determine the root rot pathogen were selected at the experimental plots of the Aktobe agricultural experimental station in 2021. Genetic analysis of isolates observed on potato dextrose agar medium from soybean root slices was carried out using the sequencing reaction of internal transcribed spacer region nucleotide sequences using the Big Dye Terminator protocol (applied biosystems) with a further comparison of data with the Gen bank database. A test for the pathogenicity of the identified isolates of the fungus was carried out. Statistical data processing was carried out using the R-studio software according to the nonparametric Kruskal Wallis test. Phylogenetic analysis of samples of soybean affected by root rot showed that the main biotic agent causing root rot was the imperfect fungus Fusarium equiseti. Sequencing of the highly informative internal transcribed spacer region of fungal isolates allowed identifying strains 1 and 2 belonging to the species Fusarium equiseti. The pathogenicity test established that isolates of the Fusarium equiseti fungus caused discoloration of seedlings and plant roots and necrosis in soybean seedlings.

Soybean is an annual legume with edible seeds. The soybean’s charcoal rot is one of the serious challenges faced in its cultivation regions, which brings severe production and economic losses. charcoal rot is the result of infection by the soil-borne fungus Macrophomina phaseolina. Though several researchers have made efforts to deal with soybean’s charcoal rot challenge, but at present, there are no soybean varieties in the market that are resistant to charcoal rot. The pathogen is thought to infect plants in their roots from contaminated soil, using unknown toxin-mediated processes. Conventional integrated approaches for managing charcoal rot in soybeans have been implemented in the field, but their efficacy is limited. So, developing soybean durable resistant varieties against M.phaseolina is the only solution to rescuing this crop. The potential approach is identifying new genetic sources and quantitative trait loci (QTLs) associated with resistance to charcoal rot in the resistant soybean population and conducting genome-wide association studies to increase understanding of underlying resistance mechanisms. The discovery of the genetic markers associated with resistance will contribute to charcoal rot resistance genotype selection for breeding programs in the future.

Root diseases have long been prevalent in Australian grain growing regions and most management decisions to reduce the risk of yield loss need to be implemented before the crop is sown. The levels of pathogens that cause the major root diseases can be measured using DNA based services such as PreDicta B. Although these pathogens are often studied individually, in the field they often occur as mixed populations and their combined effect on crop production is likely to vary across diverse cropping environments. A 3 year survey was conducted covering most cropping regions in Western Australia utilizing PreDicta B to determine soilborne pathogen levels, and visual assessments to score root health and incidence of individual crop root diseases caused by the major root pathogens including Rhizoctonia (AG-8), Gaeumannomyces graminis var. tritici (take-all), F. pseudograminearum, and Pratylenchus spp. (root lesion nematodes) on wheat roots for 115, 50, and 94 fields during 2010, 2011, and 2...

The main objective of this study was to evaluate the effectiveness of crude chloroform extract of Piper betle L. (PbC) in controlling Fusarium wilt of tomato (Lycopersicon esculentum) caused by Fusarium oxysporum f. sp. lycopersici. It was observed that 1% (w/w) amendment of the PbC in soil was more efficient in reducing the Fusarium population in soil than carbendazim and the combined amendment of carbendazim and PbC. Fusarium wilt control studies were carried out in a greenhouse. Variation in different parameters like shoot growth, root growth and mean fresh weights of tomato seedlings in all the treatments were recorded. Accumulation of total phenolics was also studied from the root tissues of tomato. Higher accumulation of total phenolics was observed in the Fusarium-infested plants as compared to that of healthy control and PbC-treated plants. Moreover, it was observed that the extract could reduce the symptoms and disease development. Electron microscopy studies were also done to observe the Fusarium infestation in the vascular bundles and to show the accumulation of total phenolics in the vacuoles of root tissue.

Subterranean clover (Trifolium subterraneum L.) is an important pasture legume in many regions of Australia, and elsewhere. A survey was undertaken in 2014 to define the levels of soilborne disease and associated pathogens in annual subterranean clover pastures across southern Australia. Most of the 202 samples processed had very severe levels of taproot rot disease (disease index 60-80%) and extremely severe lateral root rot disease (disease index 80-100%). A complex of soilborne root pathogens including Aphanomyces trifolii, Phytophthora clandestina, and one or more of Pythium, Rhizoctonia and Fusarium spp. was found responsible for severe pre-and post-emergence damping-off and root disease. This is the first study to highlight the high incidence of A. trifolii across southern Australian pastures and the first to highlight the existence of natural synergistic associations in the field between Rhizoctonia and Pythium spp., Pythium and Fusarium spp., Pythium spp. and A. trifolii, and P. clandestina and A. trifolii. Nodulation was generally poor, mainly only in the 20-40% nodulation index range. There was no relationship between rainfall zone and tap or lateral root disease level, with root disease equally severe in lower (330 mm) and higher (1000 mm) rainfall zones. This dispels the previous belief that severe root disease in subterranean clover is an issue only in higher rainfall zones. Although overall the relationship between tap and lateral root disease was relatively weak, these two root-disease components were strongly positively expressed within each pathogen's presence grouping, providing explanation for variability in this relationship across different field situations where soilborne root disease is a major problem. Most producers underestimated the levels and effect of root disease in their pastures. This study established that tap and lateral root diseases are widespread and severe, having devastating impact on the feed gap during autumn-early winter across southern Australia. Severe root disease was independent of the highly variable complex of soilborne pathogens associated with diseased roots, geographic location and rainfall zone. It is evident that soilborne root diseases are the primary factor responsible for widespread decline in subterranean clover productivity of pastures across southern Australia. Implications for disease management and options for extension are discussed.

Results of a greenhouse Armillaria ostoyae inoculation experiment, designed for screening resistant Pinus pinaster genotypes and for exploring the role of different phenotypic traits in seedling susceptibility, are reported. The experiment included 39 openpollinated pine families that comprised a random subset of the breeding population of P. pinaster in Galicia (NW Spain). We employed a non-parametric survival-time analysis to analyze patterns of survival times during 14 months after inoculation with a local A. ostoyae strain. Results indicate (i) a significant correlation between seed weight and tree susceptibil-ity, with seedlings originating from large seeds being more susceptible, (ii) a positive family mean correlation between secondary root weight and size and median life expectancy, and (iii) genetic variation of tree tolerance to A. ostoyae, with some families surviving significantly longer than others. Less susceptible families could be used in breeding programmes or directly in forest plantations to reduce the losses caused by A. ostoyae. Large within-family variation in tolerance to the disease was also observed, suggesting that non additive genetic variance was also important. Although being infected, 32 out of the 1200 inoculated trees survived the fungus infection. These tolerant genotypes comprise an attractive collection to further investigate genetic, phenotypic and environmental factors affecting pine susceptibility to Armillaria root rot.

Root rot in brinjal is one of the most important problems. In the present research, five different fungicides; Mancozeb, Copper oxychloride, Hexaconazole, Metalaxyl+Mancozeb, and Carbendazim, at 100 ppm were evaluated for their efficacy against the causative agent of this disease, Fusarium solani, In-vitro. The experiment was carried out in Completely Randomized Design with seven replications. Our result shows the difference in the efficacy of all tested fungicide against this pathogen. The application of Carbendazim at 100 ppm gave the highest inhibition of mycelium growth (100%) followed by Mancozeb (85.08%) and Metalaxyl+Mancozeb (64.3%) (at the same dose) on the 7 th day of incubation suggesting Carbendazim (100 ppm) as a better one to use for the management of F. solani.

Fusarium solani, the causative agent of root rot disease is one of the major constraints of faba bean (Vicia faba L.) yield worldwide. Essential oils have become excellent plant growth stimulators besides their antifungal properties. Foeniculum vulgare Mill. (fennel) is a familiar medicinal plant that has inhibitory effects against phytopathogenic fungi. Herein, different concentrations of fennel seed essential oil (FSEO) (12.5, 25, 50, 100, 200 and 400 μL/mL) were examined against F. solani KHA10 (accession number MW444555) isolated from rotted roots of faba bean in vitro and in vivo. The chemical composition of FSEO, through gas chromatography/mass spectroscopy, revealed 10 major compounds. In vitro, FSEO inhibited F. solani with a minimum inhibitory concentration (MIC) of 25 µL/mL. In vivo, FSEO suppressed Fusarium root rot disease in Vicia faba L. by decreasing the disease severity (61.2%) and disease incidence (50%), and acted as protective agent (32.5%) of Vicia faba L. Improv...

Phellinus sulphurascens (previously the Douglas-fir form of Phellinus weirii) is an important native pathogen causing laminated root rot in forests of western North America. Visual crown symptoms, or attacks by bark or ambrosia beetles appear only during advanced stages of the disease with extensive infection in the lower bole. Ethanol synthesis is one of many physiological responses in tree tissues stressed by pathogens. Ethanol, acetone and other volatiles from root tissues of healthy and diseased trees were analyzed using headspace gas chromatography. Xylem and phloem from 20 diseased trees at two western Oregon sites contained higher concentrations of ethanol, acetone, or other headspace volatiles than 20 healthy trees on one or more dates in September, November, or the following May. Root cross-sections from eight diseased trees were sampled along perpendicular transects and found to contain extremely variable ethanol concentrations, with highest xylem quantities in a 0-2 cm zone outside the infection boundary and lowest amounts inside the infection. Acetone concentrations were the opposite. Logistic regression models were built and tested to determine which volatiles could predict diseased trees. A model using xylem ethanol concentrations as the only parameter was selected and validated with measurements from 80 trees on the edges of P. sulphurascens infection centers at two different western Oregon sites. This model successfully predicted trees with laminated root rot (78% overall correct classification and 68% for known diseased trees), but worked best for those with infections observed in both root cores and the root collar (100% correct). Early detection of P. sulphurascens infected trees remains a challenge. Our ethanol analysis method is useful for research, but provides limited benefits for identifying individual P. sulphurascens hazard trees, or for extensive ground surveys in the forest. Whether ethanol is released to the atmosphere in sufficient quantities to confirm infection before the late appearance of crown symptoms, or bark beetles remains unknown. If it is, then development of sensors capable of tree side detection requiring minimal tissue sampling would be useful in managing this disease. We also propose a mechanism for how ethanol with host monoterpenes could play a central role in pioneering bark beetle primary host selection of trees infected with this pathogen.