Academic literature on the topic 'Bananas Bananas Virus diseases of plants'

Banana streak badnavirus (BSV) is the most widely occurring virus in banana and plantain (1) but has not been reported to be a significant problem in commercial export bananas. In early 1999, the first severe outbreak of BSV infection in commercial export bananas (Musa AAA cv. Grand Nain) was recorded at Siquirres on the Atlantic coast of Costa Rica. Disease incidence in the plantation was 60% and symptoms included foliar chlorotic streaks, stunting of plants, splitting and internal necrosis of pseudostems and fruits, cigar leaf necrosis, and bunch emergence through the pseudostem. Diseased plants within a 0.8 ha area were eliminated to prevent possible further spread of the disease. The presence of BSV in diseased plants was confirmed by enzyme-linked immunosorbent assay and immunosorbent electron microscopy (1). Cucumber mosaic virus and Banana mild mosaic virus, which also occur in banana and plantain in Latin America (2), were not detected in the plants tested. Other recent accounts of BSV occurrence in commercial banana plantations in South America (our unpublished results) suggest that BSV occurrence in export bananas may be more significant than previously thought. References: (1) F. Gauhl et al. Int. J. Pest Management 45:167, 1991. (2) D. R. Jones, ed. 1999. Diseases of Banana, Abacá and Enset. CABI Publishing, Wallingford, U.K.

We have characterized the complete genome sequence of an Australian isolate of banana streak CA virus (BSCAV). A greater-than-full-length, cloned copy of the virus genome was assembled and agroinoculated into five tissue-cultured plants of nine different Musa acuminata banana accessions. BSCAV was highly infectious in all nine accessions. All five inoculated plants from eight accessions developed symptoms by 28 weeks post-inoculation, while all five plants of M. acuminata AA subsp. zebrina remained symptomless. Symptoms were mild in six accessions but were severe in Khae Phrae (M. acuminata subsp. siamea) and the East African Highland banana accession Igisahira Gisanzwe. This is the first full-length BSCAV genome sequence reported from Australia and the first report of the infectivity of an infectious clone of banana streak virus.

Banana (Musa sapientam L.) is an economically important crop for both export and local consumption in Taiwan. Recently, leaf symptoms characteristic of banana streak disease (1) were found on banana cv. Mysore (AAB group) introduced from Australia in the germ plasm collection of the Taiwan Banana Research Institute. The citrus mealybug (Planococus citri) has been shown to transmit banana streak virus (BSV) but not banana bunchy top virus or cucumber mosaic virus (CMV) (2). When mealybugs were fed on leaves of diseased Mysore banana and transferred to healthy banana cv. Cavendish seedlings in a growth chamber, the latter developed fine chlorotic streaks characteristic of symptoms caused by BSV within 1 to 3 months. Some chlorotic streaks became necrotic. BSV was detected in diseased but not healthy leaves of Mysore and Cavendish bananas by polymerase chain reaction (PCR) with primer pairs of BSV provided by J. E. Thomas of Queensland Department of Primary Industries. Subsequently, fine chlorotic streaks were observed in leaves of Cavendish banana in several fields in southern Taiwan. Some of these diseased plants developed severe leaf necrosis, causing heart rot of spindle leaves characteristic of symptoms caused by CMV. Presence of BSV in these plants was verified by PCR assay. However, CMV was also detected by double antibody sandwich-enzyme-linked immunosorbent assay with a monoclonal antibody to CMV, indicating that these plants were simultaneously infected by both viruses. This is the first report of BSV infecting Musa spp. in Taiwan. References: (1) B. E. L. Lockhart. Phytopathology 76:995, 1986. (2) B. E. L. Lockhart. 1995 Food & Fertilizer Technol. Center (ASPAC) Tech. Bull. 143. 11 pp.

Banana has been known as one of fruits that has an important function in the rural areas. Bananas have been traditionally planted by rural farmers in the homegarden, garden and mixed-garden in West Java. However, study on bananas in Karangwangi village,Cianjur has not been carried out. Aim of study was to explore varieties (landraces) of bananas, source of local knowledge on bananas, utilization of ba-nanas and diseases of bananas. Method used in this study was quali-tative with ethnobotanical approach and some techniques, including observation and semi-structure interview were applied in this study. The result of study showed that, it was recorded 13 variations of ba-nana; main source of local knowledge on bananas from the parent and friends; utilization of bananas, including consumption of ripe fruit, made of “sale” and some banana organs, including leaves, “jantung” (male flower), pseudostem, ”bonggol” (base of pseudostem) and roots of bananas were usually used by people. Main diseases of banana was known by local people as “Pireus” (virus). We recommended more intensive study on bananas must be carried on for near future.

Effects of time of infection of banana bunchy top virus on susceptibility of three banana cultivars. Banana Bunchy Top, caused by Banana Bunchy Top Virus (BBTV), is one of the most important banana diseases in Indonesia. Approach to reduce disease incidence involves prevention of early infection especially on susceptible cultivars. This study was conducted to evaluate the response of three banana cultivars, Ambon Kuning, Tanduk, and Kepok, to different time of infection of BBTV i.e., one week and three week after adaptation period, and one week during adaptation period. Banana plants used in the study were prepared through in vitro propagation (tissue culture) and virus transmission was done using aphid vector, Pentalonia nigronervosa. In addition to observation on symptom expression, inhibition of plant height, and reduction of leaf size, conformation of virus infection was done through indirect ELISA. Virus concentration on different part of the plant, young leaf, stem, and root, tends to decrease over the time due to the ability of BBTV to move from cell to cell before replication takes place. It is evidenced that BBTV was able to infect banana in all growth stages although the younger plant is more susceptible to BBTV. Although concentration of the virus in the tested plant is considered high, symptoms expression of BBTV infection can be differentiated from moderate to very severe. Response of banana plants to infection of BBTV can be grouped into susceptible (Ambon Kuning), moderate tolerant (Tanduk), and tolerant (Kepok).

Chikungunya and yellow fever virus cause vector-borne viral diseases in humans. There is currently no specific antiviral drug for either of these diseases. Banana plants are used in traditional medicine for treating viral diseases such as measles and chickenpox. Therefore, we tested selected banana cultivars for their antiviral but also cytotoxic properties. Different parts such as leaf, pseudostem and corm, collected separately and extracted with four different solvents (hexane, acetone, ethanol, and water), were tested for in vitro antiviral activity against Chikungunya virus (CHIKV), enterovirus 71 (EV71), and yellow fever virus (YFV). Extracts prepared with acetone and ethanol from leaf parts of several cultivars exhibited strong (EC50 around 10 μg/mL) anti-CHIKV activity. Interestingly, none of the banana plant extracts (concentration 1–100 µg/mL) were active against EV71. Activity against YFV was restricted to two cultivars: Namwa Khom–Pseudostem–Ethanol (5.9 ± 5.4), Namwa Khom–Corm–Ethanol (0.79 ± 0.1) and Fougamou–Corm–Acetone (2.5 ± 1.5). In most cases, the cytotoxic activity of the extracts was generally 5- to 10-fold lower than the antiviral activity, suggesting a reasonable therapeutic window.

Banana is a fruit commodity that is consumed by many people. Banana dwarf disease is an important disease, because its presence has spread in banana plants in Indonesia. This study aims to identify the characteristics and intensity of BBTV attacks on banana plants with different planting patterns, sanitation and weed control. This research was conducted in 5 districts in Kutai Kartanegara Regency, namely Samboja, Muara Jawa, Loa Janan, Muara Badak, Loa Kulu. The method used is a survey method that is conducting direct observations in the field using modified score assessments based on morphology of diseased plants (Brooks, 1999). The data obtained were processed to determine the intensity of disease per plot with the formula of disease severity (Agrios, 1997). Disease intensity data were compared based on different banana cropping conditions, sanitation and weed control.Based on the survey results it can be concluded that, in banana tree land with a monoculture pattern, in sanitation and with weed control, the intensity of BBTV disease is higher compared to mixed cropping patterns, without sanitation and without weed control. The character of attack is generally in the assessment score 3 with the characteristics: (1) the edge of the leaf is quite severe yellowing, (2) the existence of leaf narrowing or twisting (3) the occurrence of distortion, dwarf and necrosis (4) found more than four infected banana stems in a clump.

The experiment evaluated the agronomic characteristics of 'Prata-anã' and 'Maçã' banana plants, in the São Manuel region of São Paulo state. In the first crop cycle, the number of days from planting to inflorescence and from inflorescence to harvest; the number of shoots until the appearance of inflorescence and during the harvest period; active leaves number at inflorescence appearance and during the harvest period. Were evaluated yield parameters: like average weight of bunch, hand, rachis and fruit; average fruit number per hand and bunch; average fruit diameter and length. Incidences of plague diseases, as well as their severity were also evaluated. Delineation was totally at random, with 2 treatments, 15 replications and 5 useful plants per experimental plot. Both cultivars were characterized by values of descriptive average statistics and standard deviation, for characteristic interests. Number of days from planting to harvest was similar for both 'Prata-anã' and 'Maçã', 574 and 567 days respectively. Banana plants showed good phytosanitary quality throughout the whole cycle.

Banana bunchy top virus (BBTV), Banana streak virus (BSV), and Cucumber mosaic virus (CMV) (genus Cucumovirus, family Bromoviridae [2]) cause widespread economic losses on banana (Musa sp.) throughout the world and have been reported on banana in different countries including Pakistan along its southeastern border with Iran (1). A survey was conducted from 2004–2005 to identify viruses infecting banana in greenhouses in different growing areas in northern Iran, Mazandaran Province (Sari, Babol, Behshahr, and Ghaemshahr cities). A total of 180 samples from seven banana-growing greenhouses with symptoms of mosaic, chlorosis, stunting, and fruit malformation were collected. All samples were tested for CMV with polyclonal antibodies using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) (CMV strain D subgroup I; gifted by H. Lecoq, INRA, Avignion, France). For sap inoculation onto indicator test plants, selected ELISA-positive leaf samples were ground in chilled 0.01 M phosphate buffer, pH 7.0, containing 0.15% 2-mercaptoethanol. Chlorotic and necrotic local lesions developed on Chenopodium amaranticolor and Vigna unguiculata (cv. Mashad local) 10 and 12 days postinoculation, respectively. Cucumis sativus and Nicotiana rustica also developed systemic mosaic symptoms (3). All indicator test plants were rechecked for the presence of CMV using DAS-ELISA. On the basis of serological tests and indicator host plants reactions, CMV was identified in 32% of samples including Sari (13.8%), Babol (2.7%), Behshahr (10%) and Ghahemshahr (5%), respectively. Fifty-five samples did not react with CMV antiserum but the presence of symptoms resembling BBTV and BSV (4) emphasizes the need for further investigations to confirm the presence and identities of other viruses. References: (1) J. Bird and F. L. Wellman. Phytopathology 52:286, 1962. (2) S. K. Choi et al. J. Virol. Methods 83:67, 1999. (3) A. J. Gibbs and B. D. Harrison. Descriptions of Plant Viruses. No.1. CMI/AAB, Surrey, England, 1970. (4) R. C. Ploetz et al., eds. Compendium of Tropical Fruit Diseases. The American Phytopathological Society, St. Paul, MN, 1994.

Submitted in partial fulfillment for the Degree of Master of Technology: Biotechnology, M. L. Sultan Technikon, 2002.
Fusarium species produce toxic mycotoxins that are known to exert adverse health effects in humans and animals. No attempts have been made to establish mycotoxin-producing capabilities of isolates of Fusarium species from bananas exhibiting symptoms of crown rot. Crown rot is one of the most serious post harvest problems in banana and the disease is caused by different fungal species, principally Fusarium species. Banana, which is of great economic significance in growing countries (i.e. Costa Rica, Cameroon, Ecuador) is seriously affected by crown rot and is a major cause of fruit loss
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Reduced banana yield owing to black Sigatoka Mycosphaerella fijiensis Morelet is a threat to the livelihoods of Ugandan subsistence farmers who depend entirely on the banana crop for food security. The objectives of this investigation were to: (i) assess farmers’ knowledge of black Sigatoka disease in central Uganda; (ii) document the qualities farmers would desire in the banana genotypes to be developed for black Sigatoka resistance; (iii) appraise the methods for assessing black Sigatoka resistance in diploid banana populations; (iv) determine the phenotypic variation for black Sigatoka resistance and agronomic traits in diploid and tetraploid bananas; (v) determine the influence of tetraploid and diploid parents on the black Sigatoka resistance and agronomic traits in the triploid progenies; and (vi) evaluate 2x by 2x banana progenies for yield and black Sigatoka resistance. A survey that focused on low and medium banana production zones in Uganda established that there was limited awareness of black Sigatoka disease as a constraint on banana production in the areas surveyed. It was also established that farmers liked local bananas because of their superior taste, early maturity, and marketability. There were farmers who had been exposed to new black Sigatoka resistant materials but never liked these new banana materials because of poor taste and lack of market. Farmers desired new banana materials with good taste on cooking, heavy bunches, resistance to pests and diseases, drought tolerance, and early maturing capacity in that order. The results indicated that the banana farmers in Uganda attached more importance to food quality attributes than to production attributes especially when considering new banana materials. This suggested that farmers mainly grow bananas for consumption. Three black Sigatoka assessment methods, youngest leaf spotted, disease development time and area under disease progress curve (AUDPC) were appraised using a diploid population. All the three methods were able to classify the diploid accessions into resistant and susceptible clones. The cultivar rankings of AUDPC correlated strongly with the rankings of disease development time. The cultivar rankings of AUDPC correlated positively with the rankings of youngest leaf spotted method. The youngest leaf spotted at flowering and AUDPC predicted significantly total number of leaves at flowering (R2 = 0.53). Overall AUDPC had the highest coefficient of determination (R2=0.84) in assessment of banana diploids for black Sigatoka resistance indicating that it accounted for the highest variation in disease response observed among the diploid clones. From this investigation it was recommended that AUDPC should be used to assess resistance on black Sigatoka in Musa species. A phenotypic analysis on the diploid and synthetic tetraploids, and a molecular analysis using RAPD markers on the tetraploid population were conducted. Results indicated that the diploid population had significant (P<0.001) variation for plant height, plant girth, days from flowering to harvest, bunch weight, number of suckers, youngest leaf spotted, total leaves at flowering, area under disease progress curve, and number of functional leaves at harvest. Principal component analysis showed that plant height and girth explained most of the variation observed in the diploid population. In the tetraploid population, significant differences were observed for plant height, plant girth, and number of suckers (P<0.05). In the tetraploids principal component analysis, indicated that youngest leaf spotted and total leaves at flowering had higher loadings on principal component one. Genetic distances computed from RAPD markers indicated limited genetic variability in the tetraploid population. Another investigation was also carried out to determine the influence of tetraploid and diploid parents on black Sigatoka resistance and agronomic traits in the triploid progenies generated from tetraploid-diploid crosses. The results indicated that diploids transferred black Sigatoka resistance to triploid progenies as measured by disease development over time, the number of functional leaves at flowering and at harvest. On the other hand, the female synthetic tetraploids influenced plant height and bunch weight in the triploid progenies generated from tetraploid-diploid crosses as observed from triploid progeny correlations and parent-offspring regressions. Therefore, it is important to select tetraploids with heavy bunch weights to generate high yielding triploids in tetraploid-diploid crosses. Lastly, this thesis investigated the relationship between bunch weight and black Sigatoka resistance traits in 2x by 2x progenies generated using a random polycross design. Phenotypic correlations revealed strong positive relationships between bunch weight with total leaves at flowering, youngest leaf spotted, plant girth, and days from planting to flowering among the 2x by 2x progenies. Linear regression analysis indicated that girth, total fingers and finger length significantly predicted bunch weight (R2=0.67). However, days from planting to flowering, and total leaves at flowering had strong indirect effects on bunch weight via plant girth. The results imply that selection for parents with good combining ability for girth, finger length and total fingers can improve bunch weight in a diploid population.
Thesis (Ph.D.) - University of KwaZulu-Natal, Pietermaritzburg, 2009.

In the genus Fusarium are many important plant pathogens. The diversity of hosts the genus attacks, the number of pathogenic taxa and the range of habitats in which they cause disease are the greatest in plant pathology. One important species complex within the genus Fusarium is Fusarium oxysporum Schlecht. This species complex consists more than 80 pathogenic forma specialis and is particularly difficult to control. The fungi can survive in soil for decades as specialized spores, known as chlamydospores. Interestingly, however, this species complex also contains beneficial non-pathogenic forms that can be exploited to manage Fusarium wilt diseases. In this study, the ability of non-pathogenic F. oxysporum strains, Trichoderma harzianum Rifai Eco-T®, soluble silicon, and their combination was evaluated on two important crops, banana (Musa sp. L.) and beans (Phaseolus vulgaris L.), for their potential to suppress pathogenic strains of F. oxysporum. The ability of these crops to take up and accumulate silicon in their organs, and its effect on low temperature stress was also investigated. Several endophytic fungi, mainly Fusarium spp. and bacteria, were isolated from healthy mature banana plants. After preliminary and secondary in vivo screening tests against F. oxysporum f.sp. phaseoli on beans (Phaseolus vulgaris L.) cv. Outeniqua, two non-pathogenic F. oxysporum strains were selected for further testing. These two non-pathogenic F. oxysporum strains were found to colonize banana (Musa sp.) cv. Cavendish Williams and bean plants, and to suppress Fusarium wilt of these crops. In order to improve the efficacy of these biocontrol fungi, soluble silicon was introduced. The relationship between plant mineral nutrition and plant diseases have been reported by several authors. Plants take up silicon equivalent to some macronutrients, although it is not widely recognized as an essential element. In this study, we established that roots, the target plant organ for soilborne plant pathogens, accumulated the greatest quantity of silicon of any plant organs when fertilized with high concentrations of silicon. On the other hand, the corm and stem accumulated the least silicon. Such observations contradict the concept of passive uptake of silicon via the transpiration stream in these plants as the only uptake mechanism. The prophylactic properties of silicon have been documented for many crops against a variety of diseases. In vitro bioassay tests of silicon against these wilt pathogens showed that silicon can be toxic to Fusarium wilt fungi at high concentrations (>7840 mg .-1), resulting in complete inhibition of hyphal growth, spore germination and sporulation. However, low concentrations of silicon (<490 mg .-1) encouraged hyphal growth. Silicon fertilization of banana and beans significantly reduced disease severity of these crops by reducing the impact of the Fusarium wilt pathogens on these crops. However, it could not prevent infection of plants from the wilt pathogens on its own. Synergistic responses were obtained from combined applications of silicon and non-pathogenic F. oxysporum strains against Fusarium wilt of banana. Combinations of silicon with the non-pathogenic F. oxysporum strains significantly suppressed disease severity of Fusarium wilt of banana, caused by F. oxysporum f.sp. cubense (E.F. Smith) Snyder & Hansen, better than applications of either control measure on their own. Banana production in the subtropical regions frequently suffer from chilling injury, and from extreme variations between night and day temperatures. Such stress predisposes banana plants to Fusarium wilt disease. Silicon, on the other hand, is emerging as important mineral in the physiology of many plants, ameliorating a variety of biotic and abiotic stress factors. We established that silicon fertilization of banana plants significantly reduced chilling injury of banana plants. Membrane permeability, lipid peroxidation (MDA level) and proline levels were higher in silicon-untreated plants than the treated ones, all of which demonstrated the stress alleviating effect of silicon. Low temperatures damage the cell membrane of susceptible plants and cause desiccation or dehydration of these cells. Levels of sucrose and raffinose, recognized as cryoprotectants, were significantly higher in silicon-amended banana plants than unamended plants.
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Bananas and plantains (Musa spp.) represent the fourth most important crop in the world. In 2017, an area of 5,637,508 hectares and a production of 153 million tons were reported. Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cubense (Foc), is considered one of the most destructive diseases of bananas and plantains worldwide. The pathogen Foc causes a typical wilt syndrome on infected plants, it has a saprophytic and parasitic phase in its life cycle. Fusarium wilt is a “polycyclic” disease. This pathogen shows a relatively diverse population genetic structure for a fungus apparently of asexual reproduction and is composed of different evolutionary lineages, which has 24 groups of vegetative compatibility (VCGs), two clades and nine clonal linage. Foc is a genetically diverse pathogen, although the available evidence so far indicates that it does not use the mechanisms of sexual reproduction, such as recombination, to increase its genetic diversity. Furthermore, the population of this fungus in Southeast Asia shows a high degree of variation, suggesting that Foc lineages evolved together with their hosts in Southeast Asia. Alternatively, it has been suggested that Foc has multiple independent evolutionary origins, both within and outside of the Musaceae origin center.