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Fruits and vegetables play very important role in our day-to-day life because of their nutrition parameters. In recent years organic cultivation is more popular as there is more demand for organic fruits and vegetables. Due to very high nutrition benefits and considering the easily availability of banana, it is most demandable and afforded by common man. Consumer decides the quality of banana based on their physical characteristics. Simple experiment was carried out to study and analyse physical properties, nutritional properties of two varieties of banana Cavendish Banana and Velchi banana. The study shows that the colour of banana changes gradually from dark green to yellow with brown spots which increases in ripeness. The banana weight goes on reducing with ripening days. The 21.83% and 9.8% reduction weight is observed in Cavendish and Velchi Banana respectively. The pulp to peel ratio increases with increase in ripening. Ratio varied from 1.69 to 1.77 for cavendish and 3.2 to 4.8 for Velchi. The pH value goes on increasing during the ripening days whereas once fruit is overripe it starts decreasing. The pH value varies from 4.2 to 5.4. Total Soluble Sugar gradually increases till banana becomes overripe. TSS varies from 4.5 to 26.7. The majority characteristics used for grading are colour, pulp to peel ratio, TSS and pH. This paper represents the analysis of Cavendish banana and Velchi banana based on colour, TSS and pH. The study shows TSS goes on increasing with ripening whereas pH decreases once banana overripe. [ABSTRACT FROM AUTHOR]

In India about 70% of population rely on yield from agriculture. The plants, leaves have been affected by the disease caused by insects that transfers the infection to other plants in agriculture. During the infection of these diseases the production has been decreased in the farm. Therefore it is necessary to identify these infections at the earliest. The disease detection in banana has turned out be more perplexing in the farm. The banana plant disease detection through image processing becomes more efficient also it is highly essential for farmers in evaluating the plant growth without any manual support economically. This paper proposed leaf disease detection by feature extraction using GLCM and Deep convoluted neural network (DCNN) based classification. The dataset has been collected based on pre-historic dataset of cultivation field and this data has been processed. The features have been extracted using GLCM and the image has been classified using DCNN. Then finally the disease affected area has been identified by extracting features and this feature has been classified for enhancing the accuracy of detecting the disease so we use GLCM-DCNN. Then the simulation results shows the accuracy, recall, precision and f-1 score as the parameters of proposed method. This technique will detect the disease early and helps the farmer to induce pesticides to avoid spreading of disease. [ABSTRACT FROM AUTHOR]

Abstract: Electron microscopy of leaf samples displaying streak symptoms from enset (Ensete ventricosum), a banana‐like plant widely cultivated in Ethiopia, showed the presence of bacilliform shaped virions as known for badnaviruses. DNA extracts subjected to rolling circle amplification (RCA), polymerase chain reaction (PCR) and cloning and sequence analysis revealed that the virus has a circular double‐stranded DNA genome of 7,163 nucleotides encoding predicted proteins of 21.5 kDa, 14.5 kDa and 202.5 kDa, a genome organization known for badnaviruses. The virus is phylogenetically most closely related to Sugarcane bacilliform Guadeloupe D virus with a nucleotide sequence identity of 77.2% at the conserved RT/RNase‐H region and 73.6% for the whole genome. Following the current species demarcation criteria, the virus should be considered as an isolate of a new species in the genus Badnavirus for which the name Enset leaf streak virus (ELSV) is suggested. Leaf samples from enset and banana were screened using virus‐specific primers, and ELSV was detected in six of 40 enset but not found in any of 61 banana samples. On the other hand, Banana streak OL virus (BSOLV) was detected from the majority (60%) of symptomatic banana samples but not from enset samples. This paper reports the first full‐genome sequence of a putative new badnavirus species infecting plants in the genus Ensete. In addition, this is the first report of the occurrence of BSOLV in Ethiopia. [ABSTRACT FROM AUTHOR]

It is observed that banana production is affected by numerous diseases and causes a large loss to the poor farmers. By using modern image processing technology and deep learning methods, these diseases can be found at an earlier stage and appropriate precautions can be taken at time to avoid more injury and increase banana production. In this paper, a novel banana disease recognition method is proposed. First, a banana leaf feature enhancement framework is designed to enhance the banana features under the complex environment. Then, a novel neural network, EM-ERNet, is designed based on the Resnet backbone architecture. In the EM-ERNet, dilated convolution and multi-scale convolution are combined to improve the ability of feature extraction. Batch normalization is used to prevent the network over-fitting and enhance the model robustness. The ELM algorithm optimized by particle swarm (PELM) is used to speed up the fusion network in the final fully connected layer. The experiment was conducted on the public banana disease detection database. The highest detection accuracy for crown rot, venturia, scorch rot, anthrax and normal bananas could reach 94.27, 93.36, 89.39, 88.87 and 96.39% respectively, which was better than the existing related competitors. In addition, ResNet50 takes 80 min to identify, while EM-ERNet only takes 60 min. We can see that our method improves the parameters by a quarter. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Pathology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Periodical survey on pest scenario of banana crop in the state of Odisha revealed that banana scarring beetle, Nodostoma subcostatum (Jacoby) has emerged as key pest in the region. Almost all the plantations surveyed had infestation at varying levels. The highest population and the highest damage were recorded in rainy season, though populations were recorded in other months too. The infested fruits lost marketability in case of complete damage or fetched very low market price. Farmers were unaware about the pest and its method of management. Present paper highlights the severity, seasonality and behavior of this beetle pest on banana, in odisha. [ABSTRACT FROM AUTHOR]

Bananas are one among the world's leading food crops after rice, wheat and maize. Banana cultivation is affected by various diseases. Among them, in globally banana bunchy top disease (BBTD) caused by the banana bunchy top virus (BBTV) and Fusarium wilt caused by the Fusarium oxysporum f.sp. cubense are the most serious diseases. BBTV is an isometric virus with a circular single stranded DNA (ssDNA) genome consisting of at least six components, BBTV DNA-1 to 6. The virus is transmitted by the banana aphid (Pentalonia nigronervosa). In this review paper, we are discussing the global status of BBTD, symptom expression in both vegetative and reproductive stage, resistant strategy and recent BBTV resistant banana clones development. [ABSTRACT FROM AUTHOR]

Fungal disease epidemics have the potential to bring about drastic innovations. However, in the case of the Black Sigatoka ( Mycosphaerella fijiensis) fungus in bananas, producers and international traders are still awaiting a breakthrough in crop protection research. Using the cases of Brazil and Colombia, this paper examines different agricultural research responses to the disease. Brazil opted to replace susceptible varieties with resistant ones, whereas in Colombia chemical control by private actors dominated. We argue that these different responses result from at least three interrelated factors. First, producer type-smallholder farmers or larger export-oriented plantations-influences the setting of crop protection research priorities. Second, a central, state-led role versus a private sector response influences the size and time perspective of research activities. Third, domestic markets with multiple crop varieties versus Cavendish-only export markets leads to differences in control practices and research responses. From this case study, we argue that the currently proposed innovation systems approaches in international agricultural research should adopt a broader perspective that assesses how research is interwoven with agrarian dynamics, commodity chains and particular state roles to elucidate how state-producer-researcher networks perform disease control and where and how to find new solutions. [ABSTRACT FROM AUTHOR]

Argentina's banana production is exclusively destined for domestic consumption and can be used to illustrate management deficiencies in production and post-harvest stages. Banana fruits are very sensitive to injuries and thrips (Thysanoptera) damage results in loss of commercial value. The aim of this work was to study the effects of bagging and its association with "deschire" (manual removal of male floral structures) in relation to the incidence of thrips on the flowering and fruiting of banana (Musa acuminata Colla). The study was carried out during 2010-2011 and 2011-2012 in Laguna Naineck (Formosa, Argentina). Randomized Complete Block Design (RCBD) with four treatments and four replicates was used during two production cycles. The abundance of the insects was determined in three strata of banana bunches and the incidence was estimated at harvest. The only species of thrips present during the study was Frankliniella brevicaulis Hood. A higher number young thrips were detected in the lower strata of bunches. Bagging of the banana bunches with deschire reduced the incidence of F. brevicaulis by 54% and 66% each year of study respectively and favored an increase in the length of the fingers compared to a control crop, in 9% and 10%for the first and second year of study respectively. [ABSTRACT FROM AUTHOR]

Globally, crop diseases result in significant losses in crop yields. To properly target interventions to control crop diseases, it is important to map diseases at a high resolution. However, many surveys of crop diseases pose challenges to mapping because available observations are only proxies of the actual disease, observations often are not normally distributed and because typically convenience sampling is applied, leading to spatially clustered observations and large areas without observations. This paper addresses these challenges by applying a geostatistical methodology for disease incidence mapping. The methodology is illustrated for the case of bacterial wilt of banana (BWB) caused by Xanthomonas campestris pv. musacearum in the East African highlands. In a survey using convenience sampling, 1350 banana producing farmers were asked to estimate the percentage yield loss due to bacterial wilt. To deal with the non-normal distribution of the data, the percentages were classified into two binary variables, indicating whether or not the disease occurred and whether or not the yield loss was severe. To improve the spatial prediction of disease incidence in areas with low sampling density, the target variables were correlated in a logistic regression to a range of environmental variables, for which maps were available. Subsequently, the residuals of the regression analysis were interpolated using simple kriging. Finally, the interpolated residuals were added to the regression predictions. This so-called indicator regression kriging approach resulted in continuous maps of disease incidence. Cross-validation showed that the method yields unbiased predictions and correctly assesses the prediction accuracy. The geostatistical mapping is also more accurate than conventional mapping, which uses the mean of observations within districts as the predicted value for all locations within the district, although the accuracy improvement is not very large. The maps were also spatially aggregated to district level to support regional decision-making. The analysis showed that the disease is widespread on banana farms throughout the study area and can locally reach severe levels. [ABSTRACT FROM AUTHOR]

A survey of small-holder banana farms was undertaken in February/March 2019 in Savannakhet, Salavan, Sekong and Champasak provinces in southern Lao People's Democratic Republic (Lao PDR) to establish which banana leaf pathogens were present. Twenty-five farms were visited, seven different cultivars were assessed, and 13 leaf samples with characteristic symptoms of banana freckle disease collected. Phyllosticta musarum was detected on the variety 'Kuay Nam' in each of the four provinces surveyed. Phyllosticta cavendishii was detected in Salavan, Sekong and Champasak. Phyllosticta musaechinesis was recorded from Champasak. This is the first time these three species have been recorded associated with banana freckle disease in the Lao PDR. [ABSTRACT FROM AUTHOR]

Fusarium oxysporum f.sp. cubense, causal agent of Panama disease, is one of the biggest threats to global banana production, particularly the Cavendish competent tropical race 4 (Foc TR4). It continues to spread globally with detections occurring in regions of the Middle East and new continents such as Africa and South America in the last decade. As the search was on for new management strategies and resistant cultivars to combat the disease, a banana cultivar-screening trial took place in the Northern Territory of Australia, which examined the responses of 24 banana cultivars to the soil borne fungus. These cultivars included material from TBRI, FHIA and selections from Thailand, Indonesia and Australia and evaluated for their resistance to tropical race 4 for two cropping cycles. Several cultivars displayed considerable resistance to Foc TR4, including several FHIA parental lines and hybrids, the Cavendish (AAA) selections GCTCV 215 and GCTCV 247 from TBRI and an Indonesian selection CJ19 showed either very little to no plant death due to the disease. [ABSTRACT FROM AUTHOR]

Fusarium wilt caused by the soil-borne fungus Fusarium oxysporum f.sp. cubense (Foc) is a significant constraint to banana production worldwide, with the recent expansion of banana growing regions impacted by Foc Tropical Race 4 (TR4). The lack of commercially acceptable Cavendish cultivars with Foc resistance means the only current means of effective control is through strict quarantine and inoculum management. One method of control that is currently advocated includes the removal of infected plants which have been killed using herbicide injections. The aim of this work was to examine the effect of herbicide and fungicide treatments on sporulation of the fungus. In glasshouse studies using a green fluorescent transformed Foc Subtropical Race 4 isolate, we found treatments with herbicide hastened colonisation of the banana tissue and the production of micro- and macroconidia. The use of a fungicide did not prevent sporulation of the fungus in such tissue. This study demonstrates that herbicide treated plants are a source of potential inoculum for infection of nearby plants. [ABSTRACT FROM AUTHOR]

Bananas are vital for food security in many countries, and half of banana production relies solely on 'Cavendish' (AAA), which is presently threatened by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc) tropical race 4. This particular virulent Foc strain was also found to attack other banana varieties of commercial importance. As there is no single effective management practice available so far, this study was undertaken to determine resistant sources from the genotype collection available at the ICAR-National Research Centre for Banana, Tiruchirappalli, Tamil Nadu, India for direct use by farmers and/or in breeding programmes to develop resistant hybrids. A total of 258 genotypes of different ploidies and genomic constitutions were tested against Foc race 1 (VCG 0124). In total, 19 genotypes (AA Unique-6, BB type-2, AAA Unique-1, AAA Cavendish-1, AAB Mysore-3, AAB Pome-1, AAB Plantain-4 and AAAB-1) were found to be immune; eight genotypes (AA Unique-1, BB type-3, AAA Cavendish-1, AAB Mysore-1, AAB Unique-1, AAB Plantain-1) were highly resistant; and nine genotypes (AA Unique-1, AAA Cavendish-3, AAB Silk-1, AAB Pome-4) were resistant. The genotypes that are resistant to the virulent Foc race 1 (VCG 0124) strain can be exploited directly for commercialization and/or in breeding programs to develop resistant hybrids. [ABSTRACT FROM AUTHOR]

Copyright of Espirales Revista Multidisciplinaria de Investigación is the property of Grupo Compas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phyllosticta cavendishii has been recorded in the Northern Territory (NT) of Australia occurring on non‐Cavendish bananas since 1991. The race of P. cavendishii that infects Cavendish bananas is considered exotic to Australia and classified as an emergency plant pest. In July 2013, P. cavendishii was detected on Cavendish bananas near Darwin, NT. Here, the diagnoses and field observations carried out during the Incident Definition Phase of the national biosecurity response, from July 2013 to October 2014, are reported. Of 1395 banana samples collected from 676 properties, 480 were positive for freckle disease, including 463 samples with P. cavendishii and 17 samples with P. maculata. Phyllosticta cavendishii was detected in 256 properties, including 62 properties where it was detected on Cavendish banana plants, within six distinct geographical zones across the NT. Phyllosticta cavendishii was detected on two cultivars within the Cavendish subgroup and six non‐Cavendish cultivars. Multigene characterization of Phyllosticta cultures showed that P. cavendishii was isolated from both Cavendish and non‐Cavendish cultivars. Multilocus phylogeny analyses also revealed that the P. cavendishii strain in the outbreak had identical sequence similarity to the holotype (CBS H‐20918) clade 2 P. cavendishii isolates that infect both Cavendish and non‐Cavendish cultivars in Southeast Asia and Oceania. The genetic data in this study showed that there was one P. cavendishii strain infecting both Cavendish and non‐Cavendish cultivars in the outbreak. However, historical data and field observations provided anecdotal evidence for the existence of two races of P. cavendishii, including one that does not infect Cavendish bananas. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Pathology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vegetatively propagated crops suffer from yield loss and reduced stand density and longevity caused by the build‐up of certain pests and pathogens between successive plantings via infected planting material. Here, six seedborne phytosanitary problems of banana are reviewed to evaluate whether a seed degeneration framework is a useful tool to identify approaches to achieve healthier planting materials. Phytoparasitic nematodes and weevils generate gradual declines in yields and in sucker health. Fusarium wilt and banana bunchy top virus cause progressive mat collapse across the field. Symptomless suckers from any mat in infested fields represent a risk of transmitting the disease to a new field. Xanthomonas and ralstonia wilts, due to incomplete systemicity, are intermediate in their threat to yield loss and frequency of transmission in suckers. Losses to banana streak virus are triggered by abiotic stress, although sucker transmission of episomal banana streak virus also contributes. A qualitative equation described here for seed degeneration covers a cycle beginning with the quality and risk factors of the planting material used to plant a new field and ends with the quality and risk factors of the suckers extracted from the field to plant a new field. This review of five planting material multiplication methods commonly used in banana contrasts their differing usefulness to address seed degeneration in the small farm context. It is proposed that initiatives to offset banana seed degeneration should integrate the role of off‐farm actors into decentralized initiatives rather than attempt to duplicate national seed certification frameworks from other true seed or vegetatively propagated crops. [ABSTRACT FROM AUTHOR]

Fusarium wilt, caused by the fungus Fusarium oxysporum f.sp. cubense (Foc), is one of the most important and destructive diseases in banana crops worldwide. There have been numerous studies into the infection process of this soil-borne pathogen; however, the extent of research into the movement of the pathogen through the rhizome and into the rest of the plant is limited. Furthermore, little is known about the movement of the pathogen once it reaches the aerial components of the plant. A strain of Foc sub-tropical race 4, genetically transformed with green fluorescent protein (GFP) gene, was used to monitor the movement of the pathogen through two susceptible cultivars, Cavendish 'Williams' (Musa AAA) and Lady Finger (Musa AAB). Visualization of the pathogen in planta demonstrated its presence in the roots, the rhizome and in the outer leaf sheaths of the pseudostem prior to the appearance of external symptoms. Within the non-senescing leaf sheaths, the migration of Foc was confined to the xylem vessels; this included those where the vascular tissue was visibly discolored, as well as those, which were apparently healthy. As senescence of leaf sheaths occurred, chlamydospores developed within the gas spaces, while formation of sporodochia, and hyphal growth were apparent on the outer surface of senescing leaf sheaths. These results generate a greater understanding of the epidemiology of Foc , providing much needed knowledge to assist in the future management of Fusarium wilt incursions, as well as enhancing protocols for ongoing on-farm hygiene and biosecurity. [ABSTRACT FROM AUTHOR]

Banana is the most popular and most exported fruit and also a major food crop for millions of people around the world. Despite its importance and the presence of serious disease threats, research into this crop is limited. One of those is Panama disease or Fusarium wilt. In the previous century Fusarium wilt wiped out the "Gros Michel" based banana industry in Central America. The epidemic was eventually quenched by planting "Cavendish" bananas. However, 50 years ago the disease recurred, but now on "Cavendish" bananas. Since then the disease has spread across South-East Asia, to the Middle-East and the Indian subcontinent and leaped into Africa. Here, we report the presence of Fusariumoxysporumf.sp. cubense Tropical Race 4 (Foc TR4) in "Cavendish" plantations in Laos, Myanmar, and Vietnam. A combination of classical morphology, DNA sequencing, and phenotyping assays revealed a very close relationship between the Foc TR4 strains in the entire Greater Mekong Subregion (GMS), which is increasingly prone to intensive banana production. Analyses of single-nucleotide polymorphisms enabled us to initiate a phylogeography of Foc TR4 across three geographical areas--GMS, Indian subcontinent, and the Middle East revealing three distinct Foc TR4 sub-lineages. Collectively, our data place these new incursions in a broader agroecological context and underscore the need for awareness campaigns and the implementation of validated quarantine measures to prevent further international dissemination of Foc TR4. [ABSTRACT FROM AUTHOR]

Fusarium wilt is one of the most devastating diseases on banana. The causal agent, Fusarium oxysporum f. sp. cubense (Foc) is genetically diverse and its origin and virulence are poorly understood. In this study, pathogenic Foc isolates and nonpathogenic F. oxysporum isolates from Minas Gerais in Brazil were compared using EF‐1α and IGS sequences. This allowed the examination of the origin and evolutionary potential of Foc in a country outside the region of origin of the banana plant. Two different sequence types were found among Foc isolates. One appeared to be of local origin because it was identical to the sequence type of the largest group of nonpathogenic isolates. To explore if the ‘local’ Foc isolates had acquired pathogenicity either independently through coevolution with the host, or through horizontal gene transfer (HGT) of pathogenicity genes from other, probably introduced, Foc isolates, the presence and sequence of putative SIX effector genes were analysed. Homologues of SIX1, SIX3 and SIX8 were found. SIX1 sequences were identical and exclusively found in all pathogenic isolates, while variable ratios of sequences of multicopy gene SIX8 were found among nonpathogenic and different pathogenic isolates. This observation supports the HGT hypothesis. Horizontal transfer of genes between isolates of F. oxysporum has important implications for the development of reliable diagnostic tools and effective control measures. Full genome sequencing is required to confirm HGT and to further unravel the virulence mechanisms of forma specialis cubense. [ABSTRACT FROM AUTHOR]

Silk Banana is amongst the most popular groups of bananas grown in different parts of the world. However, the commercial scale cultivation requires identification of superior genotypes with desirable attributes including growth, yield, quality and resistance to Panama wilt disease which is a major concern. Panama disease caused by the fungus Fusarium oxysporum f. sp. cubense has been wreaking havoc in banana plantations throughout the world. A large number of varieties fall prey to the pathogen and hence world’s banana production has been threatened to a considerable extent, Silk Banana being the most vulnerable. Long term use of chemicals has not only failed to provide protection against the disease but has also raised concern about the environmental health. Resistance breeding is thus only viable alternative; however, breeding in banana is hindered by a number of inherent problems. In this communication, a systematic approach was proposed taking a typical case of Silk Banana var. Nanjanagud Rasabale to preselect lines possessing Panama wilt resistance and other desired traits. The proposed methodology comprised of identification of spontaneous variants in growing regions of the variety and their subsequent screening using a multi-pronged strategy. A number of lines exhibiting superiority in terms of tolerance to panama wilt, precocity, plant stature, physicochemical and shelf life related attributes have been reported. Considering overall performance, six promising lines were identified. This methodology has wider applicability as it could be effectively exploited with suitable modifications for identifying lines with desired traits in other varieties of banana. [ABSTRACT FROM AUTHOR]

In 2016, in Miyakojima, Okinawa, Japan, banana plants (Musa × paradisiaca) ‘Shima-banana’ developed yellowing and wilt associated with vascular discoloration of the pseudostems. Fusarium oxysporum, identified based on morphological characters, was frequently isolated from the vascular tissue of the infected plant and reproduced the original symptoms on ‘Shima-banana’ after drench inoculation with a spore suspension. Thereby, we determined that the disease is Panama disease caused by F. oxysporum. This is the first official report of Panama disease (Panama-byo in Japanese) of banana in Japan. [ABSTRACT FROM AUTHOR]

Banana Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is one of the most destructive soil-borne diseases. In this study, young tissue-cultured plantlets of banana (Musa spp. AAA) cultivars differing in Foc susceptibility were used to reveal their differential responses to this pathogen using digital gene expression (DGE). Data were evaluated by various bioinformatic tools (Venn diagrams, gene ontology (GO) annotation and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses) and immunofluorescence labelling method to support the identification of gene candidates determining the resistance of banana against Foc. Interestingly, we have identified MaWRKY50 as an important gene involved in both constitutive and induced resistance. We also identified new genes involved in the resistance of banana to Foc, including several other transcription factors (TFs), pathogenesis-related (PR) genes and some genes related to the plant cell wall biosynthesis or degradation (e.g., pectinesterases, β -glucosidases, xyloglucan endotransglucosylase/hydrolase and endoglucanase). The resistant banana cultivar shows activation of PR-3 and PR-4 genes as well as formation of different constitutive cell barriers to restrict spreading of the pathogen. These data suggest new mechanisms of banana resistance to Foc. [ABSTRACT FROM AUTHOR]

The banana root borer [Cosmopolites sordidus Germar (Coleoptera: Curculionidae)] is the most harmful insect pest currently affecting organic banana plantations in Mexico. The use of entomopathogenic fungi to control C. sordidus populations is a biological control method that presents a promising alternative to conventional means. This study aimed to evaluate the virulence of native isolates of entomopathogenic fungi Cordyceps bassiana and Metarhizium anisopliae against C. sordidus adults under laboratory and field conditions. In laboratory assays, 12 isolates of C. bassiana and nine isolates of M. anisopliae were tested. In field trials, Cb174 (C. bassiana) and Ma148 (M. anisopliae) isolates and their co-application were evaluated. Cordyceps bassiana isolates Cb171 and Cb174 resulted in adult mortalities of 80.2 and 77.5% and had the lowest median lethal concentrations (LC50) of 6.4 × 106 and 5.4 × 106 conidia mL-1, respectively. Regarding the median lethal time (TL50), the most virulent isolates of C. bassiana were Cb171 and Cb190 with 9.49 and 9.55 days, respectively. For M. anisopliae, the Ma148 isolate was the most virulent (LC50 = 8.6 × 10 conidia mL- and LT50 = 12.61 days) and led to an adult mortality of 76.9%. In field trials, two tested isolates (C. bassiana Cb174 and M. anisopliae Ma148) were both able to reduce C. sordidus populations by 48.5% and their co-application by 38.1%. Percentage of mycosis in captured adults was over 50% for the entire evaluation period (1.6 months), which confirms the efficacy of entomopathogenic fungi. Both Cb174 and Ma148 are good candidates for developing formulated products to use in the integrated pest management of C. sordidus in Mexican organic banana plantations. [ABSTRACT FROM AUTHOR]

An actinomycete strain, CB-75, was isolated from the soil of a diseased banana plantation in Hainan, China. Based on phenotypic and molecular characteristics, and 99.93% sequence similarity with Streptomyces spectabilis NBRC 13424 (AB184393), the strain was identified as Streptomyces sp. This strain exhibited broad-spectrum antifungal activity against 11 plant pathogenic fungi. Type I polyketide synthase (PKS-I) and non-ribosomal peptide synthetase (NRPS) were detected, which were indicative of the antifungal compounds that Streptomyces sp. CB-75 could produce. An ethyl acetate extract from the strain exhibited the lowest minimum inhibitory concentration (MIC) against Colletotrichum musae (ATCC 96167) (0.78µg/ml) and yielded the highest antifungal activity against Colletotrichum gloeosporioides (ATCC 16330) (50.0µg/ml). Also, spore germination was significantly inhibited by the crude extract. After treatment with the crude extract of Streptomyces sp. CB-75 at the concentration 2 x MIC, the pathogenic fungi showed deformation, shrinkage, collapse, and tortuosity when observed by scanning electron microscopy (SEM). By gas chromatography-mass spectrometry (GC-MS) of the crude extract, 18 chemical constituents were identified; (Z)-13-docosenamide was the major constituent. Pot experiments showed that the incidence of banana seedlings was reduced after using Streptomyces sp. CB-75 treatment. The disease index was 10.23, and the prevention and control effect was 83.12%. Furthermore, Streptomyces sp. CB-75 had a growth-promoting effect on banana plants. The chlorophyll content showed 88.24% improvement, the leaf area, root length, root diameter, plant height, and stem showed 88.24, 90.49, 136.17, 61.78, and 50.98% improvement, respectively, and the shoot fresh weight, root fresh weight, shoot dry weight, and root dry weight showed 82.38, 72.01, 195.33, and 113.33% improvement, respectively, compared with treatment of fermentation broth without Streptomyces sp. CB-75. Thus, Streptomyces sp. CB-75 is an important microbial resource as a biological control against plant pathogenic fungi and for promoting banana growth. [ABSTRACT FROM AUTHOR]

Crown rot disease of Banana is adversely affecting the quantity and quality of the fruits for consumption and utilization. The bananas collected from the local markets of Hyderabad, Tando Allahyar and Quetta were found suffered with different types of rots such as crown rot, anthracnose, fruit rot and stem end rot. Among them crown rot of banana was found predominantly followed by anthracnose and other fruit rots. Incidence and severity varied with the markets and locations. Fusarium semitectum found predominately associated with the affected fruits showing crown rot symptoms. So, yeast (Saccharomyces cerevisiae) were evaluated against F. semitectum under in-vitro conditions. S. cerevisiae also tested against crown rot disease development of banana fruit inoculated with F. semitectum. The addition of Saccharomyces cerevisiae in the culture medium has brought 93% reduction in the growth of F. semitectum. yeast was also tested against crown rot disease development on banana fruits by direct contact method. Yeast treatment brought more than 40% reduction in crown rot disease development as compared to the untreated fruits. The present study indicates that active yeast has the potential to manage harmful plant pathogens and thus could provide an alternate, reliable and eco-friendly control of crown rot disease. [ABSTRACT FROM AUTHOR]

Aims The aims of this study were to identify the Fusarium isolates based on translation elongation factor ( tef) 1 α sequence, to determine the genetic diversity among isolates and species using selected microsatellite markers and to examine the pathogenicity of Fusarium isolates causing fruit rot disease of banana. Methods and Results One-hundred and thirteen microfungi isolates were obtained from fruit rot infected banana in Peninsular Malaysia. However, this study was focused on the dominant number of the discovered microfungi that belongs to the genus Fusarium; 48 isolates of the microfungi have been identified belonging to 11 species of Fusarium, namely Fusarium incarnatum, Fusarium equiseti, Fusarium camptoceras, Fusarium solani, Fusarium concolor, Fusarium oxysporum, Fusarium proliferatum, Fusarium verticillioides, Fusarium sacchari, Fusarium concentricum and Fusarium fujikuroi. All Fusarium isolates were grouped into their respective clades indicating their similarities and differences in genetic diversity among isolates. Out of 48 Fusarium isolates tested, 42 isolates caused the fruit rot symptom at different levels of severity based on Disease Severity Index ( DSI). The most virulent isolate was F. proliferatum B2433B with DSI of 100%. Conclusions All the isolated Fusarium species were successfully identified and some of them were confirmed as the causal agents of pre- and postharvest fruit rot in banana across Peninsular Malaysia. Significance and Impact of the Study Our results will provide additional information regarding new report of Fusarium species in causing banana fruit rot and in the search of potential biocontrol agent of the disease. [ABSTRACT FROM AUTHOR]

Fusarium proliferatumis an important pathogen and causes a great economic loss to fruit industry. Environmental pH-value plays a regulatory role in fungi pathogenicity, however, the mechanism needs further exploration. In this study, F. proliferatum was cultured under two initial pH conditions of 5 and 10. No obvious difference was observed in the growth rate of F. proliferatum between two pH-values. F. proliferatum cultured under both pH conditions infected banana fruit successfully, and smaller lesion diameter was presented on banana fruit inoculated with pH 10-cultured fungi. Proteomic approach based on two-dimensional electrophoresis (2-DE) was used to investigate the changes in secretome of this fungus between pH 5 and 10. A total of 39 differential spots were identified using matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Compared to pH 5 condition, proteins related to cell wall degrading enzymes (CWDEs) and proteolysis were significantly down-regulated at pH 10, while proteins related to oxidation-reduction process and transport were significantly up-regulated under pH 10 condition. Our results suggested that the downregulation of CWDEs and other virulence proteins in the pH 10-cultured F. proliferatum severely decreased its pathogenicity, compared to pH 5-cultured fungi. However, the alkaline environment did not cause a complete loss of the pathogenic ability of F. proliferatum, probably due to the upregulation of the oxidation-reduction related proteins at pH 10, which may partially compensate its pathogenic ability. [ABSTRACT FROM AUTHOR]

The chemical mutagens have become important tool to enhance agronomic traits of banana crop. It is being used to develop fusarium resistant lines in various susceptible banana cultivars. There are several mutagens like EMS and NaN3 available for banana crop improvement and each mutagen has its own important role as positive or negative effects on growth and development of banana plants. Explants from shoot tip culture were treated with various EMS (0.30, 0.60, 0.90 and 0.12%) and NaN3 (0.01, 0.02 and 0.03%) concentrations. The putative mutants obtained after in vitro rooting were subjected for artificial inoculation of Fusarium oxysporum f. sp. cubense. Screening putative mutants resistance to Panama disease was carried out by using syringe method of inoculation. It was observed that EMS treated mutants were more susceptible compared to NaN3 treatment. Among the NaN3 doses, 0.01% was found to produce three resistant lines during preliminary screening under greenhouse conditions. [ABSTRACT FROM AUTHOR]

Banana is an important crop in the Kagera region of Tanzania. Banana xanthomonas wilt ( BXW) was first reported in Kagera in 2006, and is now an important limiting factor in banana production, because all cultivars are susceptible and infected plants can fail to produce fruit. BXW is caused by Xanthomonas campestris pv. musacearum (Xcm), which is spread by farm tools, infected planting materials, and pollinating insects. Practices that address Xcm dissemination, such as mat removal, debudding and tool sterilization, have not prevented the spread of BXW in the region. Disease surveys were conducted in Kagera from 2007 to 2011 to assess BXW presence, monitor its intensity and evaluate its socioeconomic impacts. Spatiotemporal clusters of BXW were analysed with Arc GIS and sas. The relationship between BXW clusters and environmental variables was examined using bivariate correlations in spss; two modelling approaches, MaxEnt (maximum entropy) and logistic regression, were used to predict the potential distribution of BXW in Tanzania. Disease progress over time was best described with the Gompertz model. Significant clustering of BXW was observed in all years and hotspots were located in the Muleba, Karagwe, Misenyi and Bukoba rural districts. These findings suggest that BXW spreads rapidly over short distances. BXW clusters were positively correlated with rainfall and negatively with temperature and altitude. According to MaxEnt, precipitation was the main factor associated with BXW development. MaxEnt and logistic regression predicted a wide potential distribution of BXW in Tanzania because the climate in all banana-growing regions is conducive for its establishment. [ABSTRACT FROM AUTHOR]

Bacterial diseases of bananas and enset have not received, until recently, an equal amount of attention compared to other major threats to banana production such as the fungal diseases black leaf streak (Mycosphaerella fijiensis) and Fusarium wilt (Fusarium oxysporum f. sp. cubense). However, bacteria cause significant impacts on bananas globally and management practices are not always well known or adopted by farmers. Bacterial diseases in bananas and enset can be divided into three groups: (1) Ralstoniaassociated diseases (Moko/Bugtok disease caused by Ralstonia solanacearum and banana blood disease caused by R. syzygii subsp. celebesensis); (2) Xanthomonas wilt of banana and enset, caused by Xanthomonas campestris pv. musacearum and (3) Erwinia-associated diseases (bacterial head rot or tip-over disease Erwinia carotovora ssp. carotovora and E. chrysanthemi), bacterial rhizome and pseudostem wet rot (Dickeya paradisiaca formerly E. chrysanthemi pv. paradisiaca). Other bacterial diseases of less widespread importance include: bacterial wilt of abaca, Javanese vascular wilt and bacterial fingertip rot (probably caused by Ralstonia spp., unconfirmed). This review describes global distribution, symptoms, pathogenic diversity, epidemiology and the state of the art for sustainable disease management of the major bacterial wilts currently affecting banana and enset. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study focusing on the implementation of a two-step process involving the pre-indexing and full indexing of viruses of the Musa germplasm, from 2007 to 2013. According to the article, the organization Bioversity International established a collection of banana germplasm, which contains more than 1,500 accessions of species of bananas, as a response to banana production threats such as diseases.

Sigatoka leaf streaks caused by Mycosphaerella spp. are the most destructive fungal diseases of bananas and plantains throughout the world. The disease is not well documented so far in Ethiopia though it is so calamitous in east and central Africa. Detailed assessment accompanied by infected samples collection for identification was carried out in farmers' fields, research plots and large-scale banana plantations. The results showed black Sigatoka leaf streak is causing extensive damage with pronounced incidence (>75%) and severity (>50%) in southwest Ethiopia. It is also common on enset ( Ensete ventricosum). Mycosphaerella fijiensis is largely identified from symptomatic banana leaves and confirmed with pathogenicity tests. The incidence and severity varied significantly ( P < 0.05) among banana varieties. Ducasse and Pisang Raja showed less severity (35 and 40%) than Grande Naine, Giant Cavendish and Poyo varieties (>60%). This is the first record of black Sigatoka leaf streak associated with Mycosphaerella fijiensis on banana and enset in Ethiopia, thus untiring efforts should be directed to manage Sigatoka disease in Ethiopia. [ABSTRACT FROM AUTHOR]

Black Sigatoka disease, caused by Pseudocercospora fijiensis is a serious constraint to banana production worldwide. The disease continues to spread in new ecological niches and there is an urgent need to develop strategies for its control. The high osmolarity glycerol (HOG) pathway in Saccharomyces cerevisiae is well known to respond to changes in external osmolarity. HOG pathway activation leads to phosphorylation, activation and nuclear transduction of the HOG1 mitogen-activated protein kinases (MAPKs). The activated HOG1 triggers several responses to osmotic stress, including up or down regulation of different genes, regulation of protein translation, adjustments to cell cycle progression and synthesis of osmolyte glycerol. This study investigated the role of the MAPK-encoding PfHog1 gene on osmotic stress adaptation and virulence of P. fijiensis. RNA interference-mediated gene silencing of PfHog1 significantly suppressed growth of P. fijiensis on potato dextrose agar media supplemented with 1 M NaCl, indicating that PfHog1 regulates osmotic stress. In addition, virulence of the PfHog1-silenced mutants of P. fijiensis on banana was significantly reduced, as observed from the low rates of necrosis and disease development on the infected leaves. Staining with lacto phenol cotton blue further confirmed the impaired mycelial growth of the PfHog1 in the infected leaf tissues, which was further confirmed with quantification of the fungal biomass using absolutequantitative PCR. Collectively, these findings demonstrate that PfHog1 plays a critical role in osmotic stress regulation and virulence of P. fijiensis on its host banana. Thus, PfHog1 could be an interesting target for the control of black Sigatoka disease in banana. [ABSTRACT FROM AUTHOR]

Banana is an important staple food crop feeding more than 100 million Africans, but is subject to severe productivity constraints due to a range of pests and diseases. Banana Xanthomonas wilt caused by Xanthomonas campestris pv. musacearum is capable of entirely destroying a plantation while nematodes can cause losses up to 50% and increase susceptibility to other pests and diseases. Development of improved varieties of banana is fundamental in order to tackle these challenges. However, the sterile nature of the crop and the lack of resistance in Musa germplasm make improvement by traditional breeding techniques either impossible or extremely slow. Recent developments using genetic engineering have begun to address these problems. Transgenic banana expressing sweet pepper Hrap and Pflp genes have demonstrated complete resistance against X. campestris pv. musacearum in the field. Transgenic plantains expressing a cysteine proteinase inhibitors and/or synthetic peptide showed enhanced resistance to a mixed species population of nematodes in the field. Here, we review the genetic engineering technologies which have potential to improve agriculture and food security in Africa. [ABSTRACT FROM AUTHOR]

Fusarium infection of bananas is a global problem that threatens the production of bananas. This study looks at the effects of the infection upon the reactive oxygen species ( ROS) system, as well as the induced antioxidant properties in the roots, stems, leaves and fruits. Results show that there is a greater amount of damage in infected tissue samples as opposed to non-infected. The damage was observed to be higher in the root samples. ROS assays were divided into two classes: ROS assays and ROS-scavenging assays. Of the ROS assays, lipoxygenase was observed to be higher in the infected samples, while peroxidase (POD) and polyphenol oxidase (PPO) were significantly higher in infected stem, leaf and fruit samples. Among root samples, there was no significant difference in POD activity and PPO was lower in infected samples. Induction of ROS is important for the hypersensitive response (HR) to function properly. The ROS-scavenging enzymes, namely ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase, exhibited higher levels in the infected tissue. This is most likely to counter the build-up of the ROS enzymes and to prevent further cell death. The increase in ROS-scavenging assays also correlates with higher antioxidant properties as antioxidants play a critical role in regulating the HR free radicals. [ABSTRACT FROM AUTHOR]

Members of Fusarium oxysporum species complex (FOSC) have been extensively studied because it causes many crop diseases and losses. This complex has more than 150 putatively plant host-specific formae speciales such as F. oxysporum f.sp. cubense (Foc), the aetiological agent of Fusarium wilt of banana, Panama disease. The objective of this study was to characterize isolates obtained from rhizomes of the latundan (apple) variety of banana showing symptoms of Panama disease using morphological markers, phylogenetic analyses of the TEF -1 α and pathogenicity tests. Isolates were harvested from the states of Minas Gerais (Foc GO2), Goiás (Foc GO1 and Foc GO2A) and Bahia (Foc 807). Morphological markers of isolates observed are in accordance with the original descriptions of the F. oxysporum. Foc isolates grouped into two different lineages, and one of these is a lineage not yet recorded. Aggressiveness was assessed by a rating scale of the symptoms displayed in the shoot, rhizome and conducting vessels in latundan banana trees. The results indicated that all isolates belong to F. oxysporum f.sp. cubense, race 1. Isolate Foc GO2A proved to be more aggressive than the others. The results generated in this study contribute to knowledge of lineages diversity within Foc. [ABSTRACT FROM AUTHOR]

Meloidogyne enterolobii is one of the most important root-knot nematode in tropical regions, due to its ability to overcome resistance mechanisms of a number of host plants. The lack of new and safe active ingredients against this nematode has restricted control alternatives for growers. Egg-parasitic fungi have been considered as potential candidates for the development of bionematicides. In tissue culture plates, Pochonia chlamydosporia (var. catenulata and chlamydosporia) and Purpureocillium lilacinum strains were screened for their ability to infect eggs of the root-knot nematode M. enterolobii on water-agar surfaces. Reduction in the hatching of J2 varied from 13% to 84%, depending on strain. The more efficacious strains reduced hatchability of J2 by 57% to 84% when compared to untreated eggs, but average reductions were only 37% to 55% when the same strains were applied to egg masses. Combinations of fungal isolates (one of each species) did not increase the control efficacy in vitro. In experiments in which 10,000 nematode eggs were inoculated per plant, reductions in the number of eggs after 12 months were seen in three of four treatments in banana plants, reaching 34% for P. chlamydosporia var. catenulata. No significant reductions were seen in tomato plants after 3 mon. In another experiment with tomato plants using either P. chlamydosporia var. catenulata or P. lilacinum, the number of eggs was reduced by 34% and 44%, respectively, when initial infestation level was low (500 nematode eggs per plant), but tested strains were not effective under a moderate infestation level (5,000 eggs per plant). Under all infestation levels tested in this work, gall and egg mass indexes (MI) did not differ from the untreated controls, bringing concerns related to the practical adoption of this control strategy by farmers. In our opinion, if the fungi P. chlamydosporia and P. lilacinum are to be used as biocontrol tools toward M. entorolobii, they should focus on agricultural settings with low soil infestation levels and within an IPM approach. [ABSTRACT FROM AUTHOR]

Banana bacterial sheath rot is a new disease causing significant economic losses in banana production in China. Pathogenic bacteria infect the middle and bottom parts of the leaf sheath and produce black and brown spots. These spots lead to folding and bending of the sheath, drooping of leaves, and eventual browning and rotting of the entire leaf sheath. In this work, twenty representative strains from five different provinces in China were confirmed by Koch's postulates, and two of them (XJ5-1 and XJ5-2) were characterized by morphological, physiological, biochemical, and molecular assays. Results showed that the strains were more similar to Dickeya dadantii and were less related to Dickeya paradisiaca and Dickeya zeae based on several phenotype characteristics. Phylogenetic analysis and comparison of strains from banana and Dickeya spp. were performed using concatenated partial sequences of the seven housekeeping genes dnaJ, dnaX, gyrB, recN, fusA, gyrA and recA1, indicating that the strains isolated from banana-sheath-rot tissues were closely related to D. dadantii and distinct from other Dickeya spp. Therefore, the banana pathogen was determined to be D. dadantii. This report is the first one on the banana-sheath-rot disease caused by D. dadantii in China. [ABSTRACT FROM AUTHOR]

Black Sigatoka or black leaf streak disease, caused by the Dothideomycete fungus Pseudocercospora fijiensis (previously: Mycosphaerella fijiensis), is the most significant foliar disease of banana worldwide. Due to the lack of effective host resistance, management of this disease requires frequent fungicide applications, which greatly increase the economic and environmental costs to produce banana. Weekly applications in most banana plantations lead to rapid evolution of fungicide-resistant strains within populations causing disease-control failures throughout the world. Given its extremely high economic importance, two strains of P. fijiensis were sequenced and assembled with the aid of a new genetic linkage map. The 74-Mb genome of P. fijiensis is massively expanded by LTR retrotransposons, making it the largest genome within the Dothideomycetes. Melting-curve assays suggest that the genomes of two closely related members of the Sigatoka disease complex, P. eumusae and P. musae, also are expanded. Electrophoretic karyotyping and analyses of molecular markers in P. fijiensis field populations showed chromosome-length polymorphisms and high genetic diversity. Genetic differentiation was also detected using neutral markers, suggesting strong selection with limited gene flow at the studied geographic scale. Frequencies of fungicide resistance in fungicide-treated plantations were much higher than those in untreated wild-type P. fijiensis populations. A homologue of the Cladosporium fulvum Avr4 effector, PfAvr4, was identified in the P. fijiensis genome. Infiltration of the purified PfAVR4 protein into leaves of the resistant banana variety Calcutta 4 resulted in a hypersensitive-like response. This result suggests that Calcutta 4 could carry an unknown resistance gene recognizing PfAVR4. Besides adding to our understanding of the overall Dothideomycete genome structures, the P. fijiensis genome will aid in developing fungicide treatment schedules to combat this pathogen and in improving the efficiency of banana breeding programs. [ABSTRACT FROM AUTHOR]

The author discusses the treatment of the sigatoka disease complex on the U.S. banana, fourth most important staple food in the world, which is caused by ascomycete fungus Pseudocercospora fijiensis. He mentioned topics including the cost of fungicide control, the socioeconomic impact, and the disease management.

Bananas and plantains are considered an important crop around the world. Banana production is affected by several constraints, of which Black Sigatoka Disease, caused by the fungus Mycosphaerella fijiensis, is considered one of the most important diseases in banana plantations. The banana accession ‘Calcutta-4’ has a natural resistance to Black Sigatoka; however, the fruit is not valuable for commercialization. Gene identification and expression studies in ‘Calcutta-4’ might reveal possible gene candidates for resistant to the disease and elucidate mechanisms for resistance. A subtracted cDNA library was generated from leaves after 6, 9 and 12 days inoculated with M. fijiensis conidia on greenhouse banana plants of the accession ‘Calcutta-4’. Bioinformatic analysis revealed 99 good quality sequences. Blast2go analysis revealed that 31% of the sequences could not be categorized and, according to the Biological Process Category, 32 and 28 ESTs are related to general metabolic and cellular processes, respectively; while 10 ESTs response to stimulus. Seven sequences were redundant and one was similar to genes that may be involved in pathogen resistance including the putative disease resistance protein RGA1. Genes encoding zinc finger domains were identified and may play an important role in pathogen resistance by inducing the expression of downstream genes. Expression analysis of four selected genes was performed using RT-qPCR during the early stage of the disease development at 6, 9, 12 and 15 days post inoculation showing a peak of up regulation at 9 or 12 days post inoculation. Three of the four genes showed an up-regulation of expression in ‘Calcutta-4’ when compared to ‘Williams’ after inoculation with M. fijiensis, suggesting a fine regulation of specific gene candidates that may lead to a resistance response. The genes identified in early responses in a plant-pathogen interaction may be relevant for the resistance response of ‘Calcutta-4’ to Black Sigatoka. Genes with different functions may play a role in plant response to the disease. The present study suggests a fine up regulation of these genes that might be needed to perform an incompatible interaction. Further gene functional studies need to be performed to validate their use as candidate resistance genes in susceptible banana cultivars. [ABSTRACT FROM AUTHOR]

Eumusae leaf spot disease, caused by Mycosphaerella eumusae, is widely distributed in different banana growing countries in Asia and Africa, causing severe losses in yield and quality of banana. The aim of this study was to identify the differentially expressed defense responsive genes through subtractive suppression hybridization (SSH) in the Musa-M. eumusae interaction system. In this method, leaf samples collected at different intervals between 0 and 72 h postinoculation (hpi) of M. eumusae from resistant (Manoranjitham- AAA) and susceptible (Grand Naine-AAA) cultivars were subjected to cDNA-SSH library construction. From the SSH library, 832 clones having the insert were selected and sequenced. All these sequences were assembled using CAP3, which resulted in 498 unigenes (59.85%), consisting of 78 contigs and 420 singletons. Furthermore, the BLAST2GO analysis performed showed that, out of the 498 unigenes, only 161 (32.32%) were involved in molecular functions, cellular component and biological processes. However, among these 161 unigenes, 57 were found to have top BLAST hits. Six genes were selected based on the function and subjected to validation through qPCR. Four genes, namely ethylene responsive factor, flavin containing monoxygenase, serine glyoxylate, and metallothionein, were found to have the highest-fold regulation in the resistant cultivar at 48 hpi, followed by lipoxygenase at 36 hpi. The main findings are that resistant plants deploy HR activity as a strategy to evade the fungus followed by the activation of various ROS scavengers to maintain homeostasis and the role of phytohormones may be induced as a part of plant defense against M. eumusae. [ABSTRACT FROM AUTHOR]

* Background and Aims Banana genomes harbour numerous copies of viral sequences derived from banana streak viruses (BSVs) - dsDNA viruses belonging to the family Caulimoviridae. These viral integrants (eBSVs) are mostly defective, probably as a result of 'pseudogenization' driven by host genome evolution. However, some can give rise to infection by releasing a functional viral genome following abiotic stresses. These distinct infective eBSVs correspond to the three main widespread BSV species (BSOLV, BSGFV and BSIMV), fully described within the Musa balbisiana B genomes of the seedy diploid 'Pisang Klutuk Wulung' (PKW). * Methods We characterize eBSV distribution among a Musa sampling including seedy BB diploids and interspecific hybrids with Musa acuminata exhibiting different levels of ploidy for the B genome (ABB, AAB, AB). We used representative samples of the two areas of sympatry between M. acuminata and M. balbisiana species representing the native area of the most widely cultivated AAB cultivars (in India and in East Asia, ranging from the Philippines to New Guinea). Seventy-seven accessions were characterized using eBSV-related PCR markers and Southern hybridization approaches. We coded both sets of results to create a common dissimilarity matrix with which to interpret eBSV distribution. * Key Results We propose a Musa phylogeny driven by the M. balbisiana genome based on a dendrogram resulting from a joint neighbour-joining analysis of the three BSV species, showing for the first time lineages between BB and ABB/AAB hybrids. eBSVs appear to be relevant phylogenetic markers that can illustrate the M. balbisiana phylogeography story. * Conclusion The theoretical implications of this study for further elucidation of the historical and geographical process of Musa domestication are numerous. Discovery of banana plants with B genome non-infective for eBSV opens the way to the introduction of new genitors in programmes of genetic banana improvement. [ABSTRACT FROM AUTHOR]

A mathematical model for Banana Xanthomonas Wilt (BXW) spread by insect vector is presented. The model incorporates inflorescence infection and vertical transmission from the mother corm to attached suckers, but not tool-based transmission by humans. Expressions for the basic reproduction number are obtained and it is verified that disease persists, at a unique endemic level, when . From sensitivity analysis, inflorescence infection rate and roguing rate were the parameters with most influence on disease persistence and equilibrium level. Vertical transmission parameters had less effect on persistence threshold values. Parameters were approximately estimated from field data. The model indicates that single stem removal is a feasible approach to eradication if spread is mainly via inflorescence infection. This requires continuous surveillance and debudding such that a 50% reduction in inflorescence infection and 2-3 weeks interval of surveillance would eventually lead to full recovery of banana plantations and hence improved production. [ABSTRACT FROM AUTHOR]

The article discusses a study which reported freckle diseases in banana fruit variety Dwarf Cavendish in Mauritius in February 2014. Topics include the symptoms observed on the diseased fruits such as tiny reddish-brown spots, the study's finding that only the Cavendish banana varieties exhibited symptoms of infection, and the morphological identification of the suspected fungal pathogen using a compound light microscope.

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Optimal control theory is applied to a system of ordinary differential equations modeling banana Xanthomonas wilt within plantations. The objective is to reduce the proportion of infected plants by use of controls representing two types of preventive methods: vector and contaminated tool prevention. The optimal controls are characterized in terms of the optimality system, which is solved analytically and numerically for several scenarios. [ABSTRACT FROM AUTHOR]

Mycosphaerella musicola produces various toxins known to play a key role in pathogenicity and disease development. In our study secondary metabolites produced by M .musicola was extracted and investigated using different parameters. The investigation was aimed to understand the phytotoxic resistance of locally growing different Musa genotypes (AB-Elakki (ELA), AAA-G9 (G9) and AAB-Nanjangud Rasa Baley (NRB)) against the crude extract and partially purified lipophilic TLC fractions extracted from the culture filtrates of M. musicola. Susceptible and resistant banana genotypes against the crude extract and partially purified fractions were analyzed by electrolyte leakage assay and leaf puncher assay. The results revealed that the crude extract and TLC fractions showed varied phytotoxicity among the banana leaves belonging to different age groups and different genotypes. Phytotoxicity studies allowed us to observe that ELA and G9 exhibited resistance to crude extract and TLC fractions, indicating that these genotypes are resistant to initial M. musicola infection. [ABSTRACT FROM AUTHOR]