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In Ethiopia, enset (Ensete ventricosum, Musaceae) has been utilized as multipurpose crop since ancient time, being a measure for smallholder farmers to mitigate prolonged droughts and thus climate ...

More than 18 wild banana (Musaceae) species and hundreds of cultivars were found in Thailand, many are introduced as ornamentals. The banana family which is classified into three genera: Musa, Ensete and Musella, distributes in the old world tropics and Thailand is among their centers of origin. Many banana species possess attractive bract colors such as orange, pink, bright red, purple, and also, though less frequently found, yellow and green. Several other appealing features of the bananas are dwarf pseudostems, variegated leaves, multiple male inflorescence, uneven colored inflorescence bracts and numerous hands of fruits. Recently, three new banana species, Musa siamensis Hakkinen & Rich. H. Wallace, M. serpentina Swangpol & Somana and M. nanensis Swangpol & Traiperm were discovered in the country. These bananas have decorative potential; taxonomic revision could enhance the selection process of these taxa and bring them into the spot light as economic ornamental crops.

The history of Musaceae taxonomy in India is briefly presented. The maximum diversity and distribution of Musaceae is located in the northeastern States, with 30 taxa of which 19 are endemic to the region. This represents about 81% of the total wild Musaceae diversity in India. This also indicates that the region bordering with Bangladesh, China and Myanmar is a biodiversity-rich area for Musaceae and strengthen the view that this region is considered as one of the major centers of origin of the family Musaceae. The second largest Musaceae diversity in India is found in Andaman and Nicobar Islands, where three taxa are present all of which are endemic. In the Western Ghats, three taxa are present, including one endemic taxon, and the same is the case in Eastern Ghats. During this work, two species are found to be extinct from the wild and 19 taxa are categorized as threatened.

China was dubbed as “the Mother of Gardens” by gardener and botanist Ernest Henry Wilson who collected and shipped about 2000 species of plants from Asia to Europe and North America. Many ornamentals in western countries originated from China. This paper presents the biodiversity of native Chinese ornamental plants at ecosystem, species and genetic levels, focusing on species and genetic resources with aesthetic potentials, based on literature studies and authors’ participatory investigations. The latest statistics reported 31,362 vascular species (taxa) occurring in China, of which about 6000 species are with gardening values. The diversified ornamental plants become important components of different ecosystems. As the dominant species, some ornamental plants established the plant communities in forests and grasslands, which made the landscapes more colourful and beautiful. Famous representatives were introduced including Camellia, Rhododendron, Rosa, Lilium, Chrysanthemum, Cymbidium and others. Lots of species are with multiple uses in addition to aesthetic values, like medicinal, edible, agricultural or daily life uses. The relationship between biodiversity and cultural diversity of ornamental plants is discussed. Biodiversity of Paeonia, mei flower, Chrysanthemum, sweet osmanthus, Chinese roses and many flowers endowed special meanings to traditional Chinese culture, which enriched cultural diversity. On the other hand, the traditional Chinese culture affected the diversity of ornamental plants. Some potential ornamental plants but underutilized or neglected, including Musella lasiocarpa (Musaceae), Lycoris (Amaryllidaceae), and Leucocasia gigantean (Araceae), are presented. The strategies for conservation and development of Chinese ornamental plants are proposed.

Banana and plantain (Musa spp.) are seed-sterile vegetatively propagated crops, which originated as intraspecific hybrids of Musa acuminate and interspecific hybrids between M. acuminate and Musa balbisiana. The rich genetic diversity of this crop is, however, endangered by diseases, adverse environmental conditions and changing farming practices. To set up an efficient and effective strategy for breeding improved banana cultivars and support the choice of crossing-parents, a solid understanding of the genetic diversity of available resources is needed, underlining the need for characterization and conservation of this genetic diversity. With the aim to provide a simple and robust approach for genotyping in Musa, we have developed an optimized genotyping platform using SSR markers. The genotyping system is based on 19 microsatellite loci, originally developed by CIRAD, which are scored using fluorescently labeled primers and high-throughput capillary electrophoresis separation with high resolution. The knowledge gained during the course of this study is used by the Musa Genotyping Centre, which serves the Musa research and breeding community by determining DNA ploidy and SSR profiles of unknown samples. The Centre operates on a cost-recovery basis and guarantees that all analyses are performed under strictly controlled conditions, enabling direct comparison of various accessions from different parts of the world.

Xanthomonas wilt of banana and enset (XW) caused by Xanthomonas campestris pv. musacearum (Xcm) is a devastating bacterial disease. Infection of pre-flowering stage plants result in leaf yellowing/wilting and eventual plant death. Floral infections result in wilting of male bud bracts, followed by decaying of the rachis, premature fruit ripening and bunch rotting, and eventual death of the plant. The movement of Xcm in infected plants is systemic. However, the presence of Xcm in cord roots of banana plants has not yet been investigated. Cord roots of symptomatic pre-flowering stage and inflorescence-infected plants of an East African highland banana cultivar mixture (AAA-EA) and 'Pisang Awak' (ABB) were examined for Xcm presence, in naturally infested farmers' fields and after artificial inoculation. Pre-flowering stage plants were inoculated by cutting the three oldest leaves with a contaminated knife, while a Xcm suspension was smeared on male flower/bract scars of flowering plants. In addition, pre-flowering stage plants were inoculated by cutting the cord roots with a contaminated knife and drenching the surrounding soil with Xcm suspension. Plants were monitored during 12 months for symptom development. Overall, the presence of Xcm in the cord roots was significantly lower compared to corms. A higher incidence of cord root infection was observed in the artificially inoculated plants compared to plants assessed in farmers' fields. The incidence of cord root infections in inflorescence-infected plants increased with progressing disease development for both cultivars. The results suggest that cord roots could contribute to garden tool transmission, for example during weeding. Therefore, hand weeding and herbicide use are advised when diseased mats are present in a field. Long incubation periods and latent infections were noted after artificial cord root inoculations. The development and deployment of diagnostic kits sensitive to latent infections for routine surveillance is therefore recommended for effective XW management.

Embryogenic cell suspensions (ECS) initiated from immature male flowers of banana cultivar 'Dwarf Brazilian' (AAB, Pome subgroup) were transformed using Agrobacterium tumefaciens containing one of four constructs derived from the replicase-associated protein (Rep) gene of the Hawaiian isolate of Banana bunchy top virus (BBTV). Each construct was engineered under control of a double CaMV 35S promoter and the AMV enchancer sequence in the binary plasmid pBI121. Constructs were transferred into A. tumefaciens strain AGLO and used to transform banana ECS. Plantlets that survived antibiotic selection were acclimated to greenhouse conditions and challenged with viruliferous banana aphids (Pentalonia nigronervosa). Ten adult or late instar aphids were allowed to feed for 2-4 weeks on test plants. All test plants were kept in the greenhouse and monitored for symptom expression for a period of 6 months. Control plants transformed with empty vector pBI121 only were included in all tests. A total of 270 test plants and 63 control plants were screened for BBTV resistance using this approach. One of 32 test plants transformed with the M1 (mutant Rep gene) construct, 5 of 74 test plants transformed with the AS1 (antisense Rep gene) construct, 5 of 38 test plants transformed with the PR1 (partial Rep gene) construct, and 10 of 126 test plants transformed with the R/PR1 (full-length Rep gene fused to antisepses partial Rep gene) construct were found to be resistant to BBTV challenge and showed no bunchy top symptoms. All of the control plants became infected with BBTV under these experimental conditions. Plants that survived BBTV challenge were analysed by quantitative PCR (per) and Southern hybridisations to determine the number of transgenes that were present in their genomes. Results from these analyses indicated that the resistant plants contained from 2 to more than 9 copies of the NPTII (kanamycin resistance) transgene carried on the pBI121 plasmid.

Banana and plantain (Musa species, Zingiberales) are a relatively under researched plant group in contrast to their great socio-economic importance and their significance as one of the earliest domesticated crops. The classification of species and clones is hampered by the traditional morphology-based taxonomy, with limited knowledge on specific molecular characteristics of individual taxons. The phylogeny of the Musaceae has never been fully resolved, and the accuracy of the current classification system is a common point of debate among the scientific community. Different types of molecular markers have been used to investigate the diversity at various taxonomic levels within Musa species and have reached various degrees of success in terms of phylogenetic reconstruction. The phylogenetic history of Musaceae as a part of the order Zingiberales was investigated in previous studies (Kress et al., 2001). However, within the family Musaceae itself, few papers have addressed this question (Lescot et al., 2008; Boonruangrod et al., 2008) and the evolutionary relationships remain fuzzy. This paper is an overview of molecular-based approaches that have been employed by our research group in an attempt to shed more light on Musaceae diversity and evolutionary relationships, and thereby serve for the classification and development of reliable markers for unambiguous banana species identification.

The banana Xanthomonas wilt (BXW) disease, caused by the bacterium Xanthomouas campestris pv. musacearum (XCM), endangers the livelihoods of millions of farmers in the Great Lakes region of East and Central Africa. The disease was first identified in Uganda in 2001 and has since then also been reported in Eastern Democratic Republic of Congo, Rwanda, Kenya and Tanzania. The pathogen kills plants quickly and spreads rapidly over a large area making the disease one of the most dreaded in banana (Musa spp.). The development of disease resistant banana cultivars remains a high priority, since farmers are reluctant to employ labor-intensive disease control measures. Prospects of developing cultivars with resistance to BXW through conventional breeding are limited, as no source of germplasm exhibiting resistance against XCM has been identified. Transgenic technologies for banana may provide a timely and cost-effective alternative solution to the BXW pandemic. The ferredoxin-like amphipathic protein (pflp) and hypersensitive response assisting protein (hrap), isolated from sweet pepper (Capsicum annuum) are novel proteins that can intensify the harpinPSS-mediated hypersensitive response. The International Institute of Tropical Agriculture (IITA) has negotiated royalty-free license from Academia Sinica, Taiwan, patent holder, through the African Agricultural Technology Foundation (AATF) for access to the technology for bacterial wilt resistance. The partners, IITA, the National Agriculture Research Organization (NARO) in Uganda and AATF, have signed a tripartite agreement for development of BXW-resistant transgenic bananas. Hundreds of transgenic lines of banana cultivars have been generated, which are screened for disease resistance under laboratory conditions. Most promising lines will be evaluated for efficacy against XCM in fields.

The banana (Musa spp.) cultivars grown in the rural areas of South Africa are 'Pisang Awak' (ABB genome) (70%) and 'Cavendish' (AAA genome) (30%) in contrast to only 'Cavendish' in the commercial banana growing areas. 'Pisang Awak' is a hardy banana cultivar that is currently not grown for commercial purposes but as a domestic fruit for home use on small plots and as a fencing shrub. It does not seem to require expert commercial farming skills to cultivate and requires very little in terms of care as compared to established banana cultivars currently on the market. This makes it ideal for exploitation as a commercial crop by rural communities in these areas. However, until recently, this potential was overlooked and fruit was mostly wasted. Since the establishment of a banana-juice factory by the University of Johannesburg in 2005 in White River, South Africa, this cultivar is generating an income. Although 'Pisang Awak' is a low-yielding cultivar, it is a very good juice banana and up to 50% juice concentrate is extracted from the fruit in comparison to the 15% juice from 'Cavendish'. This project is aiming to evaluate several high-yielding juice bananas including hybrids from Honduras and to supply farmers with plants in two rural banana growing areas. Technology transfer on banana production is being done to cooperatives in selected areas and transport of fruit to ripening rooms and factories is being established. In a later stage, a packhouse will be built. This industry can be expanded significantly as the market for banana juice exists and is hardly exploited by the present juice production. Because of the organization of cooperatives in different areas, farmers do not require 30 ha or more to create an income-producing business.

Plantain (Musa spp. AAB genome) is an important staple of the humid zone of West and Central Africa. Root nematodes, specifically Radopholus similis, along with other pests and diseases are a major cause of yield loss. Farmers are unaware of the presence, symptoms and effects of nematodes. No commonly used method to clean infested plantain suckers exists. This paper presents a simple, inexpensive and highly mobile method to treat plantain suckers against pests and diseases attached to the suckers. The purpose of the paper is primarily to show that submerging plantain suckers in boiling water for a limited time (

Xanthomonas wilt caused by Xanthomonas campestris pv. musacearum has been an important constraint to enset (Ensete ventricosum) and banana (Musa spp.) in Ethiopia. It was postulated that Xanthomonas wilt has a similar epidemiology as other banana bacterial wilts, which are known to be transmitted by insect vectors and garden tools. A study to determine the role of garden tools in the transmission of Xanthomonas wilt was carried out on enset in a greenhouse at the Southern Agricultural Research Institute, Awassa, Ethiopia and on 'Pisang Awak' (AABB genome) in the field at Amaro, Southern Ethiopia. A contaminated knife was used to infect plants. The treatments in the greenhouse trials comprised of cutting: green leaves; broken green leaves; dry leaves; the pseudostem; and roots. Similar treatments were carried out on the field-grown 'Pisang Awak' plants with two additional treatments: desuckering and debudding. Debudding was done by cutting off the male bud with a contaminated machete, while a forked stick was used for control samples. In addition, bacterial ooze was smeared on fresh and dry flower and bract scars at the male part of inflorescences. All plants treated with a contaminated machete: enset and banana when cut in the pseudostem; and all banana plants when debudded got infected. Similarly, cutting green leaves and cutting broken green leaves resulted in a high disease transmission of respectively 67 and 62% in banana and 58 and 54% in enset. Similar high transmission rates (90%) were obtained for desuckering on banana. On the other hand, cutting roots with a contaminated machete resulted in low transmission levels, with 20% in bananas and 25% in enset suggesting that tool infections mainly occur above ground. This calls for rigorous tool disinfection, while desuckering and deleafing in highly infected fields should be avoided. Debudding should be carried out with a forked stick.

Using eight nuclear and four chloroplast microsatellite markers, a total of 133 banana (Musa spp.) accessions from East Africa, Bioversity International and Polynesia were characterized at the University of Hawaii. The objectives of the study were to determine variation patterns existing in the Musa AA and AAB genomes of East Africa and to determine the usefulness of microsatellites markers in differentiating accessions within the two Musa genome groups. Group average clustering produced major clusters corresponding to the genome composition of AAA, AAA-EA, AAB (plantains), AAB (dessert bananas), AA and AB. At least four distinct subclusters of 'Apple Banana' (AAB genome) were observed, namely 'Mysore' (AAB genome), 'Sukari Ndizi' (AAB geome), 'Prata' (AAB genome) and 'Silk' (AAB genome). The East African 'Muraru' (AA genome) dessert bananas formed a distinct cluster with a high similarity to AAA dessert bananas, suggesting the possibility of shared ancestry between them.

Banana (Musa spp.) is one of the most widely consumed fruits and an attractive perennial fruit crop for small farmers in Kenya. However, viral diseases such as Banana streak virus (BSV) have contributed to the poor performance of banana seedling production. Knowledge of the prevailing BSV isolates in the country and establishment of virus indexed banana plants is therefore important, since virus-free indexed mother stocks are required for micropropagation. The present study was aimed at screening for BSV in five commercial banana cultivars and establishment of a vigorous, virus-free mother stock for future supply of certified banana suckers. Cultivars used included 'FHIA-17' (AAAA genome), 'FHIA-18' (AAAB genome), 'Chinese Cavendish' (AAA genome) and 'Solio' and 'Nusu Ng'ombe' (AAA-EAHB genome). Immuno capture polymerase chain reaction (IC-PCR) technique was used to identify presence and type of isolates in each of the tissue culture seedlings before field establishment and one month and six months after their establishment in the field orchard. Results showed variation in severity of infection among cultivars in the greenhouse before field establishment with 58% infection for 'FHIA-17', 48% for 'FHIA-18', 41% for 'Chinese Cavendish', and 6% for 'Solio' and 'Nusu Ng'ombe'. One month after establishment of virus-free material, there was 10% infection detected in the first three cultivars. These results confirmed that tissue culture alone is not efficient in elimination of BSV and there is need to index all plants routinely after field establishment. Molecular indexing confirmed infection in 55% out of the 200 samples tested using three primers BSV-GF, BSV-Cav and the degenerate primer Badna 1A-4'.

Processing is often proposed to solve the seasonal surplus of bananas and plantains (Musa spp.), to reduce losses from spoilage and undersized fruits and to increase farmer incomes. To examine the contribution of small agro-industries to rural development in banana producing areas, study teams from nine countries in Asia, Africa and Latin America categorized current Musa processing businesses by type of product, size of firm and technology used, determined their strengths and weaknesses, and surveyed diverse categories of business service providers used by the processing businesses. Country teams met in October 2006 in Manila, Philippines, to draw conclusions across regions. In the nine countries less than 5% of dessert bananas, about 24% of plantains and between 30-40% of cooking bananas produced were processed. Common products included chips, dried sweet bananas, beer, wine, juice, sauce, baskets and mats from banana fiber, and banana-flavored milk products. Although Musa processing enterprises play an important role in the livelihoods of thousands of poor households, their significance as tools for rural development is limited by a number of factors, including seasonality of production, price competition from the fresh fruit market and quality issues. Limitations can be overcome to some extent by systematic and sustained investment in the business services accessible to rural populations and in the management capacity of micro-and small businesses.

A total of 1137 tissue culture banana (Musa spp.) seedlings were collected between May and July 2007 from nurseries of the Thika National Horticulture Research Centre of the Kenyan Agricultural Research Institute (KARI), Jomo Kenyatta University of Applied Technology and Agro-Genetic Technologies. The seedlings were approximately 3 months old, since potting. Leaf samples from the seedlings were indexed for Banana streak virus (BSV) at KARI-Kabete laboratory. Immuno-capture PCR specific primers to BSV-GF and BSV-Cav were used. Of the 1137 seedlings indexed, 120, 175, 112, 200, 130, 150, 100, 75 and 75 were of cultivar 'Dwarf Chinese' (AAA genome), 'FHIA 18' (AAAB genome), 'Solio' (AAA-EA genome), 'FHIA 17' (AAAA genome), 'Nusu Ng'ombe' (AAA-EA genome), 'Grand Naine' (AAA genome), 'Williams' (AAA genome), 'Uganda Green' (AAA genome) and 'Chinese Cavendish' (AAA genome), respectively. A total of 265 samples from the nine cultivars tested positive for BSV. 'Dwarf Chinese', 'Grand Naine' and 'Williams' cultivars tested positive both for BSV-Cav and BSV-GF. The PCR protocol for detection of BSV was validated. Validation tests were conducted, utilizing fresh banana leaf tissue samples from cultivars 'Lisulya' and 'Khabusi Mboki' (AAA-EA genome), greenhouse tissue cultured plantlets of 'Dwarf Chinese' and 'Ex-Rongai' (AAA genome), a positive control, consisting of freeze-dried banana leaves from Queensland University of Technology (QUT), and a PCR positive control plasmid DNA sample, also from QUT. Extraction of DNA was done using Qiagen DNeasy plant mini kit to generate a DNA template for PCR amplification.

Banana (Musa spp.) fruit production is threatened by several major pests and diseases such as black sigatoka, Fusarium wilt, burrowing nematodes and viral diseases like Banana streak virus, Banana bunchy top virus and Banana bract mosaic virus. The banana breeding program of edible bananas is hampered by high sterility, and very limited amounts of seeds. Few diploid banana clones produce viable pollen. However, the major problem with Musa germplasm enhancement is its low reproductive fertility and slow propagation rate. In vitro propagation of banana is successful and is routinely used for clonal propagation by commercial companies. On average, annually several millions of vitro plants can be produced. Somatic embryogenesis of banana has, however, not yet been commercially exploited due to highly genotypic dependence. Somatic embryogenic cell suspension is highly suitable for mutation induction and genetic transformation. Nuclear techniques have been used for mutation induction in 154 plant species, for the genetic improvement of both seed and vegetatively propagated crops. In our research project on banana at the International Atomic Energy Agency in Austria, several mutants were isolated for several traits, namely reduced height, tolerance to Fusarium wilt, early flowering, large fruit size and black Sigatoka tolerant types.

A rice chitinase gene (RCC2), multiplied in Agrobacterium strain (EHA 101), was simultaneously introduced into single buds of in vitro grown in the banana (Musa spp.) cultivar 'Rastali' (AAB genome). Plasmid pBI333-EN4-RCC2 contained a hygromycin phosphotransferase gene (hptII) as the selectable marker and gusA gene as a reporter marker to identify the transformants. Treatment A contained hygromycin at 25 mg L -1 and treatment B contained hygromycin at 50 mg L -1 in both Murashige and Skoog (MS) medium, supplemented with 5 mg l -1 of 6-Benylaminoupurine (BAP) and 2.7 g of gelrite agar. Single buds, derived from multiple bud clumps (Mbcs), were the target explants for transformation. An assay was performed to identify the minimum concentration required for two antibiotics (carbenicillin and cefotaxime) that is most effective against the Agrobacterium strain, EHA 101 and the effect on tissue regeneration capacity. Even though the transformation frequency based on the hygromycin selection medium (treatment A) was higher, no transformant could be confirmed based on PCR and southern blot analyses, as compared to the 50 mg L -1 hygromycin selection medium. Stable gusA gene expression was detectable in transformed single buds, Mbcs, shoots, leaves and roots derived from treatment B. The assay of protein extract from the transgenic plantlets showed an increased in chitinase enzyme activity over the untransformed plantlets. The presentation of Agrobacterium-mediated transformation reported here is suitable for using tiny meristem tissues to obtain fungal disease tolerant or resistant banana through genetic engineering.

To improve the identification of farmer needs and the dissemination of new cultivars of banana and plantain (Musa spp.) in West and Central Africa, the Africa Research Center on Bananas and Plantains (CARBAP) and its partners used a mother/baby approach for participatory cultivar evaluation through a regional network of platforms for dialogue and exchange between all the stakeholders of the value chain. Eight platforms have been established in Cameroon, Benin, Gabon and Guinea. Each platform includes: (a) a common reference plot with ten cultivars; (b) a network of 20 farmers testing three cultivars in their own fields chosen from the reference cultivars; (c) a steering committee to manage the platform; and (d) a local users and experts club. Plantain cultivars and hybrid, cooking and dessert banana were chosen according to the production constraints and consumer demand. The platforms are designed and managed in partnership using participatory approaches. At key steps of the cycle duration (vegetative, flowering stage) and at harvest, stakeholders are convened by the steering committee for joint evaluation. Lessons learned on varietal innovation and participation collected from diverse stakeholders (extension services, non-governmental organizations, producer organization, nursery organization, processors, traders and scientists) are discussed. During the 2-year life cycle of the project, 215 people shared their views on 30 cultivars of banana and plantain. Their capacity was built on how to grow and use banana and plantain successfully. At the end of the project, each platform continued to carry on their activities, making the impact of the Innovation on Banana and Plantain (INNOBAP) project more sustainable.

Banana Xanthomonas wilt disease (BXW, caused by Xanthomonas campestris pv) was discovered simultaneously in 2001 in Uganda and the DR Congo, and in 2002 in neighboring Rwanda. In Uganda, the disease was first seen in the central region where ABB bananas (Musa spp.) dominate. Subsequently, the disease spread into other regions in Uganda and into Kenya and Tanzania. A collaborative study was carried out in four districts in Central Uganda to establish the factors contributing to the epidemic and to assess the impact of the disease on banana yield. On average, 33% of the total banana mats were infected with BXW between 2001 and 2004. None of the banana cultivars were resistant to the disease. However, East African highland cultivars (AAA-EAHB genome) were significantly less affected than cultivars with AAB and ABB genomes. The results showed that a participatory development communication campaign against the disease had substantial impact on reducing disease incidence. Compared to pre-infection levels, the total banana yield loss due to BXW infection was estimated at 30-52% between 2001 and 2004, hence a reduction in the amount of bananas harvested by farm households. This in turn had negative livelihood impacts. Consumption of own produced bananas, sale of bananas, prices received, and farm and total household incomes were substantially lower between BXW infected farm households than their noninfected counterparts. For affected farm households that have little or no opportunities outside banana production, other interventions, in addition to the educational campaign on controlling the disease, will be required.

Somatic mutations in bananas (Musa spp.) nave been exploited for selection of favorable traits, both for consumption and commercial purposes, and they have been responsible for the current diversity of the East African highland bananas (EAHB). The role of mutations in the selection and subsequent conservation of banana cultivars by communities is not clearly understood. It is, however, believed that farmers play important roles in initiating and adjusting the proportions of cultivars on-farm, based on different traits. The purpose of this study was to: (a) initially determine the levels of somatic mutations in each clone set of the EAHB ex-situ collections; (b) establish cultivar richness and evenness to understand the conservation potential of each clone set; (c) determine the relationship between mutant traits with richness and evenness; and (d) compare the similarity between cultivar selection criteria and the mutant traits. Correlation and distance coefficients were used to determine accessions that are closely related, but not identical, on the basis of 61 morphological traits of 192 EAHB accessions of ex-situ collections in Uganda. Cultivar richness and evenness of clone sets of the landraces were then determined in three benchmark sites in Uganda and Tanzania. These measures of diversity were correlated with overall mutant traits and comparisons were made between cultivar selection criteria and the traits. Mutations were more frequent in 'Nfuuka' and a positive strong correlation between richness and mutant traits supported this. There was, however, a highly negative correlation between mutant traits and evenness. The traits that were more associated with mutations and selection criteria of farmers were related to bunches and fruits; an indication of the possible role of mutations in the selection and subsequent conservation of banana diversity on-farm.

Black Leaf Streak Disease is challenging the banana industry. Abstract — Introduction. Black Leaf Streak Disease (BLSD) is regarded as the most economically important threat that the banana industry has to face. Effectively, this foliar disease affects leaf pho- tosynthesis but, above all, reduces the greenlife of fruits, that cannot be exported in cases of severe infestation. Main characteristics of Black Leaf Streak Disease. More than 20 Mycosphaerella spe- cies have been described on bananas. Leaf spot diseases of bananas are caused by some species of this complex, of which M. fijiensis(BLSD) and M. musicola (Sigatoka disease) are the most important. M. fijiensisisaninvasivespeciesthathastotallyreplacedM. musicolainmostbanana-exportingcoun- tries,whichwasconducivetoincreasingdifficultiesinbananaleafspotcontrol.BLSDcausesincreas- ing difficulties for control. Since all banana cultivars grown in the banana industry are highly susceptible to BLSD, the control of this disease relies on aerial applications of fungicides according to either systematic frameworks (mostly contact fungicides) or forecasting strategies (mostly systemic fungicides). In a banana-exporting country where M. fijiensis has been reported, BLSD control becomes increasingly more difficult. This evolution is essentially due to the rapid emergence of fun- gicide resistance, and is conducive to a significant increase in the cost of disease control but, above all, to increasing negative environmental effects. Challenges for the banana industry. Because of the rapid adaptation of M. fijiensis, the banana industry must be prepared for significant evolution. We propose various parameters that should be monitored at different levels (disease assessment parameters, evaluation of chemical control efficiency, global evaluation of BLSD economic incidence) to rationalize such evolution. The modelization of BLSD effects on bunch mass and greenlife should enable defining acceptable disease thresholds and optimizing bunch weight and harvest stage accord- ing to agronomic practices. On the other hand, fungicide use is conducive to significant environmental impact and must be limited. Forecasting strategies should be used wherever systemic fungicides are still efficient. Finally, the predominance of a unique type of susceptible cultivar is unsustainable and the recourse to resistant varieties in an integrated strategy is undoubtedly the future of BLSD control. France / Musa / disease control / fungal diseases / Mycosphaerella fijiensis / resistance to chemicals

Crop association with arbuscular mycorrhizal fungi (AMF) often prove beneficial to crop productivity through a number of mechanisms, such as improved access to nutrients and water and pest and disease suppression. Banana and plantain (Musa spp.) are both mycorrhizal plants, with a number of studies demonstrating the strong stimulatory effect of AMF on plant growth in pots. Therefore, application of AMF to newly deflasked tissue culture plants or in nurseries may improve plant growth and possibly provide healthier plants for sale to farmers. Pot trials have also shown that inoculated plants are better able to suppress nematodes. However, how this association benefits banana and plantain plant performance under field conditions remains largely unknown. Studies are currently underway to determine the mycorrhizal associations of banana and plantain cultivars with AMF in East and Central Africa. Greenhouse studies complement field studies for comparison at the different levels. In West Africa, studies have been conducted to assess AMF association and yield impact following inoculation. Data from across Africa increasingly highlights that composition and abundance of AMF species associated with Musa spp. is highly variable. Up to 20 AMF species were found to be associated with banana plantations in East and Central Africa. Spore abundance, the inoculum reservoir that determines colonization, is largely influenced by management practices. The data generated to date increasingly illustrates the importance of AMF in banana systems and its sensitivity to crop and soil management practices. Some AMF species appear to be better than others with regard to their effects on banana growth, nutrient uptake and control of root damage by nematodes. Studies are in progress to screen AMF species and establish trials along different integrated soil fertility management practices. This paper summarizes the state-of-the-art regarding our knowledge of AMF and its (potential) impact on banana and plantain production in Africa.

The contribution of banana and plantain (Musa spp.) to our food requirements requires the identification of the research priority areas in the improvement and sustainability of these crops. Multidisciplinary research of Musa scientists and documentation of the results are highly acknowledged, as they create the means to identify production problem areas and offer solutions to the challenges that threaten fruit quality production. An analysis of Musa publications in Nigeria was undertaken to assess the most widely favored areas of research. It was observed from the analysis that scientists' choice of research focus on Musa needs to be demand-driven, especially in the areas of crop protection and breeding, to contribute positively to the improvement of the crop.

East African highland cooking banana (Musa spp., 'Matooke', AAA-EA genome) prices are sensitive to supply dynamics given their perishable nature. Despite large temporal fluctuations in farm-gate prices and food security, no efforts have been made to shift banana production towards periods of high banana prices and low food security. This study evaluated the influence of sucker emergence period on harvest period and yield, with the aim of proposing alternative desucker management that could shift production towards low supply periods. 150 AAA-EA ('Enyeru') mats were selected on ten farms in Ntungamo district (southwestern Uganda). Under farmer management, the mats were researcher-monitored weekly from 2005 to 2007 to record dates of sucker emergence, flowering and harvest and bunch weight. Date records were respectively grouped into quarters that corresponded to dry (Q1: December-February; Q3: June-August) and wet seasons (Q2: March-May; Q4: September-November). Harvest peaks occurred in Q3 and Q4 due to the significantly (P

Yield, fruit morphology, postharvest characteristics and qualities of five, locally grown, banana (Musa spp.) cultivars ('Somali', 'Malindi', 'Williams' (AAA genome, Cavendish subgroup), 'Fard' (AAB genome) and 'Negal' (ABB genome) were evaluated at a private farm at Al-Swaiq, Oman. 'Somali' produced the heaviest bunches. There were no significant differences between the other cultivars. 'Williams' had the largest number of hands. Peel color did not vary significantly between the cultivars, though 'Williams' had a tendency toward a greenish fruit color. 'Malindi' had the firmest pulp, while 'Negal' had the softest pulp. The pulp of all cultivars, apart from 'Negal', had a pH

This study identified the strengths and weaknesses of small banana (Musa spp.) processing businesses and their potential for poverty reduction in rural Tanzania. A workshop was organized that mapped and characterized the banana processing businesses, service providers and the general banana processing sector in Tanzania. Common banana products in the study areas are banana juice and local brew. Other banana by-products include hard alcohol ('gongo'), wine, dried bananas, flour, breads and biscuits. In general, processing of bananas was observed to be very limited. It is estimated that 80% of bananas produced are cooking bananas, 10% beer bananas, 8% dessert bananas and 2% plantains. Processed bananas account for 5% of sales, while fresh bananas for 95%. Banana processing businesses are limited to locally made and locally consumed products. Tanzania policies favor postharvest and value adding technologies for many products, including banana products. Specific cultivars of bananas are needed for certain products. Different banana types produce different qualities of products. The price of bananas depends on the type of bananas, i.e., cooking bananas fetch higher prices than beer bananas. Banana processing businesses are mainly focused on soft and hard drinks with little confectioneries. Service providers in banana processing are limited. Banana processing still needs a lot of development for banana producers in Tanzania.

Farmers, researchers, extension officers and policy makers need reliable yield data on banana (Musa spp.) to make informed decisions. There are no standard yield determination methods available for Musa research. Production patterns and types vary distinctly in time and space. This requires special attention when expressing yields as unit mass per unit area per unit time (t ha -1 y -1 ). Determining banana yield is challenging because: (a) bunch yields are often expressed as fresh weight, but edible dry matter percentage can vary strongly between cultivars and environments; and (b) bunch yields often include the peduncle for which often no uniform cutoff point is used. To obtain realistic and valid yield data and to compare Musa yields with those of other crops, the edible dry matter content needs to be determined and considered. In addition, many cultivars have a highly variable rate of plants reaching flowering and bunch production. Too often, yield calculations are made with the assumption that 100% of the plants produce, whereas in many fields up to 70% of the plants do not produce, especially in lowland plantain fields. Plant densities in farmer fields are often highly variable, which requires careful consideration of (a) the definition of a banana plot; (b) the size of the banana plot; and (c) the number of plants in a banana plot. Often, banana clusters consist of several mats of the same generation, leading to underestimations of the number of mats per unit area. We propose that the definition of a single banana mat is a family of plants with interconnected living corms. Crop cycle duration varies strongly as a function of cultivar, altitude, soil fertility, drought stress, and pest and disease infestation. It can vary from less than one year to over two years, leading to large (>50%) yield differences per unit time between and within cultivars. This paper describes the sources of errors and proposes measures to avoid incorrect or incomplete yield determinations.

Cost implications and lack of knowledge for ideal pest control practices are among the major factors limiting banana and plantain (Musa spp.) production in Nigeria. A trial was designed to control banana weevil (Cosmopolites sordidus), a major insect pest, and termites (Microtermes spp.), an occasional pest, by low-cost methods. The main plot treatments included the cultivars TMPX 5295 and TMPX 7152-2 (AAA genotypes) and 'Agbagba' and 'Red Ogoni' (AAB genotypes). Treatment combinations of mulching with neem (Azadirachta indica) leaves, application of poultry manure, and minimal application of insecticide (chlorpyrifos) constituted the subplot. The split-plot trial was arranged in a randomized complete block design with three replications. Numbers of weevils and termites were monitored in 2004 and 2005. Significantly lower weevil numbers were observed in plots treated with insecticide or neem mulch (with or without manure) compared with the untreated control (with or without manure). Weevil and termite numbers observed in insecticide treated plots were not significantly lower than those in the neem mulched plots during the plant or first ratoon crops. Significantly higher weevil larvae numbers were observed in the control plants (2.2 plant -1 ) compared with those that received insecticide or neem mulch applications (maximum 0.4 plant -1 ). In the first ratoon crop, significantly lower numbers of adult weevils and larvae were observed in cultivars with an AAA genotype than in the Red Ogoni cultivar. Cultivar had no significant effect on termite infestations. The interaction of treatments and cultivars significantly (P

Consumers' preference for banana (Musa spp.) fruits is a critical aspect of marketing and is determined mainly by its sensorial aspects, nutritional value and appearance. This study researched consumer preferences of banana in a major urban market in Kwara State of Nigeria. Investigated quality attributes were fruit size, number of fingers, appearance, color, texture, aroma, flavor and shelf-life. Consumers preferred fingers of medium or big size, hands containing 9-12 fingers, pulp with light yellow color, absence of black spots in the peel, firm texture, aroma and flavor of medium intensity, medium sweet fruits and a shelf-life of 7-9 days under natural conditions. Fruit taste, size and number of fingers are considered the most important parameters at purchase, while appearance, color and shelf-life are considered less important. Technologies that yield the appropriate taste, size and number of fingers should be considered for research and implementation.

Beginning 2001, the International Institute of Tropical Agriculture (IITA) in Cameroon launched a systematic deployment effort for resistant banana and plantain (Musa spp.) hybrids in collaboration with the plant health regulatory services of Nigeria and Cameroon. These hybrids were field established at the Mbalmayo research farm of IITA for evaluation of their agronomic and postharvest compliance. Data were collected for three production cycles on disease response, phenology, yield, and fruit quality. Twenty-one hybrids were evaluated in comparison with the most popular indigenous landraces ('Assang-Da', 'Ebang', 'Elat', and 'Essong'). Of these, three triploid hybrids ('PITA 21', 'PITA 23' and 'FHIA 25') and four tetraploid hybrids ('PITA 14', 'PITA 17', 'BITA 3' and 'FHIA 23') were selected with input from farmers. They exhibited higher levels of resistance to black leaf streak (BLS), shorter growth cycle and higher bunch yield in comparison to the landraces. When grown in mixture with landraces, the hybrids mitigate the intra-field propagation of BLS between susceptible plants, thereby enhancing the performance of the landraces under natural BLS infection. This constitutes an attractive scheme for deployment of the improved hybrids through on-farm participatory evaluation in Cameroon. In 2003, we initiated an outreach program with non-governmental organizations and farmer associations, aiming to foster a fast-track cultivar testing and dissemination scheme coupled with hands-on training in healthy sucker production and postharvest processing options to overcome scarcity of planting material and to carter for the anticipated excesses. This scheme fits within and complements programs of the Cameroonian government for banana and plantain, with the main objective to increase the productivity of banana and plantain in Cameroon and to enhance food security and develop trade opportunities.

In Uganda, 'Sukali Ndizi' (syn. 'Apple banana', AAB genome) are dessert bananas that are being processed into dried slices for export. Surveys with five Ugandan exporting companies suggested that export prices of dried banana slices were favorable ($6.5-12/kg), but strongly depended on the quality and certification of the product. Major bottlenecks to further expand the export seem not to be related to a lack of demand in Europe, but to the fact that quantities and quality of the exported produce are insufficient. Exporters indicated that one of the major constraints related to producing sufficient volumes is the spread of Fusarium wilt (Fusarium oxysporum f. sp. cubense), which increasingly affects 'Sukali Ndizi' production. They also indicated that other dessert bananas on the Ugandan market (e.g., 'Gros Michel' and 'Cavendish', both AAA genome) are not processed into dried slices because the processed product is largely inferior to that of 'Sukali Ndizi' in terms of taste. This study compares drying, color and taste characteristics (texture, acidity, sugar content and color) of seven alternative Fusarium wilt-resistant banana cultivars ('FHIA-01', AAAB genome; 'FHIA-17', AAAA genome; 'FHIA-23', AAAA genome; 'FHIA-25', AAB genome; 'SH-3640/10', AAAB; 'Yangambi Km 5', AAA; 'Kikundi', AAA-EA genome) with 'Sukali Ndizi'. European consumers rated the taste characteristics of 'FHIA-01' at least as good as 'Sukali Ndizi' and appreciated its color more than the latter. The taste and color of other cultivars were generally rated inferior ('SH-3640/10' > 'Kikundi' > 'Yangambi Km5' > 'FHIA-17' > 'FHIA-23' > 'FHIA-25'). 'FHIA-01' and 'Sukali Ndizi' also had the highest fresh pulp dry matter content (32 and 36%, respectively) compared to other cultivars (27%) and were less sticky than other cultivars, which facilitated the processing and packing of the banana slices. This study shows there is potential to further exploit the dried dessert banana export market using Fusarium wilt-resistant cultivars.

The East African highland bananas 'Matooke' (Musa spp.) are unique in terms of utilization, their taste and the cultural attachment to the people in the East Africa region. Research efforts have been directed towards improving these bananas for disease resistance, pest resistance and higher yields, while keeping their unique taste and other culinary qualities. This paper presents results of an on-farm participatory evaluation study of 18 conventionally bred hybrids selected from an early evaluation trial at the Kawanda Agricultural Research Institute. The 18 'Matooke' hybrids (17 with AAA genome; one with AAAA genome) and a local cultivar were planted in farmers' fields in Kasangombe sub-county, Nakaseke district in Central Uganda. The hybrids were evaluated for consumer acceptability, black Sigatoka resistance and agronomic performance The 'Matooke' hybrids 'M2', 'M9', 'M14' and 'M17' (AAA genome) were selected as the most acceptable hybrids, combining high yields with resistance to black Sigatoka.

Growth patterns of plant crop of banana (Musa spp.) cultivars 'Grande Naine' and 'Williams' (AAA genome), grown in Maragwa, Central Kenya in 2006 and 2007, were determined to establish the best maturity indices to determine harvest time. The banana plants were randomly selected from an already existing orchard where the farmer followed the recommended agronomic practices. The banana bunches were allowed to grow until half, three quarter and full maturity. Data were collected on growth parameters and postharvest quality of bunches. Bunch age and finger diameter were highly positively correlated (r = 0.881 and 0.939 for 'Grande Naine' and 'Williams', respectively). Finger diameter was correlated positively with pulp to peel ratio and total soluble solids (r = 0.941 and 0.997 for 'Grande Naine' and 'Williams', respectively). In 'Williams', finger diameter was positively correlated to pulp to peel ratio (r = 0.949) and total soluble solids (r = 0.991). Fruit growth curves for both cultivars followed the pattern of bananas grown in the tropics. The best maturity indices for determining the harvest time of 'Grande Naine' and 'Williams' may be a combination of bunch age and grade, as these correlate very well with postharvest characteristics such as pulp to peel ratio and total soluble solids.

Since an unrecorded introduction from Asia in prehistoric times, banana and plantain (Musa spp.), commonly called bananas, have become major food and cash crops in Africa. The 4 million ha of bananas in Africa represent nearly a third of global production. Increased movement of plant material in the past century also introduced pests and diseases that became new constraints to banana production in Africa and have destabilized banana production with susceptible traditional landraces. Biotic challenges to banana production in the region include fungi, bacteria, viruses, nematodes and insects. Introducing host-plant resistance, whether by conventional breeding or by biotechnology, is the most economical and sustainable means of managing pests and diseases. In recent decades, progress has been made in identifying sources of host-plant resistance, identifying germplasm in other countries most like original progenitors of African landraces and developing genomic tools to increase the efficiency of developing resistant lines. Major programs for banana breeding in Africa are located in Nigeria (International Institute of Tropical Agriculture), Cameroon (Centre Africain de Recherche sur Bananiers et Plantains), and Uganda (National Agricultural Research Organization/International Institute of Tropical Agriculture). Banana breeding is slow and land intense compared to annual crops, so increasing breeding efficiency is a valuable objective. Good progress has been made in introgression resistance to black leaf streak disease, burrowing nematodes, banana weevils, and Fusarium in elite selections. There is room for progress in producing high-yielding cultivars, resistant to multiple biotic threats with similar organoleptic qualities as traditional cultivars.

The global importance of Fusarium wilt of banana (Musa spp.) has been widely documented. The lack of viable control options, and its significance to the livelihood of millions of people around the world, makes it particularly important. In the absence of a single effective control method, control efforts are moving towards the integration of multiple control methods. In this study, the integration of biological and agronomic control methods was investigated. Single and combined applications of non-pathogenic, endophytic Fusarium oxysporum strains, Trichoderma harzianum Eco-T ® (Plant Health Products (Pty) Ltd., KwaZulu-Natal, South Africa), silicon and mulching using macadamia husks were tested against F. oxysporum f. sp. cubense on bananas under greenhouse and field conditions. The non-pathogenic F. oxysporum strains were effective biocontrol agents against Fusarium wilt of banana. Amendment with potassium silicate to plants exposed to the non-pathogenic F. oxysporum strains improved plant health of cold-stressed banana plants compared to those treated with endophytes only. A field trial was conducted at a KwaZulu-Natal South Coast banana plantation, where Fusarium wilt of banana is a serious problem. Plants that were treated with combinations of non-pathogenic F. oxysporum, T. harziarzum Eco-T ® , silicon and mulch had significantly higher number of leaves, stem height and girth size than single applications of the treatments. Mulching increased growth of feeder roots. Integration of biocontrol with agronomic practices may improve the efficacy of the biocontrol organisms and the health of the host plants, which may be sensitive to environmental changes. For instance, mulching encourages growth of feeder roots and creates a conducive microenvironment, thereby increasing microbial activity in the soil. This study demonstrated that the combined application of biocontrol organisms, silicon and mulching can provide an effective control option for banana growers dealing with Fusarium wilt in their plantations.

Banana (#Musa# spp.) production is a key economic resource in the French West Indies. It is essential that growers in this region enhance their sales by proposing new products, such as mountain bananas (AAA genome, Cavendish subgroup), in response to high market competition from other exporting regions where production costs are lower. The quality of mountain bananas is officially recognized in Europe under the label Mountain Banana on the basis of a real taste difference. All French West Indian bananas grown over 250 m above sea level, which respect agronomic specifications, can be sold under the label. Mountain bananas can be objectively distinguished from lowland bananas: at harvest, they are denser, bulkier and less susceptible to wound anthracnose caused by #Colletotriclmm mllsae#, probably due to their higher mechanical resistance. Sensorial differences have also been observed in ripe bananas. At the same harvest stage and under identical ripening conditions, mountain bananas have a firmer texture, more intense yellowish pulp, and higher sugar and aromatic compound contents than lowland bananas. A jury-taste-test analysis confirmed the sensorial differences between lowland and mountain bananas. However, mountains bananas presented the poorest contents in Mg, P and Ca, partially due to the nature of the soil components. Based on a multi-site study, temperature and rainfall during bunch growth are the main factors that distinguish mountain bananas. (Resume d'auteur)

This study describes a method of clonal propagation for one of the elite cultivars of banana developed by the Bangladesh Agriculture Research Institute (BARI). The principal characters of this cultivar 'BARI-1' (AAA genome, Sapientum subgroup) are its sweetness, good smell and high yield, which have made this particular cultivar popular in Bangladesh. In vitro cormlets were formed within 2-3 weeks when meristems were carefully isolated from field-grown plants and after proper sterilization implanted in semisolid Murashige and Skoog (MS) media fortified with 2.0 mg L -2 6-benzylaminopurine (BAP). Rate of shoot proliferation increased considerably with the synergistic effect of BAP and Kinetin. Regeneration of cormlets was geared up and shoot multiplication occurred when MS was enriched with 2.0 mg L -1 BAP and 1.0 mg L -1 Kinetin. With the increase of subculture (up to 9 th maximum), frequency of shoot proliferation was enhanced. Addition of 0.1 mg L -1 Indole-3-acetic acid and 10% coconut water to the medium increased shoot elongation and stimulated growth of the shoots, respectively. The micro shoots rooted well within two weeks in 1/2 MS supplemented with 0.5 mg L -1 Indole-3-butyric acid and in a few cases auto-root induction was observed when the number of subculture was beyond five. Rooting percentage and their growth were much better in liquid media in comparison to semi-solid media. Elimination of agar from the root induction media reduced the cost of production significantly. After proper acclimatization, rooted plantlets were transferred to polythene bags containing garden soil and humus (1:1). Two weeks after transplantation, 98% plants survived and flushed new leaves. No morphological variants were observed during the passage of micro-propagation.

In Africa, bananas (Musa spp.) are staple food crops and sources of income that are cultivated as backyard plantings, mixed-crop plantings and in commercial plantations. Continued production of bananas and plantains, however, is threatened by several important pests and diseases. Nematodes, particularly, are responsible for significant losses across Africa, and the banana weevil (Cosmopolites sordidus) damages both cooking (AAA-EA genome) and dessert bananas (AAA genome). Since its introduction onto the continent, black leaf streak has spread to all African tropical banana production areas, causing immense damage to plantations. Fusarium wilt is important in dessert banana plantings, while Xanthomonas wilt has devastated bananas in Central and Eastern Africa since 2001. Both Banana bunchy top virus and Banana streak viruses occur on the continent. Because of the limited resources available to backyard and mixed-crop growers, many pests and diseases are only partially controlled or not controlled at all, making banana production in Africa highly vulnerable. More importantly, many pests and diseases are indiscreetly disseminated because of limited resources and knowledge. For these reasons, large growing areas have been forced out of further production. Without substantial financial resources, the effect of pests and diseases in Africa can be significantly reduced by promoting the use of clean and healthy planting material, sanitation practices, and quarantine regulations to prevent dissemination of existing pathogens and pests, and the introduction of important foreign pathogens such as Fusarium oxysporum f. sp. cubense 'tropical race 4', and those causing Moko bacterial wilt and Blood bacterial wilt. Two banana breeding programs and several facilities for plant biotechnology already exist in Africa and should be used to develop banana cultivars resistant to pathogens and pests. More importantly, national and regional resources should be pooled in order to ensure sustainable banana production in Africa.

Cucumber mosaic virus (CMV) is the primary virus affecting commercial banana (Musa spp.) plantations in Ivory Coast, with the disease also present within nursery systems. However, currently no virus indexing of planting material is performed for banana in the country. This current study attempts to quantify levels of detection of CMV within banana material using flinders technology associates (FTA) cards in order to identify a reliable and reproducible method suitable for local conditions. A suite of PCR primers were developed against CMV coat protein open reading frame (CP ORF) sequence available on GenBank. TaqMan assay generated comparable CT values with either FTA or cetyltrimethyl ammonium bromide (CTAB) derived templates and was able to detect CMV RNA in leaf samples. The conventional real time polymerase chain reaction (RT-PCR) assay, RNeasy and FTA derived RNA templates reliably amplified CMV, whilst CTAB-derived RNA gave variable results. The TaqMan ® reaction was much more sensitive than the conventional RT-PCR for CMV detection in banana leaf samples. The suitability of FTA cards as a matrix for virus nucleic acid capture provides scope for its use in the transportation of banana virus samples to laboratories for diagnosis and characterisation, circumventing constraints of time-related degeneration of sample integrity. Sequence data of the CMV CP ORF region of 16 isolates from Cote d'Ivoire clustered the isolates to CMV Sub-Group IA. This is the first successful application of Real-time PCR and FTA technology for a banana virus in Africa.

Plantain (Musa spp.) is highly susceptible to root nematodes (Radopholus similes) and fungal diseases of the leaves, causing yield losses in the vicinity of 50%. 'FHIA 21' (AAB genome) is a plantain hybrid with good tolerance to pests and diseases, excellent palatability and a high level of acceptance by farmers. Plantain production in Southern Cameroon is based on slash and burn of relatively old (20-40 years) secondary forest. Forest clearing is labor and cost intensive leading to the retention of large trees, species with hard wood and those of commercial value, as well as forest bordering directly on the plantain field. Thus, plantains may be shaded to various degrees. This trial determined the growth and yield response of 'FHIA 21' to shade imposed by various levels of canopy cover of Inga edulis. Establishment was unaffected by shade, with 94% of plant survival at 99 days after planting (DAP). Canopy cover was negatively correlated with growth parameters of 'FHIA 21' plants at 99 DAP. The proportion of plants that failed to produce within 525 DAP was lowest under the lowest level of canopy cover. Failure to produce an edible bunch due to uprooting, breaking or premature death were unaffected by shade levels, whereby no effect on pre- and post-flowering failure could be discerned. The proportion of plants that produced an edible bunch and the fresh bunch yield was higher in the low canopy cover area than in high canopy cover areas. Bunch mass per producing plant, although highly variable, was not significantly affected by shade level. Root mass of I. edulis was weakly, yet significantly, positively correlated with bunch yield. 'FHIA 21' developed severe symptoms of Banana streak virus after phases of low water supply, which were more frequent at higher canopy cover levels. The hybrid appears not to be suitable for systems with high levels of shading from retained trees.

Wound anthracnose, caused by Colletotrichum musae, and early ripening is the main problem affecting the quality of export bananas (Musa spp.) from a lot of countries in the world. In the case of Guadeloupe (French West Indies), these problems generally concern bananas harvested in lowland plantations during the rainy season. Three experiments were carried out to study the influence of the physiological age of bananas, calculated on the basis of mean daily temperature sums, on their susceptibility to anthracnose. Stressful growing conditions, especially soil flooding, slowed fruit growth but had no direct effect on fruit susceptibility to C. musae or on the green life. However, fruit that had accumulated lower temperature sums were less susceptible to wound anthracnose. By varying the source-sink ratio, we show that bananas of the same grade but different physiological ages had markedly different susceptibility to C. musae. Bananas with the same temperature sum accumulation but grown in different soil and climate conditions had different levels of susceptibility. Fruit grown in cooler, highland areas were less susceptible to C. musae than fruit of the same physiological age from lowland plantations. Our results suggest that the temperature sum accumulation rate is a critical factor affecting the susceptibility of bananas to the pathogen.

Xanthomonas campestris pv. musacearum (Xcm) causes Xanthomonas wilt of banana (Musa spp.) and enset (Ensete ventricosum) in East and Central Africa. The disease is spread by insects that visit the male inflorescence, through the use of infected planting materials and by contaminated garden tools. To evaluate the most appropriate control options, the spread of bacteria within the plant following natural flower infection was studied in Luwero and Mpigi districts of central Uganda. Banana tissue samples were collected from the corm, true stem and leaf sheaths of 'Pisang Awak' (ABB genome) and 'Matooke' (AAA genome) mother plants, showing four progressive stages of disease development: stage 1 - male bud wilting; stage 2 - decaying rachis; stage 3 - premature fruit ripening; and stage 4 -rotting of fruit bunches. Thirty plants were sampled per stage and per cultivar. Additional samples were taken from attached suckers. Bacteria were isolated from surface-sterilized plant samples and identified by colony characteristics on a semi-selective medium. Following inflorescence infection, Xcm moved along the true stem, into the youngest leaf sheaths inserted on the true stem, down into the corm and into the older leaf sheaths. At early stages of inflorescence infection (stage 1), bacteria were restricted to the upper parts of the true stem in 'Pisang Awak', but had moved further down the stem in 'Matooke'. Therefore, cutting down mother plants at stage 1 could stop Xcm from reaching the corm and eventually crossing to the suckers of 'Pisang Awak' but this was less likely to be effective for 'Matooke' plants. The bacteria were recovered from suckers of both cultivars showing symptoms at stage 4, but at stage 3 only from 'Pisang Awak'. It is recommended that whole mats should be completely uprooted or killed by herbicides in case mother plants show symptoms beyond stage 1 for 'Pisang Awak' and at all disease symptom stages for 'Matooke'.

Ripening is the main physiological process affecting banana (Musa spp.) fruit quality traits. The progress of banana ripening process differs for fruit ripened on the plant versus green harvested bunches and depends on the treatment of the fruit after harvest. We investigated the effect of the mode of ripening on ethylene biosynthesis of 'IDN 110' (Musa acuminata, AA genome) banana fruit ripened (a) in planta (On-Plant); (b) ex planta in air (Air-Fruit); or (c) after acetylene treatment (Ace-Fruit). The levels of ethylene production of the whole fruit and, those of 1-aminocyclopropane-1-carboxylic acid (ACC) in pulp, and ACC oxidase (MA-ACO1 and MA-ACO2) and ACC synthase (MA-ACS1) mRNA in both peel and pulp tissues were examined. From harvesting at mature-green stage, the ripening speed of fruit was not correlated with ethylene production. Ace-Fruit took 10 days to reach overripe stage with a maximum of 22.6 μl kg -1 h -1 of ethylene production, whereas Air-Fruit and On-Plant fruit took 27 and 33 days to reach overripe stage, respectively, and produced 11.5 and 29.6 μl kg -1 h -1 of ethylene, respectively. During ripening, ACC accumulated differentially; except for On-Plant fruit, ACC level increased during ripening and concomitantly with ethylene production and MA-ACS1 mRNA level. Whatever the mode of ripening, the level of MA-ACO1 mRNA was 100-fold higher than that of MA-ACO2. The mRNA level of MA-ACO1 and MA-ACO2 were accumulated sequentially during fruit development and ripening. MA-ACO1 gene was transiently induced between mature green and ripe stages while that of MA-ACO2 increased mainly at the overripe stage. The pattern of MA-AC02 gene expression was correlated with that of ethylene production whatever the mode of ripening while this correlation was observed with MA-ACO1 only On-Plant fruit. These results suggest that: (a) the level of ripening-ethylene production of the whole fruit is not the sole factor controlling the speed of fruit ripening in planta; (b) this level is regulated at the downstream step of ACC biosynthesis mediated by the MA-ACS1 gene; and (c) the product of MA-ACO2 might be involved in this regulation in pulp tissue. These findings are also discussed in regard with improvement of banana quality traits project throughout breeding programs.

Banana (Musa spp.) fruit of 'Hom Thong' (Musa acuminata, AAA genome) and 'Namwa' (Musa x paradisiaca, ABB genome) were stored at 4 and 12°C and 85-90% relative humidity. At 4°C, peel blackening was visible on day 2 in 'Hom Thong' and on day 4 in 'Namwa'. Levels of total free phenolics, thiobarbituric acid (TBA)-reactive compounds, and in vitro peroxidase (POD) activity in the peel were not correlated with blackening. A slight increase of in vitro catechol oxidase (polyphenoloxidase) activity occurred from day 0 onward in 'Hom Thong' and could explain blackening in this cultivar, but such an increase was not found to accompany blackening in 'Namwa'. Low temperature storage resulted in a rapid increase of in vitro lipoxygenase (LOX) activity in 'Hom Thong', which was correlated with blackening. The later blackening in 'Namwa' was not accompanied by rising LOX activity. It is concluded that the early peel blackening in low temperature-stored fruit of 'Hom Thong' was correlated with increased LOX activity, which might be close to the cause of the blackening, and increased catechol oxidase activity, which is apparently involved in the blackening reaction. The peel blackening in 'Namwa', in contrast, was not correlated with any of the measured parameters.

Introduction . This protocol describes a method for obtaining well-established banana plants in the field, both for open-air and greenhouse cultivation, from hardened tissue culture nursery plants. The principle, starting material and time required are presented. Materials and methods . This part describes the process of land preparation, both in the case of planting and replanting, including preplant fertilizer requirements and irrigation recommendations, and the main horticultural practices appropriate both for planting out in the field and for the first months after planting. Special attention is given to correct irrigation, a key issue in the establishment process. Possible problem areas for troubleshooting are listed. Results . At the end of the process, vigorous plants with uniform growth and high yield potential are planted out and become optimally established in the commercial field.