Banana Bunchy Top Virus Research Articles

Application of Artificial Intelligence in the Identification of Banana Bunch Top Virus (BBTV) in Mozambique

Agricultural production faces many challenges, such as disease and pest infestation, which can lead to severe crop loss and environmental impacts due to the excessive use of chemicals. Artificial intelligence has become a key technique to solve different agricultural-related challenges. The main objective of this study was to train and validate artificial intelligence algorithms for the detection of Banana Bunchy Top Virus (BBTV) in banana crops. Approximately 2,500 images of healthy and BBTV-infected leaves were collected, stratified according to the stage of plant development, and used to calibrate and validate an artificial intelligence algorithm for the detection of BBTV. Pre-trained models such as VGG 16, ResNet50, and InceptionV3 were tested. The ResNet50 model achieved a training accuracy of 99.56% and validation precision, recall, and F1 score of 96.53%, 94.94%, and 95.73%, respectively, outperforming the other models in detecting BBTV-infected plants.

Alternative hosts of banana bunchy top virus in the Philippines and the first evidence of seed transmission of BBTV

Banana bunchy top disease is caused by banana bunchy top virus (BBTV). BBTV is transmitted locally by aphids (Pentalonia spp.), but the long-distance spread is through the movement of infected planting materials. This study investigated potential alternative hosts of BBTV in ornamental Musa and related species in the Zingiberales in the Philippines. Artificial inoculation of BBTV, molecular detection and transmission assay were used to evaluate 15 plant test species. The potential for seed transmission of BBTV through Canna indica seeds was also investigated. Seed samples were validated and quantified for BBTV presence using molecular tools, and then grown for transmission assay. Typical symptoms of BBTV in bananas, including dark green streak on the midrib and petiole and rosetting were observed on inoculated Musa coccinea (banana blossom), M. velutina (velutina), M laterita. (bronze banana) and Canna indica (Bandera Espanola). PCR assays confirmed BBTV infection in these symptomatic test plants, as well as in Curcuma longa (turmeric) which exhibited large chlorotic blotches on the leaf. BBTV was detected from both seeds and germinated seedlings of artificially inoculated and field-collected C. indica samples. This study identified M. laterita as a new host of BBTV. The susceptibility to BBTV of M. coccinea, M. velutina, C. indica, and C. longa was also confirmed. The study also provided the first evidence of seed transmission of BBTV. C indica is an ornamental plant popularly used for landscaping in the Philippines and seeds were shown to be an efficient mode of transmission of the virus with rates up to 34%. The discovery of natural infection in ornamental plants and seeds poses a risk to the banana industry and responsible propagation and appropriate quarantine protocols must be implemented.

A sensitive batch detection of banana bunchy top virus using SYBR® Green real-time PCR

A sensitive batch detection of banana bunchy top virus using SYBR® Green real-time PCR

Tissue Culture in Banana Cultivation: A Review of its Impact on Disease Management, Yield Improvement, and Sustainable Production

In several tropical and subtropical areas, bananas (Musa spp.) are an important food source and commercial crop. Disease transmission and production uncertainty are common problems with traditional propagation techniques such as suckers. By supplying consistent, high-quality, and disease-free planting material, tissue culture, known as micro propagation, represents a potential alternative. The application of tissue culture has greatly enhanced disease management in banana cultivation. Reducing the incidence of ailments like Fusarium wilt, bacterial wilt, and Banana Bunchy Top Virus (BBTV), pathogen-free plantlets are grown in controlled conditions. This strategy lessens the demand for artificial fertilizers while also promoting healthier crops and lessening the impact on the environment. Micropropagated banana plants demonstrated consistent growth, early fruiting, and increased yield in contrast to conventionally propagated plants. Tissue-cultured plants exhibit strong development and genetic uniformity, which contribute to these advantages and more consistent and dependable harvests. By promoting efficient land use and reducing the need for chemical inputs, tissue culture enhances sustainability in the production of bananas. The growing demand for bananas may be met without requiring the increase of agricultural land thanks to tissue culture techniques, which enable the large-scale production of enhanced banana cultivars at a quick rate. Furthermore, using planting material free of disease lowers input costs and crop losses, supporting more environmentally friendly farming methods.

Modeling the transmission dynamics of banana bunch top disease in banana plants

Banana Bunch Top Disease (BBTD) is a severe viral infection that poses a significant threat to banana production in tropical regions. Caused by the Banana Bunchy Top Virus (BBTV) and transmitted primarily by the banana aphid (Pentalonia nigronervosa), BBTD results in stunted growth and poor fruit production, leading to substantial economic losses. This paper presents a mathematical model to analyze the transmission dynamics of BBTD in banana plants and evaluate various control strategies using the Next Generation Matrix approach to compute the basic reproduction number R0. The study reveals that effective control of aphid populations, timely removal of infected plants, and the use of virus-free planting material significantly reduce the spread of BBTV and improve plant health. Increasing the removal rate γ and managing the transmission rate β are crucial strategies for controlling the disease, while elevated aphid infection rates λ and progression rates σ exacerbate its spread. Numerical simulations highlight the effectiveness of targeted interventions, including the application of pesticides and the introduction of resistant banana varieties. The study recommends that, in addition to current control measures, more focus should be placed on comprehensive monitoring programs, early detection of symptoms, and community education on BBTD management strategies. Enhanced efforts in these areas are crucial to reducing the incidence of BBTD and improving the resilience of banana crops.

Correction to Distribution and Diversity of Emergent Banana Bunchy Top Virus Infecting Banana and Plantain in Cameroon, Central Africa

Correction to Distribution and Diversity of Emergent Banana Bunchy Top Virus Infecting Banana and Plantain in Cameroon, Central Africa

Cryopreservation of zygotic embryos derived from BBTV resistant accessions of wild banana Musa acuminata

The wild banana species Musa acuminata encompasses numerous subspecies, some of which serve as ancestors of edible bananas. Preserving these subspecies is critical for food security, especially in regions where bananas are staple crops. While cryopreservation of M. acuminata subsp. burmanicoides zygotic embryos using air dehydration have shown high success rates, this method has not been effective for other subspecies. With at least 15 subspecies displaying various morphological traits, including seed morphology, alternative cryopreservation methods warrant exploration. In a recent study, successful cryopreservation using the droplet-vitrification method was achieved for mature zygotic embryos of accession of M. acuminata subspecies tomentosa, rutilifes, and malaccensis, all of which are resistant to the Banana bunchy top virus (BBTV). Using this approach, subjecting embryos to dehydration for 20 min in PVS2 solution and employing a regeneration medium comprising MS medium supplemented with benzyladenine and thidiazuron resulted in a success rate of 77.4 % (86 % survival rate × 90 % regrowth rate) for subsp. tomentosa and 50.4 % (70 % survival rate × 72 % regrowth rate) for subsp. malaccensis. Conversely, for subsp. rutilifes, dehydration for 10 min led to a success rate of 15.6 % (30 % survival rate × 52 % regrowth rate). Subspecies emerged as the primary factor influencing embryo regrowth, suggesting the need for protocol optimizations tailored to other subspecies. These findings highlight the potential of droplet-vitrification as a long-term preservation method for certain subspecies, while underscoring the necessity for further optimization for the other subspecies of M. acuminata.

Molecular Characterization of Isolates of the Banana Bunchy Top Virus (BBTV) from the District of Chókwè, Mozambique

Banana bunchy top virus (BBTV) was recently detected in Mozambique and appears to be limited to the provinces of Gaza, Maputo and Zambezia, but it has great potential to spread to other provinces. Despite its importance, nothing is known about the BBTV isolates that occur in Mozambique. In this study, the sequences of the S and R genes of forty isolates chosen as representatives of samples collected previously from eleven farms of the four administrative posts of the district of Chóckwè, province of Gaza, were sequenced and analyzed. The S-DNA nucleotide sequences of the analyzed isolates were highly conserved, with identity ranging from 97% to 100%. The same was observed for the R-DNA sequences, with most identities ranging between 98% and 100% among the isolates from Chókwè and above 90% when compared to the isolates from GenBank. The phylogenetic analysis showed that the Mozambican BBTV isolates belong to the Pacific–Indian Oceans (PIO) group, showing greater proximity to the isolate JQ820453 from Malawi than to the isolates from sub-Saharan countries, which were grouped in a distinct subclade. This is the first study conducted to determine the molecular characteristics of BBTV isolates present in Mozambique.

The role of insect vector Pentalonia nigronervosa in spreading banana bunchy top disease in South Sumatera

Banana (Musa spp.) is widely cultivated by the people of South Sumatra. Banana Bunchy Top disease is caused by Banana bunchy top virus (BBTV), which is transmitted by the vector Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) and asymptomatic banana used for propagation. This study aimed to investigate the role of P. nigronervosa. in determining the distribution pattern of this disease in South Sumatra. The research used survey methods in several districts and cities in South Sumatra, namely Ogan Ilir, Ogan Komering Ilir, OKU East, OKU South, OKU Induk, Palembamg, Prabumulih, Banyuasin, Musi Banyuasin, and Lubuk Linggau. Samples were taken using purposive sampling method if BBTV-infected bananas in an area. The results showed P. nigronervosa was only found in Ogan Ilir and OKU Induk districts, but in fact this disease was spread in 10 districts and cities. A total of 14 banana cultivars in South Sumatera were infected by BBTV transmitted by P. nigronervosa, namely Mas, Cavendish, Putri, Lilin, Nangka, Ambon, Udang, Barangan, Kepok, Gedah, Rottan, Raja, Kapas and Raja Nangka. The highest banana population and percentage of banana plants infested by BBTV was found in the Ogan Ilir district in Mas and Lilin cultivars.

Banana bunchy top virus movement protein induces resistance in banana against Fusarium wilt

Banana Fusarium wilt, which is known as Panama disease and caused by Fusarium oxysporum f. sp. cubense (Foc), is a destructive disease that can lead to plant death and complete loss of banana plantations. For obtaining resistant varieties against Fusarium wilt, research is required to elucidate the mechanisms of genetic resistance to Foc. In this research, the banana plants infected with banana bunchy top virus (BBTV) showed resistance to Foc. RNA-seq results showed that the infection with Foc upregulated many resistance-related genes in BBTV-positive plants, especially genes related to ROS production. It was also found that more H2O2 in BBTV-positive plants was induced during Foc infection. The movement protein (MP) of BBTV could increase H2O2 levels by promoting the accumulation of MaSGT1a (suppressor of the G-two allele of SKP1) via direct interaction. Thus, the resistance to Foc induced by BBTV may attribute to MP increasing MaSGT1a protein levels to induce ROS production. MaSGT1a could promote the accumulation of R proteins MaRPM1 and MaRPP8, and increase H2O2 levels in Nicotiana benthamiana. The expression of R proteins in Nicotiana benthamiana caused an increase in H2O2 levels and promoted resistance to Foc. Thus, the MP of BBTV could induce plant defense through interaction with MaSGT1a. We speculate that MaSGT1a is likely involved in R gene-mediated resistance and thereby promotes the resistance of banana against Foc.

In silico Characterization of Banana Bunchy Top Virus (BBTV) and Its Genetic Variation Globally

Banana bunchy top disease is one of the most prevalent viral infections associated with banana farming. It is a rapidly spreading disease. Currently, there are very few fully sequenced isolate reports from India and around the world. When in silico analysis was conducted on various Banana Bunchy Top Virus (BBTV) various genome components at nucleotide level (DNA-R and DNA-U3), and amino acid level (DNA-C and DNA-U3) maximum genetic variability was observed in all reported strains of BBTV. When comparing DNA-R (Replicative protein) to DNA-S segment (Coat protein) most Indian isolates are in agreement with isolates from countries in East and Southeast Africa and belong to the PIO (Pacific-Indian Oceans) group of BBTV isolate classification. BBTV coat protein model demonstrated the highest degree of protein binding to NBS-LRR class resistance protein. Furthermore, the Ramachandran plot was used to validate the BBTV CP model, and Procheck and the PROSA web server were used to enhance the structure. The greatest binding affinity of the BBTV coat protein was seen with the NBS-LRR class resistance protein (receptor) when the BBTV coat protein model interacted with it. Three mutagenic epitope (IADEFYVERL, SKRFLLVLDD and WEFFKQCAFSS) were predicted from BBTV coat protein region. Consequently, our work presents the Indian subcontinent as a possible hotspot for rapid demographic development from an extremely small viral population size, adding significantly to the knowledge already known on BBTV worldwide.

Biochemical changes in some banana cultivars infected by Banana bunchy top virus

Bunchy top is one of the major diseases on bananas that caused economic losses. This study aimed to determine changes in protein content, the concentration of phenolic compounds, the amount of chlorophyll, and sugar content in several Banana bunchy top virus (BBTV)-infected banana cultivars. The research involved the artificial inoculation, extraction, and biochemical analysis of banana seedlings from the cultivars Mas, Cavendish, Kepok, and Raja. Inoculation was performed using the vector Pentalonia sp.. A factorial complete randomized design (CRD) was used as the experimental design. Each experimental unit consisted of 5 repetitions. Protein, phenol, chlorophyll, and sugar content measurements were performed using a UV-Vis spectrophotometer. Test samples were in the form of fresh leaves from BBTV-infected and non-BBTV-infected plants. Regression analysis and tests for significance were performed to determine the biochemical changes that occurred after testing. The results showed that the average levels of phenols, chlorophyll, protein, and total sugars in BBTV-infected plants were significantly altered. The chlorophyll content decreased from 82–87% in Mas, Cavendish, and Raja cultivars. Total plant phenol in all BBTV-infected cultivars increased by 69.2 to 348.3 ppm. Specificity was evident in the change in protein concentration, which increased by 95 ppm and 84.5 ppm in the Mas and Cavendish cultivars, respectively. This contrasts with the Kepok and Raja cultivars, which decreased by 660.5 ppm and 113.6 ppm, respectively. Sugar levels increased from 3133.9 to 3298.6 ppm in all BBTV-infected breeds. According to the data, BBTV infection has been shown to cause physiological and biochemical changes in Mas, Cavendish, Kepok, and Raja.

Distribution and diversity of emergent Banana bunchy top virus infecting banana and plantain in Cameroon, Central Africa

AbstractInvasions of arthropod vectors and viruses are the main factors associated with emerging plant viral diseases. The presence of the Banana bunchy top virus (BBTV, genus Babuvirus), an aphid‐transmitted virus responsible for the banana bunchy top disease (BBTD), was first confirmed in 2008 in the South region of Cameroon. This study reports on surveys over 14 years to determine the status of BBTV spread and virus diversity in Cameroon. A total of 544 fields extending through 81 districts in 7 regions were surveyed in 5 phases: (1) 2009–10, (2) 2012, (3) 2013–14, (4) 2016–17, and (5) 2022. BBTV was detected in 36 sites, all located in the Ambam district in the South region, with an incidence in the virus‐affected fields ranging from 5% to 40%, with an average incidence of 14.8%. The findings indicate BBTV expansion from the location of first detection in 2008 to about 4–25 km in all directions, with the virus spread range of about 700 km2, as of the last survey in 2022. Phylogenetic analysis using complete nucleotide sequences of the BBTV‐R and BBTV‐S gene aligned Cameroon isolates with the sub‐Saharan Africa subgroup of the Pacific‐Indian Oceans (PIO) group of BBTV isolates, suggesting a likely virus invasion from neighbouring central African countries where BBTV presence had been reported in the 1980s. Knowledge of BBTV distribution provided through the detection and delimiting surveys has contributed to the efficient targeting of interventions to limit the expansion of an emerging virus threat to banana production in Cameroon.

Preference of Pentalonia nigronervosa for infected banana plants tends to reverse after Banana bunchy top virus acquisition

Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) is the vector of the Banana Bunchy Top Virus (BBTV), the most serious viral disease of banana (Musa spp.) in the world. Before acquiring the virus, the vector is more attracted to infected banana plants in response to the increased emissions of volatile organic compounds (VOCs). Here, we test the hypothesis that BBTV acquisition directly modifies the preference of P. nigronervosa for infected banana plants, and that the change in preference results from the alteration of the organs linked to the VOC detection or to the behaviour of the vector. We found that the preference of P. nigronervosa for infected banana plants reverses after virus acquisition in dessert banana, while it remains similar between healthy and infected banana plants before and after the acquisition of BBTV. At the same time, aphids reared on infected bananas had smaller forewing areas and hind tibia length than aphids reared on healthy bananas, although the number of secondary rhinaria on the antennae was lower on dessert banana-reared aphids than plantain-reared aphids, this was not affected by the infection status of the aphid. These results support the "vector manipulation hypothesis—VMH" of pathogens to promote their spread. They have implications for the BBTV management.

First report of banana bunchy top virus infecting Colocasia esculenta (L.) Schott, from India

First report of banana bunchy top virus infecting Colocasia esculenta (L.) Schott, from India

Potential of Cameroonian isolates of Beauveria bassiana and Metarhizium anisopliae for the biocontrol of the banana aphid, Pentalonia nigronervosa, vector of banana bunchy top virus.

Metarhizium anisopliae (Metschnikoff) Sorokin and Beauveria bassiana (Balsamo) Vuillemin are entomopathogenic fungi commonly used in microbial control of arthropods. In this study, we evaluated the insecticidal potential of six isolates of B. bassiana (BIITAC10.3.3, BIITAC6.2.2, and BIITAC8.1.5) and M. anisopliae (MIITAC11.3.4, MIITAC6.2.2, and MIITAC6.4.2) from Cameroon, against the banana aphid Pentalonia nigronervosa Coquerel, the vector of the banana bunchy top virus (BBTV). Pathogenicity tests were initially conducted using B. bassiana and M. anisopliae isolates at a concentration of 3.2 × 106 conidia/ml on P. nigronervosa adults sourced from four agroecologies in Cameroon. Four isolates (BIITAC6.2.2, BIITAC10.3.3, BIITAC8.1.5, and MIITAC6.2.2) were highly pathogenic, causing greater than 75% aphid mortality in all populations. A significant decrease in aphid fecundity was observed with BIITAC6.2.2, MIITAC6.2.2, and BIITAC10.3.3. These three isolates were in a test of a series of four fungal concentrations (3.2 × 101, 3.2 × 102, 3.2 × 104, and 3.2 × 106 conidia/ml). produced LC50 of 1.31 × 101 and 3.12 × 10-2 for BIITAC10.3.3 and MIITAC6.2.2, respectively. MIITAC6.2.2 had the lowest LC90 (1.55 × 103). Our results strongly support the continued development of biopesticides based on one or more of the three fungal entomopathogens for the control of banana aphids as a component of an Integrated Pest Management (IPM) strategy for the reduction of the prevalence and transmission of BBTV under field conditions.

Cytopathological effects of banana bunchy top virus and production of BBTV free banana plants using in vitro culture technique.

Cytopathological effects of banana bunchy top virus and production of BBTV free banana plants using in vitro culture technique.

A new genus of alphasatellites associated with banana bunchy top virus in Southeast Asia.

Autonomously replicating alphasatellites (family Alphasatellitidae) are frequently associated with plant single-stranded (ss)DNA viruses of the families Geminiviridae, Metaxyviridae, and Nanoviridae. Alphasatellites encode a single replication-initiator protein (Rep) similar to Rep proteins of helper viruses and depend on helper viruses for encapsidation, movement, and transmission. Costs versus benefits of alphasatellite-helper virus association are poorly understood. Our surveys in Southeast Asia (SEA) for wild and cultivated banana plants infected with banana bunchy top virus (BBTV, Nanoviridae) and Illumina sequencing reconstruction of their viromes revealed, in addition to a six-component BBTV genome, one to three distinct alphasatellites present in sixteen of twenty-four BBTV-infected plants. Comparative nucleotide and Rep protein sequence analyses classified these alphasatellites into four distinct species: two known species falling into the genus Muscarsatellite (subfamily Petromoalphasatellitinae) previously identified in SEA and two novel species falling into the tentative genus Banaphisatellite (subfamily Nanoalphasatellitinae) so far containing a single species recently identified in Africa. The banaphisatellites were found to be most related to members of the genus Fabenesatellite of subfamily Nanoalphasatellitinae and the genus Gosmusatellite of subfamily Geminialphasatellitinae, both infecting dicots. This suggests a dicot origin of banaphisatellites that got independently associated with distinct strains of monocot-infecting BBTV in Africa and SEA. Analysis of conserved sequence motifs in the common regions driving replication and gene expression of alphasatellites and BBTV strains revealed both differences and similarities, pointing at their ongoing co-evolution. An impact of alphasatellites on BBTV infection and evasion of RNA interference-based antiviral defences was evaluated by measuring relative abundance of BBTV genome components and alphasatellites and by profiling BBTV- and alphasatellite-derived small interfering RNAs. Taken together, our findings shed new light on the provenance of alphasatellites, their co-evolution with helper viruses, and potential mutual benefits of their association.

Effect of Banana bunchy top virus on the life cycle and fecundity of its insect vector

Pentalonia nigronervosa and Pentalonia caladii are insect vectors of Banana bunchy top virus (BBTV) on banana plants. The virus that circulates in the body of its insect vector may affect the insect’s physiology or life cycle. This study aimed to determine the life cycles and fecundity of P. nigronervosa and P. caladii after they acquired BBTV. The experiment used a completely randomized design with 4 treatments, i.e., viruliferous (P1) and non-viruliferous (P2) P. nigronervosa, viruliferous (P3) and non-viruliferous (P4) P. caladii. Viruliferous and non-viruliferous aphids were obtained by feeding the insects on BBTV-infected and healthy banana leaves, respectively. The experimental results showed that both species’ life cycles and fecundity of viruliferous and non-viruliferous aphids differed significantly. Nymphs and adult periods of P1 were 2.70 days and 1.26 days shorter than those of P2, respectively; while nymphs and adult periods of P3 were 0.9 days and 1.8 days shorter than those of P4, respectively. The average fecundity of P1 (34.22+0.82) was higher than that of P2 (19.64+0.55), and P3 (25.80+0.60) was higher than that of P4 (19.32+0.45). This proves that BBTV causes a shorter life cycle and higher fekundity of aphid vectors.

Comparative RNA-seq analysis of resistant and susceptible banana genotypes reveals molecular mechanisms in response to banana bunchy top virus (BBTV) infection

Bananas hold significant economic importance as an agricultural commodity, serving as a primary livelihood source, a favorite fruit, and a staple crop in various regions across the world. However, Banana bunchy top disease (BBTD), which is caused by banana bunchy top virus (BBTV), poses a considerable threat to banana cultivation. To understand the resistance mechanism and the interplay of host suitability factors in the presence of BBTV, we conducted RNA-seq-based comparative transcriptomics analysis on mock-inoculated and BBTV-inoculated samples from resistant (wild Musa balbisiana) and susceptible (Musa acuminata ‘Lakatan’) genotypes. We observed common patterns of expression for 62 differentially expressed genes (DEGs) in both genotypes, which represent the typical defense response of bananas to BBTV. Furthermore, we identified 99 DEGs exclusive to the 'Lakatan' banana cultivar, offering insights into the host factors and susceptibility mechanisms that facilitate successful BBTV infection. In parallel, we identified 151 DEGs unique to the wild M. balbisiana, shedding light on the multifaceted mechanisms of BBTV resistance, involving processes such as secondary metabolite biosynthesis, cell wall modification, and pathogen perception. Notably, our validation efforts via RT-qPCR confirmed the up-regulation of the glucuronoxylan 4-O-methyltransferase gene (14.28 fold-change increase), implicated in xylan modification and degradation. Furthermore, our experiments highlighted the potential recruitment of host's substrate adaptor ADO (30.31 fold-change increase) by BBTV, which may play a role in enhancing banana susceptibility to the viral pathogen. The DEGs identified in this work can be used as basis in designing associated gene markers for the precise integration of resistance genes in marker-assisted breeding programs. Furthermore, the findings can be applied to develop genome-edited banana cultivars targeting the resistance and susceptibility genes, thus developing novel cultivars that are resilient to important diseases.