Dwarf Cavendish Research Articles

Stability of fruit ripening traits of banana (Musa species) across postharvest environments

Banana (Musa species) is the fourth most important export crop worldwide after cereals, oil crops and sugar. In spite of this socio-economic significance, the crop suffers massive postharvest losses caused by mechanical fruit damage, limited infrastructure for fruit ripening, postharvest diseases and physiological disorders. Although use of optimum postharvest environments such as packaging and storage temperatures can reduce fruit loss and improve ripening quality; information regarding the interaction between varieties and postharvest environments and stability of fruit ripening traits across postharvest environments is limited. The objectives of this study were to determine the magnitude of interaction of varieties with postharvest environments on fruit ripening traits and to identify stable banana variety for ripening across postharvest environments. Seven commonly grown banana varieties (Dwarf Cavendish, William I, Grand Naine, Poyu, Giant Cavendish, Butazu and Local variety) were laid out in a completely randomized design with five replications in ten varied postharvest environments. The result indicated that pulp and peel ratio had negative high principal component one (PCA1) score whereas the PCA1 score for postharvest period, peel weight and fruit weight were positive and high. Cluster analysis grouped Dwarf Cavendish and Grand Naine; Poyu and Butazu varieties together for postharvest traits whereas the local variety was clustered separately. This study has demonstrated that hybridization of local with the introduced varieties can be done to improve postharvest traits. AMMI depicted significant variation for genotype, postharvest environments and their interactions for all traits. The magnitude of environmental effect was higher than the genotype and interaction effects. AMMI and GGE biplot analyses identified Gran Naine, Poyu and William I as consistent for ripening traits across postharvest environments.

Determination of the Effects of Some Post-Harvest Treatments on the Quality of Banana Fruits During Storage and After Ripening

In this study, it was aimed to impact the effect of different post-harvest treatments on the shelf life of banana fruits of 'Dwarf Cavendish' banana cultivar after storage and ripening. 1) Modified atmosphere packaging (MAP), 2) 1-methylcyclopropene (1-MCP) + MAP, 3) Three different treatments (MAP + ethylene absorbent (EA)) were applied and only those using macro-aperture PE packaging were considered as control. Banana fruits were stored at 13°C and 90% RH for 30 days. Quality analyses were performed on samples taken at 10-day intervals. After 30 days of storage, the banana fruits were ripened to the ripeness level of No.3 and quality changes were determined after 4 days of shelf life. The treatments significantly limited the color change, softening of the peel and flesh, increased total soluble solids (TSS), ethylene secretion and respiration rate, especially in the last period of storage compared to the control. Green bananas treated with 1-MCP + MAP showed the best results during storage, but ripening problems were experienced. MAP + EA treatment delayed the coloration of banana fruits, softening of the flesh and increases in the TSS content during shelf life. MAP + EA treatment gave the best results both in terms of storage of banana fruits at green maturity and their resistance after ripening.

Type of stomata and peel structure associated with programmed cell death of senescent spotting in banana

Senescent spotting or brown spot on bananas, is regarded as a form of programmed cell death (PCD). These spots appear in areas where stomata are present on the banana peel, there is no report describing the relationship between these spots and stomata on peel. This research aims to investigate whether senescent spotting in banana is involved in the PCD of stomata on peel. Three banana cultivars, ‘Khai-Kasetsart 2’ (KK2), ‘Dwarf Cavendish’ (CVD), and ‘Hom Thong’ (HT) bananas were examined for senescent spotting. KK2 banana exhibited more severe senescent spotting than CVD banana, while HT bananas did not display brown spot. Electrolyte leakage and DNA degradation increased before the spotting was observed in KK2 and CVD bananas. The peel structure revealed compact cells in CVD and HT bananas, whereas KK2 banana had a loose cell structure. Notably, KK2 banana had a high stomata density correlate with weight loss. Interestingly, the stomata type of KK2 banana was the same as CVD banana, being the typical type, while HT had a sunken type. The spotting zone of KK2 and CVD bananas revealed that stomata were more open than in the healthy zone. Additionally, the outer ground tissue of spotting zone flattened and collapsed, while the healthy zone did not exhibit this flattening and collapsing. Observations of cell morphology in the spotting zone of KK2 banana showed a detached plasma membrane, organelle destruction, and the presence of cell corpse with an absence of cytoplasm clearance. In conclusion, the result provides an evidence that stomata type on the banana peel involve in PCD, resulting in senescent spotting.

The Combined Effect of Lemon Peel Extract and Calcium Chloride on the Physical and Biochemical Quality Parameters of the Dessert Banana (Musa acuminata var. Dwarf Cavendish) Fruit

The dessert banana is a popular fruit worldwide, but its ripening process is greatly accelerated by high temperatures, which eventually leads to an unpleasant taste and the appearance of spots on the skin of the fruits. To slow down the ripening of bananas, expensive strategies are used, which are usually not practical for conventional farmers in less developed countries. In this study, we try to find a less costly alternative. Therefore, the effects of coatings of lemon peel extract (2.5%, 5%, and 10%), calcium chloride (4%), and glycerol (2%) on the shelf life and postharvest quality of the banana fruit (Cavendish) stored at 19–22 °C and 40–60% relative humidity were investigated. Treatment with a mixture of 2.5% lemon peel extract and 2% glycerol resulted in an extension of the shelf life of the dessert banana by up to 6 days and no detectable fungal infestation. The coating solution is an effective alternative to extend the shelf life and reduce quality losses in bananas.

PHYSICOCHEMICAL, MICROBIOLOGICAL AND SENSORY EVALUATION OF SHELLED BANANA JUICE

This work aimed to evaluate the physical-chemical, microbiological and sensorial characteristics of unpeeled banana vitamin. The bananas of the cultivar Nanica (Musa acuminata Dwarf Cavendish) were in the 7th stage of maturation. The UHT whole milk used had 3% fat. The treatments were 0%, 10%, 25% and 35% addition of banana peel to the banana smoothie. The physical-chemical analyzes (acidity, pH, density, moisture, ash and fat) were carried out in triplicate, according to the methods of Adolfo Lutz. For microbiological evaluation, the analyzes of total coliforms (35ºC) and thermotolerant coliforms (45ºC) were performed using the multiple tube method and the results expressed in MPN/g. Sensory assessment was applied to 50 untrained panelists using a nine-point structured hedonic scale blind test. Data were subjected to ANOVA and Tukey's test with 5% significance to verify interactions between means. The acidity showed a statistically significant difference, with an average of 1.59%. The mean pH was 6.57 and showed statistical differences between treatments. For density, moisture, fat and ash, the averages were 1,543 g / dm3, 84.17%, 1.03% and 0.83%, respectively. Microbiological analyzes were negative for total coliforms and thermotolerant coliforms, indicating that good manufacturing practices were efficient. For sensory evaluation, the highest acceptance rate was for the treatment of 25% and 54% of the tasters consume banana smoothie at least once a month. The results of the physical-chemical analyzes allow us to infer that the peeled banana smoothie is a low-fat food, thus showing that it can be considered a low-calorie food. Microbiological analyzes showed that the vitamin was produced within good manufacturing practices, as the results for coliforms were negative for all samples. Sensory analysis allowed us to verify that the treatment with the best acceptance rate was the one with 25% of bark, but we will indicate the treatment with 35% of bark, since there was no statistical difference between the formulations in relation to acceptance.
 Keywords: food waste use, low cost food, quality control

Study on the preparation and use of edible coating of fish scale chitosan and glycerol blended banana pseudostem starch for the preservation of apples, mangoes, and strawberries

Agro-industries and the fish processing sector generate large amounts of waste, which may be converted into useful ingredients for preserving fruit. Studies show that starch-based edible film still needs some improvement because it’s brittle and weaker, which might be improved by adding chitosan. The study aimed to investigate the optimal composition of edible film-forming material prepared from banana pseudostem starch and fish-scale chitosan to preserve the selected fruits. In the current study, chitosan and starch were extracted from the waste of Nile tilapia fish scale and Dwarf cavendish banana pseudostem as found to be 29.66 ± 0.46 % and 4.26 ± 0.21 %, respectively. Central composite response surface experimental design combined banana pseudostem starch, chitosan, and glycerol to prepare the edible films. Using the Design-expert program, the ideal film-forming composition with an overall acceptability of 0.968 was identified based on the physico-mechanical characteristics of the created composite edible films. It comprised 15 mL of 1 % banana pseudostem starch, 3.2 mL of 0.5 % chitosan, and 0.6 mL of 30 % glycerol. The persistence of the microbial load on coated and uncoated fruits throughout the storage was also assessed in the study. The microbial and fungal growth was significantly lower (>37 %) in optimal edible film-coated fruits than in the control fruits. After 28 days of storage of fruits at room temperature, the microbial count (in CFU/mL) on the edible coated surfaces of apples, mangoes, and strawberries was found to be 2.04 ± 0.32x103, 2.71 ± 0.29x103, and 2.5 ± 0.51x104, respectively. Also noticed the fungus counts of 1.86 ± 0.48x03 (in apples), 1.09 ± 0.11x104 (in mangoes), and 1.56 ± 0.04x104 (in strawberries) in the studied coated fruits after 28 days of storage. Furthermore, the film-coated fruits had a significantly lower weight loss than uncoated fruits. Thus, the studied banana pseudostem starch-chitosan-glycerol composite edible coating potentially preserves by inhibiting the development of natural microbes when storing apples, mangoes, and strawberries, and it is adequate to extend their shelf life.

Macropropagation in Banana: Response to Hormone and Genome in Sucker Production

Banana (Musa spp.) is the most important fruit crop of the world. The production of banana propagules for different scales of its cultivation by local farmers is still an important researchable issue as micropropagation is the only available source for plantlets production. An experiment on macro-propagation of banana belonging to three different genomic groups (AAA, AAB, ABB) was conducted at the Department of Plant Physiology, BCKV Mohanpur, West Bengal to study the induction of sucker through application of BAP @40 ppm. The substrate used for planting the corms were a mixture of sawdust + Trichoderma @ 15 g kg-1 of sawdust + vermicompost @ 15 g kg-1 of sawdust. Observations recorded were weight of the corm, days to appearance of the first primary suckers, number of primary suckers, number of secondary suckers, number of tertiary suckers and total number of suckers. The number of primary suckers induced ranged between 1.67 in Dwarf Cavendish (AAA) to 5.33 in Lacaton (AAA), while the number of secondary suckers induced ranged between 0.67 in Srimanti (AAA) to 22.00 in Manohar (AAB). The number of tertiary suckers induced were only observed in the genomic composition AAB with 4.00 and 0.67 in both the genotypes Madhurangbale and Manohar respectively. Days to bud appearance varies from 7.33 in Madhurangbale (AAA) to 29.33 days in Basrai (AAA). The weight of the corm also varied from 5.56 kg in Madhurangbale (AAA) and 2.06 kg in Kothia (ABB).

Transgenic expression of Arabidopsis ELONGATION FACTOR-TU RECEPTOR (AtEFR) gene in banana enhances resistance against Xanthomonas campestris pv. musacearum.

Banana Xanthomonas wilt (BXW) caused by Xanthomonas campestris pv. musacearum (Xcm) is a severe bacterial disease affecting banana production in East and Central Africa, where banana is cultivated as a staple crop. Classical breeding of banana is challenging because the crop is clonally propagated and has limited genetic diversity. Thus, genetic engineering serves as a viable alternative for banana improvement. Studies have shown that transfer of the elongation factor Tu receptor gene (AtEFR) from Arabidopsis thaliana to other plant species can enhance resistance against bacterial diseases. However, AtEFR activity in banana and its efficacy against Xcm has not been demonstrated. In this study, transgenic events of banana (Musa acuminata) cultivar dwarf Cavendish expressing the AtEFR gene were generated and evaluated for resistance against Xcm under greenhouse conditions. The transgenic banana events were responsive to the EF-Tu-derived elf18 peptide and exhibited enhanced resistance to BXW disease compared to non-transgenic control plants. This study suggests that the functionality of AtEFR is retained in banana with the potential of enhancing resistance to BXW under field conditions.

Divergent endophytic viromes and phage genome repertoires among banana (Musa) species.

Viruses generally cause disease, but some viruses may be beneficial as resident regulators of their hosts or host microbiomes. Plant-associated viruses can help plants survive by increasing stress tolerance or regulating endophytic communities. The goal of this study was to characterize endophytic virus communities in banana and plantain (Musa spp.) genotypes, including cultivated and wild species, to assess virome repertoires and detect novel viruses. DNA viral communities were characterized by shotgun sequencing of an enriched endosphere extract from leaves and roots or corm of 7 distinct Musa genotypes (M. balbisiana, Thai Black, M. textilis, M. sikkimensis, Dwarf Cavendish, Williams Hybrid, and FHIA-25 Hybrid). Results showed abundant virus-like contigs up to 108,191 bp long with higher relative abundance in leaves than roots. Analyses predicted 733 phage species in 51 families, with little overlap in phage communities among plants. Phage diversity was higher in roots and in diploid wild hosts. Ackermanniviridae and Rhizobium phage were generally the most abundant taxa. A Rhizobium RR1-like phage related to a phage of an endophytic tumor-causing rhizobium was found, bearing a holin gene and a partial Shiga-like toxin gene, raising interest in its potential to regulate endophytic Rhizobiaceae. Klebsiella phages were of interest for possible protection against Fusarium wilt, and other phages were predicted with potential to regulate Erwinia, Pectobacterium, and Ralstonia-associated diseases. Although abundant phage-containing contigs were functionally annotated, revealing 1,038 predicted viral protein domains, gene repertoires showed high divergence from database sequences, suggesting novel phages in these banana cultivars. Plant DNA viruses included 56 species of Badnavirus and 26 additional non-Musa plant viruses with distributions that suggested a mixture of resident and transient plant DNA viruses in these samples. Together, the disparate viral communities in these plants from a shared environment suggest hosts drive the composition of these virus communities. This study forms a first step in understanding the endophytic virome in this globally important food crop, which is currently threatened by fungal, bacterial, and viral diseases.

Processing of encapsulated flaxseed oil‐rich banana‐based (Dwarf cavendish) functional fruit leather

AbstractBanana fruit leather enriched with flaxseed oil in the form of encapsulates was prepared. Initially, the optimized conditions of 836 W power for 4 min for blanching of banana using microwave were obtained by Response Surface Methodology with residual polyphenol oxidase activity and vitamin C retention taken as responses. The addition of maltodextrin, citric acid, and pectin for blending with banana puree to obtain a non sticky puree having low pH was also optimized, while keeping the quantity of sugar constant. The blend was added with 5% encapsulates of flaxseed oil (FSO) in alginate used as wall material. The blend was dried in a tray drier at 40, 50, and 60°C and the drying behavior of the leather was studied. Henderson and Pabis model satisfactorily described the drying kinetics of banana leather. GAB model described well the sorption behavior of the leather. Fat content in the optimized leather increased to 3.27% due to addition of FSO. The ash content in the enriched leather was 5.56 ± 0.03%. Phenolic content increased from 91.84 ± 0.06 mg GAE/100 g to 100.90 ± 0.05 mg GAE/100 g for the enriched leather as compared to the control. The study revealed that the banana leather can be considered as a functional snack food due to the availability of flaxseed oil (rich in ω‐3 fatty) and high phenolic acid content.Practical ApplicationsBanana can be processed into functional fruit leather with the addition of flaxseed oil encapsulated beads to complement the fast moving consumer goods market. Developing the banana leather by drying enhances its shelf life while encapsulation increases the stability of flaxseed oil for a prolonged storage of the product. Flaxseed oil is rich in ω‐3 fatty acid, an important bioactive compound required for good human health. Moreover, modeling of the drying behavior allows optimization of the process, which is necessary for designing of energy efficient industrial flow dryers. Therefore, this study on development of a novel functional product and drying kinetics will give a new edge to the industrial processing of similar snack products with a potential alternative to reduce the waste of banana as a raw material.

Effects of Banana Clones and Spacing on Growth, Yield and Fruit Quality of some Banana Cultivars

Afield experiment was carried out at the National Institute for the Promotion of Horticultural Exports (NIPHE) research farm, University of Gezira, Wad Medani, Sudan, to study the effects of banana clones and spacing on vegetative growth, crop earliness, yield and yield components, fruit green life and fruit quality of some introduced banana clones under Gezira state conditions. Treatments consisted of six new banana clones, namely, Williams hybrid clone 1 (WH1), Williams hybrid clone 2 (WH2), Grand Nain clone 1 (GN1), Grand Nain clone 2 (GN2), Zelig and Bio, which were introduced from South Africa by NIPHE. The introduced clones were compared with the local cultivar Dwarf Cavendish (DC). All clones were grown at spacings of 2x2 m and 3x3 m. These treatments were arranged in a split plot design with three replications and four plants each. Results showed that vegetative growth parameters, crop earliness, yield and yield components, fruit green life and fruit quality were significantly affected by spacing and banana clones. WH1 and Zelig obtained the best vegetative growth, whereas DC obtained the worst growth. Zelig and Bio scored the highest yield and yield components, while DC scored the lowest yield in the three ratoons. WH1 took the largest number of days from shooting to harvesting, whereas Zelig recorded the highest exportable yield in the three ratoons.

Comparative role of Dwarf Cavendish banana leaf formulated biochar and compost in corn - nutrient uptake and its relationship with yield

Comparative role of Dwarf Cavendish banana leaf formulated biochar and compost in corn - nutrient uptake and its relationship with yield

Evaluation of Dessert Banana (Musa spp.) Cultivars for Growth, Phenological, Yield and Yield Components at Raya Azebo Districts of Tigray Region, Northern Ethiopia

The experiment was carried out to investigate the performance of dessert banana cultivars at Raya Azebo with the aim of selecting well adaptable and high yield banana cultivar/s. To achieve the goal of the study, the experiment was laid out in randomized complete block design and replicated thrice. From the experiment, different growth, phenological, yield, and yield-related data were collected, and analyzed using SAS software version 9.3. Dwarf Cavendish cultivar flowered earlier (549.70 days). The maximum number of days (627.20) from planting to fruit setting was recorded on Ducase Hybrid cultivar. Ducase Hybrid gave significantly the maximum bunch weight for the mother (21.04 kg) and daughter (24.53 kg) tree. The maximum number of hand bunch‑1 was recorded on Ducase Hybrid cultivar on both mother (11.31) and daughter (12.17) tree. Ducase hybrid gave significantly the maximum (357.80 qt/ha) marketable fruit yield hectare‑1on the mother tree. On the daughter tree, Ducase hybrid gave significantly the highest (392.5 qt/ha) marketable fruit yield hectare­-1. The average of mother and daughter tree cropping cycle revealed that Ducase hybrid gave first ranked highest marketable fruit yield (375.15 qt/ha), but sensitive to wind. Williams‑I gave the second ranked highest (334.95 qt/ha) marketable fruit yield hectare‑1. Thus, Williams-I cultivar is recommended for the local area. Further, study on water requirements and biochemical content is crucial.

Morphological and molecular characterization of banana clones growing in Turkey

This study was conducted to estimate genetic relationships among banana clones growing in Turkey via some morphological parameters and two molecular marker systems. In terms of yield parameters such as bunch weight, hand number, fruit weight, and total fruit number, Grand Nain (GN) clone came to the forefront with the highest values. It was followed by Azman (AZ), Dwarf Cavendish (DC), and Erdemli Yerli (EY) clones, respectively. To see the variation between clones more clearly, 24 RAPD (Random Amplified Polymorphic DNA) primers and 48 SRAP (Sequence Related Amplified Polymorphism) primer combinations were used in molecular analysis. The total number of amplified bands was 194, and 142 of them were polymorphic for RAPD analysis. The total and polymorphic bands per primer ranged from 0 to 14. A total of 272 bands were obtained from SRAP analysis, of which 154 were polymorphic. The total number of bands per primer varied between 0 and 11, and the number of polymorphic bands varied between 0 and 10. According to the dendrogram formed by unweighted pair group method with arithmetic averages (UPGMA) analysis, clones were collected in two main groups. In all evaluation methods, EY was completely separated from the other clones. GN, DC, and AZ were gathered on a single branch in the dendrogram. As a result of the SRAP assessment, DC and GN were the closest related clones. Contrary to the SRAP results, GN and AZ were identified as the most genetically related clones in morphological and RAPD assessments. This study showed that morphological and molecular characterization could be useful to assess the relationship among banana clones.

First report of banana freckle disease caused by Phyllosticta cavendishii in Mauritius

Banana (Musa sp.) is among the most important fruit crops grown in Mauritius with significant socioeconomic and cultural considerations. The annual production of banana approximates to around 8000 tonnes (Statistics Mauritius, 2018). Dwarf Cavendish is the main variety grown commercially in Mauritius. During the hot and humid month of February 2014, symptoms consisting of dark black spots were observed on unripe banana of Dwarf Cavendish from the region of Nouvelle Découverte (super humid zone). A disease incidence of more than 50% with a moderate to severe level of severity across the field was reported by the extension services of the Food and Agricultural Research and Extension Institute. On the fruits, the initial symptom was tiny reddish-brown spots, bordered by dark green water-soaked margins (Figure 1). As the spots enlarged and coalesced, the surface became rough and turned black. These spots had a rough texture like sand-paper, similar to the description described by Wong et al. (2012). Comparable symptoms were observed on the leaves (Figure 2). Results from a rapid island-wide survey showed that only the Cavendish-type banana varieties displayed symptoms of infection. Out of 98 banana fields surveyed (50.9 ha), 65% were affected. Morphological identification of the suspected fungal pathogen was done using a compound light microscope. A sterile needle was used to tease pycnidia on leaves in a drop of sterile water to release conidia, before being mounted in clear lactic acid for microscopic examination. Conidia (Figure 3) formed singly at the apex of the conidiogenous cell were hyaline, aseptate, oblong to ellipsoidal, coarsely guttulate and measured 7.1-15.6 × 4.4-8.3 μm. The apical mucilaginous appendage arising from the conidium was straight to curved and was 5.1-12.9 μm long. Spermagonia were 70–125 μm in diameter and 50–85 μm high. Dumbbell-shaped spermatia (Figure 4) were hyaline, aseptate, biguttulate and measured 7.5-9.5 × 1.3-1.8 μm. These morphological characters are consistent with the species description of Phyllosticta cavendishii (Wong et al., 2012). Lesions from 11 samples of leaf and fruit with fruiting bodies were ground in liquid nitrogen followed by genomic DNA extraction. Extraction of DNA was done on c. 50 mg fresh plant tissue using the Biosprint 15 DNA Plant Kit (Qiagen, Germany). Tissues were first homogenized using a Tissuelyser (Qiagen, Germany) in a 2 ml microcentrifuge tube containing a 3 mm metal bead for two 30 second bursts at 30Hz. Two microliters of the eluted DNA was used as template in an ITS PCR amplification using AmpliTaq Gold 360 Mastermix (Applied Biosystems, USA) and 0.5 μM each of primers GMF1 and GMR2 (Wong et al., 2012). Thermal cycling conditions were 95°C for 10 min followed by 40 cycles of 95°C for 30 sec, 55°C for 30 sec and 72°C for 1 min. Final extension of PCR products was done at 72°C for 10 min. Amplicons (550bp) were directly sequenced using the same primer pair. Resulting sequences were analysed using BlastN as well as by manual comparison to known sequences of Phyllosticta isolates which cause freckle disease of banana. The causal agent from all 11 samples tested was found to be Phyllosticta cavendishii. The ITS sequences were deposited in GenBank (Accession Nos. MW520341-MW520351) and at the Queensland Plant Pathology Herbarium (BRIP 72048 to 72058). Pathogenicity was tested using twenty mature green healthy fruits of banana variety Dwarf Cavendish. Fruits were surface sterilised using 0.2% sodium hypochlorite for 2 mins, rinsed with sterilised distilled water and allowed to dry before inoculation. Ten fruits were artificially inoculated on the outer surface, clearly marked, with a conidial suspension of 106 conidia/ml, prepared from pycnidia extracted from field infected tissue. Control fruits were treated with sterile distilled water. All the fruits were covered with plastic bags for 48 hours and incubated at room temperature, 80% relative humidity and with a 12-hour photoperiod. After 7 days, typical minute black spots identical to those observed in the field, appeared on inoculated fruits, whereas controls remained healthy. The morphological characteristics of the fungus were consistent with those previously observed, hence fulfilling Koch's postulates. To our knowledge, this is the first report of Phyllosticta cavendishii causing banana freckle disease in Mauritius. The authors acknowledge the Centre for Plant Science, Queensland Alliance for Agriculture and Food Innovation for the molecular identification of Phyllosticta cavendishii and also Dr Yu Pei Tan from the Brisbane Plant Pathology Herbarium for accessioning isolates and submission into GenBank.

SILICON IN THE ANATOMY AND PHYSIOLOGY OF BANANA PLANT LEAVES UNDER TEMPORARY IMMERSION BIOREACTORS

Banana is a crop with outstanding economic and social expression throughout the world, therefore, it is important to use appropriate methods of propagation. The micropropagation is an appropriate method because it is disease-free, unlike traditional methods that spread pests and diseases. The objective of this study was to evaluate the effect of silicon on foliar anatomy and chlorophyll content of banana plants culturedin vitro using temporary immersion bioreactor technology. Explants of ‘Dwarf Cavendish’ banana established in vitro were inoculated in bioreactors containing MS liquid medium. Treatments included silicon concentration (0 and 1 mLL-1) and frequency of immersions (every 4, 6, and 8 hours) lasting 1 minute per immersion. Cultures were maintained in a growth room at 27 ± 2 °C under LED light (50 μmol m-² s-¹) with a 16 h of photoperiod for 36 days. After that period, anatomical characteristics and chlorophyll content were evaluated. Higher values were observed for some characteristics validated in plants cultivated with silicon when compared to control. Silicon addition resulted in increased thickness of the leaf’s limb tissues, resulting in a larger mesophyll (563.122µm) which is the set of measurements of all leaf’s limb tissues, it also provided greater adaxial and abaxial stomatal density (0.108817µm and 0.305085µm) respectively, greater adaxial and abaxial polar diameter/equatorial diameter ratio (1.982 and 2.069) respectively, and increased chlorophyll a content (0.000134 mg·g-1 fresh weight) and a/b ratio (1.710425) of plants of banana ‘Dwarf Cavendish’ cultured in bioreactors.

Rate of banana fruit ripening depends on genome composition and gene expression of ethylene signaling and ethylene biosynthesis

Expression of the genes in banana peel involved in ethylene signaling and ethylene biosynthesis was investigated in three groups of cultivars showing different fruit-ripening times: a fast-ripening group (Thong Som and Namwa Pakchong 50), an intermediate-ripening group (Khai Kasetsart 2, Sa and Hom Thong), and a slow-ripening cultivar (Dwarf Cavendish). A decrease in pulp firmness was correlated with peel yellowing in these three ripening groups. Also the respiration climacteric peak correlated with the speed of ripening. The fast-ripening group had a B-genome composition and a high level of ACO gene expression. The transcriptsof MaERS1, MaERS3, MaEIL1-4, and MaACS1, MaACO1 genes had differential expression levels. A reduced expression level of the ethylene receptor gene (MaERS3) was observed in the fast-ripening group, while the expression of the MaERS1 gene increased markedly at the mature green stage until the peel turned yellow. However, there was less change in both receptor genes in the intermediate-ripening group. In the slow-ripening group, the expression levels of these receptor genes continuously increased throughout the ripening time concomitant with the expression of the MaCTR1 gene. These results indicated that ethylene biosynthesis (MaACS1 and MaACO1) was being delayed. In conclusion, the distinct regulation of banana fruit-ripening time, resulting from the reduced expression level of ethylene receptor genes, depended on the combination of the B and A genomes contributing to each subspecies.

On-farm Evaluation and Demonstration of Improved Banana (Musa spp) Technologies under Small-scale Irrigation Schemes of Selected Lowland Districts of Bale Zone, South-eastern Ethiopia

On-farm evaluation and demonstration of improved banana technology were carried out under small-scale irrigation scheme in selected lowland districts of Bale Zone. FRG approach was employed and two FRGs in every selected scheme were established with 20 members each. The evaluation and demonstration was implemented on four farmers in each scheme and a total of sixteen (16) farmers were used. Each farmer’s field was considered as replication of the trial. Hence; a total of four improved banana varieties namely Giant Cavendish, Dwarf Cavendish, Poyo and Grand Nain were evaluated. From the study result; there were significant differences between mean yield and yield components of banana varieties. The highest number of finger per bunch (142) was recorded for Giant Cavendish followed by Dwarf Cavendish (141) and then Grand Nain (135) varieties whereas the minimum number of finger per bunch (101) was recorded on Poyo variety. On the other hand, the average length of randomly sampled fingers showed that the longest finger (16.54 cm) was obtained from Giant Cavendish variety whereas the shortest finger length (10.36cm) was recorded for Poyo variety. The average yield of banana has also determined for its variation between verities and there was significant (p<0.05) difference among the mean yield of varieties. Accordingly, maximum yield was recorded from Dwarf Cavendish (17.66 ton ha -1 ) followed by Giant Cavendish (16.73 ton ha -1 ) and Grand Nain (15.49 tonha -1 ) whereas the lowest yield was obtained from Poyo (10.42 ton -1 ) variety. Dwarf Cavendish, Giant Cavendish and Grand Nain banana varieties has recorded 40.99%, 37.66% and 32.73% yield advantage over Poyo variety respectively. In addition, farmer’s preferences towards the varieties were collected through supervision and by organizing mini field day. From farmer’s feedback during demonstration; Grand Nain banana variety was ranked as 1 st selection by the farmers on the bases of market preference, sweetness, medium fruit size and average good yield compared to other varieties. Moreover, Dwarf Cavendish and Giant Cavendish banana varieties were evaluated and ranked as 2 nd and 3 rd selection by the farmers compare to poyo varieties on the bases of market preference, fruit size and fruit sweetness. Hence; by combining informal research by farmers with formal on-farm testing; Grand Nain, Dwarf Cavendish and Giant Cavendish banana varieties were selected and recommended for further scaling-up in the test area and similar condition under irrigation production system. Keywords: Dwarf Cavendish, Giant Cavendish, Grand Nain, Poyo and FRG DOI: 10.7176/CER/13-5-02 Publication date: August 31 st 2021

Karyotype Variation in Eight Cultivars of Indian Dessert Banana (Musa acuminata L.) of Section Eumusa From Odisha, India

Banana (Musa spp.) cultivars especially dessert banana are important cash crop with high market demand all over the world as an integral part of the diet. The need for assessment of cytogenetic characters in Musa cultivars is inevitable as out of thousands of cultivars, cytogenetic characterization of most of them remains unresolved due to difficulties like small chromosome size, diversity in ploidy levels and high cultivar diversity which behave differently to standardized cytogenetic protocols. In this report, somatic chromosome number, detailed karyotype analysis including total chromosome length, volume, form percentage, Interphase Nuclear Volume (INV) were accessed on eight dessert type of Musa accessions from different places of Odisha. All the cultivars studied were found triploid (2n = 33) with a basic chromosome number of x=11. The karyotype formulae were assigned to each cultivar by grouping the chromosome according to their shared characteristics. The total chromosome length ranged from 54.95 µm in cv. Robusta to 81.5 µm in cv. Kathia with symmetric karyotype in all the studied cultivar. Karyotype formula revealed structural alteration of chromosome with Total Form percentage (TF%) variation from 35.65% in cv. Amritapani to 41.68% in cv. Patakpura that confirms more number of nearly median constricted chromosome as compared to sub-median chromosome. The total chromosome volume recorded from 10.78 µm3 in cv. Robusta to 15.99 µm3 in cv. Khatia and the INV varied from 1336.44 µm3 in cv. Dwarf Cavendish to 2048.37 µm3 in cv. Patakpura. The recorded structural variation might be due to differential genome specific condensation of chromosome. Chromosome length and volume found statistically significant among the cultivars.

TitleAntibiogram of Key Microorganisms of Health Importance, Found on Different Species of Banana (Musa spp.)

Aim: The aim of this study was to isolate, enumerate, identify and ascertain the antibiotic profile of the bacterial isolates associated with key body parts (Cut stalk, Tip, Endocarp, Vascular Tissue and Epicarp) of Banana fruits (Cavendish, Dwarf Cavendish, Red, Lady Finger and Grand Nain Banana) collected from Port-Harcourt, Rivers State.
 Study Design: The study employs statistical analysis of the data and interpretation.
 Place and Duration of Study: Five local markets which includes Oil Mill, Fruit Garden, Creek Road, Mile One and Mile Three Markets, all located in the city of Port-Harcourt, Rivers State were used for this study. Sample collection lasted for a week and the analysis was carried out every day and it lasted for six months.
 Methodology: A total of seventy-five (75) banana (Cavendish, Dwarf Cavendish, Red, Lady Finger and Grand Nain Banana) fruit samples were collected randomly, for a period of three months from five different markets (Oil Mill, Fruit Garden, Creek Road, Mile One and Mile Three Markets) in Rivers State. The collected samples were grouped into three groups (Unripe, Healthy-Looking and Spoiled) and were subjected to standard microbiological procedures which includes standard plate counts, identification, sensitivity testing using Kirby-Bauer disk diffusion method and molecular identification of the isolates.
 Results: A total of 83 bacteria were isolated from the different sampled parts (Cut stalk, Tip, Endocarp, Vascular Tissue and Epicarp) of the banana fruit samples. 18.88%. Escherichia coli showed high level of resistance to Cefotaxime (100%) > Augmentin (94.7%) > Gentamycin (78.9%) > Levofloxacin (10.5%). There was complete resistance to Cefotaxime, Levofloxacin, Imipenem/Cilastatin, Ofloxacin and Azithromycin in all isolates of Staphylococcus aureus and susceptibility at 70.8%, 79.2% and 20.8% to Augmentin, Ceftriaxone sulbactarm and Erythromycin, respectively. Pseudomonas aeruginosa were susceptible to Augmentin (25.0%), Imipenem/Cilastatin (66.7%), Gentamycin (83.3%) and Ceftriaxone Sulbactarm at 8.3%. While complete resistance was seen in Cefotaxime, Nalidixic Acid, Nitrofurantoin and Cefexime. The antimicrobial susceptibility pattern of all isolates of Bacillus flexus which shows complete resistance to Cefotaxime, Ceftriaxone Sulbactarm, Cefexime, Imipenem/Cilastatin and Azithromycin. While susceptibility was seen in Levofloxacin at 100% and 22.2%, 33.3% and 11.1% seen in Ciprofloxacin, Gentamycin and Augmentin, respectively. The isolates of Proteus mirabilis showed complete susceptibility in Imipenem/Cilastatin and CefrtiaxoneSulbactarm and complete resistance in Augmentin, Cefotaxime, Gentamycin, Nalidixic Acid, Nitrofurantoin, Cefuroxime, Ampiclox, Cefexime and Levofloxacin. Klebsiella pneumoniae to Levofloxacin and 45.5% susceptibility to Augmentin, Ofloxacin, Ceftriaxone and Ampiclox at 54.5%, 27.3% and 18.2%, respectively. While complete resistance was seen in Cefotaxime, Nalidixic Acid, Nitrofurantoin, Cefuroxime and Cefexime.
 Conclusion: Conclusively, this study revealed the Antibiotic susceptibility pattern of the isolated bacteria. Treatment guidelines for use of antibiotics should be formulated based on the hospital formulary and the sensitivity patterns. This should be reviewed occasionally to ensure rational use of antibiotics