Plantain Cultivars Research Articles

Molecular characterization of banana bract mosaic virus from India reveals recombination and positive selection in the VPg gene

Banana bract mosaic virus (BBrMV), a member of the genus Potyvirus, family Potyviridae, is an important viral pathogen affecting banana and plantains in India. The present study was undertaken to determine the genetic variation and molecular evolution of BBrMV infecting different cultivars of banana and plantain in the Indian subcontinent, based on the viral genome-linked protein (VPg) gene. Sequence identity of this gene from 29 BBrMV isolates showed a range of nucleotide (nt) and amino acid (aa) identity of 75–100% and 95–100%, respectively. Phylogenetic analysis based on nt revealed that except for two isolates (TN1 and TN2), all the other Indian isolates clustered together. Different functional motifs of the VPg gene previously reported were found to be conserved. A single possible recombination event was detected using a recombination detection programme. A codon-based selection analysis revealed that most of the codons in the VPg gene were under purifying selection except for those at position 46, 47, 71, 107, 149, 153, 156, 175, 176, and 178, which were under positive selection. Gene flow between different Indian populations of BBrMV from banana was relatively low. This is the first report on genetic diversity and evolution of the VPg gene of BBrMV. Since VPg is identified as a virulence determinant in resistance mediated by the eukariotic intiation factor 4E (eIF4E) in several plant-potyvirus interactions, any mutation in the VPg interacting domain may abolish the interaction with eIF4E or its isoforms in vitro and prevent viral infection in planta. Therefore, understanding the population structure of BBrMV based on VPg would potentially provide insight into the diversification and infection cycle of this virus.

English

Plantain is one of the most important sources of food in the African lowlands stretching from the lowlands of Guinea and Liberia to the central basin of the Democratic Republic of Congo (DR Congo). Because plantain cultivars do not produce seeds, plantain cultivation is based on vegetatively transplanted lateral shoots/suckers. The way by which plantain reached the African continent is still under speculation. The aim of this study was to shed light on the history of plantain cultivars through a linguistic/synonymy study in northern Democratic Republic of Congo. We report the diversity of plantains in 18 villages across the Bas-Uele province based on a survey. Three villages in which plantain production systems dominated were selected in each territory, and ten households were consulted in each village. In each selected village, a focus group discussion was conducted with a group of at least 30 men, and with a separate group of 30 women to establish a list of plantain cultivars grown and known. A total of 46 cultivars were identified and 294 synonyms detected. The cultivar names are mostly related to animal features and agronomic traits, although there is a need to revisit the list for more specific traditional names. The local differences in cultivar identity, density and distribution are explained partly due to the influence of humid forest versus savanna landscapes, but the main part seems to be due to previous movements of Benza, Boa, Ngbandi, Rambo and Zande ethnic groups with their own set of cultivars. We demonstrate that the recorded synonymy data are useful for a tentative partial reconstruction of the history of some cultivars. This is useful for the genetic improvement of plantain cultivars, which most probably will have to rely for a great deal on the unraveling and management of epigenetic mechanisms. Key words: Bas-Uele, cultivar, diversity, ethnic group, plantain, synonymy.

Carotenoids in the pulp and peel of bananas from 15 cultivars in two ripening stages

ABSTRACT The current study aims to evaluate the occurrence and concentration of carotenoids in the pulp and peel of 14 banana and one plantain cultivars in two ripening stages. We analyzed the occurrence and content of lutein, α-carotene, β-carotene, β-cryptoxanthin, and lycopene - by high performance liquid chromatography with UV-visible detection, the content of total carotenoids by spectrophotometry. In the unripe pulp, the ‘Ouro’ cultivar stood out with lutein concentration 13 times higher than that of the ‘Marmelo’. As for α-carotene and β-carotene, ‘Terrinha’ plantain stood out with mean concentration of 1195.30 and 1126.11 μg (100 g MF-1), respectively. Total carotenoids ranged from 159.66 to 2553.51 μg (100 g MF-1) in ‘Caipira’ and ‘Terrinha’, respectively. In the ripe pulp there was 36% increase in the lutein content in comparison to the unripe pulp and there was 7.3 and 8.5% reduction in α-carotene and β-carotene levels, respectively. The total carotenoid concentration in the ripe pulp was 17% higher than that found in the unripe pulp. The unripe peel showed lutein predominance, although ‘Terrinha’ stood out with higher α-carotene and β-carotene concentrations than those found in the other cultivars. Lutein concentration hardly changed due to fruit ripening; however, there was slight reduction in α-carotene and β-carotene concentrations.

The morphological diversity of plantain in the Democratic Republic of Congo

This work focused on the morphological characterization of plantain cultivars collected in the period 2005-2014 in 280 villages across 9 provinces of the Democratic Republic of Congo. These cultivars were established in two field collections at the University of Kisangani.Existing descriptors were adapted to better differentiate their variation to address better the taxonomic handicap and the synonymy handicap to improve future research on plantains.Most of the collected cultivars were French plantains (64 out of 98), followed by False Horn (23) and Horn (10) plantains. The bunch type was the main striking difference which allows the quick separation of plantain cultivars into three main types. Other striking differences within plantain were the size of the pseudostem (giant, medium-sized and small-sized) and the bunch orientation (which was generally pendulous or sub-horizontal, and rarely horizontal and erect). These three descriptors were considered as main descriptors. Other descriptors (pseudostem colour, immature fruit peel colour, fruit shape, fruit apex, fruit position, number of hands, fruit size, number of fingers per hand and flower relicts at the fruit apex) allowed the differentiation of one cultivar from another within the same main group of bunch type, pseudostem size or bunch orientation. These descriptors are considered as secondary descriptors. Rare descriptors allowed to differentiate one cultivar from all the others in the subgroup. This approach makes the cultivar description logical and faster because it moves from general to particular characteristics, and it offers a platform for reflections on the Pan-African scale of plantain diversity. Highlights • Adapted descriptors according to the degree of their differentiating performance is feasible in plantain characterization. • The bunch type, the plant size and the bunch orientation allow a quick separation between plantain cultivars. • French plantains are the most numerous in the DR Congo. • The most recorded colour (of the pseudostem of fruit immature peel) is the green.

Research Article Agronomic performance of plantain genotypes and genetic variability using Ward-MLM algorithm

Plantains in Brazil are produced from the `Terra Maranhao’, ‘Terrinha’ and ‘D´Angola’ cultivars, which are all susceptible to black Sigatoka, weevils and nematodes. Therefore, the development of resistant plantain cultivars with agronomic characteristics aligned with market demands is the most efficient way to overcome these barriers regarding fruit production. The objectives of this work were to evaluate plantain cultivars for agronomic and physicochemical characteristics, and to estimate their genetic variability using ISSR molecular markers. The experimental design used was randomized block with ten plantain genotypes distributed in five blocks with four plants per plot. Ten agronomic and five physicochemical characteristics were measured. The agronomic, physicochemical and molecular (ISSR) characteristics were analyzed together using the Ward-MLM algorithm. Based on the agronomic and physicochemical evaluations, the ‘Red Yad’, ‘Curare Enano’ and ‘Chifre de Vaca’ genotypes could potentially be recommended to farmers, especially due to their short height and higher bunch mass and number of hands. The analysis of the combined data using the Ward-MLM algorithm identified genetic variability that, although restricted, can be used for genetic improvement strategies. To the best of our knowledge this is the first work that validates new plantains under Brazilian conditions, increasing cultivar options for farmers.

Effect of narrow-leaved plantain cultivar on development of two geometrid pests, Scopula rubraria and Epyaxa rosearia

ABSTRACTThe increased use of narrow-leaved plantain Plantago lanceolata as forage in New Zealand has led to the emergence of two native moths, Scopula rubraria and Epyaxa rosearia, as significant pests. Plantain is known to contain defensive compounds against insects and a laboratory study was undertaken to compare the growth and development of both moth species on four plantain cultivars and one breeding line. Larval feeding and development was found to vary with plant line and leaf age, with Ceres Tonic and especially SF Boston the most favourable plantain lines for both pests. No E. rosearia completed larval development on mature foliage from Luisetti Tuatara or the breeding line JC Upright. While the differences between plant lines appeared to be related to foliar digestibility and metabolisable energy indices, rather than glycoside levels, the results indicate that narrow-leaved plantain has attributes that could be exploited to achieve better resistance against these pests.

Pancake Formulations Based on Plantain Flour ( Musa AAB)

In order to contribute to the reduction of postharvest losses of bananas and plantains and to diversify uses of plantain in Cameroon, flours obtained from a local plantain cultivar (Big ebanga) were used for pancakes production. The results of physicochemical parameters of flours varied significantly (P < 0.05). In addition, the optimization of pancakes formulation enabled to retain three most appreciated preparations by consumers. Formulations were differently encoded, depending on their composition. They were further added to the conventional one based on wheat flour, also encoded, and the four products were submitted to a sensory evaluation gathering 72 tasters. They gave their valuation on the colour, taste, texture, aroma and the overall quality of each product following a hedonic scale of 9 points: 9 (I like extremely) to 1 (I don’t like). Statistical analyses show that product 430 (made of 100% wheat flour) indicated an overall average appreciation of 7.29 while the product 136 (made of 100% of plantain flour) has an overall average rating of 6.76. After ANOVA, DUNCAN test showed no significant difference between the overall quality of product 430 and product 136. This study clearly indicates that plantain flour can be used for the preparation of pancakes that meet consumer’s expectations.

First Characterisation of Volatile Organic Compounds Emitted by Banana Plants

Banana (Musa sp.) ranks fourth in term of worldwide fruit production, and has economical and nutritional key values. The Cavendish cultivars correspond to more than 90% of the production of dessert banana while cooking cultivars are widely consumed locally around the banana belt production area. Many plants, if not all, produce Volatile Organic Compounds (VOCs) as a means of communication with their environment. Although flower and fruit VOCs have been studied for banana, the VOCs produced by the plant have never been identified despite their importance in plant health and development. A volatile collection methodology was optimized to improve the sensitivity and reproducibility of VOCs analysis from banana plants. We have identified 11 VOCs for the Cavendish, mainly (E,E)-α-farnesene (87.90 ± 11.28 ng/μl), methyl salicylate (33.82 ± 14.29) and 6-methyl-5-hepten-2-one (29.60 ± 11.66), and 14 VOCs for the Pacific Plantain cultivar, mainly (Z,E)-α-farnesene (799.64 ± 503.15), (E,E)-α-farnesene (571.24 ± 381.70) and (E) β ocimene (241.76 ± 158.49). This exploratory study paves the way for an in-depth characterisation of VOCs emitted by Musa plants.

Black Sigatoka severity and growth performance of two plantain cultivars in Omu-Aran, Southern Guinea Savannah of Nigeria

Black Sigatoka severity and growth performance of two plantain cultivars in Omu-Aran, Southern Guinea Savannah of Nigeria

Agronomic Performance of Plantain Cultivars (Musa spp.) in Efficient Mixing Situation for the Control of Black Sigatoka in Southern Côte d’Ivoire

Agronomic Performance of Plantain Cultivars (Musa spp.) in Efficient Mixing Situation for the Control of Black Sigatoka in Southern Côte d’Ivoire

English

Agronomic performances of local and exotic Musa species were evaluated across seven agro-ecologies in Eastern Democratic Republic of Congo. Generally, all the cultivars performed well. Mean bunch yields varied between 11 and 42 kg across different use groups and agro-ecologies. Introduced cultivars had higher or comparable yields to the local cultivars across agro-ecologies. The exotic beer cultivar ‘NARI 27’ generally outperformed other beer types. The green cooking exotic types ‘NARITA 4’ and ‘NARITA 2’ produced bunches of up to 37 and 39 kg, respectively at altitudes of 1066 and 1111 m, though having smaller bunches of 21 to 25 kg, at 900 and 1707 m in comparison to the local type ‘Barhabeshya’ (30 to 37 kg). Yields were mainly influenced by soil factors and altitude. Yields generally increased with increase in OM, N, P, K, Ca, and pH. Altitude had a non-linear relationship with the time from planting to flowering, with the time from planting to flowering declining at higher altitudes. In contrast, the fruit filling phase increased linearly with altitude. Bunch weights of most cultivars declined with increasing altitude; particularly, when N, K, P and OM concentrations were low; possibly because most assimilates go towards sucker development at the high altitudes. For example, bunch weights of ‘Barhabeshya’, ‘Mbwazirume’ and ‘Nshika’ strongly declined (R2 = -0.56-0.99) with increasing altitude. ‘Ndundu’, ‘FHIA21’ and ‘Gros Michel’ thrived well at high altitude sites. Such variations in cultivar adaptability plus cultivar attributes, e.g. height can be exploited by selectively promoting cultivars in specific agro-ecologies/niches. Key word: Agro-ecologies, cultivar, fruit filling phase, Kivu provinces, plantain cultivar, yield.

Composición química y distribución de materia seca del fruto en genotipos de plátano y banano

Se evaluó la distribución de materia seca en el racimo y atributos de composición química del fruto en 12 cultivares de plátano y banano de la Colección Colombiana de Musáceas (CCM) y se determinaron acercamientos entre los cultivares por medio de un análisis estadístico de componentes principales y de conglomerados. Las variables porcentajes de pulpa fresca y seca, porcentaje de cáscara seca, contenido de almidón, K, Ca, Cu, Mn, azúcares totales, cenizas, Fe, Zn y B representaron la mayor diferenciación de los cultivares. Los cultivares Orishelle (grupo 1) y FHIA-1 (grupo 2) presentaron los niveles más elevados de los minerales Fe y Zn. Orishelle representa una importante fuente de minerales para la nutrición humana pues se resalta su alto contenido de Fe (51,7 ppm) que se encuentra por encima del promedio general de los demás cultivares evaluados (29,1 ppm), mientras que los mayores niveles de azúcares totales se encontraron en el híbrido FHIA-21 (grupo 2) y el cultivar Gross Michel coco (subgrupo 3B). Los porcentajes más altos de materia en pulpa con respecto a la materia total del racimo los mostraron el material Pisang Mas (subgrupo 3B) (83 %) y los cultivares África 1 (subgrupo 3A) (82,6 %) y Gross Michel coco (82,1 %). Los cultivares Cachaco (grupo 2) y Dominico (subgrupo 3A) mostraron los mayoresporcentajes de cáscara fresca por racimo.

Plantain‐starch: Microstructural, physicochemical, and morphological characteristics of two cultivars grown in Malaysia

Starches isolated from mature green “Nangka” and “Tanduk” plantain (Musa paradisiaca L) cultivars grown in Malaysia were appraised for their morphological, physicochemical, and structural properties. The amylose contents of “Nangka” and “Tanduk” starches were 31.79 and 26.08% and the degree of relative crystallinity were 62.1 and 52.1%, respectively. Both cultivar starches presented an A‐type diffraction pattern, which has rarely been reported for banana starches. Gelatinization temperatures evaluated by differential scanning calorimeter were higher for “Tanduk” starch than “Nangka” starch. The scanning electron micrograph of “Nangka” starch granules was larger than “Tanduk” starch with an average particle size of 38.77 and 23.91 μm, respectively. In addition, “Nangka” starch produced lower molar mass (Mw) and gyration radius (RG) compared to “Tanduk” starch.

Resistance toFusarium oxysporumf. sp.cubensetropical race 4 in African bananas

Bananas (Musa spp.) constitute one of the most important staple food crops in Africa. Two major groups of bananas exist in Africa: the East African highland banana (EAHB, AAA) in East and Central Africa, and the plantains (AAB) in West Africa. Neither of these groups has been affected by Fusarium oxysporum f. sp. cubense (Foc) race 1, which is the primary fungal pathogen in the continent for banana. The susceptibility of EAHB and plantains to Foc tropical race 4 (TR4) is unknown, and was the focus of this study. A collection of 14 genetically diverse EAHB and plantain cultivars were evaluated in China and The Philippines to determine field resistance to Foc TR4. A field heavily infested with TR4 was used in Guangzhou, China, and another one in Davao City in The Philippines. Disease incidence was determined according to leaf yellowing, pseudostem splitting and confirmed rhizome discoloration. The fungus was also re-isolated from diseased materials and identified by polymerase chain reaction (PCR) using Foc TR4-specific primers. All EAHB and plantain cultivars, except EAHB 'Ibwi', proved to be resistant to the tropical strain of Foc race 4, with disease incidence ranging from 0-5% only. In The Philippines, 'Ibwi' developed Fusarium wilt at an incidence of 32% compared to 46% for 'Williams' and 79% for 'Grand Naine's (both AAA genome, Cavendish subgroup). Similar results were observed in China where most cultivars were severely affected by the corm weevil. Our preliminary results indicate that African bananas are less vulnerable to Foc TR4 compared with some susceptible cultivars in Asia. A more extensive screening of African bananas is required considering the diversity of EAHB and plantains grown in that region.

Plantain cultivars (Musa spp. AAB) grown at different altitudes demonstrate cool temperature and photoperiod responses relevant to genetic improvement

Knowledge of plant development in plantains is needed to manage seasonal variation in production and better match critical development phases with appropriate seasons. Plantains have juvenile, mid-vegetative and floral phases leading up to flowering (bunch emergence). We examined whether the juvenile phase showed a cool temperature response, whether the mid-vegetative phase was sensitive to photoperiod and how these phases were related to growth of lateral shoots (suckers) up to flowering. We examined published data of an experiment of five plantain cultivars grown at four altitudes, and therefore temperatures (1000m, 24°C to 2200m, 16°C) within 1° latitude of the equator in the Democratic Republic of Congo. Four of the five cultivars showed a cool temperature response in the juvenile phase. Plants grown in cool temperatures (16°C) ended the juvenile phase after producing 7 leaves. In warmer climates (24°C) 15 leaves were produced before the juvenile phase ended. All five cultivars demonstrated a high capacity to respond to photoperiod in the mid-vegetative phase. There were detectable differences in capacity of the cultivars to respond to photoperiod, Ps. ‘Vuhindi’ had the least capacity (Ps=90) and ‘Musilongo’ and ‘Vuhembe’ the greatest (Ps=145). Across altitudes, suckers began to appear above ground at just after the end of the juvenile phase and there was a strong positive linear correlation (r2=0.97) between the calculated phyllochron (10–27 days) and the proportion of lateral buds that grew into suckers. With a phyllochron of 10 days about 10% of the lateral buds present on the plant produced lateral shoots up to flowering. At 27 days, from 40% to 80% of the lateral buds produced suckers depending on the cultivar. The responses of the juvenile phase to low temperature and the mid-vegetative phase to photoperiod in Musa spp. opens the opportunity to alter plant development and produce cultivars better suited to the climates where they are currently grown and to extend this range.

Organoleptic and Horticultural Characterization of Selected Elite Cultivars of Plantain (Musa paradisiaca L.) for Value Addition and Food Security in Nigeria

Organoleptic and Horticultural Characterization of Selected Elite Cultivars of Plantain (Musa paradisiaca L.) for Value Addition and Food Security in Nigeria

The triploid East African Highland Banana (EAHB) genepool is genetically uniform arising from a single ancestral clone that underwent population expansion by vegetative propagation.

All East African Highland Banana varieties are genetically uniform having arisen from a single clone introduced to Africa. East African Highland bananas (EAHBs) are a subgroup of triploid (AAA genome) bananas of importance to food security in the Great Lakes region of Africa. Little is known about their genetic variation, population structure and evolutionary history. Ninety phenotypically diverse EAHB cultivars were genotyped at 100 SSR microsatellite markers to investigate population genetic diversity, the correlation of genetic variability with morphological classes, and evolutionary origins since introduction to Africa. Population-level statistics were compared to those for plantain (AAB) and dessert (AAA) cultivars representing other M. acuminata subgroups. EAHBs displayed minimal genetic variation and are largely genetically uniform, irrespective of whether they were derived from the distinct Ugandan or Kenyan germplasm collections. No association was observed between EAHB genetic diversity and currently employed morphological taxonomic systems for EAHB germplasm. Population size dynamics indicated that triploid EAHBs arose as a single hybridization event, which generated a genetic bottleneck during foundation of the EAHB genepool. As EAHB triploids are sterile, subsequent asexual vegetative propagation of EAHBs allowed a recent rapid expansion in population size. This provided a basis for emergence of genetically near-isogenic somatic mutants selected across farmers and environments in East Africa over the past 2000 years since EAHBs were first introduced to the African continent.

The Particle Size and Thermal Properties of Flour from three Plantain (Musa Paradisiaca) Cultivars Grown in Nigeria

Flour from three plantain cultivars (Agbagba, Cadaba and French horn) commonly grown in Nigeria were investigated for their particle size, bulk density and thermal properties. The results showed that Agbagba cultivar had the least particle size (10.04%) at 125µm sieve size and significantly increased to 29.45% at 180µm sieve size. Cadaba and French horn plantain cultivars showed a particle size of 56.54% and 36.20% at 125µm sieve size, respectively and decreased significantly with increase in sieve sizes. The bulk density ranged from 28.62% to 30.50% and showed no significant differences between the cultivars. The moisture content ranged from 7.65% (French horn) to 8.7% for (Cadaba) and showed no significant difference (p > 0.05). Also, there were no significant differences (p > 0.05) observed in specific heat capacity, thermal conductivity and thermal diffusivity between the cultivars studied. The data thus obtained showed that chemical composition of the cultivars may influence thermal properties and this will serve as a useful engineering tool for the design and development of sieves and dryers for plantain flour.

In-vitro assay and inactivation kinetics of polyphenol oxidase of some Nigerian banana and plantain cultivars

Activity of polyphenol oxidase (PPO) from the pulp of three banana cultivars grown in Nigeria, namely: plantain, light green-skinned banana and red-skinned banana at unripe and ripe states were investigated. The efficiency of extraction of crude PPO enzyme and in-vitro assay of its activity were determined. Polyethylene glycol detergent gave the highest extraction efficiency. Enzyme activity and rate of browning were found to be highest in plantain and least in light green-skinned banana. Enzymes from all the cultivars were specific towards O-diphenolic compounds and not to monophenolics. The optima pH of PPO of the cultivars tends towards neutrality (6.6-7.0). Enzyme activity was destroyed between 2 and 4 min at 80°C. Thermal inactivation kinetic parameters revealed plantain's PPO to be the most thermal stable. Sodium metabisulphite was the most effective chemical inhibitor of the PPO. The electrophoretic patterns of banana PPO showed heterogeneity with greater number of bands in ripe.

In-vitro assay and inactivation kinetics of polyphenol oxidase of some Nigerian banana and plantain cultivars

Activity of polyphenol oxidase (PPO) from the pulp of three banana cultivars grown in Nigeria, namely: plantain, light green-skinned banana and red-skinned banana at unripe and ripe states were investigated. The efficiency of extraction of crude PPO enzyme and in-vitro assay of its activity were determined. Polyethylene glycol detergent gave the highest extraction efficiency. Enzyme activity and rate of browning were found to be highest in plantain and least in light green-skinned banana. Enzymes from all the cultivars were specific towards O-diphenolic compounds and not to monophenolics. The optima pH of PPO of the cultivars tends towards neutrality (6.6-7.0). Enzyme activity was destroyed between 2 and 4 min at 80°C. Thermal inactivation kinetic parameters revealed plantain's PPO to be the most thermal stable. Sodium metabisulphite was the most effective chemical inhibitor of the PPO. The electrophoretic patterns of banana PPO showed heterogeneity with greater number of bands in ripe.