Tissue Culture Banana Plantlets Research Articles

Evaluation of Constraints Encountered by Banana Growers in Adopting Water Management Practices using Henry Garrett Ranking Technique

Aim: To analyze the constraints endured by banana growers in adopting Water Management Practices.
 Methodology: Vellore district of North Eastern Zone in Tamil Nadu was purposively selected for the study as it had highest number of revenue blocks under critical groundwater explosion. Two villages from Anaicut block namely Melarasampatti and Vananthanghal were selected for the study. Banana is one of the water intensive crops which has number of water management practices to be followed. Hence banana was selected for the study. Constraints in adopting water management practices was assessed by using Henry Garrett Ranking technique. A total of 80 respondents were selected for the analysis.
 Results: Poor quality of drippers (71.68), Insufficiency of drippers for the entire field (63.95), Non availability of materials for mulching (63.16), Physical damage to drippers and microtubers while performing intercultural operations (59.39), Clogging of drippers due to salt water (54.93), Lack of knowledge about tissue cultured banana plantlets (50.86) were the major constraints encountered by the farmers.
 Conclusion: We are in crucial need to extirpate these constraints to improve the adoption of water management practices among banana growers.

Biotization of tissue culture banana plantlets with Methylobacterium salsuginis to enhance the survival and growth under greenhouse and open environment condition

Aim: This study aimed to investigate the impact of M. salsuginis TNMB03 biotization on tissue culture banana cv. Grande Naine plantlets growth and survival under greenhouse and open environmental condition (exposed to direct sunlight). Methodology: Banana plantlets were transferred from culture flasks to protray and maintained under the greenhouse and open environmental condition for 30 days with or without M. salsuginis TNMB03 treatment. After 30 days, plant growth parameters like pseudostem height, girth, number of leaves, leaf area, fresh and dry biomass, root parameters, plantlet survival, chlorophyll a and b, total chlorophyll, carotenoids and soluble protein and Methylobacterium population in upper and lower surface of leaf, as well as endophytic population were assessed. Results: This study showed that the plantlets biotized with M. salsuginis TNMB03 had better acclimatization response under both the experimental condition than that of uninoculated plantlets. Positive influence on the survival and growth of M. salsuginis TNMB03 biotized plantlets was observed when transferred directly to greenhouse and open environmental condition. Inoculation of M. salsuginis TNMB03 increased the plant height, girth and number of leaves, root length, lateral root and biomass in comparison to the uninoculated plantlets in greenhouse and open environment. Uninoculated plantlets kept under open environment had lower chlorophyll content and sun scorching damages compared to M. salsuginis TNMB03 inoculated plants, which had dark green leaves and increased chlorophyll content. Interpretation: This study shows a new potential technique of using M. salsuginis TNMB03 in tissue culture plantlets, which can help in enhancing the growth of plantlets transferred from culture vessel to greenhouse or open environmental condition without undergoing the routine acclimatization procedure.

Diversity and functional characterization of endophytic Methylobacterium isolated from banana cultivars of South India and its impact on early growth of tissue culture banana plantlets.

This study aimed at determining the distribution, colonization and growth promoting nature of Methylobacterium spp. in tissue culture banana plantlets. Leaf samples from different field grown banana cultivars were used for Methylobacterium spp., isolation. Metabolic profile and functional characterization for plant growth-promoting traits of the isolates were assessed. The isolates were confirmed using 16S rRNA gene sequencing analysis, which resulted in six distinct species of Methylobacterium namely M. radiotolerans, M. salsuginis, M. thiocyanatum, M. rhodesianum, M. rhodinum and M. populi. Methylobacterium spp. inoculation experiment was conducted under hydroponic system in tissue culture banana plantlets (germ free) with eight selected isolates. A significant increase in growth parameters of Methylobacterium treated plantlets compared to uninoculated control was observed. Methylobacterium salsuginis TNMB03-gfp29 was developed and colonization micrograph was obtained using confocal laser scanning microscopy (CLSM) and scanning electron microscopy in different parts of banana plantlets (root, stem and leaves). Field grown banana plants found to harbour diverse endophytic Methylobacterium population. Our finding suggests that endophytic Methylobacterium species may provide significant plant growth promoting compounds/nutrients to the banana plants. The experimental results demonstrated the efficacy of Methylobacterium spp. as a potential bioinoculant and can be exploited as a phyllosphere and rhizosphere based bioinoculant for the initial establishment and growth of tissue culture banana plantlets. This study extended our knowledge on the distribution of Methylobacterium spp. in banana plants and endophytic colonization nature of this particular genus in plants. In addition, efficient isolate (M. salsuginis TNMB03) identified in this study may be promoted as bio-inoculants for banana plants after field evaluation.

Evaluation of Plant Growth Parameters by In vitro and Ex vitro Inoculation of Micropropagated Banana Plantlets with Rhizospheric and Endophytic Bacterial Inoculum

Banana propagation is dependent on propagation by tissue culture for industrial purposes. Due to lack of native endophytes in tissue culture plantlets, reintroduction of beneficial microorganisms to tissue culture plantlets become popular as a useful foundation for improving the level of establishment, increasing plant growth parameters, protecting the plantlets against pest and diseases and overall performance for field plantation. In the present study, rhizospheric and endophytic four bacterial species (Pseudomonas fluorescens, Bacillus putida, Bacillus pumilus, Bacillus amyloliquefaciens were isolated from different parts of healthy banana plants such as root, leaf and pseudostem. Banana tissue culture plantlets were cultured for root formation stage on MS medium and used as host for artificial inoculation. Then, bacterial inoculation was carried out with tissue culture plantlets both in vitro and ex vitro conditions. All banana plantlets used for this experiment were successfully acclimatized and survived in the greenhouse. The experiment consisted of three treatments: (1) bacterial inoculum with in vitro rooted plantlets for 2 weeks (2) bacterial inoculum with ex vitro (hardening) plantlets (3) control with sterilized distilled water. Among these treatments, in vitro inoculation affected significantly increased plant height, number of leaves and plant girth for all data collection times with the highest increment indices: (24.0, 7.0, and 7.3). Ex vitro inoculation showed the second highest increment indices: (22.0, 6.9 and 6.3) for plant height, number of leaves and plant girth, respectively. The lowest number of plant growth parameters were observed in control treatment for all four data collection time (19.0, 6.2, and 6.0). According to the results, application of mixtures of bacterial inoculum was effective for enhanced plant growth parameters of tissue culture banana plantlets under greenhouse condition. In addition, two weeks artificial inoculation during in vitro plantlets stage was found the most suitable method for application of microbes with tissue culture banana plantlets which can promote the microbial rhizosphere of banana prior to field plantation.

Socio-Economic Factors and their Influence in Adoption of Agricultural Technologies Under Subsistence Economy; A Case of Tissue Culture Banana in Uganda

Uptake of improved agricultural technologies like banana tissue culture still remains low despite the efforts that have been put in place to enhance its adoption. A survey was carried out on 115 smallholder farmers in central Uganda to establish the influence of various socio-economic factors on the adoption of tissue culture banana between January and July 2018. Findings from the study revealed that respondents’ main occupation (P = 0.028), market accessibility (P = 0.006) and proximity to the source of planting materials (P = 0.000) were the major drivers to adoption of tissue culture banana. The study thus recommended the establishment of regional distribution centres for tissue culture banana plantlets, increased investment in extension in order to strengthen the farmer-researcher linkage and increased market access.

In vitro mutagenesis using bio-beam irradiation on in vitro culture of Cavendish banana cultivar (Musa acuminata Colla) explants

Banana, Musa acuminata cv. Cavendish, was commonly propagated by use of suckers from selected field grown clumps. An in vitro technique has in recent years provided with rapid and efficient system propagation. However, high demand for planting material has caused significant shortages and subsequently attempts at improving the efficiency of in vitro propagation technique have been initiated. The current study investigated the effect of gamma irradiation using bio-beam on in vitro propagation of banana cv. Cavendish. The main objective was to assess the effect of mutation induction using gamma source on growth and development of plantlets while in culture. Tissue cultured banana plantlets were used as source of explant materials. The plantlet was trimmed of leaves and halved before culturing on Murashige and Skoog (MS) media. Then, the explants radiated with gamma source using Ion-Beam with selected dose [0 (control), 30 Gy, 60 Gy, 90 Gy, 120 Gy and 150 Gy] and transferred to fresh MS media with 5 mg/l of BAP. The analysis showed dosage of 30 Gy and 60 Gy produced significant survival rate and favourable effect on growth especially on plant height, shoot number, leaf production and root production. Thus, this study contributed to develop in vitro mutagenesis of M. acuminata cv. Cavendish through gamma rays coupled with in vitro system for future breeding of new varieties of banana.

Growth estimation during hardening phase of tissue cultured banana plantlets using bootstrapped artificial neural network

Growth estimation during hardening phase of tissue cultured banana plantlets using bootstrapped artificial neural network

Cost-effective tissue culture media for large-scale propagation of three commercial banana (Musa spp.) varieties

ABSTRACTCost-effective tissue culture protocols have been established for the commercial multiplication of three banana varieties, ‘Rasthali’ (AAB – Silk), ‘Grand Naine’ (AAA – Cavendish), and ‘Udhayam’ (ABB – Pisang Awak). Reverse osmosis water and 3% (w/v) table sugar were used as the low-cost water and carbon source, respectively. Six different gelling agent treatments were tested: sago alone (T1), Isabgol alone (T2), sago + agar (T3), Isabgol + agar (T4), sago + Isabgol (T5), and agar alone as a control (T6). Full-strength Murashige and Skoog (MS) medium supplemented with 3 mg l–1 6-benzylaminopurine (BAP) and 1 mg l–1 indole-3-acetic acid (IAA) were used for culture initiation and subculturing. Rooting was accomplished on low-cost MS medium containing 1.0 mg l–1 α-napthaleneacetic acid (NAA), 1.0 mg l–1 indole-3-butyric acid (IBA), and 250 mg l–1 activated charcoal. Statistical analysis indicated that sago + Isabgol (T5) produced the maximum number of shoots (10 per explant) in ‘Udhayam’ and ‘Rasthali’, while sago alone (T1) produced the maximum number of shoots (6 per explant) in ‘Grand Naine’. The genetic stability of tissue-cultured banana plantlets produced using these low-cost substitutes was assessed using inter-simple sequence repeat (ISSR) markers. The results indicated that the ISSR profiles of the five treatments and the control (T6) were similar, indicating genetic stability using these cost-effective tissue culture protocols. Reductions in cost over the control (l–1 of MS medium) ranged from 65% to 86%, while the per plant production cost was reduced by 12.5%–20.0%. Adoption of these treatments (T1–T5) as low-cost tissue culture protocols for in vitro propagation would reduce production costs significantly, leading to an expansion of the area planted with tissue-cultured banana, thereby increasing productivity.

BIO-EFFICACY EVALUATION OF A NEW COPPER BASED FUNGICIDE AGAINST FOLIAR DISEASES OF 'CAVENDISH' BANANA UNDER HIGHLAND CONDITION IN MINDANAO, PHILIPPINES

The control of banana leaf diseases is one of the major constraints for the production of dessert bananas for export. Their management requires frequent application of systemic and contact fungicides. Ionic copper concentrate (ICC) is a new ionized copper formulation developed for control of leaf diseases. In a yield trial ten tissue cultured banana plantlets (‘Williams’) were used per plot, to compare three rates of ICC (100, 125 and 150 ml/ha) alone and in combination with mineral spray oil (7 L/ha plus 0.07 L/ha emulsifier) against the standard Mancozeb 600 OS (with 7 L/ha mineral oil plus 0.07 L/ha emulsifier) and Chlorothalonil 720 SC fungicides for control of foliar diseases under highland condition (870 m a.s.l.) in Mindanao, Philippines. ICC rates in combination with mineral oil significantly reduced Mycosphaerella fijiensis compared to the ICC with no oil. ICC at the different concentrations with mineral oil also resulted in a comparable number of functional leaves relative to the standard Mancozeb 600 OS and Chlorothalonil 720 SC treatments. ICC 125 and 150 ml/ha with Phyllosticta musarum mineral oil gave a comparable result compared with the standard Mancozeb 600 OS against leaf freckle (Phyllosticta musarum). However, the different rates of ICC with oil were inferior to Chlorothalonil 720 SC for the control. All rates of ICC without oil were inferior compared to the standard fungicides and compared to ICC with mineral oil against Mycosphaerella fijiensis and Phyllosticta musarum. Similarly, all rates of ICC applied alone had no significant effect against Haplobasidium sp. causing Malayan leaf spot. The different rates of ICC with mineral oil reduced Malayan leaf spot compared to the ICC without oil, but were inferior to both standard fungicides. All treatments of ICC with or without oil showed no toxicity on fruit or oil flecking on the leaves.

Contamination of bananas with beauvericin and fusaric acid produced by Fusarium oxysporum f. sp. cubense.

BackgroundFusarium wilt, caused by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases of banana. Toxins produced by Foc have been proposed to play an important role during the pathogenic process. The objectives of this study were to investigate the contamination of banana with toxins produced by Foc, and to elucidate their role in pathogenesis.Methodology/Principal FindingsTwenty isolates of Foc representing races 1 and 4 were isolated from diseased bananas in five Chinese provinces. Two toxins were consistently associated with Foc, fusaric acid (FA) and beauvericin (BEA). Cytotoxicity of the two toxins on banana protoplast was determined using the Alamar Blue assay. The virulence of 20 Foc isolates was further tested by inoculating tissue culture banana plantlets, and the contents of toxins determined in banana roots, pseudostems and leaves. Virulence of Foc isolates correlated well with toxin deposition in the host plant. To determine the natural occurrence of the two toxins in banana plants with Fusarium wilt symptoms, samples were collected before harvest from the pseudostems, fruit and leaves from 10 Pisang Awak ‘Guangfen #1’ and 10 Cavendish ‘Brazilian’ plants. Fusaric acid and BEA were detected in all the tissues, including the fruits.Conclusions/SignficanceThe current study provides the first investigation of toxins produced by Foc in banana. The toxins produced by Foc, and their levels of contamination of banana fruits, however, were too low to be of concern to human and animal health. Rather, these toxins appear to contribute to the pathogenicity of the fungus during infection of banana plants.

Yield Effects of Tissue Culture Bananas in Kenya: Accounting for Selection Bias and the Role of Complementary Inputs

AbstractWe analyse yield effects of tissue culture (TC) banana technology in the Kenyan small farm sector, using recent survey data and an endogenous switching regression approach. TC banana plantlets, which are free from pests and diseases, have been introduced in East Africa since the late 1990s. Although field experiments show significant yield advantages over traditional banana suckers, a rigorous assessment of impacts in farmers’ fields is still outstanding. A comparison of mean yield levels between TC adopters and non‐adopters in our sample shows no significant difference. However, we find evidence of negative selection bias, indicating that farmers with lower than average yields are more likely to adopt TC. Controlling for this bias results in a positive and significant TC net yield gain of 7%. We also find that TC technology is more knowledge intensive and more responsive to irrigation than traditional bananas. Simulations show that improving access to irrigation could lift TC productivity gains to above 20%. The analytical approach developed and applied here and the finding of negative selection bias may also be relevant for the evaluation of other agricultural technologies.

Accessing and producing tissue cultured banana plantlets in Costa Rica and Jamaica: Insights on the distributive consequences of emerging technologies

This paper analyzes the distributive dynamics associated with production, access to, and use of tissue-cultured banana plantlets in Costa Rica and Jamaica. In particular, it studies the research, commercialization, and production strategies undertaken in these two countries. It identifies the actors involved, the mechanisms implemented to produce and improve access to tissue cultured plants, as well as barriers to broad-based adoption. The discussion is framed by the concept of absorptive capacities and more particularly, by a revised perspective that differentiates between potential and realized capacities. In so doing, it emphasizes the dynamic aspects behind the process of moving from potential to realized capacities. Inherent aspects of tissue culture technology overlap and interact with socio-economic conditions; and become key to the dynamics of knowledge advancement, production, and distribution of benefits. In this context, policy choices play a major role in directing the dynamics towards a more distributed technological development.

Growth stimulation effects of smoke-water and vermicompost leachate on greenhouse grown-tissue-cultured ‘Williams’ bananas

A common problem often experienced by both small and large scale banana farmers is the reduction in quality and yield of bananas due to soil moisture deficits and declining soil fertility. To overcome this, mechanisms of improving yield without compromising environmental integrity or public health are being embraced. Globally, researchers have continued to evaluate the competence of environmental-friendly organic fertilizers and smoke solutions to improve the growth, yield and quality of various crops. In the present study, the effect of smoke-water (1:1,000; 1:500 and 1:250 dilutions) and vermicompost leachate (1:20; 1:10 and 1:5 dilutions) treatments on the growth of greenhouse grown bananas was evaluated. Soil drenching (smoke-water and vermicompost leachate) and foliar application (smoke-water) were tested on 1-month-old tissue-cultured banana seedlings under greenhouse conditions. After 3 months, growth parameters such as number and length of roots and shoots; number of leaves and leaf area as well as their fresh and dry weights were analyzed. Soil drenching with smoke-water significantly increased the root length (1:1,000 and 1:500 dilutions) as well as fresh and dry weight (1:1,000; 1:500 and 1:250 dilutions) when compared to foliar application. Vermicompost leachate (1:10 and 1:5 dilutions) significantly enhanced the shoot length, root length, leaf area and dry weights. Vermicompost leachate (1:20; 1:10 and 1:5 dilutions) also significantly increased the number of off-shoots. The positive effect on rooting is beneficial for acclimatization and establishment of tissue-cultured banana plantlets in nurseries and subsequent transfer to the field. Moreover, the high cost of inorganic fertilizers as well as environmental safety concerns makes the use of smoke-water and vermicompost leachate potential alternatives to improving the growth and cultivation of bananas.

Elucidation of the taxonomy and pathological status of Pyricularia associated with banana blast in Australia

In September 2010, banana blast symptoms were observed on leaves of tissue cultured banana plantlets cv. Dwarf Cavendish. The pathogen was identified as Pyricularia angulata, based on disease symptoms, fungal morphology, pathogenicity and ITS sequencing. Previous Pyricularia spp. samples and records were confirmed as being P. angulata. This report elucidates the identity and pathological status of P. angulata in Australia.

The effect of rhizobacterial inoculation on growth and nutrient accumulation of tissue-cultured banana plantlets under low N-fertilizer regime

Banana, an important fruit crop, requires high amounts of N-fertilizers for commercial cultivation. This, however, is costly and can be hazardous to the soil environment when used excessively. Biofertilizer is globally accepted as an alternative source of N-fertilizer and can substantially supplement the N requirement while enhancing the uptake of water and mineral nutrients of crop plants. An experiment was conducted to observe the effect of plant growth promoting rhizobacterial inoculation on growth, nutrient uptake of bananas grown under hydroponics condition. The design of the experiment was randomized complete block with five replicates. The following six treatments were imposed: T1 (control; N0-PGPR), T2: (N0+Sp7), T3: (N0+ UPMB10), T4: (N33%+ Sp7), T5: (N33% + UPMB10), and T6: (N100%-PGPR). The results showed that inoculation by UPMB10 with minimal fertilizer-N supply increased (P < 0.05) the primary root elongation and secondary root initiation and subsequently increased (P < 0.05) the root biomass. The same treatment also increased (P < 0.05) N concentration in pseudostem and leaves and Ca concentration in roots. The total accumulation of N, P, K, Ca and Mg were increased due to inoculation; a consequence of increased plant growth. Plants with this treatment produced an equivalent total dry matter as those supplied with 100% N.

Artificial inoculation of banana tissue culture plantlets with indigenous endophytes originally derived from native banana plants

Fusarium wilt disease of banana is one of the most harmful fungal diseases affecting banana production worldwide. We hypothetically proposed that the loss of indigenous endophytes in tissue culture propagation of banana might be related to increased disease severity on banana plants. In the present study, a mixture of uncultivated endophytes, which was originally derived from native healthy banana plant in plantation, was used to artificially inoculate banana tissue culture plantlets. A broad spectrum of bacterial communities was detected in the roots of artificially inoculated plantlets by 16S ribosomal RNA gene analysis, and γ-Proteobacteria was identified as the dominant group. Banana wilt pathogen Fusarium oxysporum f. sp. cubense race 4 was inoculated to the plantlets after potting to investigate disease progress. With early diagnosis of fungal pathogen infection, 54% reduction was detected in artificially inoculated plantlets compared to endophyte-free control plantlets. The re-introduction of naturally-occurring endophytes into tissue culture banana plantlets led to a 67% suppression rate of wilt disease at the fifth month after pathogen infection on plantlets in the greenhouse. In addition to disease suppression, growth of host plantlets was also promoted with the inoculation of endophytes. The artificial inoculation method provided a foundational understanding of ecological enrichment to control banana wilt disease in future.

Biohardening with Plant Growth Promoting Rhizosphere and Endophytic bacteria induces systemic resistance against Banana bunchy top virus

Tissue culture banana has emerged as one of the leading global agro based industrial technologies. However, the banana plants are found to be more susceptible to pests and diseases due to their pliable nature and lack of withstanding in the natural environment. Banana bunchy top disease (BBTD) caused by Banana bunchy top virus (BBTV) is the most serious virus disease of banana and plantain world wide. Biopriming (or) biohardening refers to treatment of tissue culture banana plantlets with microbial inoculants to strengthen the plantlets against biotic and abiotic stresses. Forty plant growth promoting endophytic bacteria (PGPE) were isolated from the corm and roots of banana and tested for the ability to induce systemic resistance against BBTV. Phenotypic and molecular characterization of the endophytic bacteria revealed the presence of Pseudomonas and Bacillus species. Micropropagated banana plantlets were tested for the presence of BBTV by ELISA, DIBA and PCR and the uninfected plants were biohardened with two rhizobacterial ( Pseudomonas fluorescens, Pf1, CHA0) and endophytic bacterial (EPB5, EPB22) strains. Plants treated with mixtures of rhizobacterial and endophytic bacterial formulations viz., EPB5 + EPB22 + Pf1 + CHA0 was significantly effective in reducing BBTV under field conditions recording 33.33% infection with 60% reduction over control. The expression of defense-related enzymes and pathogenesis related proteins were more in the plants treated with rhizosphere and endophytic bacterial formulations than the control plants. The morphological and physiological characters were also well pronounced in the treated plants indicating its plant growth promoting nature. Thus, the present study clearly demonstrated that PGPR and PGPE mediated induction of systemic resistance in banana plants against BBTV have the potential role in the management of BBTD.

The Effects of HIV/AIDS on Livelihoods and Adopting Tissue-cultured Technology among Banana-farming Households in Central Kenya

Increasing agricultural productivity is one of the important adaptations for farming households to enable them to attain sustainable livelihoods in times of crisis. Adoption of appropriate agricultural technologies is key to increasing productivity and rural household income. Yet several factors influence the adoption of agricultural technologies, which may constraint the technology?s potential contribution to development and poverty reduction. This study investigated the factors influencing the adoption of tissue-cultured bananas in the context of HIV/AIDS in rural Kenya. It adapted the sustainable livelihood approach and studied the assets, livelihood activities, strategies and outcomes of the farming households. A combination of quantitative and qualitative methods was used to collect the data. Qualitative methods included key informant interviews, focus group dis¬cussions, and in-depth interviews, while a survey among 254 banana-farming house¬holds provided quantitative data. The sample was stratified according to use or non-use of the tissue-cultured banana. Within each stratum, both HIV/AIDS-affected and non-affected house¬holds were selected. The results indicate that adoption of tissue-cultured banana is highly related to the house¬hold?s availability of savings, possession of farm equipment and security of land tenure. Households? HIV/AIDS status does not seem to influence continued use. How¬ever, the death of an adult household member does negatively influence this. The more adult household members lost through death the less likely a household is to continue using tissue-cultured banana plantlets. Farming households that have contact with extension services are also more likely to adopt tissue-cultured plantlets. However, extension service providers are faced with challenges in providing information on appropriate technology for HIV/AIDS-affected households. Diversification of income-generating activities is positively related to tissue-cultured banana adoption.

Screenhouse and Field Persistence of Nonpathogenic Endophytic Fusarium oxysporum in Musa Tissue Culture Plants

Two major biotic constraints to highland cooking banana (Musa spp., genome group AAA-EA) production in Uganda are the banana weevil Cosmopolites sordidus and the burrowing nematode Radopholus similis. Endophytic Fusarium oxysporum strains inoculated into tissue culture banana plantlets have shown control of the banana weevil and the nematode. We conducted screenhouse and field experiments to investigate persistence in the roots and rhizome of two endophytic Fusarium oxysporum strains, V2w2 and III4w1, inoculated into tissue-culture banana plantlets of highland cooking banana cultivars Kibuzi and Nabusa. Re-isolation of F. oxysporum showed that endophyte colonization decreased faster from the rhizomes than from the roots of inoculated plants, both in the screenhouse and in the field. Whereas rhizome colonization by F. oxysporum decreased in the screenhouse (4-16 weeks after inoculation), root colonization did not. However, in the field (17-33 weeks after inoculation), a decrease was observed in both rhizome and root colonization. The results show a better persistence in the roots than rhizomes of endophytic F. oxysporum strains V2w2 and III4w1.

Potential implications of biopriming in banana (Musa spp) plantlets against banana bunchy top virus (BBTV)

Transplant media as a means for the introduction of biological agents is currently being investigated in a variety of crops. This study aimed to investigate the impact of microbial inoculation in micropropagated banana plantlets to enhance their resistance against Banana bunchy top virus (BBTV). Virus indexed micropropagated plantlets of banana were subjected to root colonization followed by foliar spraying with bacterial strains Pseudomonas fluorescens Pf1, CHA0 and Bacillus subtilis EPB22 during primary and secondary hardening stage in the nursery, at the time of repotting and 3 months after planting in the pot. Microbe inoculated plantlets showed enhanced PR proteins and defense enzymes besides reducing banana bunchy top disease incidence under glasshouse condition. The results indicated the effective use of beneficial microbes in reducing the disease incidence of BBTV in tissue culture banana plantlets. In addition, the molecular characterization of endophytes isolated from banana plantlets, using SDS-PAGE and RAPD-PCR revealed that endophytes were categorized into two distinct groups. These results emphasize the significance of microorganisms in protection of young plantlets from transplanting stresses in field. Further, the use of beneficial microorganisms instead of chemicals sustains an ecological niche in the agricultural ecosystem.