Plant viruses cause various disease in crops and are responsible for huge economic losses. Understanding their mode of infection and spread is crucial for developing control strategies. Genome packaging is an important step in the process of viral maturation. Three systems of viral genome packaging are known till date. The type I packaging system, found in most of the small plant viruses, involves

Rice sheath blight, a major devastating disease caused by Rhizoctonia solani, poses huge threat to global rice production. Despite being the most hostile necrotrophic fungus with a wide host range, the mechanism involved in R. solani pathobiology is poorly understood. The evolutionarily developed nonhost resistance (NHR) provides broad-spectrum disease resistance to food crops. According to previous

Yellow passion fruit (Passiflora edulis f. flavicarpa) is rich in nutrients. In March 2018, anthracnose symptoms were observed in a storeroom in Baoting, Hainan province, China. The pathogen namely Colletotrichum brevisporum was isolated and identified from symptomatic fruits based on the morphological and multi-gene phylogenetic analyses derived from an internal transcribed spacer (ITS), beta-tubulin

Monilinia kusanoi causes shoot blight, leaf blight and fruit rot of several Prunus species, and is currently known to be present only in Japan and Korea. Despite the restricted distribution range, the risk remains that the pathogen could spread with the transportation of plant material, especially since no DNA based diagnostic methods are available to detect this fungus. In this study, a new TaqMan

The Australian canola industry was established in the 1970s and has expanded since that time, particularly in the last two decades. This review addresses the changes in farming practices since the year 2000 and the epidemiological and management consequences for blackleg, caused by the fungus Leptosphaeria maculans, the main disease impacting Brassica napus production. To help understand the change

Xanthomonas oryzae pv oryzae, the causative pathogen of bacterial leaf blight (BB) disease is one of the most prevalent rice diseases in Malaysia. Breeding for resistance requires information on the pathogenic variability of X. oryzae for decision-making on the deployment of appropriate resistance genes. In this study, nine Near Isogenic rice Lines (NILs) carrying single BB resistance genes (Xa) used

Verticillium dahliae is a soil-borne phytopathogen and the causal agent of Verticillium wilt. It affects many agriculturally important crops around the world, including cotton. In Australia, the billion-dollar cotton industry is increasingly impacted by Verticillium wilt. Internationally it has been reported that the defoliating V. dahliae Vegetative Compatibility Group (VCG) 1A causes severe damage

In this study, we evaluated a collection of 585 barley landraces along with 10 checks at Sinana Agricultural Research Center (SARC) and Bale-Goba research sites in 2018/19 and 2019/20 cropping seasons for resistance to net blotch (Pyrenophora teres F. teres (Ptt)). The experiments were laid out in an augmented complete block design. Data on agronomic performance and disease response were recorded.

Cowpea aphid-borne mosaic virus (CABMV) is the main pathogen that affects passion fruit, causing woodiness disease in Brazil. The identification of sources of resistance in Passiflora is necessary for the development of resistant cultivars. The objective of this work was to evaluate the reaction of eight species of Passiflora to CABMV and to verify leaf anatomical changes caused by CABMV. Inoculations

Puccinia striiformis f. sp. tritici is a responsible pathogen for wheat stripe rust, which can be dispersed for a long distance by upper air flow. Understanding its origin and migration is vital to control the disease. We analyzed the population structures of the pathogen, which include 297 samples from Yunnan, Guizhou, Sichuan, Shaanxi, and Gansu in 2008 and 2011, by using the concatenated gene Cdc2-(Ef-1α)-Mapk1

The fungus Aspergillus tubingensis is widely known from its use in industrial fermentation and other processes. More rarely, it is an opportunistic pathogen of humans or plants. In the present study, we found one rotten pomegranate fruit (Punica granatum) with black patches of rot and sporulation on the surface. Three A. tubingensis strains were isolated from this specimen. These were identified based

Leaf spot of soapberry, Sapindus mukorossi is a disease new to China. The disease significantly reduces not only the plant’s ornamental value but also its medicinal properties. Identification of pathogens timely assists preventing and controlling this disease. In July 2019, foliage of soapberry on the campus of Nanjing Forestry University, China, was infected by the disease, and the disease incidence

Grapevine powdery mildew, caused by the fungus Erysiphe necator (formerly Uncinula necator), is a widespread disease which can reduce yield and quality of grapes and compromise wine quality. As an obligately biotrophic pathogen of a woody perennial crop, E. necator presents challenges for researchers studying aspects of biology, epidemiology and management. The disease can be difficult to detect, especially

Ascochyta blight of faba bean, caused by Ascochyta fabae (teleomorph: Didymella fabae) is one of the most destructive diseases of faba bean in Tunisia. Temporal and spatial development of ascochyta blight were studied and characterized during 2010–2011 and 2011–2012 in three faba bean fields located in Oued Mliz, Oued Beja and Mornag, using mathematical and geostatistical analyses. Mass Disease Index

Betasatellites are single-stranded DNA molecules associated with most monopartite begomoviruses of family Geminiviridae. They are symptoms modulating molecules and depend on their helper viruses for replication, encapsidation and movement. To investigate the genetic diversity of cotton leaf curl Multan betasatellite (CLCuMuB), different Pakistani isolates of betasatellites were retrieved from the NCBI

Maize (Zea mays L.) is a staple food in many parts of the world. In addition to being used as grain, animal feed, production of corn ethanol, starch, syrup etc., it has been widely consumed as a vegetable in the form of baby corn and sweet corn. Banded leaf and sheath blight (BLSB) is one of the major diseases affecting maize and is caused by Rhizoctonia solani f. sp. sasakii Exner. In the experiment

The aim of this work was to characterize the secondary metabolite (SMs) profile of Stemphylium lycopersici, a necrotrophic fungus that causes the disease known as grey leaf spot. We detected twenty-four SMs in cultures of S. lycopercisi within the extracts of 19 isolates. Each of them presented a characteristic unique profile. While highly virulent isolates synthesized a high number of metabolites

A previous field trial showed that marketable yield increased and root-knot nematode populations declined when the swollen roots of sweetpotato were surrounded by a sawdust-based amendment. Further evidence that such amendments provide worthwhile levels of nematode control was obtained in this study. Customised pots filled with an organic amendment or amended soil were kept in a greenhouse or buried

Pumpkin (Cucurbita maxima) plants showing begomovirus-like yellowing, curling and stunting symptoms were observed in the Barka Governate, Oman in December 2016. Cloning and sequencing of rolling circle amplified circular DNA molecules showed the plants to be infected with watermelon chlorotic stunt virus (WmCSV); a bipartite Old World begomovirus that is a serious pathogen of cucurbit crops across

Phytophthora wilt, caused by Phytophthora capsici Leon., is the most devastating disease of chilli in Bhutan. In this study, effects of bed heights to improve soil drainage, animal manures and fungicides on Phytophthora wilt on chilli were evaluated on naturally infested plots at the wet lowlands site of Bhur and in a farmer’s field at a drier, higher altitude site at Darachu in Bhutan. The experimental

The discovery of Cryphonectriaceae and more specifically species related to the Eucalyptus canker pathogen Chrysoporthe cubensis on shrubs and trees in the Melastomataceae, has deepened our understanding of relevant, and potentially globally threatening tree pathogens. Recent isolations of Cryphonectriaceae associated with cankers on Tibouchina spp. in Brazil gave rise to an apparently undescribed

Dr. Bandamaravuri Kishore Babu name was included in error and he is not associated with this manuscript.

Chukrasia tabularis is a rare and valuable tree in the mahogany family (Meliaceae) which has been planted with fruit trees in home gardens in Vietnam more than 60 years. Recently, households have become concerned with sporadic trees wilting and dying. In this study we explore this new tree decline. The trunk of diseased trees, with cankers and wilt symptoms, and soil from around roots were sampled

Phytophthora root rot (PRR) caused by Phytophthora medicaginis (Pm) is an important disease of chickpea in Australia. There are limited control options, with avoiding planting chickpeas in paddocks with a high PRR risk a key management strategy. Currently, risk assessment is based solely on paddock history of PRR, without any measure of Pm inoculum. We developed a qPCR test to quantify Pm inoculum

The original version of this article unfortunately contained mistakes introduced during the production process.

The Australian red cedar (Toona ciliata), a forest species native to southwestern Asia, has aroused commercial interest for its high-quality timber. Phyllachora was recently reported in this species in Brazil, but there is a lack of knowledge about its epidemiology and control. Currently, no methodologies exist for quantifying the severity of this disease in cedar trees. In the present study, a diagrammatic

Phoma koolunga is one of three species that cause ascochyta blight (synonym: blackspot) of field pea (Pisum sativum L.) in Australia. P. koolunga was first described in 2009 in South Australia and has since been reported in Western Australia and Victoria. However, the origin of the pathogen and its host range remain largely unknown. The aim of this study was to examine the host range of P. koolunga

Cocoa pod isolates of Phytophthora palmivora (Ppal) from different locations in Papua New Guinea (PNG) were grown in the presence of cellophane to determine their abilities to mechanically penetrate this barrier and to gain access to the growth media below. Four Ppal isolates, MAG14, MAG30, MAG50, NSP11 and the plant root pathogenic oomycete P. cinnamomi for comparison, were tested for their cellophane

The effects of meteorological conditions around silking (Si) and physiological maturity (PM) on production of fumonisins (FB=FB1 + FB2) in maize kernels were analyzed. Kernel FB contents were determined on kernel samples collected from an experimental susceptible hybrid (n = 35) and a Bt commercial hybrid (n = 23) planted in several growing seasons/sites from the Argentinean Pampas. Considering the

Stem rot caused by Sclerotium rolfsii is a destructive disease that induces serious yield losses in groundnut (Arachis hypogaea L.) around the world. This study used a multifaceted approach to screen 121 groundnut genotypes from different subspecies and botanical varieties for resistance to S. rolfsii under field conditions. Five wild species of Arachis were also assessed in a greenhouse study. In

The production of malting barley under dryland and irrigated environments in South Africa (SA) has increased recently, making it the second most important winter crop after wheat. To assess the potential vulnerability of adapted barleys from SA to wheat stem rust (caused by Puccinia graminis f. sp. tritici, Pgt, race PTKST) and rye stem rust (Puccinia graminis f. sp. secalis, Pgs, isolate UVPgs1),

Citrus exocortis viroid, citrus bent leaf viroid, hop stunt viroid and citrus dwarfing viroid were detected for the first time in Lao PDR. Samples were collected from citrus trees across southern Lao PDR for laboratory testing in Australia. RNA was extracted and amplified using quantitative reverse transcription polymerase chain reaction (qRT-PCR); viroid identities were confirmed by sequencing.

Between 2016 and 2017, symptoms of witches’ broom, proliferation, drying of twigs and ball-like structures formation were observed in Pinus brutia in urban green areas and parks in Isfahan (Iran). All samples from affected P. brutia trees resulted positive in nested-PCR using primer pairs targeting the phytoplasma 16S rRNA gene. Amplicons were obtained only from all the symptomatic pine tree samples

Corymbia citriodora subsp. variegata (CCV) is an economically and ecologically important timber species, native to eastern Australia. It is highly susceptible to Quambalaria pitereka, a coevolved endemic pathogen, and Austropuccinia psidii, an exotic invasive pathogen. Genes associated with resistance to Q. pitereka are specific and uncorrelated with the genes associated with resistance to A. psidii

The study was aimed to develop rust resistant genotypes with genome of prominent wheat variety HS240 by pyramiding of linked leaf rust and stem rust resistance genes Lr19 and Sr25 with stripe rust resistance gene Yr15. The genotypes FLW13 and FLW20 were used as gene donors for transfer of Yr15 and Lr19/Sr25, respectively. The molecular markers scs265, wmc221, PSY1-E1, and Gb linked to Lr19/Sr25 and

Diseases caused by pathogens, alone or in combination with other stress factors, are a major threat to the future health of urban forests. Root diseases caused by Phytophthora species are frequently evident in urban environments due to conducive environments for these pathogens, and to conditions predisposing trees to attack. Urban environments are also an important pathway for the introduction of

Exserohilum turcicum is the causal agent of northern leaf blight (NLB) disease in sorghum and maize. Early detection of this economically important pathogen is essential for effective disease management to limit yield losses. Here we present a real-time quantitative PCR (qPCR) assay specific for E. turcicum detection and biomass quantification in sorghum and maize. In planta fungal quantification was

The aim of this work was to study the gene clusters that code for secondary metabolites within the genome of Stemphylium lycopersici and evaluate their toxicity in plant tissue since they are probably responsible for the necrotrophic symptoms provoked by S. lycopersici on plants of the Solanaceae family. We analyzed the draft genome sequences using the antiSMASH software to identify potentially toxic

In April 2019, a new basal stem and root rot disease, which caused severe wilting of Crossandra infundibuliformis in Jinniu Park in Haikou City, Hainan province. Plants with typical disease symptoms were random collected from Jinniu Park. The pathogen causing basal stem and root rot of C. infundibuliformis was identified as Fusarium solani from the isolates, based on morphological observation, rDNA-ITS

Rice blast (Magnaporthe grisea) is an epidemic rice disease that reduces rice yield and quality worldwide. The objective of this study was to present and evaluate a data reconstruction method for assessment of rice leaf blast severity using hyperspectral imaging technology at the late vegetative growth stage. Experiments were carried out on Mongolian rice, which is susceptible to the disease. To carry

Australia produces some of the highest sweetpotato yields in the world but the health of the soil used to produce the crop is declining because it is repeatedly tilled to kill volunteer sweetpotatoes, incorporate cover crop residues and prepare beds for planting. Additional disturbance occurs when the swollen roots are harvested. An on-farm study showed that it is possible to replace this tillage-dominated

Anthracnose is one of the most destructive grapevine diseases in warm and humid regions, but no efficient tools are available to quantify disease symptoms in different parts of the plant. Therefore, this study aimed to develop and validate standard area diagrams (SADs) to evaluate grapevine anthracnose on the fruit and shoot. For fruit SAD development, fruit clusters showing signs of anthracnose symptoms

Temperature is one of the key factors influencing the viral disease development in plants. In this study effect of temperature on SYMMV accumulation and systemic movement was studied in French bean, mungbean and soybean cultivars by keeping them at temperatures range 22-25 °C, 26-29 °C and 30-33 °C. The proliferation of the virus under these conditions was confirmed through symptomatology, DAC-ELISA

Spermospora avenae causes the economically important red leather leaf disease of oats, which reduces grain yield and hay quality. It was first reported in the USA in 1936 and subsequently in Australia in 1978. Despite this, its phylogenetic placement is unknown, attributed merely to Ascomycota. Twenty-three S. avenae single spore isolates were obtained from affected crops in South Australia and western

Sting nematode (Belonolaimus longicaudatus) is one of the most destructive nematode pests in the United States. It is native to the sandy coastal plains of the south-eastern states and causes severe damage to a wide range of plants including turf grasses, ornamentals, forages, vegetables, agronomic crops and trees. Ibipora lolii, a closely related nematode, occurs in Australia and is a widespread and

Okra (Abelmoschus esculentus L. Moench) serves as a vegetable of great food, medicinal and industrial value. The production of the crop is, however, constrained by lack of improved high yielding, virus and pest resistant varieties. The current study sought to identify resistance in ten okra cultivars to okra mosaic disease and okra yellow vein mosaic disease within the coastal savannah agro-ecological

A review of the records of plant viruses, viroids and phytoplasmas in Tasmania has found evidence for 51 viruses and one viroid. Based on insufficient evidence, 22 viruses and reports of at least three phytoplasmas are unconfirmed. Most of these unconfirmed pathogens are probably present but further work is required to confirm this. Forty two of the listed viruses are aphid transmitted, including 15

The objective of this study was to assess genotype by environment interaction for area under disease progress curve values in spring barley grown in South-West Poland by the additive main effects and multiplicative interaction model. The study comprised of 25 spring barley genotypes (five cultivars: Basza, Blask, Antek, Skarb and Rubinek as well as all possible 10 two-way mixtures and 10 three-way

RNA silencing or RNA interference (RNAi) is an endogenous mechanism of gene regulation and adaptive defence against invading microbes of higher organisms, triggered by double-stranded RNA. Viruses circumvent this host defence by encoding specific proteins, RNA silencing suppressors (RSSs). Evidence has been mounting that, in common with RNA viruses, the movement of geminiviruses in plants is countered

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This study analysed the phenotypic and genotypic variation among 511 Pseudomonas savastanoi pv. phaseolicola (Psp) isolates, causing halo blight in mungbeans. Collected from symptomatic mungbean (Vigna radiata) crops throughout Australia between 2005 and 2018, a total of 352 Psp isolates were phenotypically screened. Our in planta screening against a set of four mungbean cultivars with known susceptible

Late leaf spot (LLS) and rust diseases are the major devastating diseases in groundnut that lowers crop yield and fodder quality. Marker assisted backcross breeding was employed to introgress LLS and rust diseases resistance QTL region from GPBD 4 into an India’s popular groundnut variety TMV 2. The MABC approach was exercised using a total of eight disease resistance-linked markers viz.., IPAHM103

In 2016, begomovirus-like symptoms were observed in mungbean (Vigna radiata) and black gram (Vigna mungo) in Pakistan. Symptomatic and asymptomatic leaf samples were collected and total genomic DNA was extracted. Full length begomovirus and betasatellite genomes were PCR amplified and cloned in plasmid pTZ/57RT cloning vector. The cloned molecules were subjected to Sanger sequencing. Based on Sequence

Tephrosia, an important medicinal plant, and a potential livestock feed, was found to be affected by a leaf yellowing disease at the Ziway field site of the International Livestock Research Institute. A total of fifty samples from 300 plants were collected from twenty Tephrosia species in three consecutive planting seasons; 2015, 2016 and 2017. The samples were screened for viral infection by dot-blot

Bacterial blight in pomegranate caused by Xanthomonas axonopodis pv. punicae (Xap) is an increasing threat to pomegranate cultivation in India. To prevent economic losses, it is pivotal to detect the infection in latent stages rather than in symptomatic stages. We have developed an enhanced loop-mediated isothermal amplification (LAMP) technique for the detection of latent Xap infection in pomegranate

Powdery mildew haustoria are easier to be observed by light microscopy in trichome cells compared to epidermal cells of infected leaves. The objective of this study was to explore the relationship between the hyphal length and the number of haustoria in type I trichome cells of tomato (Solanum lycopersicum Mill.) leaves. The trichome cells of tomato cv. Moneymaker were inoculated with conidia of tomato

Two new taxa, Neofusicoccum variabile and Pseudofusicoccum africanum were not validly published according to Art. 40.7 (Shenzhen).

Barley, host to the wheat and rye attacking forms of the stem rust pathogen, Puccinia graminis (Pg), is considered inherently more resistant to Pg than wheat. To investigate whether this enhanced basal defence is associated with early infection or colonisation processes, adult plants of selected barley and wheat entries were inoculated with Pg f. sp. tritici (Pgt) races BNGSC and PTKST, and Pg f. sp

The aim of this study is to determine the severity of the disease Septoria leaf spot in tomato plants, through computational analysis of digital images of leaves affected. We collected and obtained digital images of tomato leaves with absence and presence of the disease with varying degrees of severity. From a script written in R with the EBImage package, the image was decomposed into three levels