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Pathogenicity of Musicillium theobromae (Turconi) Zare & W. Gams (syn. Stachylidium theobromae Turconi, Verticillium theobromae E.W. Mason & S. Hughes) causing Banana cigar end rot disease has fulfilled Koch’s Postulates for the first time. To assess and prove the pathogenicity, M. theobromae mycelial discs and conidia were inoculated in triplicate to surface-disinfested green banana fruits. The bananas were infected both through artificial wounds as well as through intact unwounded fruits. After inoculation, the bananas were covered with moist cotton and incubated for 30 days at 23°C. Plain moist cotton was used on the controls. Those inoculated treatments kept under high relative humidity exhibited symptoms of banana cigar end rot disease. The controls and those kept under low relative humidity did not develop symptoms and remained healthy. The results indicated that both optimum temperature and high relative humidity are necessary for infection onset and disease development. It was also determined that infection can occur both through wounds and intact unwounded fruit epidermis. The cultural characteristics in M. theobromae were also investigated. It was found that the best mycelial growth occurred on potato dextrose agar (PDA) and the optimum pH for mycelial growth was 8.
Influence of Fusarium oxysporum f. sp. cubense (E.F. Smith) Snyder and Hansen on 2,4-diacetylphloroglucinol (DAPG) production in the rhizosphere of banana cultivar Rasthali by Pseudomonas fluorescens was investigated. The purified extracts of Pfm strain of P. fluorescens isolated from banana rhizosphere inhibited the growth and spore germination of F. oxysporum f. sp. cubense under laboratory conditions. DAPG extracted from the cultures of the strain was observed as distinct spots in thin layer chromatographic plates at Rf value of 0.88. The extracts of soil inoculated with P. fluorescens and challenge inoculated with F. oxysporum f. sp. cubense eluted at retention time ranges from 20.00 min to 21.30 min. The quantity of DPAG production was less in the extracts of soil inoculated with P. fluorescens and challenge inoculated with F. oxysporum f. sp. cubense as compared to P. fluorescens alone inoculated soil. The talc formulation of Pfm strain also reduced vascular discolouration due to the pathogen in banana plants when inoculated at 15 g/plant.
Banana fruits are highly perishable and prone to microbial infection that cause significant damage. Fungicides and pesticides that are used to control this infection are toxic to man and animals, hence there is the need for environmentally friendly control measures of fruit rot pathogens. Simultaneous inoculation of fruits with Trichoderma species and rot pathogens resulted in rot on the fingers, but rot produced by T. asperellum NG-T161 alone or in combination with the pathogens was reduced, compared to rot produced by the pathogens alone. Treatment of fruits with conidia and culture filtrates of T. asperellum NG-T161 for 30 min prior to inoculation with the pathogens provided a better control than their simultaneous application. Only Trichoderma species were recovered on plated portions of rotted tissues from inoculations with the pathogens and the antagonists on the fruits. At 50% (v/v) the filtrates inhibited the mycelial growth of Fusarium oxysporum and Colletotrichum musae by 49.7 and 60.3% respectively but Lasiodiplodia theobromae was not inhibited. T. asperellum strains were found to be mycoparasitic on banana fruit rot pathogens. Conidia and culture filtrates of T. asperellum NG-T161 controlled the rot on banana fruits. It could be developed into a biopesticide for the control of postharvest banana fruit rot pathogens.
Development of embryogenic cultures having high regeneration efficiency from important, commercial varieties of banana is a prerequisite for genetic manipulation and for in vitro propagation. In the present study, we have studied the induction of somatic embryogenesis from young immature male inflorescences of the banana cul­tivar Lal Kela (red banana) on M2 medium (Ma et al., 1991) supplemented with 2,4-D. Cell suspension cultures initiated from this callus exhibited embryogenic stages. So­matic embryos developed into plantlets on / strength MS basal medium with 100 mg l-1 ME + 0.1% AC and 0.2% gelrite. Plants regenerated through somatic embryogenesis showed minor variation when assessed by randomly amplified polymorphic DNA (RAPD) and sequence characterized amplified regions (SCAR) markers.
This study was executed to investigate the potential of agar-agar, a nontoxic and non-degradable gelling agent, as a promising coating agent to improve and protect banana fruit against fungal postharvest diseases i.e., crown, finger, neck and flower end rots which are caused by fungal isolates of Colletotrichum musae and Fusarium moniliforme. Coated-banana fruit samples with different concentrations of agar-agar suspension particularly at 2.0 g · l−1 exhibited a significant reduction in incidence and severity of postharvest diseases compared to untreated fruit. Banana fruits dipped in agar suspension at 2.0 g · l−1 for 5, 10 and 15 min showed significant reduction in disease incidence and severity. Moreover, application of agar suspension as a coating agent at 2.0 g · l−1 significantly decreased weight loss (%), firmness loss (%), and soluble solid concentration of banana fruit for 15 days at 25 ± 2°C. Scanning electron microscopy observation confirmed that the fruit coated with agar colloid at 2.0 g · l−1 had significantly fewer cracks and showed smoother surfaces than untreated fruit. This explains the quality improvement in agar-coated fruit compared to uncoated fruit. Overall, agar colloid, a safe coating agent, could be used to protect banana fruit against postharvest rot diseases and extend fruit storage life during ripening and storage.
This study investigated heavy metals in soils and agricultural products near an industrial district in Dongguan City. The concentrations of Cu, Zn, Pb, Cd, Hg, and As in soil and agricultural products from vegetable and banana fields were determined. Results indicated that except for Zn in one sample and Cd in five samples, the majority of the samples were notably enriched by heavy metals compared with background values. The concentrations of heavy metals (mg·kg⁻¹ dry soil) in agricultural soils in the study area ranged from 22.2 to 93.0 for Cu, 31.2 to 213.6 for Zn, 47.6 to 133.5 for Pb, 0.01 to 0.67 for Cd, 0.15 to 0.56 for Hg, and 20.5 to 28.9 for As. Among these soil samples, concentrations of Cu, Zn, Cd, and Hg in 20.6%, 8.8%, 29.4% and 38.2% soil samples, respectively, exceeded Chinese maximum allowable concentrations (MAC) for agricultural soil. The concentrations of Zn, Pb, and Cd were significantly higher in vegetable than in banana fields. Cu, Zn, Pb, Cd, and Hg accumulated in the topsoil of vegetable fields, but only Pb and Hg accumulated in banana fields. Zn, Cd, and Hg accumulated more easily in flowering cabbage than other vegetables. Cu, Zn, and As were accumulated more easily in banana than lettuce, bunching onion and eggplant. Therefore, the findings suggest more attention should be focused on the accumulation of heavy metals in banana. This study presents a practical methodology for screening crops with lower bio-concentration factors for heavy metals to reduce metal contaminants in the general food supply chain.
W pracy podjęto próbę wykorzystania owoców banana o daleko posuniętej dojrzałości konsumpcyjnej do otrzymywania mrożonych deserów. Banany po pokrojeniu na plastry poddano obróbce wstępnej tj. blanszowaniu w 30% syropie cukrowym, zakwaszonym kwasem cytrynowym, bądź 24 godzinnemu moczeniu w 50% zakwaszonym syropie cukrowym z różnymi dodatkami, w tym z kwasem L-askorbinowym, wodorosiarczynem sodu oraz chlorkiem wapnia. Zabiegi te wykonano w celu stabilizacji barwy, usunięcia substancji gazowych i ewentualnego utwardzenia. W surowcu, spreparowanych plastrach oraz w produkcie po 6. miesiącach zamrażalniczego przechowywania oznaczono zawartość suchej masy, cukrów, kwasów, protopektyn, pektyn, polifenoli, witaminy C, wapnia, SO2 oraz aktywność peroksydazy. Ocena sensoryczna produktów wykazała, że przeprowadzenie blanszowania nie gwarantuje otrzymania dobrej jakości mrożonych deserów. Spośród 6. różnych prób poddanych moczeniu tylko próba, w której do syropu dodawano 0,8% kwasu cytrynowego, 0,2% kwasu L-askorbinowego i 1% chlorku wapnia gwarantowała otrzymanie mrożonek o jakości sensorycznej zbliżonej do oceny dobrej.
The foraging behavior of greater short-nosed fruit bats (Cynopterus sphinx) on wild banana (Musa acuminata) and subsequent dispersal of seeds were studied in the Tropical Rainforest Conservation Area, Xishuangbanna Tropical Botanical Garden, Yunnan province, by direct observation of marked fruits, mist netting, and seed collection. The mean number (± SE) of individual C. sphinx captured by mist net were 2.2 ± 0.33/day and 1.4 ± 0.32/day in the rainy season (September to October) and dry season (November to December), respectively; the difference was not significant. The number of seed pellets expelled was 9.0 ± 1.12/day and 7.2 ± 1.37/day in the rainy and dry seasons respectively; again the difference was not significant. The removal curves for marked fruit were similar for 10 focal trees. Fruits were consumed heavily within two weeks after ripening and all the marked fruit were removed within one month. The difference in seed dispersal was significant between different feeding roosts indicating that patterns of seed dispersal may not be uniform. We found the seeds of M. acuminata can be dispersed by C. sphinx to a distance of about 200 m, and C. sphinx can be considered as an effective seed disperser of M. acuminata.
Improved soil fertility is a requirement for enhanced crop production. Combination of inorganic and organic fertilizers improve crop productivity while reduce environmental degradation. An experiment was carried out at Eastern University, Sri Lanka to study the effect of Foliar Application of Banana Pseudostem Sap on Yield of Cowpea (Vigna unguiculata L. Walp.) in sandy regosol. The experiment was laid out in Randomized Complete Block Design having five treatments viz; recommended inorganic fertilizer N, P, K as basal and N as topdressing (T1), N, P, 1⁄2 K as basal with recommended N as topdressing and foliar spray of 1% , 3%, 5% and 7% banana pseudostem sap solution (T2-T5) at 3rd, 5th, 7th and 9th week after planting. The results revealed that significant difference (P<0.05) were noted on number of pods per plant at 1st and 2nd picking. Higher number of pods per plant, maximum pod length and girth were in T2 while low in T1. Sun dried weights of pods and number of seeds per pod were significantly (P<0.05) varied at each picking. Further, cowpea yield at each picking were higher in T2 compared to tested treatments. The present study suggested that, among the tested treatments N, P, 1⁄2 K as basal with recommended N as topdressing and foliar spray of 1% Pseudostem sap solution at 3rd, 5th, 7th and 9th WAP would be the most suitable for cowpea production in sandy regosol.
Energy consumption has increased steadily over the last four decades as the population has grown and more countries have become industrialized. On the other hand waste disposal has become the major concern of developing cities. Many countries such as Ethiopia have abundant raw materials for biofuels, yet these have not been explored. This study was designed to utilize banana peels for the production of bioethanol using the yeast Saccharomyces cerevisiae. The effects of factors in hydrolysis (the effect of hydrolysis parameters) were investigated and the optimum combination factor was carried out with response surface design. The parameters were varied over 3 levels and 17 experimental runs were conducted to produce fermentable sugar. The optimum results were obtained at 1.50 % v/v acid concentration, 91.02 0C temperature and 21.66 min retention time. At this optimum condition, fermentation with and without benzyl penicillin was performed to determine its effect on bioethanol.
An efficient protocol was developed for in vitro mass propagation of the commercial cultivar Musa acuminata cv. Dwarf Cavendish through shoot apices culture. Shoot apices with 2-3 pairs of leaf primordia were induced from sliced rhizome explants on Murashige and Skoog (1962) medium supplemented with 6.0 mg/l BA, 150 mg/l Ads and 3% (w/v) sucrose. Multiple shoots were induced from meristematic domes on the same medium. Addition of 1.0-1.5 mg/l IAA to the culture medium and incubation in continuous light (24 h) increased the yield of multiple shoots. The high multiplication coefficient was maintained stable up to the 5th subculture; thereafter it declined. Rooting was readily achieved upon transferring the shoots onto half-strength MS medium supplemented with 500 mg/l activated charcoal and 2% (w/v) sucrose. Micropropagated plantlets were hardened in a polyethylene house and successfully established in soil. There was no morphological variation among the micropropagated plants.
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