Embrapa Cassava and Tropical Fruits

Salvador, Brazil

Embrapa Cassava and Tropical Fruits

Salvador, Brazil

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Dita M.A.,Embrapa Cassava and Tropical Fruits | Dita M.A.,Plant Research International B.V. | Waalwijk C.,Plant Research International B.V. | Buddenhagen I.W.,1012 Plum Lane | And 3 more authors.
Plant Pathology | Year: 2010

This study analysed genomic variation of the translation elongation factor 1α (TEF-1α) and the intergenic spacer region (IGS) of the nuclear ribosomal operon of Fusarium oxysporum f. sp. cubense (Foc) isolates, from different banana production areas, representing strains within the known races, comprising 20 vegetative compatibility groups (VCG). Based on two single nucleotide polymorphisms present in the IGS region, a PCR-based diagnostic tool was developed to specifically detect isolates from VCG 01213, also called tropical race 4 (TR4), which is currently a major concern in global banana production. Validation involved TR4 isolates, as well as Foc isolates from 19 other VCGs, other fungal plant pathogens and DNA samples from infected tissues of the Cavendish banana cultivar Grand Naine (AAA). Subsequently, a multiplex PCR was developed for fungal or plant samples that also discriminated Musa acuminata and M. balbisiana genotypes. It was concluded that this diagnostic procedure is currently the best option for the rapid and reliable detection and monitoring of TR4 to support eradication and quarantine strategies. © 2010 Plant Research International. Journal compilation © 2010 British Society for Plant Pathology.

Barros E Silva A.E.,Federal University of Paraiba | Dos Santos Soares Filho W.,Embrapa Cassava and Tropical Fruits | Guerra M.,Federal University of Pernambuco
Cytogenetic and Genome Research | Year: 2013

Sites of 5S and 45S rDNA are more commonly located on different chromosomes of most angiosperms. Previous investigations have shown that in the subfamily Aurantioideae these sites may appear closely linked (adjacent sites), as in Poncirustrifoliata, or completely isolated, as in some species of Citrus. In the present work, the distribution of rDNA sites was investigated in representatives of 9 genera of Aurantioideae by FISH and CMA banding, aiming to understand the evolution of adjacent sites in the subfamily. A total of 57 rDNA sites were observed, 40 of them being adjacent to each other. All adjacent sites displayed the 45S rDNA array more terminally located. Assuming that the linked 5S-45S rDNA arrangement was the ancestral condition in Aurantioideae, the isolated rDNA sites observed in Clausena excavata,Bergera koenigii, and Fortunella obovata, as well as the complete linkage loss in Citrus maxima and C. medica indicates that unlinked sites arose independently several times in the evolution of the group. The linkage loss may be due to independent dispersion of one or both rDNA sequence families followed by deletion of the corresponding array in the adjacent site. The possible mechanisms behind these events and their occurrence in other groups are discussed. © 2013 S. Karger AG, Basel.

PubMed | University of California at Riverside, Embrapa Recursos Geneticos e Biotecnologia, University of Brasilia and Embrapa Cassava and Tropical Fruits
Type: | Journal: Annals of botany | Year: 2017

Endoparasitic root-knot nematodes (RKNs) (Meloidogyne spp.) cause considerable losses in banana (Musa spp.), with Meloidogyne incognita a predominant species in Cavendish sub-group bananas. This study investigates the root transcriptome in Musa acuminata genotypes 4297-06 (AA) and Cavendish Grande Naine (CAV; AAA) during early compatible interactions with M. incognita METHODS: Roots were analysed by brightfield light microscopy over a 35 d period to examine nematode penetration and morphological cell transformation. RNA samples were extracted 3, 7 and 10 days after inoculation (DAI) with nematode J2 juveniles, and cDNA libraries were sequenced using lllumina HiSeq technology. Sequences were mapped to the M. acuminata ssp. malaccensis var. Pahang genome sequence, differentially expressed genes (DEGs) identified and transcript representation determined by gene set enrichment and pathway mapping.Microscopic analysis revealed a life cycle of M. incognita completing in 24 d in CAV and 27 d in 4279-06. Comparable numbers of DEGs were up- and downregulated in each genotype, with potential involvement of many in early host defence responses involving reactive oxygen species and jasmonate/ethylene signalling. DEGs revealed concomitant auxin metabolism and cell wall modification processes likely to be involved in giant cell formation. Notable transcripts related to host defence included those coding for leucine-rich repeat receptor-like serine/threonine-protein kinases, peroxidases, thaumatin-like pathogenesis-related proteins, and DREB, ERF, MYB, NAC and WRKY transcription factors. Transcripts related to giant cell development included indole acetic acid-amido synthetase GH3.8 genes, involved in auxin metabolism, as well as genes encoding expansins and hydrolases, involved in cell wall modification.Expression analysis in M. acuminata during compatible interactions with RKNs provides insights into genes modulated during infection and giant cell formation. Increased understanding of both defence responses to limit parasitism during compatible interactions and effector-targeted host genes in this complex interaction will facilitate the development of genetic improvement measures for RKNs.

De Matos A.P.,Embrapa Cassava and Tropical Fruits | Cordeiro Z.J.M.,Embrapa Cassava and Tropical Fruits | De Oliveira E Silva S.,Embrapa Cassava and Tropical Fruits | Amorim E.P.,Embrapa Cassava and Tropical Fruits | Ferreira D.M.V.,Agencia de Defesa Sanitaria da Bahia
Acta Horticulturae | Year: 2011

Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc) was first reported in Brazil in 1930 on 'Maça&tild;' (AAB, Silk). Currently, the disease is present in all banana production regions of the country. Growing resistant cultivars provides the most efficient control for Fusarium wilt. In this work, seven diploid (AA) and fourteen tetraploid (AAAB) banana hybrids were evaluated in field trials for resistance to Foc in infested soil. The banana cultivars 'Maça&tild;' and 'Figue Pome Naine' (AAB, Silk) were used as susceptible controls. All diploid hybrids, namely '011601', '130404', '130406', '131801', '422306', '51A1901' and 'SH3263', showed resistance to the pathogen during both first and second crop cycle. Among the fourteen tetraploid hybrids evaluated, 'PV42-53', 'PV42-68', 'PV42-81', 'PV 42-85', 'PV42-142', 'PV42-143', 'ST42-08', 'ST12-31', 'PV03-44', 'FHIA-03' and 'SH36-40' expressed resistance to Fusarium wilt during two crop cycles, while 'PV42-129', 'PC42-01' and 'YB 42-21' behaved as susceptible. Results also showed that seven out of ten hybrids obtained from crossings in which 'M53' (AA) was used as male parent showed resistance to Foc, thus suggesting that 'M53' is a promising parent for use in banana breeding programmes aiming at developing Fusarium wilt-resistant cultivars.

Souza E.H.,Federal University of Bahia | Soares T.L.,Federal University of Bahia | Souza F.V.D.,Embrapa Cassava and Tropical Fruits | Santos-Serejo J.A.,Embrapa Cassava and Tropical Fruits
Acta Horticulturae | Year: 2010

The difficulty in the micropropagation of many species of Heliconaceas has been mainly due to the high frequency of endogenous contamination. Embryo culture techniques have been used to generate normal seedlings to be used as initial explants. This work aimed to develop a plant production protocol using zygotic embryos from Heliconia rostrata and H. bihai. Embryos from mature fruits were disinfested, excised and cultivated in MS medium solidified with 8% of agar, 6% of sucrose (MS + 6% S) and pH 5,8, autoclaved at 120°C for 20 minutes. The treatments were: T01: Control (MS + 6% S); T02: (MS + 6% S) + 0,25% activated charcoal; T03: (MS + 6% S) + 1,0 mg L-1 BAP; T04: (MS + 6% S) + 1,0 mg L-1 BAP + 0,25% activated charcoal; T05: (MS + 6% S) + 1,0 mg L-1 BAP + 1,0 mg L-1 GA3; T06: (MS + 6% S) + 1,0 mg L-1 BAP + 1 mg L-1 GA3 + 0,25% of activated charcoal. The embryos were maintained in dark conditions for 45 days with temperature of 27±1°C. Treatment T02 promoted the best percentage of germination (100%) for both species and T05 the lower results with 20% and 35% of germination for H. rostrata and H. bihai respective at 30 days of culture. Callus formation was observed in T05 and T06. The activated charcoal was essential to embryo germination. These seedlings were used as explants in the micropropagation assays in MS medium supplemented with these treatments: T01: MS; T02: MS + 0,25% of activated charcoal; T03: MS + 4,0 mg L-1 de BAP; T04: MS + 4,0 mg L-1 BAP + 0,25% of activated charcoal. For the multiplication stage the best medium was the control treatment with no growth regulators and no activated charcoal. A bacterial contamination appeared during subsequence subculture making the micropropagation of these species unfeasible.

Carvalho L.M.J.,Federal University of Rio de Janeiro | Oliveira A.R.G.,Federal University of Rio de Janeiro | Godoy R.L.O.,Embrapa Food Technology | Pacheco S.,Embrapa Food Technology | And 4 more authors.
Food and Nutrition Research | Year: 2012

Background: Over the last decade, considerable efforts have been made to identify cassava cultivars to improve the vitamin A nutritional status of undernourished populations, especially in northeast Brazil, where cassava is one of the principal and essentially only nutritional source. Objectives: The aim of this study was to evaluate the total carotenoid, β-carotene, and its all-E-, 9-, and 13-Z-β-carotene isomers content in seven yellow sweet cassava roots and their retention after three boiling cooking methods. Design: The total carotenoid, β-carotene, and its all-E-, 9-, and 13-Z-β-carotene isomers in yellow sweet cassava samples were determined by ultraviolet/visible spectrometry and high-performance liquid chromatography, respectively, before and after applying the cooking methods. All analyses were performed in triplicate. Results: The total carotenoid in raw roots varied from 2.64 to 14.15 mg/g and total β-carotene from 1.99 to 10.32 μg/g. The β-carotene predominated in all the roots. The Híbrido 2003 14 08 cultivar presented the highest β-carotene content after cooking methods 1 and 3. The 1153 - Klainasik cultivar presented the highest 9-Z-β-carotene content after cooking by method 3. The highest total carotenoid retention was observed in cultivar 1456 - Vermelhinha and that of β-carotene for the Híbrido 2003 14 11 cultivar, both after cooking method 1. Evaluating the real retention percentage (RR%) in sweet yellow cassava after home cooking methods showed differences that can be attributed to the total initial carotenoid contents. However, no cooking method uniformly provided a higher total carotenoid or β-carotene retention in all the cultivars. Conclusion: Differences were found in the cooking methods among the samples regarding total carotenoid or β-carotene retention, suggesting that the different behaviors of the cultivars need to be further analyzed. However, high percentages of total carotenoid or β-carotene retention were observed and can minimize vitamin A deficiency in low-income populations. © 2012 Lucia M. J. Carvalho et al.

Dita M.A.,Embrapa Cassava and Tropical Fruits | Dita M.A.,Plant Research International | Waalwijk C.,Plant Research International | Paiva L.V.,Federal University of Lavras | And 3 more authors.
Acta Horticulturae | Year: 2011

Several disease resistance screening protocols for Fusarium wilt of banana (causal agent Fusarium oxysporum f. sp. cubense-Foc) under greenhouse conditions have been reported. Here, we report a standardised rapid and reliable greenhouse bioassay for this pathosystem. This is indispensable for banana phenotyping, particularly since the occurrence of tropical race 4 (TR4), which is a significant threat for the global Cavendish-based banana export industry. Using a double-pot system, hardened 3-months-old tissue-culture plants of 'Grand Naine' (AAA, Cavendish subgroup) were individually inoculated with three TR4 isolates and one race 1 isolate with known pathogenicity on 'Silk' (AAB) bananas. All TR4 isolates caused similar symptoms and no differences regarding incubation period or severity were observed. In addition, all TR4 isolates were successfully recovered from the symptomatic rhizomes on Komada medium.

Silva H.S.A.,Embrapa Cassava and Tropical Fruits | Tozzi J.P.L.,Environmental Microbiology Laboratory | Terrasan C.R.F.,Claro | Bettiol W.,Environmental Microbiology Laboratory
Biological Control | Year: 2012

A total of 234 strains of endophytic bacteria (217) and fungi (17) from coffee tissues were evaluated for their potential to control coffee leaf rust (Hemileia vastatrix) and to promote the growth of coffee seedlings. None of the fungal strains induced plant growth or reduced disease severity. Bacterial strains 85G (Escherichia fergusonii), 161G, 163G, 160G, 150G (Acinetobacter calcoaceticus) and 109G (Salmonella enterica) increased plant growth; the maximum increase was induced by strain 85G. This strain in vitro produced phosphatase and indol acetic acid. In an exploratory assay to control rust on coffee leaf discs, nine bacterial strains: 64R, 137G, 3F (Brevibacillus choshinensis), 14F (S. enterica), 36F (Pectobacterium carotovorum), 109G (Bacillus megaterium), 115G (Microbacterium testaceum), 116G and 119G (Cedecea davisae) significantly reduced disease severity when applied 72 or 24. h before challenging with the pathogen. Strains 3F, 14F, 109G, 115G, 119G, and 137G significantly reduced the severity of coffee leaf rust when compared to the diseased control in the seedling assay, when applied 72. h before challenging with the pathogen. Strain 109G was the most effective in this assay. Urediniospore germination was reduced 66% by strain 3F. There was no correspondence between the organisms that promoted seedling growth and those that reduced coffee leaf rust severity on seedlings or leaf discs. © 2012 Elsevier Inc.

Ribeiro L.R.,Federal University of Recôncavo da Bahia | Amorim E.P.,Embrapa Cassava and Tropical Fruits | Cordeiro Z.J.M.,Embrapa Cassava and Tropical Fruits | De Oliveira E Silva S.,Embrapa Cassava and Tropical Fruits | Dita M.A.,Embrapa Cassava and Tropical Fruits
Acta Horticulturae | Year: 2011

Among the major constrains to banana breeding for Fusarium wilt (FW) resistance is the long period necessary for evaluations in the field and the lack of an effective method for early detection of resistant genotypes. This work aimed to establish a screening method for FW resistance under greenhouse conditions and validate its reliability by challenging cultivars with different levels of FW resistance. Two types of substrates (vermiculite and washed river sand) and three inoculums sources (conidial suspension from 1-week-old colonies grown in Potato-Dextrose-Agar-PDA, conidial suspension produced after stress of 1-week-old colonies and Foc-colonised corn meal-sand (CMS) medium) were studied by inoculating 45-dayold plantlets of 'Silk' (AAB, susceptible) in a double-tray system. Symptoms were observed in plants grown in both substrates, but highest incidence occurred in washed river sand. Low infection rates were observed using conidial suspension from PDA-grown colonies. By contrast, inocula from stressed colonies and CMS caused consistent symptom expression. Using washed river sand as substrate and inoculum from PDA-grown stressed colonies and/or Foc-colonised CMS, plantlets of the cultivars 'Tropical' (AAAB) and 'Thap Maeo' (AAB) (field intermediary resistance) were challenged. Plantlets of 'Silk' and 'Grande Naine' (AAA) were used as susceptible and resistant controls, respectively. While the incubation period in 'Silk' was 13 days after inoculation (dai), initial symptoms were only observed at 17 dai in 'Tropical' and 'Thap Maeo'. No symptoms were observed in 'Grande Naine'. The disease progress evaluated based on external symptoms and rhizome discolouration scales allowed discriminating cultivars according to resistance levels. Since experiments were repeated three times with similar results, our research suggests that the method here described could be suitable for early detection of banana genotypes resistant to Fusarium wilt.

Souza F.V.D.,Embrapa Cassava and Tropical Fruits | Canto A.M.M.E.,Federal University of Recôncavo da Bahia | Souza A.S.,Embrapa Cassava and Tropical Fruits | Costa M.A.P.C.,Federal University of Recôncavo da Bahia
Revista Brasileira de Fruticultura | Year: 2010

This work aimed to evaluate the influence of naphthaleneacetic acid (NAA) and gibberellic acid (GA 3) plant regulators in in vitro etiolation and subsequent regeneration of the PE x SC-60 pineapple hybrid. Nodal segments of in vitro plants with approximately 5-7 cm height were incubated in basic MS culture medium supplemented with 0.0; 0.5 and 1.0 mg L -1of naphthaleneacetic acid (NAA) in combination with gibberellic acid (GA 3) in concentrations of 0.0; 0.5 and 1.0 mg L -1, and maintained at 27 °C ± 1°C under dark condition. Evaluations were carried out at 90 and 180 days after incubation period. The best results for length of etiolated stems were obtained with 1.0 mg L -1 of NAA. In the experiment followed by the regeneration, stems with 3 cm from the etiolation treatment, were cultivated in proliferation medium and the number of regenerated plants per treatment was evaluated at 60 days of cultivation. The treatment that promoted the best etiolation of plants also promoted the worst regeneration rates, demonstrating the residual effect of the auxin used in the previous step in the regeneration of plants of the pineapple hybrid evaluated.

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