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This study was conducted at the tissue culture laboratory in Pakistan. Suckers obtained from the banana cv. Grand Nain to explore the effects of different concentrations of BAP and IAA. After inoculation with Murashige and Skoog (MS) medium supplemented with different concentrations of 6-Benzylaminopurine (BAP) and the Indole-3- acetic acid (IAA) the suckers first turn into the brown after 5-10 days then turned into a green mass-like structure after 30 days. From this mass-like structure shoots and roots were developed. Among the different concentrations, BAP 7.5 mg/l and IAA 0.5 mg/l showed the highest number of shoots 0.75, 2.75 and 6.25 per explant and shows the highest shoot lengths which 1.03 cm, 2.45 cm and 3.40 cm respectively. IAA is essential for only roots proliferation. The roots of different lengths were produced when the concentration of IAA 0.5 mg/l was used and 2.93 cm, 4.63 cm and 5.88 cm roots length produced at 15, 30 and 45 days after occultation respectively. Then these plants were transferred to the greenhouse for hardening acclimatization with the environment, the hardening process took place, and the established plantlets are ready for planting.

Finding a rich and natural source of potassium nutrient is a major challenge facing banana cultivation. In this study, four different sources of Potassium: potassium sulphate, slow release (feldspar), bio-fertilizer (yeast & potassin) and potassium thiosulphate were used to evaluate their effects on growth & fruit production of Grand Nain banana cultivar grown at Luxor Governorate condition, Egypt. The results indicated that using yeast or feldspar alone or in combination as a source of potassium and potassin significantly increased all growth aspects, yield and fruit quality compared to fertilize by potassium sulphate (check treatment); Moreover, there were insignificant differences in these studied traits due to fertilize with yeast, feldspar alone or in combination as well as spraying potassium thiosulphate or potassin. Using yeast or feldspar plus yeast were very effective in enhancing all growth aspects, yield, bunch traits and fruit characteristics compared to untreated ones; So, it is evident from the foregoing result that using feldspar or yeast alone or in combination improved the growth, nutritional status and fruiting of Grand Nain banana plants;. In addition, they are beneficial in organic farming production since they improve the soil structure and fertility; also, reduce the cost of production and environmental pollution.

Climate change and rising sea levels increasingly threaten agriculture, especially in the coastal regions. Banana cultivars, especially the Cavendish clones, are sensitive to salinity stresses, which results in decreased production. In the current study, we evaluated the water deficit stress remediating effects of silicon nanoparticles (SiO2 NPs) on micropropagated banana cv. “Grand Nain” - either under in vitro conditions in the laboratory or ex vitro in the greenhouse. In vitro water deficit was induced with polyethylene glycol (PEG-8000). Addition of in vitro SiO2 NPs enhanced shoot growth and chlorophyll content. Malondialdehyde content (MDA) and electrolyte leakage (EL) were reduced in 3% PEG-stressed plants following the addition of the 150 mg/l SiO2 NPs (38.73 nmole and 4.93%) compared with the control plants (51.67 nmole and 5.76%). In the greenhouse study, plants under salt and water deficit treatments were sprayed with SiO2 NPs at (0, 200, 400 and 600 mg/l). Under salinity stress conditions, SiO2 NPs improved photosynthesis as the stressed plants had similar chlorophyll content as control unstressed plants (23.33). SiO2 NPs at 400 mg/l application increased K+ level (10.54%) and decreased Na+ levels (1.17%). Under simulated water deficit stress conditions, 600 mg/l SiO2 NPs significantly increased K+ and K+/Na+ percent (10.37 and 14.40%) along with improvement in chlorophyll content index at all levels of SiO2 NPs application. The overall results revealed that SiO2 NPs application can improve chlorophyll content, induce K+ uptake, modulate Na+ levels and decrease cell wall damage in the treated plants comparing to the untreated plants under abiotic stress. Our results suggest that the application of SiO2 NPs can help maintain plant integrity in the banana cultivar ‘Grand Nain’ under simulated abiotic stress.

Protected cultivation (in greenhouses) is an effective cropping system to produce bananas in Turkey and much more profitable than open-field conditions. 'Grand Nain' is the most popular cultivar grown in greenhouses in Turkey, but it may be possible to increase yield and fruit quality, and subsequently grower incomes, by testing new cultivars. The objective of this study was to evaluate in subtropical conditions the performance of five new Cavendish cultivars ('CV 902', 'Jobo, MA13', 'Williams' and 'MA13' ) previously selected in open-field tropical conditions, compared to 'Grand Nain' ( control). All new Cavendish cultivars were introduced in Turkey from VITROPIC SA, France. All cultivars were produced by in vitro micropropagation of meristems, and then deflasked and grown in nurseries to 2 5 cm for planting. The trials were undertaken in three different locations (Alanya, Anamur and B0zyaz1, Turkey) in greenhouses. Various parameters were recorded over two crop cycles including: stem circumference, stem height, total leaf number, bunch stem circumference, number of hands and finger per bunch, finger length and circumference at harvest and bunch weight. The B0zyaz1 location showed better performance in many aspects of plant growth compared to the other two sites. 'Williams' had on average the highest pseudostem circumference and height but also the highest bunch weight (50.27 kg). The bunch weight of 'MA13' and 'CV 902' was 47.65 and 42.66 kg, respectively, whereas the control ('Grand Nain') and 'Jobo' had a lower bunch weight. 'Williams', 'MA13' and 'CV 902' were more productive than 'Grand Nain' in greenhouse conditions. In addition, no somaclonal variations were observed in any of the three experimental locations. These results suggest that the new selections have potential to provide higher yields in Turkey in protected cultivation, providing higher returns to growers, compared to local selections.

Banana (Musa spp.) is one of the important fruit crops of the tropics. Higher productivity in banana is possible through improved planting material and nutritional management. The objective of experiment includes studying the response of various level of nitrogen and bio fertilizer on growth and yield parameters of banana. The experiment contains fifteen (15) treatment combinations with three replications laid out in a randomized block design with factorial concept. The treatment consists as three levels of nitrogen (100%, 80% and 60%) and five levels of bio-fertilizers (Azotobacter, Azospirillum, Rhizobium, 50% of B1 + 50% of B2+ 50% of B3 and No bio-fertilizer (Control)). The treatment received 100% recommended dose of nitrogen (RDN) along with Azotobacter (20ml two times) noted positive reaction towards all growth parameters also significantly positive response to yield parameters i.e. weight of bunch (kg) number of hands per bunch, number of fingers per bunch, weight of third hand (kg), yield (t/ha).

Banana (Musa acuminate Colla, cultivar Grand Nain) is the main crop in Canary Islands, covering an area of about 9000 ha with a production in 2017 of 437.782 t of banana worth 104.4 million Euros. Today, one of the most used pest control method is the Integrated Pest Management (IPM), which takes into account the different management options for pest control, giving priority to the least harmful solutions. This research aims to improve the use of IPM to control populations of Chrysodeixis chalcites through understanding growing stage and specific preferences on banana plants as preliminary experiments. Our main focus was to investigate the oviposition preference of C. chalcites (Esper) adults by counting all present eggs and larvae on the plant seven days after adult release into cages. The combination of two plants through three growing stages (young plant, mature plants without bunch and mature plants with bunch) were tested over 48 banana plants into six different field cages. Significant difference in ovipositional behaviour was found between the three growing stages of banana plants. In order to detect C. chalcites populations on banana plantations, it can be suggested to look firstly to the 5th leaf on young plants, secondly to the 8th leaf on pants with bunch, and finally plants without bunch. In all cases, more eggs and first instar larvae were found on young plants and on the underside of the leaves.

To enhance the multiplication rate in Musa acuminata Colla (banana; ‘Grand Nain’) organogenesis, higher amounts of thiamine along with different sugar types and concentrations were evaluated at the proliferation phase. Thiamine at 1, 10, 50, 100, and 200 mg L−1 was compared with 0.1 mg L−1 thiamine found in conventional Murashige and Skoog (MS) medium. Maximum proliferation of banana was induced with 100 mg L−1 thiamine. Additionally, 15, 30, and 45 g L−1 sucrose, glucose, fructose, and sorbitol combined with regular and optimal levels of thiamine were tested. Glucose at 30 g L−1 most improved shoot proliferation alone and enhanced shoot proliferation further, when combined with 100 mg L−1 thiamine, followed by sucrose and fructose, whereas sorbitol completely inhibited growth and caused tissue browning. All evaluated vegetative traits were significantly affected by sugar type and concentration, and thiamine levels, unlike the photosynthetic pigments. Moreover, genetic stability of the plants recovered from the enhanced protocol was confirmed by inter-simple sequence repeats (ISSR) and randomly amplified polymorphic DNA (RAPD) analysis. A total of 230 bands generated by both marker types were monomorphic for the randomly selected regenerated plants, compared with their mother plant. Thus, the proliferation medium supplemented with 30 g L−1 glucose and 100 mg L−1 thiamine could be recommended for banana organogenesis. Results herein are of great importance and helpful in enhancing the commercial in vitro propagation protocols of banana, without the need of increasing the number of subcultures, which can cause somaclonal variation.

New banana plantations of Turkey are mostly established with meristem culture-propagated plants because starting materials greatly influence yield and quality in these plantations. This study was conducted to select superior banana clones from Grand Nain, Dwarf Cavendish and Azman cultivars grown in open fields and greenhouses in Turkey. The study also aimed to determine selection efficiency breeding for stem height, number of hands, the number of fruits, bunch weight, fruit weight and fruit length. The selected genotypes exhibited a large variation in yield and related quantitative traits. The genotypes showing the highest yield and quality traits were selected. Although the traits used for selection contributed to selection efficiency, stem height had the greatest contribution. The superior banana clones were found to be stable and could reliably be used in establishment of new banana plantations to increase yield and quality in subtropical conditions in Mediterranean region in Turkey.

In tropics, combined stresses of drought and heat often reduce crop productivity in plants like Musa acuminata L. We compared responses of two contrasting banana genotypes, namely the drought-sensitive Grand Nain (GN; AAA genome) and drought tolerant Hill banana (HB; AAB genome) to individual drought, heat and their combination under controlled and field conditions. Drought and combined drought and heat treatments caused greater reduction in leaf relative water content and greater increase in ion leakage and H2 O2 content in GN plants, especially in early stages, while the responses were more pronounced in HB at later stages. A combination of drought and heat increased the severity of responses. Real-time expression patterns of the A-1 and A-2 group DEHYDRATION-RESPONSIVE ELEMENT BINDING (DREB) genes revealed greater changes in expression in leaves of HB plants for both the individual stresses under controlled conditions compared to GN plants. A combination of heat and drought, however, activated most DREB genes in GN but surprisingly suppressed their expression in HB in controlled and field conditions. Its response seems correlated to a better stomatal control over transpiration in HB and a DREB-independent pathway for the more severe combined stresses unlike in GN. Most of the DREB genes had abscisic acid (ABA)-responsive elements in their promoters and were also activated by ABA suggesting at least partial dependence on ABA. This study provides valuable information on physiological and molecular responses of the two genotypes to individual and combined drought and heat stresses.

Climatic changes affect agriculture and alter cultivated land area worldwide. Among which, low-temperature has a general negative impact on plant growth and productivity especially on tropical and subtropical species. To assess the effect of cold stress on banana, two global cultivated varieties (i.e. Grand Nain and Williams) were used for in vitro physio-biochemical evaluation. Cold stress was performed at constant 5 °C for 6, 12, 24 and 48 h, to assess the changes in the pool of proline, total phenolics, total soluble carbohydrates, K+ and Ca+ 2 ions as well as the photosynthesis related pigments chlorophyll and carotenoids). Significant differences between cultivars and among exposure times were found in most of the studied traits. Results indicated that cold-stressed plants were capable to enhance their cold tolerance by over-accumulation of cryoprotectants, particularly under extended cold stress. Importantly, Williams showed more tolerance than Grand Nain by accumulating higher amounts of total phenolics, total soluble carbohydrates, higher concentrations of K+ and Ca+ 2 ions as well as more content of the photosynthetic pigments, compared to Grand Nain. Meanwhile, Grand Nain produced greater amounts of proline than Williams. These findings suggest that compatible solutes increased in relation to cold tolerance mechanisms which modulate chilling-induced oxidative damage in banana. These imperative mechanisms could be utilized as important tools and selectable markers for cold tolerance screening in banana genotypes which could be helpful in breeding programs.

Effects of gum Arabic (GA) (5 and 10%), salicylic acid (SA) (1 and 2 mM) and their combination (10% GA plus 1 mM SA) postharvest dipping on quality and biochemical changes of ‘Grand Nain’ bananas were studied during shelf life (SL) conditions (20 ± 2 °C, 60–70% RH) for 9 days. All treatments, especially 10% GA plus 1 mM SA, decreased weight loss than control. GA at both rates retained higher peel green color than other treatments during SL. GA at both rates and SA at high rate SA retained higher firmness only after 6 days of SL. Total soluble solids (TSS) concentration increased during SL and was lower at both rates of GA and high rate of SA than control. Titratable acidity (TA) concentration decreased during SL and was higher at both rates of GA, low rate of SA and GA plus SA treatments than control. Peel browning index gradually increased during SL and was lower at high rate of GA than control. Membrane stability index (MSI) decreased during SL and was higher at both rates of GA than other treatments after 6 and 9 days of SL. Total phenols and flavonoids concentrations in peel and pulp and vitamin C in pulp fluctuated during SL and showed no consistent response to applied treatments. As overall, GA retained higher total phenols and flavonoids concentrations, whilst SA showed no clear effects. Free radical scavenging capacity (FRSC) of both peel and pulp increased during SL and was higher at GA and SA treatments than control. The relations of such biochemical changes with α-amylase, xylanase, polygalacturonase, peroxidase and polyphenoloxidase activities were discussed. In conclusion, GA treatment especially at 10% retained quality of ‘Grand Nain’ bananas during SL and being suggested as natural alternatives to synthetic chemicals.

Banana (Musa spp) is considered as one of the most important fruit crops in Egypt, where it occupy an area of 27.5 thousand ha. Field experiments on banana cv. Grand Nain for two consecutive seasons (2016 and 2017) were conducted in Horticulture Research Station located in El-Kanter Elkharia, Kaluobia Governorate. The main objective of this study was to investigate the possibility of reducing the mineral fertilizers applied to the banana crop by using compost and potassium silicate treatments. Three rates of compost (15, 20 and 25 kg per mate) were applied with 50% of the recommended rate of mineral fertilizers along with or without potassium silicate at a rate of 60 ml per mate. These treatments were compared with recommended rates of mineral fertilizers mixed with and without potassium silicate. Obtained results showed that application of compost led to enhance all studied parameters and recorded highly significant differences particularly under the treatments combined with potassium silicate and 50% of the recommended rate of mineral fertilizers. The highest level of compost with potassium silicate treatment recorded the uppermost values of growth, yield and quality of banana fruits. Moreover, the same treatment recorded significant increments in total sugar and T.S.S% in fruits as compared with the recommended dose of mineral fertilizers.

This experiment was carried out during 2013- 2014 (first ratoon) and 2014-2015 (second ratoon) seasons to study the effect of spraying seaweed extract at three concentration 0, 0.1, 0.2 % and/or trimming (without one & two hand) on Grand Nain banana bunches in sandy soil. Trimming of hands was done after bunch shooting, seaweed extract sprayed three times: 1) after bunch shooting directly, 2) 15 days later 3) 30 days later. Time to harvesting, bunch weight (kg), estimated yield (ton), estimated increasing rate of yield (%), finger diameter (cm), finger weight (g) finger length (cm), soluble solids content (SSC) and titratable acidity percentage were determined. Obtained results showed that trimming with two hands gave the highest values for the above mentioned characters compared with one hand. Time of harvesting tended to decrease with hand trimming of banana. The highest values of bunch weight, yield, increasing rate of yield and finger parameters were obtained from Grand Nain banana plants trimming two hands with spraying seaweed extract at 2 % .Seaweed (Ascophyllu mnodosum L.) is a known source of plant growth regulators which an important roles in metabolism and productivity of plants. Moreover, hand trimming is practiced to increase the finger parameters. From the obtained results it could be concluded that, spraying seaweed extract at 2% with trimming two hands improved time to harvesting, yield as well as physical and chemical characteristics of the fruits of Grand Nain banana plants. A superior effect was attributed to using seaweed extract and trimming rather than control.

The present experiment was conducted at Regional Horticultural Research Station, ASPEE College of Horticulture and Forestry, Navsari Agricultural University, Navsari during 2017-18 and 2018-19. An experiment was laid out in a randomized block design, comprising of three levels of potassium silicate and silicic acid (1, 2 and 3 ml/l/plant) along with control. The treatments were replicated thrice. The effects of foliar applications at 2nd, 3rd and 4th months after planting of different levels of potassium silicate and silicic acid on yield and yield attributes of banana cv. Grand Nain were recorded. The results indicated that foliar application of potassium silicate @ 3ml/l/plant at 2nd, 3rd and 4th MAP recorded significantly the maximum length and girth of bunch, weight of bunch,number of hands per bunch, fingers per bunch, weight of 3rd hand, length of finger and finger weight from 3rd hand and fruit yield.

The present experiment was conducted at Regional Horticultural Research Station, ASPEE College of Horticulture and Forestry, Navsari Agricultural University, Navsari during 2017-18 and 2018-19. An experiment was laid out in a randomized block design, comprising of three levels of potassium silicate and silicic acid (1, 2 and 3 ml/l/plant) along with control. The treatments were replicated thrice. The effects of foliar applications at 2nd, 3rd and 4th months after planting of different levels of potassium silicate and silicic acid on leaf nutrient content and flowering of banana cv. Grand Nain were recorded. The results indicated that foliar application of potassium silicate @ 3ml/l/plant at 2nd, 3rd and 4th MAP recorded significantly the maximum leaf nutrient content viz., N, P, K and chlorophyll content. The same treatment significantly reduced the number of days to harvest after flower initiation and crop duration whereas number of days to flowering was found non-significant.

Banana, an important tropical fruit crop, often faces drought, heat and its combination during its growth, leading to decreased yields. The combined stresses caused 100% yield loss in Grand Nain (GN) as compared to only 46% in Hill Banana (HB). To understand the response of combined stresses, we studied the stress-responsive NAC gene sub-family under individual and combined drought/heat stresses under controlled and field conditions in the stress-sensitive GN (AAA genotype) and stress-tolerant HB (AAB genotype). Under drought, expression of most stress-NACs increased with progression of drought in either one or the other genotype with little overlap. Heat stress caused a continuous decline in expression of most genes in HB unlike in GN where many NACs were up-regulated although to a lesser scale than for drought. Combination of the two stresses elicited a very different response compared with individual stresses. GN responded strongly to the combined stress with up-regulation of most genes unlike that seen in drought. Surprisingly, NAC genes in HB did not respond much to the more severe combination of the stresses despite being up-regulated strongly by drought. The response of the NACs to combined field stress was similar to that under controlled conditions. Most of the stress-NACs were strongly up-regulated upon treatment with exogenous ABA within 30–60 min, the increase being more prominent in GN. The studies suggest that the B genome in the stress-tolerant HB may counter more drastic combined stresses without taking recourse to the expression of stress NACs.

Banana streak badnavirus (BSV) is the most widely occurring virus in banana and plantain (1) but has not been reported to be a significant problem in commercial export bananas. In early 1999, the first severe outbreak of BSV infection in commercial export bananas (Musa AAA cv. Grand Nain) was recorded at Siquirres on the Atlantic coast of Costa Rica. Disease incidence in the plantation was 60% and symptoms included foliar chlorotic streaks, stunting of plants, splitting and internal necrosis of pseudostems and fruits, cigar leaf necrosis, and bunch emergence through the pseudostem. Diseased plants within a 0.8 ha area were eliminated to prevent possible further spread of the disease. The presence of BSV in diseased plants was confirmed by enzyme-linked immunosorbent assay and immunosorbent electron microscopy (1). Cucumber mosaic virus and Banana mild mosaic virus, which also occur in banana and plantain in Latin America (2), were not detected in the plants tested. Other recent accounts of BSV occurrence in commercial banana plantations in South America (our unpublished results) suggest that BSV occurrence in export bananas may be more significant than previously thought. References: (1) F. Gauhl et al. Int. J. Pest Management 45:167, 1991. (2) D. R. Jones, ed. 1999. Diseases of Banana, Abacá and Enset. CABI Publishing, Wallingford, U.K.

The activities of starch degradation enzymes (SDEA), α-amylase (AMY, EC: 3.2.1.1), Invertase (INV, EC: 3.2.1.26), and phosphorylase (PHO, EC: 2.4.1.14), were quantified in the pulp of 'Grand Nain' banana fruit. Practically, the bananas were set in many doses of ATP (0, 0.5, 1.0, and 1.5 mM) for 10 min, hence processed at store condition (25 ± 1 °C and 63 ± 2 % RH) for 12 days of storage. The activities of starch degradation enzymes (SDEA) such as a-amylase (AMY, EC: 3.2.1.1), Invertase (INV, EC: 3.2.1.26), and phosphorylase (PHO, EC: 2.4.1.14), were quantified in the banana pulp of 'Grand Nain' fruit. Later fruits were immersed in different concentration of ATP (0, 0.5, 1.0, and 1.5 mM) for 10 min, then stored at ambient condition (25 ± 1 °C and 63 ± 2 % RH) for the period of up to 12-days. Generally, low initial SDEA at harvest time was noticed then increased up to the end of storage time. The increases in SDEA were independently due to ATP concentrations. Throughout the storage duration, ATP 1.5 mM treatment displayed higher activity of SDEA than other ATP and control treatments, then, the sugar profile was increased. However, the fruit quality, ATP 1.5 mM minimized of fruit softening, alleviated fruit browning and enhanced carotenoid synthesis. Moreover, it was controlled by ethylene and respiration rate plus it reduced the accumulation of MDA and ion leakage percentage during the storage period. In view of these processes, ATP treatment at 1.5 mM will result which affects the SB and fruit quality.

Adaptation trial of desert type banana varieties was conducted at Ginnir districts of Bale zone south eastern Ethiopia. Seven desert types of improved banana varieties and one local variety were planted at three PA’s of Ginnir districts. Analysis of variance revealed that there is significant variation among the varieties. Accordingly, Jiant Cavendish recorded the highest number of finger per bunch (90.33) followed by Dwarf Cavendish (90), the longest and the heaviest finger while the lowest number of finger per bunch recorded from Poyo as well as lower yield comparative with local variety. On the other hand, Dwarf Cavendish and Jiant Cavendish gives higher yield than others and recorded 67.47%, 22.04% yield advantages over local varieties, whereas, Jiant Cavendish recorded 64.48%, 14.87% yield advantage over local variety and national average productivity of the crop. Additionally, Grand Nain recorded 60.82%, 6.09% yield advantage over local variety and national average productivity of the crop. Therefore, these three varieties (Dwarf Cavendish, Jiant Cavendish and Grand Nain), well adapted and recorded maximum yield advantage over local and national average productivity of banana and thus recommended for banana producing community at study area.

The present study investigated the phenolic profiles of the pulp and peel of nine plantain cultivars and compared them to those of two dessert bananas of commercial interest (Grand Nain and Gros Michel), alongside a newly created hybrid, resistant to black sigatoka disease (F568). Identification and quantification of phenolic compounds were performed by means of HPLC-ESI-HR-MS and HPLC-DAD. Hydroxycinnamic acids, particularly ferulic acid-hexoside with 4.4-85.1 μg/g of dry weight, dominated in the plantain pulp and showed a large diversity among cultivars. Flavonol glycosides were predominant in plantain peels, rutin (242.2-618.7 μg/g of dry weight) being the most abundant. A principal component analysis on the whole data revealed that the phenolic profiles of the hybrid, the dessert bananas and the pure plantains differed from each other. Plantain pulps and peels appeared as good sources of phenolics, which could be involved in the health benefits associated with their current applications.

In Puerto Rico, bananas (including plantains) are important agricultural commodities; their combined production totaled over 158,000 tons in 2011. Black leaf streak (BLS) and Sigatoka leaf spot diseases, caused by Mycosphaerella fijiensis and Mycosphaerella musicola, respectively, are responsible for significant losses of this crop, due to the high susceptibility of the most important cultivars. Diploid, triploid and tetraploid hybrids were introduced from international breeding programs for evaluation in Isabela, Puerto Rico. Accessions were established in the field in a randomized complete block design and were evaluated over two cropping cycles (2007–2010) for response to BLS and agronomic traits. Significant differences (P = 0.05) in BLS severity were observed among accessions throughout both crop cycles and were most pronounced at harvest. When averaged across production cycles, severity indices at harvest ranged from very resistant (20% of the leaf surface affected) for ‘FHIA 02’ to extremely susceptible (97%) for ‘Grand Nain’. Yield attributes varied widely among the accessions, including mean bunch weights (6.9–41.0 kg), numbers of hands per bunch (6.6–13.4), and the numbers of fruit per bunch (57.0–239.2). Several accessions, mainly from the Fundacion Hondurena de Investigacion Agricola (FHIA), were BLS resistant and had short pseudostems, and large bunches. They could potentially replace susceptible cultivars in commercial production or play roles in a nascent organic market.

Banana (Musa spp.) is one of the world's most important crops cultivated in tropical and subtropical regions of the world. Banana is a major source of macro-elements, especially potassium, and contains health-beneficial ingredients such as resistant starch, total dietary fibers, rapidly digestible starch, and slowly digestible starch. Oligosaccharides (fructooligosaccharides and inulin) and polyphenols ((+)-catechin, (-)-epicatechin, (-)-epigallocatechin, and gallic acid) are other ingredients present in bananas that have found application in the prevention of muscular contractions, regulation of blood pressure, prevention of colon cancer and diabetes, and in the cure of intestinal disorders when unripe. This review identifies the different commercial and noncommercial banana cultivars and their utilization. Commercial cultivars include Williams (M. acuminata cv. Williams), Dwarf Cavendish (M. acuminata cv. Petite Nain), Chinese Cavendish (M. acuminata cv. Chinese Cavendish), Grand Nain (M. acuminata cv. Grand Nain), and Goldfinger (M. acuminata cv. Goldfinger), with Mabounde and Luvhele identified as noncommercial varieties. Banana postharvest utilization includes its use as functional foods, prebiotics, probiotics, nutraceuticals, and processing into value-added products.

The root-lesion nematode Pratylenchus goodeyi is a common pest of banana in Kenya, which results in significant yield losses. An emerging option for the management of banana nematodes includes the use of endophytic fungi, which cause no damage to their hosts but often extend benefits, such as enhanced protection against various biotic and abiotic constraints. In the current study, non-pathogenic Fusarium oxysporum strains originating from banana (Musa spp.) in Kenya (4MOC321 and 11SR23) and Uganda (V5w2) were evaluated for their efficacy against P. goodeyi in tissue culture-derived plantlets (cv. Giant Cavendish and cv. Grand Nain) in pots. Pratylenchus goodeyi densities were 47-60% lower in endophyte-inoculated relative to non-inoculated plants and root necrosis damage was reduced by >30%. Endophyte treatment had no effect on plant growth parameters compared with untreated control plants. The performance of the two Kenyan strains was equally effective as the positive control (V5w2), thus demonstrating their potential as nematode bio-control agents under Kenyan growing conditions.

For many plants, particularly those of tropical and subtropical origin, chilling injury occurs as a result of their exposure to low, but nonfreezing temperatures. Banana fruits are highly susceptible to chilling injury, but little is known about the role of genes that scavenge reactive oxygen species in fruits during chilling injury. In this study, a catalase gene, designated MaCat2, was isolated from Musa acuminata cv. Grand Nain fruits. The full-length cDNA sequence is 1,479 bp, and based on phylogenetic analysis, it is related to catalase type 2 genes from Elaeis guineensis and Zantedeschia aethiopica. Expression studies revealed that the MaCat2 gene was induced in severe stress of banana fruits. MaCat2 expression in banana peel increased in response to both low temperature and physical damage, but not so under heat stress or during normal fruit ripening. These findings suggest that MaCat2 is induced in banana peel by cold treatment and is regulated at transcriptional level, possibly playing a role in chilling injury response of banana fruit.

The yield response of four popular banana cultivars from southeast Asia to infection with a population of Radopholus similis collected from banana in Davao, Philippines, was investigated in a microplot experiment. Bunch weight reduction of nematode-infected plants ranged from 25 to 68% for all four southeast Asian banana cultivars and Grand Nain (AAA), the susceptible reference cultivar included in the study. The banana cv. Latundan (AAB) had a nematode population density of 185, 38 and 27 nematodes at 6 months after planting, flowering and harvesting, respectively, and a low bunch weight reduction (25%) compared with the other banana cultivars examined, possibly suggesting that this cultivar is partially resistant to R. similis.

During the growth of micro-propagation of 1 million Grand nain plantlets to 10 million, from elite and infection-free mother rhizomes, sterilized by standard techniques in the laboratory, profiles of bacterial and fungal contamination were monitored in growth rooms (24±2°C, 60% RH, 4000 Lux) as a function of rainy season, winter and summer. The incidence of contamination was correlated with air quality in the growth rooms as well as temperature, relative humidity and rainfall. Subsequently the 45 days matured plantlets were subjected to primary hardening (27±1°C, 70% RH, 15000 Lux) for additional 45 days, during which mortality rate was monitored as a function of pest/disease attack, cold injury, heavy rain, sun shock, handling and accidents. This was followed by subjecting the plants to secondary hardening for another 45 days (ambient conditions) at 50% light cut off due to shade nets, during which similar profiles were monitored. It was observed that the incidence of contamination was highest (3.4%) during rainy season (June-September), reduced (1.9%) during winter and was lowest (1.0%) during summer, almost corroborated by quality of air inside and outside the laboratory. Similar profile was witnessed during primary hardening too, where mortality rate was 1.2% in rainy season, 1.1% in winter and 0.6% in summer. The mortality rate was 0.3% due to handling, 0.2% due to pest/disease attack and

The most devastating disease currently threatening to destroy the banana industry worldwide is undoubtedly Sigatoka Leaf spot disease caused by Mycosphaerella fijiensis. In this study, we developed a transformation system for banana and expressed the endochitinase gene ThEn-42 from Trichoderma harzianum together with the grape stilbene synthase (StSy) gene in transgenic banana plants under the control of the 35S promoter and the inducible PR-10 promoter, respectively. The superoxide dismutase gene Cu,Zn-SOD from tomato, under control of the ubiquitin promoter, was added to this cassette to improve scavenging of free radicals generated during fungal attack. A 4-year field trial demonstrated several transgenic banana lines with improved tolerance to Sigatoka. As the genes conferring Sigatoka tolerance may have a wide range of anti-fungal activities we also inoculated the regenerated banana plants with Botrytis cinerea. The best transgenic lines exhibiting Sigatoka tolerance were also found to have tolerance to B. cinerea in laboratory assays.

This investigation was carried out during two successive seasons of 2004 and 2005 to study the effect of fertilization by using two types of organic manures, i.e. cattle or town refuse at different levels (50, 75 and 100%) from its recommended dose with or without biofertilizers mixture, i.e. microbien and phosphoren in combination with 50% mineralized NPK on growth, chemical composition as well as yield and its quality of Grand Nain banana plants in comparison to banana plants only fertilized with mineralized 100% NPK of the recommended dose. The best results obtained that from banana plants inoculated and fertilized with cattle manure at rate of 100% . In addition, biofertilizers with organic manure improved growth, chemical composition as well as fruit yield and its quality. Increasing the rate of either organic manure with or without inoculation had a positive increment on all studied parameters, especially with the high rate. Chemical constituents of Grand Nain banana fruits were greatly improved as a result of using N in both organic and mineral sources rather than adding N completely via only mineral source. Organic fertilization with cattle or town refuse had a favorable effects on fruit quality since in increase finger weight and concentration of soluble solids and total sugar as well as decreasing concentration of starch and nitrate in fruits except the high rate of town refuse. Organic fertilization by using cattle manure at the rate of 100% combined with 50% mineralized NPK of the recommended rate and inoculated by biofertilizers gave the best results with all studied characteristics of Grand Nain banana plants .

SummaryThere are no reports on the possible protective role of trehalose in tropical monocot plants such as banana, when exposed to salt stress. In the present work, banana plants (Musa acuminata ‘Grand Nain’) were transformed with a fusion of two genes from Saccharomyces cerevisiae involved in the biosynthetic pathway of trehalose [trehalose-6-phosphate synthase (tps); and trehalose-6-phosphate phosphatase (tpp)] under the control of the Arabidopsis rd29A drought-stress inducible promoter. Transformed (rd29A::tps-tpp; TF) and wild-type (WT) plants were subjected to three different concentrations of NaCl (100, 200, or 300 mM) for 9 d. The trehalose concentration in the leaves of WT plants was approx. 3.5 µg g−1 fresh weight (FW) when not exposed to salinity, and increased only slightly (to 4.0 µg g−1 FW) when exposed to 100 or 200 mM NaCl. In TF plants, however, the trehalose concentration was approx. 4.0 µg g−1 FW when not exposed to salinity, but increased with salinity, reaching values of ≥ 8.0 µg g−1 ...

SummaryWe manipulated the source (leaf system) and sink (bunch) in banana cultivars ‘Williams’ and ‘Grand Nain’ to determine the effect on two subsequent ratoon cycles. Ratoon growth and bunch characteristics were measured on plants, in a plantation, that were treated in two seasons: one warm and sunny season, and the other cool and cloudy. Removing bunches or leaves affected growth of the ratoon in the first 3 months after treatment, and this effect differed between seasons. Defoliating bunched plants in the warm and sunny season caused the first ratoon crop to bunch 5.1 weeks earlier than those on intact plants. Defoliation in both seasons reduced the height and bunch size of ratoon plants, especially in ‘Williams’. Bunch removal in the cool and cloudy season reduced the cycle time by 2.5 weeks. The bunch is a higher priority C-sink than the ratoon, and there is an indication that floral induction in banana plants is influenced by environmental conditions independently of internal plant effects.

Introduction. Bananas are traditionally propagated by suckers: nevertheless, the advan- tage of using tissue-cultured plants for banana production has been demonstrated in recent years. Des- pite the large-scale use of micropropagated plants in the subtropical regions, little information is available on the performance of these crops in tropical countries. So we compared the yield potential of some Cavendish banana cultivars propagated either by traditional suckers or by tissue culture. Materials and methods. A randomized complete block experiment was established in a commercial plantation in Cameroon to compare the performance of three tissue-cultured banana plants of Grand Nain, Williams and Zelig cultivars and two conventionally-propagated plants of Grand Nain and Williams. Morpholo- gical, phenological and yield component data were collected for six crop cycles. Results. All the plants grew vigorously and produced quality exportable fruits. However, the tissue-cultured plants consistently produced heavier bunches and higher yields than the conventionally-propagated plants. The highest yields (65.92 t·ha -1 for Grand Nain, 64.60 t·ha -1 for Williams and 65.58 t·ha -1 for Zelig) were obtained for the tissue-cultured plants in the third crop cycle compared with 51.43 t·ha -1 and 59.02 t·ha -1 obtained for the traditionally-propagated Grand Nain and Williams plants, respectively. There were no significant yield differences between the plants of different origin in the second and fourth cycles, respectively. However, the tissue-cultured Williams and Zelig plants outperformed the other plants in the sixth crop cycle. Conclusion. The tissue-cultured plants of the three Cavendish cultivars studied performed better than the plants resulting from conventional suckers. The best cultivar for commercial plantation used, that is located in a tropical environment, was Williams. In general, to obtain an optimum benefit, we would recommend the use of tissue-cultured plants over a period of 6-7 years with good management practices. Cameroon / Musa / varieties / plant propagation / propagation materials / ratooning / micropropagation / yields Evaluation, en zone tropicale et sur six cycles de recolte, de bananiers Cavendish propages soit par rejets, soit par culture de tissus.

La producción del plátano (Musa spp.) en países de Centro y Sur América y el Caribe está limitada por enfermedades bacterianas. En Puerto Rico, la producción de clones de plátano hawaiiano 'Hua Moa' se ve afectada por una condición conocida como aborto del racimo o 'choke neck'. Esta condición en algunos casos está acompañada por síntomas de pudrición blanda, por lo que se cree puede estar relacionado con bacterias fitopatógenas. El propósito de este estudio fue identificar las bacterias relacionadas con la pudrición blanda de tejidos en plantas con la condición de aborto del racimo y determinar su virulencia en otros clones de plátano y guineo. Se aislaron bacterias de pseudotallos de Hua Moa en tres localidades de Puerto Rico, usando medios semiselectivos y agar nutritivo. Se determinó la patogenicidad en discos de papa y pseudotallos de plátano dentro de cámaras húmedas en condiciones in vitro. Las bacterias patogénicas se identificaron mediante el sistema BIOLOG®. En condiciones de invernadero se confirmó la patogenicidad de Burkholderia gladioli, Pseudomonas spinosa, Erwinia chrysanthemi y Pseudomonas aeruginosa en plátano (Maricongo, FIAH-121, Enano Común y Hua Moa) y de guineo (Grand Nain) usando una escala de 1 a 9. Todos los clones evaluados en condiciones de invernadero fueron susceptibles a E. chrysanthemi, posible agente causal de la pudrición blanda una vez se presenta el aborto del racimo. Burkholderia gladioli se informa por primera vez afectando a plátano y guineo. Esta bacteria fue más virulenta en Hua Moa y Grand Nain, con severidad 7 y 5, respectivamente, que en Maricongo, severidad 3. Pseudomonas spinosa y P. aeruginosa produjeron niveles de severidad menores de 4 comparado con E. chrysanthemi y B. gladioli que produjeron niveles de severidad mayores de 4. Esta investigación se realizó bajo condiciones in vitro y de invernadero y muestra que las principales bacterias relacionadas a la pudrición blanda en plantas con la condición de aborto del racimo en el campo son E. chrysanthemi y B. gladioli. Se recomienda realizar estudios de campo evaluando plantas hasta la etapa reproductiva para determinar si estas bacterias se relacionan además como agentes causales del aborto del racimo.

The feedback regulation of ethylene biosynthesis in banana [Musa sp. (AAA group, Cavendish subgroup) cv. Grand Nain] fruit was investigated in an attempt to clarify the opposite effect of 1-methylcyclopropene (1-MCP), an ethylene action inhibitor, before and after the onset of ripening. 1-MCP pre-treatment completely prevented the ripening-induced effect of propylene in pre-climacteric banana fruit, whereas treatment after the onset of ripening stimulated ethylene production. In pre-climacteric fruit, higher concentrations of propylene suppressed ethylene production more strongly, despite their earlier ethylene-inducing effect. Exposure of the fruit ripened by propylene to 1-MCP increased ethylene production concomitantly with an increase in 1-aminocyclopropane-1-carboxylate (ACC) synthase activity and ACC content, and prevented a transient decrease in MA-ACS1 transcripts in the pulp tissues. In contrast, in the peel of ripening fruit, 1-MCP prevented the increase in ethylene production and subsequently the ripening process by reduction of the increase in MA-ACS1 and MA-ACO1 transcripts and of ACC synthase and ACC oxidase activities. These results suggest that ethylene biosynthesis in ripening banana fruit may be controlled negatively in the pulp tissue and positively in the peel tissue. This differential regulation by ethylene in pulp and peel tissues was also observed for MA-PL, MA-Exp, and MA-MADS genes.

SummaryThe effects of progressive water stress and subsequent re-hydration on fruit growth and mineral nutrient content were investigated in banana plants (Musa acuminata AAA, ‘Grand Nain’) under field conditions. Water stress was imposed by suspending irrigation from flower emergence for 63 d, then continuous re-watering was restored. These adverse conditions reduced fruit growth, fruit size, yield, and delayed fruit maturation. Fruit fresh and dry weights decreased with photosynthetic rate and soil moisture content during the stress period. In relation to nutrient accumulation, the main effect of drought was to reduce potassium levels, which is the major mineral nutrient in banana. In contrast, all the other minerals analysed either increased (i.e., calcium, sodium, iron and zinc), or remained stable (i.e., nitrogen, phosphorus, magnesium, manganese and copper) under the drought treatment, which generated a positive effect on the organoleptic properties of the fruit. After re-hydration, the mineral nutr...

The incorporation of growth retardants (GR) such as ancymidol (ANC) or paclobutrazol (PBZ) in liquid culture media during multiplication stage of bananas decreases the excessive growth of stems and leaves. However, it is unknown if these chemicals have residual effect on further plant growth. To study the effect of ANC and PBZ on Grand Nain banana shoots, they were subcultured for five cycles in the multiplication stage and evaluated in elongation-rooting and acclimatization stages. Multiplication basal medium was Murashige and Skoog supplemented with 1.0 mg l−1 thiamine-HCl and 17.7 μM 6-benzylaminpurine (6-BAP), 9.75 μM ANC or 8.5 μM PBZ. Multiplied Grand Nain banana shoots were transferred to elongation-rooting stage and later on to ex-vitro conditions. The evaluation of GR residual effect and somaclonal variation on Grand Nain banana plants was determined through a comparative study of several morphological parameters in elongation-rooting and acclimatization stages. All morphological parameters evaluated in the elongation-rooting stage showed a similar performance with the exception of the pseudo-stem diameter of the vitroplants treated with both GR. There were significant differences for plant height in the acclimatization stage when shoots were multiplied in a medium containing ANC. The similarities of the parameters evaluated in both stages and the normal morphology recovery of vitroplants multiplied with PBZ suggest that there were no residual effects by adding PBZ to the culture media. The addition of ANC induced significant differences in plant height during the acclimatization stage.

Two Agrobacterium -mediated plant transformation protocols were evaluated for the generation of transgenic banana tissues ( Musa acuminata var. Grand Nain). Co-cultivation versus vacuum infiltration of meristematic banana tissues was compared. The binary vector pC2301 was used for the initial transformation and the histochemical detection of GUS. PCR assays demonstrated that the transformation protocol was successful. Infiltrated samples transformed with pCambia 2301 showed a wider GUS response than the co-cultivated tissues. The specific β-glucuronidase activity was also higher in the infiltrated tissues than in co-cultivated ones and was also comparable to that found in other work. The vector BIBAC2 (bearing a 50 kb insert of foreign gDNA) was also transformed with these protocols showing the potential of this procedure on future genomics for this cultivar.

Centrifugation-assisted Agrobacterium-mediated transformation (CAAT) protocol, developed using banana cultivars from two economically important genomic groups (AAA and AAB) of cultivated Musa, is described. This protocol resulted in 25-65 plants/50mg of settled cell volume of embryogenic suspension cells, depending upon the Agrobacterium strain used, and gave rise to hundreds of morphologically normal, transgenic plants in two banana cultivars from the two genomic groups. Development of a highly efficient Agrobacterium-mediated transformation protocol for a recalcitrant species like banana, especially the Cavendish group (AAA) cultivars, required the identification and optimisation of the factors affecting T-DNA delivery and subsequent plant regeneration. We used male-flower-derived embryogenic cell suspensions of two banana cultivars (Cavendish and Lady Finger) and Agrobacterium strains AGL1 and LBA4404, harbouring binary vectors carrying hpt (hygromycin phosphotransferase) and gusA (β-glucuronidase) or nptII (neomycin phosphotransferase) and a modified gfp (green fluorescent protein) gene in the T-DNA, to investigate and optimise T-DNA delivery and tissue culture variables. Factors evaluated included pre-induction of Agrobacterium, conditions and media used for inoculation and co-cultivation, and the presence of acetosyringone and Pluronic F68 in the co-cultivation media. One factor that led to a significant enhancement in transformation frequency was the introduction of a centrifugation step during co-cultivation. Post co-cultivation liquid-media wash and recovery step helped avoid Agrobacterium overgrowth on filters supporting suspension culture cells. Marker-gene expression and molecular analysis demonstrated that transgenes integrated stably into the banana genome. T-DNA:banana DNA boundary sequences were amplified and sequenced in order to study the integration profile.

Abstract Twenty-eight genotypes (bred diploids, seed-fertile triploids and tetraploid hybrids) of Musa spp. were evaluated in pot tests in Honduras for resistance and tolerance to Radopholus similis through comparison with reference genotypes (Grand Nain as susceptible and Pisang Jari Buaya and Yangambi Km5 as resistant). Eleven tests were carried out, each with seven to 12 Musa genotypes. Tissueculture plants (TC) or plants grown from a corm (Co) were inoculated with 1000 or 3500 nematodes per plant, respectively. Data on nematode population densities, fresh root weight, percentages dead roots, root necrosis and root bases on the corm with lesions were taken 13-23 weeks after inoculation. In most tests, Gros Michel and Highgate were as susceptible to R. similis as Grand Nain. Resistance was shown by both TC and Co plants of SH-3142, SH-3362, SH-3648 and SH-3723, and by Co plants of SH-2095, SH-3624, the female parents Calcutta 4 and Prata Enana, and the hybrid FHIA-01. Moderate resistance was shown by TC plants of SH-3624 and Co plants of SH-3437, the female parent Pelipita and the hybrids FHIA-18 and FHIA-23. The other genotypes were susceptible to R. similis although the male parents SH-3386 and SH-3640, and the hybrid FHIA-21 had some degree of resistance. FHIA-03 was susceptible but showed tolerance to R. similis.

The pattern of change in the endogenous levels of several plant hormones and hydroxycinnamic acids in addition to growth and photosynthetic performance was investigated in banana plants (Musa acuminatacv. “Grand Nain”) subjected to various cycles of drought. Water stress was imposed by withholding irrigation for six periods with subsequent rehydration. Data showed an increase in abscisic acid (ABA) and indole-3-acetic acid (IAA) levels, a transient increase in salicylic acid (SA) concentration, and no changes in jasmonic acid (JA) after each period of drought. Moreover, the levels of ferulic (FA) and cinnamic acids (CA) were increased, and plant growth and leaf gas exchange parameters were decreased by drought conditions. Overall, data suggest an involvement of hormones and hydroxycinnamic acids in plant avoidance of tissue dehydration. The increase in IAA concentration might alleviate the senescence of survival leaves and maintained cell elongation, and the accumulation of FA and CA could play a key role as a mechanism of photoprotection through leaf folding, contributing to the effect of ABA on inducing stomatal closure. Data also suggest that the role of SA similarly to JA might be limited to a transient and rapid increase at the onset of the first period of stress.

The chemical composition of the lipophilic extract of ripe pulp of banana fruit from several banana cultivars belonging to the Musa acuminata and Musa balbisiana species (namely 'Chinese Cavendish', 'Giant Cavendish', 'Dwarf Red', 'Grand Nain', 'Eilon', 'Gruesa', 'Silver', 'Ricasa', 'Williams' and 'Zelig') was studied by gas chromatography-mass spectrometry for the first time. The banana cultivars showed similar amounts of lipophilic extractives (ca. 0.4% of dry material weight) as well as qualitative chemical compositions. The major groups of compounds identified in these fractions were fatty acids and sterols making up 68.6-84.3% and 11.1-28.0%, respectively, of the total amount of lipophilic components. Smaller amounts of long chain aliphatic alcohols and a-tocopherol were also identified. These results are a relevant contribution for the valorisation of these banana cultivars as sources of valuable phytochemicals (omega- and omega-6 fatty acids, and sterols) with well-established beneficial nutritional and health effects. (C) 2014 Elsevier Ltd. All rights reserved.

Culled bananas (dwarf 'Brazilian', 'Grand Nain', 'Valery', and 'Williams') sampled from packing houses on the islands of Hawaii, Kauai, Maui, Molokai, and Oahu identified specific "faults" that were at risk from oriental fruit fly, Bactrocera dorsalis (Hendel), infestation. Faults at risk included bunches with precociously ripened bananas, or bananas with tip rot, fused fingers, or damage that compromised skin integrity to permit fruit fly oviposition into fruit flesh. No Mediterranean fruit fly, Ceratitis capitata (Wiedemann), or melon fly, B. cucurbitae (Coquillett), infestations were found in culled banana samples. Field infestation tests indicated that mature green bananas were not susceptible to fruit fly infestation for up to 1 wk past the scheduled harvest date when attached to the plant or within 24 h after harvest. Recommendations for exporting mature green bananas from Hawaii without risk of fruit fly infestation are provided. The research reported herein resulted in a USDA-APHIS protocol for exporting mature green bananas from Hawaii.

Controlled atmosphere (CA) during vessel transportation is a standard procedure in shipment of preclimacteric bananas (Musa sp. AAA, cv. 'Grand Nain') from Central America to North America or Europe. The purpose of the CA treatment is to reduce the risk of premature ripening in transit, known commercially as ripe and turning. On arrival at their destination, CA is interrupted and bananas are transported to ripening facilities where they are treated with ethylene. In order to understand the impact of preclimacteric CA storage on ripening speed and post-ripening characteristics of bananas, an experiment was conducted that simulated vessel storage under air or CA conditions, followed by commercial ripening. Green bananas were stored under 3% O 2 or air conditions for 15 days at 14°C and 95% RH in a flow-through system at flow rates of 10 l/h. Ten replicates of 18 kg of bananas per replicate were used per treatment. Respiration rates were measured daily with gas chromatography. To reduce variability among treatments, each hand of a bunch was divided in two, numbered and stored under CA or air. After storage, fruit was ventilated in air for 2 days at 14°C and then exposed to 300 μl/liter ethylene for 24 h at 16°C. Fruit was stored at 16°C after treatment with ethylene. Six postharvest parameters (L, 'a' and 'b' values, firmness, Brix, color by color chart) were evaluated daily after ethylene application. CA-stored fruit had higher firmness and lower Brix values for the first 3 days after ethylene treatment. These differences disappeared as fruit reached commercial 'retail-store' ripeness. No significant differences were found in any of the color parameters.

We have identified and characterized the abundant protein from the pulp of banana fruit (Musa acuminata cv. Grand Nain), and have isolated a cDNA clone encoding this protein. Comparison of the amino terminal sequence of the purified 31 kDa protein (P31) suggests that it is related to plant chitinases. Western analyses utilizing rabbit anti-P31 antiserum demonstrate that this protein is pulp-specific in banana. A full-length cDNA clone homologous to class III acidic chitinase genes has been isolated from a pulp cDNA library by differential screening. The identity of this clone as encoding P31 was verified by comparisons between the amino-terminal peptide sequence and the cDNA sequence and cross-hybridization of the translation product of the cDNA clone with P31 antiserum. Northern and western blot analyses of RNA and protein isolated from banana pulp at different stages of ripening indicate that the cDNA and protein are expressed at high levels in the pulp of unripe fruit, and that their abundance decreases as the fruit ripens. Based on its expression pattern and deduced amino acid sequence and composition, we hypothesize that the physiological role of P31 is not for plant protection, but as a storage protein in banana pulp.

The origin of somatic embryos derived from rhizome explants of triploid Musa cv. Grand Nain was the subject of histological studies during different phases of ontogenetic development. The investigation revealed that the majority of somatic embryos showed normal root formation and consisted of highly vacuolated cells in the poorly structured shoot apex. The embryogenic mass and somatic embryos were mostly derived from several morphologically competent cells. Single cell origin depended on the presence of organogenetically functional vascular cells of rhizome explants and occurred infrequently. The implications of these findings for genetic improvement of banana and plantain by in vitro mutation breeding and gene technology are discussed.

Plant regeneration by somatic embryogenesis was attempted with diploid (Musa acuminata ssp. malaccensis) and triploid ('Grand Nain') bananas. Explants inoculated in vitro were, respectively, immature zygotic embryos and male flower bud primordia. An histological study showed that the embryogenic process involves a sequence of similar events for both species. A yellow-green compact callus was initiated, which consisted of an actively dividing meristematic zone surrounded by several layers of starchy cells. A white and friable callus, characterized by the presence of proembryonic cells, bicellular proembryos and proembryonal masses in its periphery gradually appeared, which finally gave rise to somatic embryos from which plants were recovered. Induction media contained 2,4-D (and also NAA and IAA for the triploid); zeatin and kinetin were necessary for embryo maturation and 6-BA and IAA were used for germination.

Four new phenalenone-type phytoalexins, named musanolones C-F, have been isolated from infected rhizomes of banana plants (Musa acuminata; AAA cultivar Grand Nain). These phytoalexins were biosynthesized de novo by the plants upon infection by Fusarium oxysporum f. sp. cubense race 4, Panama's disease causal agent. The structures of the new phytoalexins were elucidated using spectroscopic data and chemical correlations. Hydroxyanigorufone has been previously described as a constitutive natural product, from Anigozanthos rufus, but it was never described as a phytoalexin. The chemical shift for all of the hydrogen and carbon atoms in the musanolones C-F were unambiguously established by mono- and bi-dimensional, homo- and hetero-nuclear NMR experiments (1H NMR, 13C NMR, COSY, HMQC and HMBC). Preliminary in vitro assays of all the musanolones tested until now show a strong inhibitory activity on the growth of the germination tube of F. oxysporum f. sp. cubense race 4.

The effect of three shade levels on morphology, growth and productivity of ‘Grand Nain’ (AAA) bananas during their first and second production cycles was studied in the Jordan Valley, Israel. In vitro propagated plants that were planted in the field in April 1990 were shaded with black saran screens of different densities, installed above the canopy level. The resultant photosynthetic photon flux density (PPFD) was reduced to 80%, 60% or 30% of the unshaded control. Although only the heaviest shade affected plant vegetative growth in the first cycle, bunch weight was reduced by 7% and 32% under medium and heavy shade, respectively. A highly significant effect on vegetative growth and production was observed during the second cycle. Flowering date was delayed by 6 days, 9 days and 15 days, and bunch weight was reduced by 8%, 21% and 55% under light, medium and heavy shade, respectively. Yield was reduced by all levels of shade, owing to the combined effect of reduced bunch weight and a lower stand. Shading reduced the rate of leaf emergence, leaf and foliage area, plant height and pseudostem circumference. The leaves had thinner laminae, with a reduced number of stomata and higher chlorophyll content. Our observations indicate a significant effect of long-term shade on bananas, and the utilization of high levels of PPFD by the banana plant.

En un suelo sin labrar de la subestación de Adjuntas se evaluaron los cultivares Johnson, Ziv, Grand Nain, Valery y la Selección 3-A de guineos durante 50 meses. Las plantas retuvieron 10 o más hojas funcionales hasta la etapa de floración, número mínimo requerido para engordar, pero el cultivar Johnson consistentemente mantuvo más hojas libres de sigatoka. Todos los cultivares se comportaron similarmente para el peso del racimo y la producción total. El peso medio del racimo fue de 18.1 kg y la producción anual 31,027 kg/ha ó 1,705 cajas de frutas mercadeables. La remoción de 1, 2 y 3 manos inferiores del racimo inmaturo redujo substancialmente el tamaño y el peso del racimo y el rendimiento total. Sin embargo, esta práctica aumenta la calidad de las frutas y, por consiguiente, la obtención de mejores precios.