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1.
R. G. Loor A. M. Risterucci B. Courtois O. Fouet M. Jeanneau E. Rosenquist F. Amores A. Vasco M. Medina C. Lanaud 《Tree Genetics & Genomes》2009,5(3):421-433
The native Theobroma cacao L. population from Ecuador, known as Nacional, is famous for its fine cocoa flavour. From the beginning of the twentieth
century, however, it has been subjected to genetic erosion due principally to successive introductions of foreign germplasm
whose hybrid descendants gradually replaced the native plantations, implying a decrease in cocoa quality. We attempted to
trace this native cacao within a wide pool of modern Ecuadorian cacao population. Three hundred and twenty-two cacao accessions
collected from different geographical areas along the pacific coast of Ecuador and maintained in two living collections were
analysed using 40 simple-sequence repeat markers. Most of Ecuadorian cacao accessions displayed a high diversity and heterozygosity
level. A factorial analysis of correspondence (FAC) showed a continuous variation among them, with a few ones, grouped at
an extreme side of the FAC cloud, showing higher levels of homozygosity and lower introgression level by foreign cacaos. A
paternity analysis revealed that these highly homozygous individuals are the most probable ancestors of the modern Nacional
hybrid pool. These particular accessions studied could represent the native Nacional cacao present in Ecuador before the foreign
introductions. Their identification will help to conserve valuable genetic material and to improve cocoa quality in new cacao
varieties. 相似文献
2.
The main constraint and continuing threat to cocoa production in Latin America is disease caused by two basidiomycete fungi
belonging to the genus Crinipellis (Agaricales), both of which are currently on an invasive front. Classical biological control, in which coevolved natural enemies are
considered to offer the most potential for sustainable control of invasive alien organisms, is investigated as a management
strategy. Our initial approach has been to search for the suspected coevolved host (Theobroma gileri) of one of these pathogens, Crinipellis roreri, the causal agent of frosty pod rot, in the mesic forests of north-west Ecuador; to isolate the endophytes and mycoparasites
associated with both host and pathogen; to screen selected fungi in the greenhouse and laboratory, in order to determine their
biocontrol potential. Endophytes were isolated directly in the field from healthy tree boles and pods, and over 40 genera
were recorded, mainly representing anamorphs of Hypocreales in the genera Acremonium, Clonostachys, Trichoderma and Verticillium, as well as basidiomycetes belonging to the Agaricales and Polyporales. Of the endophytic fungi tested, most can be inoculated into and recovered from asymptomatic cocoa seedlings. Twenty-eight
mycoparasitic species were isolated from diseased pods and selected mycoparasites as well as endophytes were screened against
C. roreri using the pre-colonised plate method. Consistently high mycoparasitism of the C. roreri pseudostroma was demonstrated, particularly by a complex of Clonostachys and Trichoderma species. 相似文献
3.
Rey Gaston Loor Solorzano Olivier Fouet Arnaud Lemainque Sylvana Pavek Michel Boccara Xavier Argout Freddy Amores Brigitte Courtois Ange Marie Risterucci Claire Lanaud 《PloS one》2012,7(11)
Ecuador’s economic history has been closely linked to Theobroma cacao L cultivation, and specifically to the native fine flavour Nacional cocoa variety. The original Nacional cocoa trees are presently in danger of extinction due to foreign germplasm introductions. In a previous work, a few non-introgressed Nacional types were identified as potential founders of the modern Ecuadorian cocoa population, but so far their origin could not be formally identified. In order to determine the putative centre of origin of Nacional and trace its domestication history, we used 80 simple sequence repeat (SSR) markers to analyse the relationships between these potential Nacional founders and 169 wild and cultivated cocoa accessions from South and Central America. The highest genetic similarity was observed between the Nacional pool and some wild genotypes from the southern Amazonian region of Ecuador, sampled along the Yacuambi, Nangaritza and Zamora rivers in Zamora Chinchipe province. This result was confirmed by a parentage analysis. Based on our results and on data about pre-Columbian civilization and Spanish colonization history of Ecuador, we determined, for the first time, the possible centre of origin and migration events of the Nacional variety from the Amazonian area until its arrival in the coastal provinces. As large unexplored forest areas still exist in the southern part of the Ecuadorian Amazonian region, our findings could provide clues as to where precious new genetic resources could be collected, and subsequently used to improve the flavour and disease resistance of modern Ecuadorian cocoa varieties. 相似文献
4.
Cocoa agroforestry is less resilient to sub‐optimal and extreme climate than cocoa in full sun
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Issaka Abdulai Philippe Vaast Munir P. Hoffmann Richard Asare Laurence Jassogne Piet Van Asten Reimund P. Rötter Sophie Graefe 《Global Change Biology》2018,24(1):273-286
Cocoa agroforestry is perceived as potential adaptation strategy to sub‐optimal or adverse environmental conditions such as drought. We tested this strategy over wet, dry and extremely dry periods comparing cocoa in full sun with agroforestry systems: shaded by (i) a leguminous tree species, Albizia ferruginea and (ii) Antiaris toxicaria, the most common shade tree species in the region. We monitored micro‐climate, sap flux density, throughfall, and soil water content from November 2014 to March 2016 at the forest‐savannah transition zone of Ghana with climate and drought events during the study period serving as proxy for projected future climatic conditions in marginal cocoa cultivation areas of West Africa. Combined transpiration of cocoa and shade trees was significantly higher than cocoa in full sun during wet and dry periods. During wet period, transpiration rate of cocoa plants shaded by A. ferruginea was significantly lower than cocoa under A. toxicaria and full sun. During the extreme drought of 2015/16, all cocoa plants under A. ferruginea died. Cocoa plants under A. toxicaria suffered 77% mortality and massive stress with significantly reduced sap flux density of 115 g cm?2 day?1, whereas cocoa in full sun maintained higher sap flux density of 170 g cm?2 day?1. Moreover, cocoa sap flux recovery after the extreme drought was significantly higher in full sun (163 g cm?2 day?1) than under A. toxicaria (37 g cm?2 day?1). Soil water content in full sun was higher than in shaded systems suggesting that cocoa mortality in the shaded systems was linked to strong competition for soil water. The present results have major implications for cocoa cultivation under climate change. Promoting shade cocoa agroforestry as drought resilient system especially under climate change needs to be carefully reconsidered as shade tree species such as the recommended leguminous A. ferruginea constitute major risk to cocoa functioning under extended severe drought. 相似文献
5.
Jacques H. C. Delabie Benoît Jahyny Ivan Cardoso do Nascimento Cléa S. F. Mariano Sébastien Lacau Sofia Campiolo Stacy M. Philpott Maurice Leponce 《Biodiversity and Conservation》2007,16(8):2359-2384
By maintaining a forest-like structure, shaded cocoa plantations contribute to the conservation of ants that usually live
in the soil, leaf litter or canopy of tropical forests. Here we synthesize the available information on the diversity and
community structure of ants in shaded cocoa plantations in the Atlantic forest region of Brazil, compare ant assemblages in
cocoa agroforests with forests and other forms of agriculture, and discuss how these shaded plantations contribute to the
conservation of the ants in the Atlantic Forest region. We also discuss ants of economical importance and of special interest,
including Camponotus, Dolichoderus, Gnamptogenys, Pachycondyla, Pseudomyrmex and other litter dwelling genera. We discuss the situation of the tramp ant Wasmannia auropunctata in the Bahian cocoa-producing region where it is considered as native, and that of the two cryptobiotic genera Thaumatomyrmex and Typhlomyrmex, as well as that of proven and possible endangered army ant and Ponerini species. A total of 192 ant species from four strata
were found in extensive sampling of a cocoa plantation with a relatively simple shade canopy (comprised primarily of Erythrina). Species richness in the cocoa plantations corresponded roughly to that of low diversity native forests, and species composition
of cocoa plantations was most similar to native habitats (forest and mangroves) while ant composition in other agricultural
habitats was most similar to that of urban areas. Although occurrences of Wasmannia auropunctata were similar in cocoa plantations and forests, abundance of Thaumatomyrmex and Typhlomyrmex, generally thought to be rare ants, was relatively high in cocoa plantations. These results, from cocoa plantations with
relatively simple shade, demonstrate the importance of cocoa for ant conservation in the Atlantic forest region of Brazil.
It is likely that cocoa plantations with a greater number of vegetation strata and higher tree species richness (such as traditional
cabruca plantations) provide even more important habitat for ants generally and for ant species of conservation concern. 相似文献
6.
A. A. BRUNT 《The Annals of applied biology》1975,80(2):169-180
The virulent strain A of cocoa swollen-shoot virus (CSSV) severely decreased the growth and yield of Amelonado cocoa (Theobroma cacao) trees kept free of capsids (Distantiella theobroma and Sahlbergella singularis) and the dieback fungus (Calonectria rigidiuscula) in Ghana. Fifteen per cent of graft-inoculated Amelonado trees showed symptoms within 4 months, and 48, 80 and 100% within 6, 12 and 20 months, respectively. Infected trees, whether shaded or unshaded, began to decline 6 months after infection, and deteriorated rapidly during the next 27 months by which time 16 % had died and most others were moribund; fertilizer applications had no significant effect on the rate at which infected trees deteriorated. Yields of pods and dry cocoa were greatly reduced 2 yr after infection and were very low after 3 yr; yields were significantly reduced by virus infection but there were no significant further effects of applying fertilizer. These results confirm that CSSV strain A alone is very damaging and often eventually lethal to Amelonado trees in Ghana, and indicate that the conflicting results obtained previously in Ghana and Nigeria were probably due to differences in the virulence of the CSSV strains tested. In contrast, the virus had much less effect on cocoa trees of the Amazon type; only 3% of graft-inoculated Amazon trees showed symptoms within 4 months, and 43, 84 and 97% after 1, 2 and 3 yr, respectively. Slight deterioration of tree canopies was first detected c. 15 months after infection and, although it continued slowly during the next 21 months, the decline was much less severe than that of Amelonado trees. Yields of both unshaded and shaded trees were apparently reduced by virus infection, but yield losses were much smaller than those of Amelonado trees. These results support the present objectives of controlling the spread of CSSV in Ghana by roguing infected trees, and selecting cultivars with greater tolerance to infection for future use. 相似文献
7.
Bassirou Ndoye Rasoul Shafiei Nastaran Shah Sanaei Ilse Cleenwerck Marius K. Somda Mamoudou Hama Dicko Lat Souk Tounkara Amadou Tidiane Guiro Frank Delvigne Philippe Thonart 《Journal of applied microbiology》2022,132(6):4130-4149
It has been more than a decade since Acetobacter senegalensis was isolated, identified and described as a thermotolerant strain of acetic acid bacteria. It was isolated from mango fruits in Senegal and used for industrial vinegar production in developing countries, mainly in sub-Saharan Africa. The strain was tested during several spirit vinegar fermentation processes at relatively high temperatures in accordance with African acclimation. The upstream fermentation process had significant stress factors, which are highlighted in this review so that the fermentation process can be better controlled. Due to its high industrial potential, this strain was extensively investigated by diverse industrial microbiologists worldwide; they concentrated on its microbiological, physiological and genomic features. A research group based in Belgium proposed an important project for the investigation of the whole-genome sequence of A. senegalensis. It would use a 454-pyrosequencing technique to determine and corroborate features that could give this strain significant diverse bio-industrial applications. For instance, its application in cocoa bean fermentation has made it a more suitable acetic acid bacterium for the making of chocolate than Acetobacter pasteurianus. Therefore, in this paper, we present a review that summarizes the current research on A. senegalensis at its microbial and genomic levels and also its specific bio-industrial applications, which can provide economic opportunities for African agribusiness. This review summarizes the physiological and genomic characteristics of Acetobacter senegalensis, a thermotolerant strain isolated from mango fruits and intended to be used in industrial vinegar fermentation processes. It also explores other bio-industrial applications such as cocoa fermentation. Vinegar fermentation is usually performed with mesophilic strains in temperate regions of the world. Developing countries, such as Senegal, import vinegar or make ‘fake’ vinegar by diluting acetic acid obtained from petrochemicals. The use of a thermotolerant Acetobacter senegalensis strain as a solid functional starter culture, as well as the design of a new adapted bioreactor, has significantly contributed to food security and the creation of small- to medium-sized enterprises that produce mango vinegar in West Africa. 相似文献
8.
Pierre Walet N'Guessan Ahoua Yapi Franois Kouam N'Guessan Norbert N'Dri Kouam Christiane Nathalie Gouamen Romain Aka Aka Klotioloma Coulibaly Mathias Gnion Tahi Boak Kon Emmanuel Koffi Kassin Evelyne Marise Assi Brigitte Honorine Sahin Boguinard Guiraud Alain Acka Jacques Kotaix 《Journal of Applied Entomology》2019,143(10):1065-1071
From 2013 to 2018, surveys were conducted in counties not previously surveyed in order to determine species of mealybugs present in the cocoa orchard in Côte d'Ivoire as well as their abundance according to the age of cocoa trees. Immature and mature cocoa trees were inspected to hand‐height in 5 and 29 counties infected with Cacao swollen shoot virus (CSSV). In each cocoa farm, mealybugs were searched for on fruits, leaves, flowers, twigs and trunks. Mealybug species were identified, and colonies were counted. Five mealybug species were identified on immature cocoa trees: Ferrisia virgata, Formicococcus njalensis, Planococcus citri, Planococcus kenyae and Pseudococcus longispinus. In addition to these species, four species, Dysmicoccus brevipes, Maconellicoccus hirsutus, Phenacoccus hargreavesi and Pseudococcus jackbeardsleyi were identified on mature cocoa trees. On immature cocoa trees, Fo. Njalensis, Pl. citri and Ps. longispinus comprised were, respectively, 35%, 33% and 19% of colonies, respectively. On mature cocoa trees, Fo. Njalensis and Pl. citri comprised 63.2% and 21.0%, and others species 15.8%. Nevertheless, the abundance of mealybug species varied according to the age of cocoa trees. The preferred organs of mealybugs were pods (74.1%) followed by twigs (13.4%) and flowers (7.4%). Previously, the mealybug Paracoccus burnerae (Brain) was found on Theobroma cacao, which is the first record for this species in Côte d'Ivoire and on this host‐plant. 相似文献
9.
The presence of ochratoxin A (OTA) in cocoa and chocolates has been reported. There is no previously published data available
on the source and development of OTA producing moulds and OTA itself in cocoa,i.e. where the mycotoxin enters the cocoa supply chain.
A selection of fresh and undamaged cocoa pods from various growing regions was examined for mycotoxin OTA content. In addition,
a small selection of damaged or mouldy cocoa pods was included in the examination. It was shown that the ripening phase of
healthy cocoa pods from the tree up to being harvested was not a critical period for the occurrence of the mycotoxin OTA.
The mycotoxin OTA was not detectable in any of the analysed cocoa pods.
Presented at the 28th Mykotoxin-Workshop, Bydgoszcz, Poland, May 29–31, 2006 相似文献
10.
The mycotoxin deoxynivalenol (DON) is one of a group of mycotoxins known as type B trichothecenes and is particularly formed
by the mould speciesFusarium graminearum andFusarium culmorum. The frequency of the occurrence of DON in certain raw materials and the concentrations found make it one of the world’s
most significant mycotoxin contaminants. Positive findings of the toxin especially have been established in cereal-based foods,
as well as in oilseeds.
The main objective of this study was to set up a current situation assessment of the possible occurrence of deoxynivalenol
in cocoa and cocoa products. As there was no analytical method for determining DON in cocoa and cocoa products, a special
method was developed. The applicability and consistency of the method was confirmed by performing recovery assays on various
cocoa products. A special post-column derivatisation procedure was developed to increase selectivity and raise sensitivity
by a factor of 80.
The method was used to test 230 samples for possible DON content, ranging from cocoa beans to cocoa bean shells, nibs, cocoa
liquor and cocoa powders through to finished cocoa-based products. The results suggest that DON may occasionally occur in
cocoa beans in very low concentrations.
Presented at the 29th Mykotoxin-Workshop, Fellbach, Germany, May 14–16, 2007 相似文献
11.
Canker disease of Theobroma cacao L. caused by Phytophthora palmivora (Butler) Butler gives rise to serious damage in Fiji and is common in the S.W. Pacific area. Fusarium decemcellulareBiick (imperfect stage of Calonectria rigidiuscula (Berk. & Br.) Sacc.) was constantly associated with P. palmivora in disorders of cocoa but was not found to be a primary pathogen. Most Amelonado cocoa trees were resistant to canker but there were differences in the reactions of other Forastero and of Trinitario types. The F1 generation of a local Trinitario selection, itself resistant, showed segregation resulting in a proportion of very susceptible plants. Isolates of P. palmivora from black pod, canker and green twigs were equally pathogenic, both to pods and seedling stems. Sporangial dimensions, particularly the length/breadth ratio, differed from those reported elsewhere. It is uncertain whether the reason that cocoa canker is more serious in some countries than others is because of differences in the pathogenicity of P. palmivora strains to bark or the genetic differences of the cocoa grown. 相似文献
12.
Theobroma cacao—The Food of the Gods, provides the raw material for the multibillion dollar chocolate industry and is also the main source of income for about 6 million smallholders around the world. Additionally, cocoa beans have a number of other nonfood uses in the pharmaceutical and cosmetic industries. Specifically, the potential health benefits of cocoa have received increasing attention as it is rich in polyphenols, particularly flavonoids. At present, the demand for cocoa and cocoa‐based products in Asia is growing particularly rapidly and chocolate manufacturers are increasing investment in this region. However, in many Asian countries, cocoa production is hampered due to many reasons including technological, political and socio‐economic issues. This review provides an overview of the present status of global cocoa production and recent advances in biotechnological applications for cacao improvement, with special emphasis on genetics/genomics, in vitro embryogenesis and genetic transformation. In addition, in order to obtain an insight into the latest innovations in the commercial sector, a survey was conducted on granted patents relating to T. cacao biotechnology. 相似文献
13.
Jean-Justin Essia Ngang Germaine Yadang Christiant Pascal Kouebou Sandrine A. Youte Fanche Danielle L. Tsochi Kougan 《Biocontrol Science and Technology》2015,25(3):245-259
Thirteen Lactic acid bacteria strains isolated from fermenting cocoa and seven reference strains were used in order to assess their antifungal properties towards three ochratoxin A (OTA) producing fungi (Aspergillus carbonarius, Aspergillus niger and Aspergillus ochraceus). Furthermore, two of the isolates strains (A19 and A21) identified as belonging to the genus of Pediococcus as well as Lactobacillus plantarum B4496, Lactobacillus brevis 207 and Lactobacillus sanfranciscensis BB12 showed interesting in vitro broad antifungal activities towards the three ochratoxin-producing fungi with inhibition percentages ranging from 15% to 66.7%. Treatment of cell-free supernatant at 100°C affected antifungal activity suggesting that the main compounds responsible for this activity were of proteic nature, and hence could be bacteriocins. Application of isolate A19 in cocoa fermentation as starter inhibited the growth of each of the OTA-producing species. At the end of fermentation in boxes inoculated with A19, A. niger was not detectable while A. carbonarius concentration was found to be 2 Log CFU/g of wet beans. The assessment of the ochratoxin produced during fermentation of cocoa inoculated with A. carbonarius indicated that the use of isolate A19 as starter could reduce their level of growth so as to have only a toxin production of 0.0012 ± 0.0005 μg/kg after 40 days of storage, while this was 2.45 ± 0.35 μg/kg of fermented and dried cocoa beans in the absence of A19. This work is a contribution for the application of biological control of OTA-producing fungi during cocoa production. 相似文献
14.
Camila R. Cassano Götz Schroth Deborah Faria Jacques H. C. Delabie Lucio Bede 《Biodiversity and Conservation》2009,18(3):577-603
In southern Bahia, Brazil, large land areas are used for the production of cocoa (Theobroma cacao), which is predominantly grown under the shade of native trees in an agroforestry system locally known as cabruca. As a dominant forest-like landscape element of the cocoa region, the cabrucas play an important role in the conservation of the region’s biodiversity. The purpose of this review is to provide the scientific
basis for an action plan to reconcile cocoa production and biodiversity conservation in southern Bahia. The available research
collectively highlights the diversity of responses of different species and biological groups to both the habitat quality
of the cabrucas themselves and to the general characteristics of the landscape, such as the relative extent and spatial configuration of
different vegetation types within the landscape mosaic. We identify factors that influence directly or indirectly the occurrence
of native species in the cabrucas and the wider landscape of the cocoa region and develop recommendations for their conservation management. We show that the
current scientific knowledge already provides a good basis for a biodiversity friendly management of the cocoa region of southern
Bahia, although more work is needed to refine some management recommendations, especially on shade canopy composition and
density, and verify their economic viability. The implementation of our recommendations should be accompanied by appropriate
biological and socioeconomic monitoring and the findings should inform a broad program of adaptive management of the cabrucas and the wider cocoa landscape. 相似文献
15.
A study was made to determine the extent of morphological variation in Planococcoides jalensis (Laing), the most important mealybug vector of cocoa swollen shoot virus (CSSV) in West Africa, and to resolve if more than one Planococcoides species is present. Fourteen populations of P. njalensis collected on cocoa from different localities in Ghana and one population each on Gliricidia sepium (Jacq.) Steud and Coffea canephora Pierre were compared by measured and meristic female characters using two types of morphometric analysis, Discriminant Functional Analysis and Principal Component Analysis. The analyses showed that P. njalensis exhibited a wide range of intraspecific morphological variation, particularly in meristic characters, but failed to identify new Planococcoides species. The results are discussed in relation to the control of the mealybug vectors of CSSV and to the suitability of Gliricidia as a shade tree for cocoa. 相似文献
16.
To better understand how rainforest regenerates after agriculture I sampled the seed rain and seed bank, and set out seeds and seedlings, on microsites defined by distance to the forest in fields both in Puerto Rico and Ecuador. I found that (1) total seeds, species richness and life-form richness were twice as great in the Ecuador seed rain compared to Puerto Rico but Puerto Rico seeds were more evenly distributed among species and (2) total seedlings from the seed bank were similar between Puerto Rico and Ecuador, (3) the majority of seeds were lost to predation among all species and study sites, (4) seed disease was absent in P. aduncum and Miconia prasina, and no seeds germinated for Gonzalagunia spicata and P. riparia, (5) in Ecuador pathogenic disease claimed more seeds than germinated for all species, and Solanum ovalifolium was the only species that had seeds germinate but did not lose seeds to disease, (6) also in Ecuador, insect predation was significantly lower in the forest border for P. aduncum, and seed disease was significantly greater at the 10 m micro site for S. ovalifolium, (7) distance has a significant effect on seedling height and basal diameter, (8) losses of leaf area due to herbivory and pathogens were always low and (9) biomass and leaf specific mass were significantly reduced in the border and forest microsites. I conclude that Ecuador fields had more seeds, species, and life-forms than Puerto Rico fields, predation was the most severe post-dispersal seed filter in all fields, seeds that survived predation on Puerto Rico were lost either to disease or germination but to both mechanisms in Ecuador, all three seed mechanisms in Ecuador fields showed distance effects of seedling growth but not survivorship. 相似文献
17.
Clément D Lanaud C Sabau X Fouet O Le Cunff L Ruiz E Risterucci AM Glaszmann JC Piffanelli P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(8):1627-1634
We have constructed and validated the first cocoa (Theobroma cacao L.) BAC library, with the aim of developing molecular resources to study the structure and evolution of the genome of this perennial crop. This library contains 36,864 clones with an average insert size of 120 kb, representing approximately ten haploid genome equivalents. It was constructed from the genotype Scavina-6 (Sca-6), a Forastero clone highly resistant to cocoa pathogens and a parent of existing mapping populations. Validation of the BAC library was carried out with a set of 13 genetically-anchored single copy and one duplicated markers. An average of nine BAC clones per probe was identified, giving an initial experimental estimation of the genome coverage represented in the library. Screening of the library with a set of resistance gene analogues (RGAs), previously mapped in cocoa and co-localizing with QTL for resistance to Phytophthora traits, confirmed at the physical level the tight clustering of RGAs in the cocoa genome and provided the first insights into the relationships between genetic and physical distances in the cocoa genome. This library represents an available BAC resource for structural genomic studies or map-based cloning of genes corresponding to important QTLs for agronomic traits such as resistance genes to major cocoa pathogens like Phytophthora spp (palmivora and megakarya), Crinipellis perniciosa and Moniliophthora roreri.Communicated by J.W. Snape 相似文献
18.
Stephen L. Sain Kwabena K. Oduro Douglas B. Furtek 《Plant Cell, Tissue and Organ Culture》1994,37(3):243-251
Leaf strips from cocoa tree (Theobroma cacao L.) clones ICS-16 and SIC-5 were cocultivated with the supervirulent Agrobacterium tumefaciens strain A281-Kan. A281-Kan contains a wild-type Ti plasmid and an additional plasmid, pGPTV-Kan, which confers kanamycin resistance to transformed plant cells after integration and expression of the neomycin phosphotransferase II (nptII) gene. Transformed cells were selected on callusing medium containing 100 g ml-1 kanamycin. NptII assays confirmed that kanamycin-resistant cultures of ICS-16 and SIC-5 expressed the nptII gene, whereas control cultures did not. Genomic Southern blot analyses demonstrated single T-DNA insertions into ICS-16 and SIC-5. T-DNA/cocoa DNA border regions from transformed cultures were cloned and sequenced, revealing that in both transformed cell lines, the right T-DNA border was at the 5 end of the 25 bp right border repeat. Cocoa DNA probes from the T-DNA/cocoa DNA insertion sites were used in Southern blot analyses and showed that T-DNA from pGPTV-Kan had inserted into a unique region in ICS-16 and into a repetitive region in SIC-5. This study establishes that foreign genes can be inserted and expressed in cocoa using A. tumefaciens-mediated gene transfer. 相似文献
19.
Jerome Niogret Arni Ekayanti Paul E. Kendra Keith Ingram Smilja Lambert Nancy D. Epsky Jean-Philippe Marelli 《Entomologia Experimentalis et Applicata》2020,168(3):221-227
Insects ensure the survival of their offspring by depositing their eggs in suitable environments. Even generalist egg-laying insects often show preferences for specific host plants. The cocoa pod borer (CPB), Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillariidae), successfully infests and reproduces on relatively few host plants, but has a major economic impact only on cocoa, Theobroma cacao L. (Malvaceae). Choice tests were performed in the laboratory to compare the frequency of insect visits, the duration of the visits, and the number of eggs laid on the fruits for each combination of host plants tested – that is, cocoa clones or fruits of rambutan (Nephelium lappaceum L.), Fijian longan (Pometia pinnata JR Forst & G Forst, both Sapindaceae), and langsat (Lansium domesticum Corrêa, Malvaceae). Our laboratory study showed that, when given the choice, CPB significantly favored cocoa pods over other host fruits (rambutan, langsat, or Fijian longan). Females also deposited more eggs on unripe fruits than on ripe fruits of similar size. The preference to lay eggs on specific cocoa clones in the bioassays did not reflect the level of the clone resistance to CPB damage reported from the field. Consequently, oviposition preference of female CPB does not seem to be the main factor explaining field resistance of some cocoa clones to CPB infestation. 相似文献
20.
Intercropping is often promoted for effective mutualism between species, thus compensating for external inputs. However, for
optimal farm design resulting in superior production and nutrition, an accurate assessment of plant inter- and intra-specific
competition is required. In predominant shade tree-cocoa (Theobroma cacao) systems, inconclusive evidence remains on species interactions, limitations to resource availability and subsequent growth
and nutritional response, particularly in early growth. We examined cocoa biomass and foliar nutrition as well as nutrient
supply through rates of decomposition and N mineralization after 1-year growth. Our approach employed fertilization and mixed
planting treatments in an additive design of cocoa in monoculture (control), under artificial shade, and intercropped under
two separate shade species (Terminalia superba and Newbouldia laevis). Intercropping had no effect on cocoa biomass production in comparison to monoculture cocoa. However, artificial shading
stimulated foliage and root production both with and without fertilization, suggesting strong effects of light regulation
on growth in the absence of belowground competition. Nutritionally, intercropping suppressed K uptake in cocoa foliage as
K concentration was reduced by 20–25%, signifying dilution of this nutrient, presumably due to interspecific competition for
mobile elements. Foliar N content under N. laevis was raised, where N concentration kept up with growth under this intercropped species. Intercropping also delayed decomposition
rates, suggesting slower but sustained release of available nutrients into the topsoil. Cocoa under artificial shade, both
with and without fertilization, exhibited the greatest nutrient responses as compared to unfertilized monoculture cocoa, where
P uptake was stimulated most (175 and 112%), followed by K (69 and 71%), and then N (54 and 42%). Intercropping with shade
trees failed to increase cocoa biomass, however, nutrient uptake was sustained for N and P, suggesting low interspecific competition.
When fertilizers are undesirable or unavailable, intercropping of appropriately selected shade trees will not competitively
suppress early growth of cocoa but will improve light regulation and nutritional status of cocoa saplings. 相似文献