Blight Disease Research Articles

Major Cereal Crop Production in Kabhrepalanchok

Agriculture is one of the most vulnerable sectors to climate change impact. The main purpose of the study is to find the recent production of major cereal crops as rice, maize, and wheat per unit area in Banepa municipality, as a case study to the local trends and adaptation. The study was conducted among the household of ward No. 1, 3, 4, 5, 7, 8, 9, 10, and 11 in the Municipality. Field observation, in-depth interview, focus group discussion, Questionnaire survey methods were adopted for information collection, cross-validation with verification and using a secondary source of the information. Monthly precipitation and monthly minimum and maximum air temperatures data of Dhulikhel station were used to study their annual and seasonal trends.
 Time-series annual yield data in rice, maize, and wheat were collected from the Ministry of Agriculture and Livestock Development. Production was also accessed from the local level in a cross-sectional survey. Temperature and precipitation were collected from the Department of Hydrology and Metrology. The Survey indicated that yields have increased for major cereal crops and this led to an increase in the use of chemical fertilizer, chemical pesticides, improved seed, and improved management practices. The impacts of these changes have resulted in an increased attack of white grub in roots and maize smut in cobs, rice blast in panicle and stem, rust and blight disease and grain borer in wheat. The major issues for farmers were found to be a deficit of inorganic fertilizers, an insufficient supply of quality seeds and an unsystematic market. The coping mechanism for climate change in farming was not applied due to a lack of knowledge, facilities, and access to improved technologies. The farmers expected advanced technological know-how along with other facilities for climate-resilient farming.
 This study concludes that change in climate is affecting the agriculture in Banepa Municipality of Kabhrepalancchok. The existing local and institutional strategies are not sufficient and sustainable to cope with climatic vagaries. It is very important to address the problems in this region with institutional support and through a long-term policy perspective.

Image Features Based Intelligent Apple Disease Prediction System

A pattern classifier (PC) is used to solve a variety of non-separable and complex computing problems. One of the key problems is to efficiently predict a type of disease in a typical fruit tree. The timely and accurately predicted disease in an apple tree may help a farmer to take appropriate preventive measures in advance. In this article, an apple disease diagnosis system is developed to predict the apple scab and leaf/spot blight diseases. In this article, low level and shape-based features are used for the development of an intelligent apple disease prediction system. First, the key image features like entropy, energy, inverse difference moment (IDM), mean, standard deviation (SD), perimeter, etc., are extracted from the apple leaf images. The model for the proposed system is trained by using multi-layer perceptron (MLP) pattern classifier and eleven apple leaves image features. The Gradient descent back-propagation algorithm is used for building the intelligent system to carry out the pattern classification. The proposed system is tested using some random samples and exhibits excellent diagnosis accuracy of 99.1%. The sensitivity of the proposed prediction model is 98.1% and specificity of ~99.9%.

An Efficient in vitro Assay to Predict Resistance and Pathogenicity in the Fusarium Head Blight-Hordeum Vulgare Pathosystem

Background: Barley (Hordeum vulgare L.) worldwide is affected seriously by Fusarium Head Blight (FHB) disease caused by several Fusarium species. In vitro assays permitting for easy, efficient and reliable prediction of the head blight reaction in the whole plant should be investigated. Objective and Methods: The in vitro ability of 16 fungal isolates of four FHB species to confer disease on individual plant organs was evaluated using a coleoptile infection assay. Four quantitative components (Seed Germination (SG), Coleoptile Length (CL), Coleoptile Weight (CW) and Root Weight (RW)) were analyzed in two widely cultivated barley cultivars, Arabi Aswad (AS) and Arabi Abiad (AB), with known quantitative resistance. Results: Differences in inoculated pathogenicity and resistance treatments were observed on young plant parts relative to water controls, indicating that these FHB species were found to be suitable for the differential expression of all tested quantitative components. There was a wide variation in pathogenicity among the 16 FHB isolates and susceptibility among AS and AB. The 16 FHB isolates can be separated into the first group with larger number of isolates, upon infection with which AB really was more susceptible to FHB infection than AS, and isolates of the second group with leaser number of isolates for which AS and AB react was the opposite. On AB, rather susceptible, inoculation with FHB species resulted in significantly less SG, CL, CW and RW, compared with AS, which showed a greater resistance. The very good resistance of AS was confirmed by the measurements of quantitative resistance components described in this study. When infected with FHB isolates, all indicators of a more susceptible cultivar seemed to be 10-20% less than those of a resistant cultivar. Moreover, the values of all analyzed components were significantly correlated with the data of pathogenic indices generated in vitro, and under controlled and field conditions with a large diversity depending on AS and AB. Conclusion: Appropriate in vitro conditions were determined for the coleoptile infection assay to maximize differences in disease reactions components among FHB isolates and the two barley cultivars. Results suggest that all measured components predict resistance and pathogenicity occurring at the earliest and latest barley development stages during FHB infection. Our data also highlighted, for the first time, the utility of CW and RW for the determination of resistance and pathogenicity in the FHB-barley pathosystem. The coleoptile infection test was confirmed to be adequate to in vitro, growth chamber and field data by the presence of the first group, which prevailed in all other tests generated under different experimental conditions. The in vitro coleoptile infection assay may offer a real possibility of simple, rapid and reliable screening of resistance in barley cultivars and pathogenicity of FHB species.

Economic Comparison of Pomegranate Production with Darakshak (Bioconsortium) and Conventional Chemical use in Karnataka

Pomegranate production with Darakshak and conventional chemical use in Karnataka (2017-18) revealed that per acre annual cost of cultivation of pomegranate was less in Darakshak users (`1,10,347) than conventional chemical users (`1,21,342 ). Fruit yield increased by 13.5 percent to the Darakshak users (6.750 tonnes) compared to conventional chemical users (5.838 tonnes). Darakshak improved the fruit quality and reduced the fruit cracking problem. Hence, Darakshak users received higher returns than chemical users. The majority of the farmers expressed that bacterial blight was the major production problem followed by irrigation, and decreasing yield. Pomegranate producers opined that Darakshak is more effective on blight disease besides improving the crop health, and quality of the fruit. Conventional chemical users expressed that the usage of chemicals harmed human health followed by the incidence of water pollution. It contaminated in the soil and reduced soil fertility.

Diversity in the population of Fusarium graminearum isolated from wheat and corn in Alberta, Canada

A survey was conducted in southern Alberta, Canada, to collect Fusarium stalk rot and Fusarium head blight (FHB) disease samples from corn and wheat fields, respectively, with an aim to understand the diversity in the population of Fusarium graminearum. From 77 wheat and 80 corn samples, 79 isolates of F. graminearum were obtained. These 79 isolates were evaluated for their growth rate, sporulation ability, pathogenicity and trichothecene genotype. Eighty-two percent of the isolates were recovered from corn, which suggests corn residue may be better suited than wheat for perpetuating the FHB pathogen. Three genotypes with potential of producing 3-ADON, 15-ADON and NIV were present in the population, and among them, 15-ADON producing genotype was predominant, and 3-ADON genotype produced more spores than the 15-ADON genotype. The proportion of 3-ADON genotype is increasing overtime in Alberta. The impact of increasing population of 3-ADON genotype is worthy of to be monitored for the management of FHB. There were variations in the population of F. graminearum isolates for growth rate, sporulation and pathogenicity but revealed no association among the parameters suggesting other factors like host susceptibility and environment play a significant role in the development of FHB.

Genome Sequence of Fusarium graminearum Strain CML3066, Isolated from a Wheat Spike in Southern Brazil

Fusarium graminearum is a global fungal pathogen of wheat and other small grains, causing Fusarium head blight (FHB) disease, also known as wheat scab. We report here the annotated genome of a deoxynivalenol/15-acetyl-deoxynivalenol-producing Brazilian strain called CML3066, isolated from FHB-symptomatic wheat spikes collected in 2009.

First report of Exserohilum leaf spot: a unique halophilic pathogen in Cucumis sativus in the South Bengal area of India

Cucumber (Cucumis sativus L.) is a nutritious domesticated vegetable which belongs to Cucurbitaceae family. India ranks 30th in global cucumber production and its total output is 1,61,000 metric tons annually. In the investigation a different kind of leaf spot disease was observed on 2 months old cucumber leaves samples from cucumber fields in Baruipur, West Bengal, India (Latitude: N 22° 22.262′, Longitude: E 88° 24.5086′). The spots appeared were large, greyish brown in colour surrounded by a yellow to brownish halo, measuring 2 × 1 cm in average. These lesions expanded gradually from circular to angular spots ultimately resulting in necrosis and defoliation. The isolated fungus showed greyish black to dark olive mycelial growth. Microscopic characterization revealed straight to slightly curved conidia and distoseptate with a distinctly protruding basal hilum. Through microscopic observation and ITS sequencing the organism was identified to be Exserohilum rostratum. E. rostratum was previously known for causing blight disease in maize as well as human immune system diseases. E. rostratum, E. longirostratum and E. mcginnisii are identified as human pathogens. Koch’s postulates were carried out and distinct symptoms were observed in cucumber. As because there is no such record, this is the first time the host pathogen combination is separated in India.

Disease Detection in Paddy Crop using CNN Algorithm

In this paper, we propose a technique for early detection of the diseases like blast and blight in paddy crop using one of the deep learning algorithms called as CNN algorithm [8]. The entire system works on the Raspberry-pi which acts as processing unit for the proposed system. The well trained keras model to predict the disease in paddy leaf is developed using CNN algorithm [5]. As the symptoms of the blast and blight disease are detected using feature of the paddy leaf, so the model is trained using the diseased image data set. The pi-camera will capture the image of the leaf and the captured image will be processed by the python script running on raspberry pi. The images will be captured at different angle with respect to raspberry-pi. The trained model will predict whether the processed image of the leaf contains the symptoms of the disease. The proposed system also includes the feature which will alert the farmer about spreading of the disease by using the GSM module to send the message to the farmer of the field. Also the pesticides are suggested to farmers to control the further growth of the germs causing the disease. In India paddy is grown as the staple crop. The paddy crop is mostly damaged due to the leaf diseases called as blast and blight disease[4]. About 20%-30% of the yield will be destroyed by the blast and blight diseases respectively [14]. Hence, by implementing the above proposed system the disease can be detected at the early stage and loss can decreased.

Identification of Novel QTL Conferring Sheath Blight Resistance in Two Weedy Rice Mapping Populations

BackgroundRice sheath blight (ShB) disease, caused by the pathogenic fungus Rhizoctonia solani, causes significant yield losses globally. US weedy rice populations, which are de-domesticated forms of indica and aus cultivated rice, appear to be more resistant to ShB than local japonica cultivated rice. We mapped quantitative trait loci (QTL) associated with ShB resistance using two F8 recombinant inbred line populations generated from crosses of an indica crop variety, Dee-Geo-Woo-Gen (DGWG), with individuals representing the two major US weed biotypes, straw hull (SH) and black hull awned (BHA).ResultsWe identified nine ShB resistance QTL across both mapping populations. Five were attributable to alleles that affect plant height (PH) and heading date (HD), two growth traits that are known to be highly correlated with ShB resistance. By utilizing an approach that treated growth traits as covariates in the mapping model, we were able to infer that the remaining four QTL are involved in ShB resistance. Two of these, qShB1–2 and qShB4, are different from previously identified ShB QTL and represent new candidates for further study.ConclusionOur findings suggest that ShB resistance can be improved through favorable plant growth traits and the combined effects of small to moderate-effect resistance QTL. Additionally, we show that including PH and HD as covariates in QTL mapping models is a powerful way to identify new ShB resistance QTL.

Pseudomonas taiwanensis (MTCC11631) mediated induction of systemic resistance in Anthurium andreanum L against blight disease and visualisation of defence related secondary metabolites using confocal laser scanning microscopy

Abstract An attempt to evaluate induced systemic resistance in anthurium against blight disease caused by Xanthomonas axonopodis pv. dieffenbachiae (Xad) was studied. Plant associated Pseudomonas taiwanensis and elicitor compounds were used for plant application in greenhouse experiments to evaluate the resistance development against anthurium blight. Application of rhizobacteria P1 and P9 resulted in significant disease reduction to 80.0% and 85.0% respectively. Application of salicylic acid, mancozeb and K2HPO4 also resulted in reduction of disease at 35 days after inoculation. Elevated production of defence related enzymes, proteins and phenols were observed. Application of rhizobacteria P1 resulted in highest production of polyphenol oxidase and phenolic compounds. Production of phenylalanine ammonia lyase was maximum in mancozeb treated plants compared to other treatments. Maximum production of peroxidase enzyme was found in K2HPO4 treated plants whereas application of elicitor compound salicylic acid caused maximum production of defence related proteins compared to other treatments. Confocal microscopic studies revealed that P1 and P9 treated plant petiole showed increased auto fluorescent emissions indicating the distribution of defence related secondary metabolites and phenolic compounds as compared to control plants. Root colonization assay displayed significant results implicating that Rif+ and Cyclo+ resistant rhizobacterial isolates could successfully grow in the root tissue, establishing endophytic association within the host tissue.

Impact of seed dressing and systemic fungicidal sprays in controlling the magnitude and spread of the late blight (Phytophthora infestans) disease in addition to augmenting the yield of superior grade potato tubers

Impact of seed dressing and systemic fungicidal sprays in controlling the magnitude and spread of the late blight (Phytophthora infestans) disease in addition to augmenting the yield of superior grade potato tubers

English

English

Research Article Genetic and phenotypical correlations, path analysis and genetic gain in two populations of corn with resistance to leaf spot, rust, and blight disease

Research Article Genetic and phenotypical correlations, path analysis and genetic gain in two populations of corn with resistance to leaf spot, rust, and blight disease

Efficacy of Bacterial endophytes against Rice pathogens under in vitro conditions

In an attempt to develop effective biocontrol system for management of sheath blight and stem rot diseases in rice, seven bacterial endophytes were isolated from the rice leaves and evaluated for their antagonistic activity against Rhizoctonia solani and Sclerotium oryzae. Among seven isolates, two isolates viz., CEY3 and CES7 showed highest pathogen suppression of sheath blight and stem rot as (60.0% & 56.5%) and (52.2%, 58.0%), respectively.

Different effects of phytohormones on Fusarium head blight and Fusarium root rot resistance in Brachypodium distachyon

ABSTRACT Fusarium graminearum is a devastating pathogen of small grain cereals causing both Fusarium head blight (FHB) and Fusarium root rot (FRR). Exogenous application of phytohormones has been shown to affect FHB resistance. In contrast to FHB, FRR remains poorly characterised and it is unknown whether phytohormones play similar roles in FHB and FRR. In this present study, B. distachyon floral tissues at mid-anthesis and root tissues from seedlings were exogenously treated with several phytohormones before inoculation with F. graminearum. The canonical defence-associated phytohormones had differing effects on FHB and FRR. Salicylic acid (SA) significantly increased susceptibility to FRR but not to FHB while jasmonic acid (JA) and ethylene increased resistance to FRR but increased susceptibility to FHB. Additionally, the growth-associated phytohormones auxin and cytokinin significantly increased resistance and susceptibility, respectively, to both diseases. This study is the first to compare phytohormone effects between FHB and FRR in the same host. Highlight The tissue-dependent effects of defence phytohormones and tissue-independent effects of development phytohormones on F. graminearum-induced Fusarium head blight and Fusarium root rot diseases in the model cereal Brachypodium distachyon. Abbreviations: ACC, 1-aminocyclopropane-1-carboxylic acid; BABA, 3-aminobutanoic acid; dpi, days post inoculation; FHB, Fusarium head blight; FRR, Fusarium root rot; IAA indole-3-acetic acid; JA, jasmonic acid; NAA, 1-naphthaleneacetic acid; PDA, potato dextrose agar; RNL, root necrosis length; SA, salicylic acid

Genetic analysis of microsatellites associated with resistance against bacterial leaf blight and blast diseases of rice (Oryza sativa L.)

Bacterial leaf blight (BLB) and blast are among the most destructive diseases of rice. In order to develop new varieties that can resist various races of the pathogens Xanthomonas oryzae pv. oryzae (Xoo) and Magnaporthe oryzae, which cause these two diseases, respectively, it is important to identify suitable markers and a marker-aided selection strategy. Seventeen foreground microsatellites associated with resistance against BLB and blast were screened for polymorphism for possible adoption in a breeding program for resistant cultivar development. A total of 472 background simple sequence repeats (SSRs) were also screened for polymorphism in order to recover the recurrent parent genome. All 72 F1 progenies were also analysed with the 17 foreground and 472 background markers in comparison to the alleles of their parents. The markers were validated using 218 BC2F2 plants. The result revealed six tightly linked polymorphic foreground markers (Xa21FR, pTA248, Xa13prom, MP, RM21 and RM13) associated with resistance against Xoo pathotype P7.7 and two microsatellites (RM6836 and RM8225) associated with resistance against blast pathotype P7.2. A total of 79 polymorphic background markers were identified for recovering the recurrent parent genome. The result also showed that the markers had goodness of fit (blast resistance) to 1:2:1 ratio for single gene model in BC2F2 progenies. These genetically confirmed microsatellite markers were recommended for use in marker-assisted backcross breeding and other marker-assisted selection of BLB and blast resistance genes in order to develop varieties with durable and broad spectrum resistance against the two major rice diseases.

Interaction between Fusarium head blight and crown rot disease incidence and cultural practices on wheat in the south of Iraq, Basra province

BackgroundThis study was conducted to estimate Fusarium head blight (FHB) and crown rot (FCR) disease incidence on wheat and their interaction with cultural methods (cultivar types, planting time, seed rate, crop rotation, and fertilizer practices) that are used in wheat cropping system in the south of Iraq, Basra province.ResultsThe results showed that the mean average of FHB and FCR was 27.2% and 31%, respectively. This displays that very nearly one-third of wheat crop planted in those 14 fields were infected by both diseases but not very severely, except in two fields (D and HM), which were devastating, 54% and 71% and 41% and 52% for FHB and FCR, respectively. The highest level of incidence for both diseases was associated with the earlier and latest planting dates 28 Oct. and 10 Dec., while the lowest was with 1, 10, and 23 Nov. A 200 and 120 kg/ha were the highest and lowest seed rates used in this study. The selected wheat fields differed in their pre-crop rotations (legume, corn, sorghum, okra, and continuous cropping system of wheat) in a previous year. The amount of added fertilizers (urea, DAP, and NPK) to the studied fields was in a high variation. The seven wheat cultivars examined in this study showed different levels of susceptibility to both diseases.ConclusionThe results verified that most of the agricultural practices examined in this study were associated with positive correlation for FHB and FCR in the occurrence of disease incidence. Except the cultivar type and fertilizer application had unclear relationship with the incidence of both diseases.

Identification and Characterization of Gonatobotryum apiculatum Causing Leaf Spot and Blight on Sinowilsonia henryi

Sinowilsonia henryi is a rare and endangered plant, as well as an endemic species in China. In July 2018, leaf spot and blight disease was observed on S. henryi in Yichang, Hubei, China. A fungus isolated from disease tissues was identified as Gonatobotryum apiculatum based on morphology and sequence analyses of ITS and LSU regions. Phylogenetic analyses indicated that the species belongs to Dothioraceae (Dothideales). Morphologically, the species produced two distinct types of conidia from authentic media, both conidia were described here. Pathogenicity tests showed that the fungus is a pathogen causing leaf spots on S. henryi. This is the first report of leaf spot and blight disease on S. henryi caused by G. apiculatum in China.

Double Line Clustering based Colour Image Segmentation Technique for Plant Disease Detection.

Agriculture is one of the most essential industry that fullfills people's need and also plays an important role in economic evolution of the nation. However, there is a gap between the agriculture sector and the technological industry and the agriculture plants are mostly affected by diseases, such as the bacterial, fungus and viral diseases that lead to loss in crop yield. The affected parts of the plants need to be identified at the beginning stage to eliminate the huge loss in productivity. In the present scenario, crop cultivation system depend on the farmers experience and the man power, but it consumes more time and increases error rate. To overcome this issue, the proposed system introduces the Double Line Clustering technique based disease identification system using the image processing and data mining methods. The introduced method analyze the Anthracnose, blight disease in grapes, tomato and cucumber. The leaf images are captured and the noise has been removed by non-local median filter and the segmentation is done by double line clustering method. The segmented part compared with diseased leaf using pattern matching algorithm. The efficiency of the system is implemented in tomato, grape, cucumber plants leaf images and the results are analyzed in terms of the error rate, sensitivity, specificity, accuracy and time. The result of the clustering algorithm achieved high accuracy, sensitivity, and specificity. The feature extraction is applied after the clustering process which produces minimum error rate.

Heat stress transcription factor OsSPL7 plays a critical role in reactive oxygen species balance and stress responses in rice

The rice spotted leaf gene, OsSPL7, induces lesion mimic (LM) spots under heat stress. Herein, we provide several lines of evidence elucidating the importance of OsSPL7 in maintaining reactive oxygen species (ROS) balance via the regulation of downstream gene expression. osspl7 knockout (spl7ko) mutants showed LM and growth retardation. Transgenic rice lines strongly overexpressing OsSPL7 (SPL7OX-S) exhibited LM accompanied by accumulated H2O2, whereas moderate expressers of OsSPL7 (SPL7OX-M) did not, and neither of them exhibited severe growth defects. Transient expression of OsSPL7-GFP in rice protoplasts indicated that OsSPL7 localizes predominantly in the nucleus. Transcriptional activity assay suggested its function as a transcriptional activator in rice. Disease evaluation showed that both SPL7OX and spl7ko enhanced resistance to Magnaporthe oryzae and Xanthomonas oryzae pv. oryzae, the causal agents of blast and blight diseases in rice, respectively. Additionally, SPL7OX enhanced tolerance to cold stress, whereas spl7ko showed a phenotype opposite to the overexpression lines. RNA sequencing analyses identified four major groups of differentially expressed genes associated with LM, pathogen resistance, LM-pathogen resistance, and potential direct targets of OsSPL7. Collectively, our results suggest that OsSPL7 plays a critical role in plant growth and balancing ROS during biotic and abiotic stress.