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Ceratocystis wilt, currently one of the main diseases of cacao tree, is difficult to control, and the priorities are to find sources of resistance and to develop quick methodologies for evaluation. A quick methodology has been developed, the leaf disc (LD) method. In the present study, the resistance to C. cacaofunesta of 39 clones of cacao (Theobroma cacao L.), under field conditions and through the LD method has been evaluated. Woody branches and leaf discs (1.5 cm diameter) were inoculated with 30 μL and 20 μL, respectively, of the suspension with 3 × 104 CFU/mL of Ceratocystis cacaofunesta. Sixty days after inoculation in the field, inoculated and control branches were collected to evaluate the length, width, and area of the lesions. In leaf discs, the number of perithecia formed was counted after four days. Twenty-six new sources of resistance to C. cacaofunesta were selected through both inoculation methods. The LD method can be applied to a higher number of genotypes (increasing selection intensity) and much earlier than the field method.

The cacao tree surface is a substrate for various microorganisms. However, the species which live on the surface have hardly been described. The aims of this study were to evaluate the diversity of native cacao yeasts and to investigate their possible interaction with Moniliophthora perniciosa. A total of 225 yeast strains were isolated from the surface of leaves, fruits, and flowers of 20 cacao genotypes selected as carriers of resistance genes to M. perniciosa and M. roreri, which are the causal agents of witches’ broom (WB) and frosty pod rot diseases (FPR), respectively. The yeast isolates were molecularly identified based on sequences of the D1/D2 and ITS1/ITS4 regions of the rDNA. A total of 20 taxa distributed into 11 genera was found: Hannaella (23), Cryptococcus (9), Candida (11), Hanseniaspora (4), Kwoniella (1), Occultifur (3), Rhodotorula (17), Pichia (2), Sporobolomyces (1), Wicherhamomyces (1), and Yamadazyma (1). Phylloplane tissues showed the greatest richness: 55% of species and 81.82% of identified genera. Six yeast strains (Candida orthopsilosis—LEV 225; Hanseniaspora uvarum—LEV 162, 210, 211; and Rhodotorula paludigena—LEV 166, 168) exhibited the desired traits for a BCA agent: antibiosis in cocultivation, antibiosis by volatile compounds, germination inhibition, and production of killer toxins. This study is the first to show the great diversity of yeasts found in the cocoa phytobiome and the discovery of at least six microorganisms with excellent potential as BCA against cocoa witches’ broom disease.

Xylosandrus compactus is one of the significant beetle pests on perennial crops, which has become an increasing problem on cacao productivity and sustainability in South Sulawesi, Indonesia. The beetle is also known as ambrosia beetle due to the obligate association with symbiotic fungi. The beetle and infested plant parts were collected from infested Theobroma cacao in the field, then the beetles identified morphologically and the associated fungi isolated. In this study, we found that the beetles attacked all stages of cocoa growing in the field such as seedling, young trees and mature trees with visible symptoms including the appearance of round bore holes with powdery frass on the tree trunk and branches. Also, we found the beetle being distributed in three main cocoa areas in South Sulawesi. According to the beetle´s characteristic, the female has the black colour of the body (head and elytra), size 1–2 mm and the shining slope. Six types of fungi were isolated from infected plant parts and the beetle X. compactus: Fusarium-like colony (two isolates), Lasiodiplodia-like colony, Ceratocyctis-like colony and Diaporthe-like colony (two isolates). Among the fungi isolated, several fungi were known as the pathogen. The beetle and its associated fungi are responsible for the typical dieback symptoms, decline and sudden death inflicted on a number of cacao trees. The occurrence of X. compactus on cacao tree is reported for the first time from Sulawesi, Indonesia. The beetle pest infestation will become a significant threat to the future of the cacao industry in Sulawesi, Indonesia.

The cumulative effects of cacao swollen shoot virus (CSSV) mild strains N1 and SS365B on growth and yield of cacao (Theobroma cacao L.) were evaluated in a 12-year field trial at the Cocoa Research Institute of Ghana (CRIG). The treatments consisted of mixed hybrid cacao plants inoculated with N1 or SS365B prior to sowing and a non-inoculated control. Growth of mild strain-inoculated cacao plants did not differ significantly from that of non-inoculated plants. However, growth of N1-inoculated cacao plants was significantly higher than that of SS365B-inoculated ones. The yield of N1-inoculated cacao plants did not differ significantly from that of the non-inoculated plants. However, yield of SS365B-inoculated plants was significantly lower compared to N1-inoculated and the non-inoculated plants. In comparison with the non-inoculated control, yield was 77% and 20% lower in SS365B- and N1-inoculated cacao plants, respectively. Virus indexing conducted over a period of six months on randomly collected budwood from the field revealed the presence of mixed infection of CSSV strains in the field. Cacao tree mortality did not differ among the treatments. These results provide further evidence that the CSSV mild strain N1 is milder in its effect on cacao growth and yield than SS365B and suggest that the former would be a more suitable candidate for cross protection in cacao.

O cacau é uma cultura perene de grande valor econômico na região norte brasileira, todavia apresentadificuldades de armazenamento e secagem que mantenham a qualidade do produto final. Com isso, o objetivo dopresente estudo foi dimensionar um equipamento para mensurar o ângulo de repouso de grão e analisar as sementes docacaueiro (Theobroma cacao L.), demonstrando suas características físicas ângulo de repouso, volume unitário,porosidade e esfericidade, com intuito de colaborar com futuros estudos de dimensionamento de silos, secadores ecorreias transportadoras. O trabalho foi conduzido no município de Tomé-Açu com a construção de um protótipo eposterior comparação a outro já estabelecido com 10 repetições, a esfericidade foi realizada com obtenção dos eixosortogonais de 15 sementes, o volume unitário considerou o volume de um elipsoide triaxial com 15 repetições,porosidade da massa de grãos foi determinada pelo método direto pela inserção de um fluido de óleo vegetal em umamassa conhecida. Os resultados foram submetidos ao teste de média (T) com p-valor

Chocolate and cocoa are manufactured from cacao beans produced by the cacao tree (Theobroma cacao). These products may contain cadmium (Cd), which originates from contaminated soil. Here, we surveyed the Cd concentrations in dark chocolate, milk chocolate, white chocolate and cocoa powder products purchased at retail stores in Japan, using inductively coupled plasma mass spectrometry. The Cd concentrations in these chocolate and cocoa powder products ranged from 0.00021 to 2.3 mg/kg and from 0.015 to 1.8 mg/kg, respectively. A weak positive correlation was found between the Cd concentration and the content of cocoa solids stated on the product labels. A comparison between these results and the maximum levels (MLs) set by the European Union revealed that the Cd concentrations in chocolate and cocoa powder products on the Japanese market exceeded the MLs for eight of the 180 chocolate products and 26 of the 140 cocoa powder products.

Cocoa, derived from the Theobroma cacao tree, contains, among other compounds, methylxanthines such as theobromine, and polyphenols mainly flavonoids belonging to the flavanol family. It has been reported that cocoa consumption is beneficial for cardiovascular and brain health, in the protection against cancer, but it remained to know what happen in allergic diseases. In this talk, I will explain the influence of a cocoa-enriched diet in two models of allergy in rats, including the effects on the anaphylactic response. Moreover, I will introduce the results using particular cocoa populations. Apart of the preclinical studies developed in rats, the results of an observational study in university students are included. In summary, although more studies are needed, it will be demonstrated the potential of cocoa intake in the prevention of allergic reactions.

Cocoa mirids, Sahlbergella singularis and Distantiella theobroma, are the most economically important insect pests of cocoa in West and Central Africa, where they can cause up to 40% losses in cocoa yields. Sahlbergella singularis is the most common species in Cameroon and was therefore targeted in this study. During a two-year trial in 15 cocoa plantations in Ayos and Konye, in the Centre and Southwest regions of Cameroon respectively, the most effective colour – white, purple or green – of sex pheromone traps was examined for integration into mirid management programmes. Similar temporal patterns in S. sahlbergella male trap catches were observed with all three colours, but the green trap caught more S. singularis (Ayos: 0.968 ± 0.091 [SEM]; Konye: 0.640 ± 0.076/trap/month) compared with purple traps (Ayos: 0.674 ± 0.068; Konye: 0.441 ± 0.058), and white traps (Ayos: 0.467 ± 0.049, Konye: 0.253 ± 0.041). Trap reflectance showed wavelength peaks typical for purple in both short (approximately 380–480 nm) and long wavelengths (>650 nm), and ~530 nm for green. Reflectance peaks exceeded 100% of the incident light in the 400–450 nm range from the white, suggesting the presence of optical brighteners. Trap catches support the hypothesis that S. singularis ocelli are more responsive to light of shorter wavelengths. Despite the low attractiveness of the sex pheromone to S. singularis, a optimisation of the colour of the trap can improve S. sahlbergella monitoring, mass trapping, and other control measures which could ultimately lead to reductions of insecticide use and to conservation of beneficial arthropods, particularly cocoa flower pollinators that are critical for improving cacao tree productivity.

SUMMARYIn Côte d'Ivoire, the world's largest cocoa producer, cacao (Theobroma cacaoL.) is usually grown from seed. The genetics consist of a mix of amelonado, trinitario and selected hybrids. This mix of varieties generates high phenotypic variabilities, including variability in tree productivity, within cacao populations in both smallholder and industrial plantations. Tree-to-tree variability in yield has been reported in cacao breeding trials under different environmental conditions. However, it has never been considered a limiting factor for agronomical performance of seedling-based cacao plantations. Around 10 000 cacao trees from seven plots under different environmental conditions in a cacao plantation in Côte d'Ivoire were monitored for 2 years. Pod production of individual trees was recorded and annual average tree pod yields were assessed. High heterogeneity in cacao-tree yields was observed in all plots, with coefficients of variation ranging from 56 to 102%. The distribution of cacao-tree yields in each plot was positively skewed. Analysis of these distributions showed that unproductive trees represented a significant proportion of cacao tree populations (7%), and the 20% least productive trees accounted for 3% of production. The 20% most productive trees were responsible for 46% of the total pod production of a plot. This heterogeneity reflects a major imbalance in the agronomical performances of low- and high-yielding trees and also represents possible efficiency gaps in seedling-based cacao plantations, which could be overcome through innovative corrective strategies, opening new pathways for improvement of cacao-based cropping systems.

En la Amazonia colombiana, el cultivo de cacao (Theobroma cacao L.) presenta bajo rendimiento debido a que la alta acidez del suelo limita el uso eficiente de nutrientes. Por lo tanto, esta investigación evalúa el efecto del encalamiento y la fertilización en un suelo ácido (Typic Udorthents) de la Amazonia colombiana sobre el uso eficiente de nutrientes (uen), en términos de la eficiencia agronómica (ea) y la eficiencia de recuperación del fertilizante (erf) para nitrógeno (N), fósforo (P) y potasio (K), y cuatro clones universales de cacao fino de sabor y aroma. Se utilizó un diseño en bloques completos al azar con arreglo factorial, siendo el factor A cuatro clones (a1: ICS-1, a2: CCN-51, a3: ICS-39, y a4: TSH-565) y el factor B cuatro niveles de fertilidad (b1: control absoluto; b2: suelo 90 días después de encalado (dde); b3: control absoluto más N - P - K, hasta alcanzar los requerimientos del cultivo; b4: b2 más N - P - K, hasta alcanzar los requerimientos del cultivo). Los resultados muestran que el encalado y la fertilización afectaron el uen y el rendimiento; mientras tanto, el más bajo rendimiento se presentó en b1 para todos los clones, sugiriendo que la fertilidad del suelo natural no es suficiente para el desarrollo del cultivo de cacao; además, el clon CCN-51 mostró mayor habilidad en el uso de nutrientes que los restantes clones. En este sentido, los cuatro clones respondieron de forma diferencial de acuerdo con la ea y la erf, evidenciando la influencia del genotipo y de las condiciones edafoclimáticas de la zona, así como las preferencias específicas de pH y nutrientes para cada clon.

The main ingredients of chocolate are usually cocoa powder, cocoa butter, and sugar. Both the powder and the butter are extracted from the beans of the cacao tree (Theobroma cacao L.). The cocoa butter represents the fat in the beans and possesses a unique fatty acid profile that results in chocolate’s characteristic texture and mouthfeel. Here, we used a linkage mapping population and phenotypic data of 3,292 samples from 420 progeny which led to the identification of 27 quantitative trait loci (QTLs) for fatty acid composition and six QTLs for fat content. Progeny showed extensive variation in fat levels and composition, with the level of palmitic acid negatively correlated to the sum of stearic acid, oleic acid, and linoleic acid. A major QTL explaining 24% of the relative level of palmitic acid was mapped to the distal end of chromosome 4, and those higher levels of palmitic acid were associated with the presence of a haplotype from the “TSH 1188” parent in the progeny. Within this region of chromosome 4 is the Thecc1EG017405 gene, an orthologue and isoform of the stearoyl-acyl carrier protein (ACP) desaturase (SAD) gene in plants, which is involved in fatty acid biosynthesis. Besides allelic differences, we also show that climate factors can change the fatty acid composition in the beans, including a significant positive correlation between higher temperatures and the higher level of palmitic acid. Moreover, we found a significant pollen donor effect from the variety “SIAL 70” which was associated with decreased palmitic acid levels.

The cacao tree (Theobroma cacao L.) is a species of great importance because cacao beans are the raw material used in the production of chocolate. However, the economic success of cacao is largely limited by important diseases such as black pod, which is responsible for losses of up to 30–40% of the global cacao harvest . The discovery of resistance genes could extensively reduce these losses. Therefore, the aims of this study were to construct an integrated multipoint genetic map, align polymorphisms against the available cacao genome, and identify quantitative trait loci (QTLs) associated with resistance to black pod disease in cacao. The genetic map had a total length of 956.41 cM and included 186 simple sequence repeat (SSR) markers distributed among 10 linkage groups. The physical “in silico” map covered more than 200 Mb of the cacao genome. Based on the mixed model predicted means of Phytophthora evaluation, a total of 6 QTLs were detected for Phytophthora palmivora (1 QTL), Phytophthora citrophthora (1 QTL), and Phytophthora capsici (4 QTLs). Approximately 1.77–3.29% of the phenotypic variation could be explained by the mapped QTLs. Several SSR marker-flanking regions containing mapped QTLs were located in proximity to disease regions. The greatest number of resistance genes was detected in linkage group 6, which provides strong evidence for a QTL. This joint analysis involving multipoint and mixed-model approaches may provide a potentially promising technique for detecting genes resistant to black pod and could be very useful for future studies in cacao breeding.

The cacao tree (Theobroma cacaoL.) is a species of great importance because cacao beans are the raw material used in the production of chocolate. However, the economic success of cacao is largely limited by important diseases such as black pod, which is responsible for losses of up to 30-40% of the global cacao harvest. The discovery of resistance genes could extensively reduce these losses. Therefore, the aims of this study were to construct an integrated multipoint genetic map, align polymorphisms against the available cacao genome, and identify quantitative trait loci (QTLs) associated with resistance to black pod disease in cacao. The genetic map had a total length of 956.41 cM and included 186 simple sequence repeat (SSR) markers distributed among 10 linkage groups. The physical “in silico” map covered more than 200 Mb of the cacao genome. Based on the mixed model predicted means ofPhytophthoraevaluation, a total of 6 QTLs were detected forPhytophthora palmivora(1 QTL),Phytophthora citrophthora(1 QTL), andPhytophthora capsici(4 QTLs). Approximately 1.77% to 3.29% of the phenotypic variation could be explained by the mapped QTLs. Several SSR marker-flanking regions containing mapped QTLs were located in proximity to disease regions. The greatest number of resistance genes was detected in linkage group 6, which provides strong evidence for a QTL. This joint analysis involving multipoint and mixed-model approaches may provide a potentially promising technique for detecting genes resistant to black pod and could be very useful for future studies in cacao breeding.

[EN] The cacao bud mite, Aceria reyesi (Nuzzaci 1973) (Eriophyidae), reported as causing serious damage to the cacao tree in Central and South America, is studied based on type specimens from Venezuela and adults and immatures specimens from Costa Rica, Ecuador and the Brazilian states of Amazonas, Bahia and Rondônia, offering a supplementary description and the first report of this species in Costa Rica and Ecuador. The probable origin and the potential geographic distribution of this noxious phytophagous mite is discussed, and a detailed morphological comparison between A. reyesi and the related eriophyid species Gymnaceria cupuassu Oliveira, Rodrigues & Flechtmann 2012, both associated with Theobroma species (Malvaceae) of economic importance, is given., Thanks are also due to Coordenadoria de Aperfeicoamento de Pessoal do Ensino Superior (CAPES) and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) Brazil, for the D.Sc. fellowhips to ANC. DN is a fellow researcher of CNPq.

In higher plants, sucrose synthase (Sus, EC 2.4.1.13) is widely considered as a key enzyme involved in sucrose metabolism. Although, several paralogous genes encoding different isozymes of Sus have been identified and characterized in multiple plant genomes, to date detailed information about the Sus genes is lacking for cacao. This study reports the identification of six novel Sus genes from economically important cacao tree. Analyses of the gene structure and phylogeny of the Sus genes demonstrated evolutionary conservation in the Sus family across cacao and other plant species. The expression of cacao Sus genes was investigated via real-time PCR in various tissues, different developmental phases of leaf, flower bud and pod. The Sus genes exhibited distinct but partially redundant expression profiles in cacao, with TcSus1, TcSus5 and TcSus6, being the predominant genes in the bark with phloem, TcSus2 predominantly expressing in the seed during the stereotype stage. TcSus3 and TcSus4 were significantly detected more in the pod husk and seed coat along the pod development, and showed development dependent expression profiles in the cacao pod. These results provide new insights into the evolution, and basic information that will assist in elucidating the functions of cacao Sus gene family.

The cacao tree (Theobroma cacao L.) is the only source for the key raw material in chocolate manufacturing. However, fresh cocoa seeds do not develop any chocolate flavour during chocolate manufacturing because they do not contain the precursors necessary. The latter are formed only during the fermentation process that the seeds are subjected to in the countries of origin. During this in most cases spontaneous fermentation of the fruit pulp surrounding the seeds, the pulp is degraded by yeasts and bacteria. This degradation results in heat and organic acid formation. Heat effect and tissue acidification are the key parameters guiding flavour precursor formation. Accordingly, not microorganisms themselves but exclusively their metabolites are necessary for successful fermentation. In the present study we subjected fresh cocoa seeds to three types of fermentation-like incubation with defined amounts of acetic acid, controlled temperature regime and in the absence of microorganisms. All raw cocoa samples were of high reproducible quality as determined by biochemical quality parameter analysis. We conclude that control of the heat effect and the acidity is the reason for these quality characteristics and that application of this technique may permit standardization and mechanization of cocoa fermentation.

Stem canker caused by Phytophthora palmivora and Phytophthora megakarya is a serious disease of cacao (Theobroma cacao L.). Studies of the genetics of resistance to this disease is important to identify an effective procedure to use in breeding resistant varieties. The objective of this study was to determine mode of inheritance, combining ability and heritability of resistance to stem canker in cacao. A 6 × 6 full diallel mating design was used to generate 36 F1 hybrids which were evaluated for resistance to stem canker with three replications under artificial inoculation with 1 mm2 agar plug taken from actively growing colonies of 10-day old cultures of P. palmivora and P. megakarya. Twelve months later, the canker lesions on outer bark of the stem of the seedlings were measured and the canker lesions inside was also measured after scraping the bark. There were significant (p 50%) of GCA suggest that additive gene effects were more important than non-additive gene effects. The overall direction of results showed that using one of the following parents: P1 (Alpha B36), P4 (T17/524) and P5 (T65/238) as the female produced progenies with better resistance to stem canker disease than when they were used as the male parent. The majority reflected the resistance level of the female parent, suggesting that resistance to stem canker in cacao is influenced by maternal inheritance. Cacao genotypes Alpha B36, T17/524 and T65/238 showed significant negative GCA effects for resistance to stem canker suggesting that these genotypes will transmit the trait to their progenies and therefore recommended for cacao breeding. Narrow sense heritability for stem canker resistance was low indicating large component of dominance effects and influence of environment in inheritance of resistance to stem canker in cacao. However, the very high broad sense heritability (0.99) coupled with large variation within the cacao tree population indicate that progeny testing and within family selection would be appropriate in breeding against stem canker in cacao.

In commercial terms, Criollo cacao trees (Theobroma cacao L.) are reputed to be the source of the commercial product (fermented and dried cocoa beans), which sells for the best price on the market. Nevertheless, the term “Criollo” has numerous meanings and interpretations depending on if it is used by commercial users or botanists, growers or breeders. Our review aims to specify which cocoas can justifiably carry the Criollo name. “Criollo” is a botanical subspecies of Theobroma cacao, i.e. Theobroma cacao subsp. cacao; however, the true Criollos form just one of the ten currently accepted genetic groups in the species. We thus provide an overview of genetic studies on the subject (published or not), along with what is currently known about “True Criollo” or “Ancient Criollo” cacao trees. In fact, there are few representatives in collections that are duly acknowledged to be true Criollos, particularly in the two International Cocoa Genebanks, where only seven clones are available. It is nonetheless certain that some true Criollos do exist in other collections but have not been formally identified (by genetic studies) as members of the Criollo genetic group. Likewise, some true Criollos, be they cultivated or subspontaneous, exist in Mexico and Central and South America (Venezuela and Colombia). However, certain clones called “modern Criollos”, which are closely related to the true Criollos but arise from hybridization with other genetic groups, are more common.

The aims of this research were to determine mass proportion of cacao pod, proximate composition of cacao pod shell, and effects of solvents and extraction parameters on the pigments yield from cacao pod shell. The results indicated that cacao pod contains shell, husk and bean with pulp at 8.15, 70.15 and 21.70% by fresh weight, respectively. Cacao pod shell has low content of crude protein, crude lipid and ash at 1.26, 0.16 and 2.30% by fresh weight and 9.69, 1.23 and 17.69% by dry weight, respectively. A suitable solvent is suggested to apply for extraction of pigments from cacao pod shell to be 80% methanol. Extraction temperature, extraction time and ratio of solvent to material are also recommended for obtaining both high absorbance of extract and pigments yield from cacao pod shell to be at 60C, 80 min and 10:1 (v/w), respectively. Practical Applications The cacao tree (Theobroma cacao L.) is wildly grown in tropical and subtropical areas. The annual amount of cacao pod shell in all over the world is estimated around 6.4 million tones; this shell amount is equal to 1.5 times of cacao bean amount to be produced. Therefore, the cacao pod shell is a potential source for pigment production to apply in food industry and other industries.

Les sols ferralitiques presentent des problemes de fertilite. Cette situation requiert une fertilisation raisonnee conciliant les exigences environnementales et les contraintes de production de plants. Cette etude vise a deceler l’apport de Jatropha curcas L. en matiere organique grâce au compostage et par addition de la sciure de bois. Les substrats ont ete mis dans des sachets en polyethylene pour recevoir les feves de cacaoyer ( Theobroma cacao L.) semees a plat. Ils se composent de 40% de compost de Jatropha curcas et de 60% de terre, puis de 40% d’un compost de Jatropha curcas avec la sciure de bois et 60% de terre. Le temoin est constitue uniquement de terre. Il ressort de la comparaison des parametres de germination et de croissance des plants qu’il existe uniquement une difference significative pour le diametre au collet dans le substrat 1 par rapport aux deux autres, selon le test de Newman-Keuls. Le substrat compose de J. curcas et de 60% de terre est le mieux indique pour la production de plants de cacaoyers sains et vigoureux dans ces conditions. Il serait souhaitable d’utiliser un compost mature lors des etudes complementaires. © 2019 International Formulae Group. All rights reserved Mots cles: Jatropha, cacaoyer, compost, pepiniere, germination, croissance English Title: Regeneration of the cocoa-tree ( Theobroma cocoa L.) on a substrate based on Jatropha curcas L. compost English Abstract The ferralitic soils present problems of fertility. This situation requires a reasoned fertilization reconciling the environmental requirements and the constraints of production of seedlings. This study aims at detecting the contribution of Jatropha curcas L. as organic matter thanks to the composting and by addition of the sawdust. The substrates were put in polyethylene bags to receive beans of cacao-tree ( Theobroma cocoa L.) sown flat. They are composed of 40% of compost of Jatropha curcas and 60% of soil, then of 40% of a compost of Jatropha curcas mixed to sawdust and 60% of soil. The witness is only made up of ground. It appears from the comparison of the germination and growth parameters of the seedlings that there exists only one significant difference for the diameter of the collet in substrate 1 compared to the two others, according to the test of Newman-Keuls. The substrate made up of J. curcas and 60% of soil is best indicated for the production of seedlings of healthy and vigorous cacao-trees under these conditions. It would be desirable to use a mature compost for the complementary studies. © 2019 International Formulae Group. All rights reserved Keywords: Jatropha , cacao-tree, compost, seedbed, germination, growth

Cacao (Theobroma cacao L.) is of significant economic importance in several tropical countries but its yield potentials are low mainly because of poor soil fertility especially low levels of potassium (K). Cacao has a high demand for K to maintain healthy growth and production. Knowledge of K use in cacao will help the development of suitable crop management practices and will aid breeding varieties adapted to environments with a limited soil K supply. Using a plant growth chamber, we investigated the growth and physiological traits among three cacao varieties at three levels of growth medium K (52, 156, and 469 mg·plant −1 ). Significant K effects were observed on growth traits including stem diameter, root length, chlorophyll b, and the ratio of chlorophyll a/b. Significant K effect was also found on carbohydrate metabolites, such as fructose, glucose, myo-inositol, raffinose and starch. However, no K effect was observed in other growth and physiological indicators, including biomass of seedling and net photosynthetic rate. There were significant genotype differences on seedling growth indicators, including stem diameter, stem height, total biomass, leaf biomass, leaf area, root length, chlorophyll a + b and carotenoids. Genotype difference was also found on all measured carbohydrate and starch metabolites, except maltose and raffinose. Results of this study indicate that although K plays a critical role in cacao tree growth and productivity, cacao may be less sensitive to K deficiency during the seedling stage. The present results improved our understanding about K and plants interaction in cacao seedlings, which is useful for crop management and germplasm utilization.

Cacao beans are produced in pods (fruits) of the trees of Theobroma cacao L. Cacao pods are produced after pollination of the small cauliflorous flowers covering the branches and trunk of the tree. Despite abundant flowering, only 0.5–5 % of cacao flowers become pollinated. Pollinated flowers then develop into immature pods, commonly known as cherelles. Despite abundant flowers and pod set of trees, few cherelles develop into mature pods. Up to 75 % of cherelles are lost to a thinning condition known as cherelle wilt. Additionally, cherelles can be lost at an early stage to insect, stramenopile, and fungal pests. This chapter will discuss the physiological changes in young fruit that cause cherelle wilt, as well as the physiological changes induced in pods caused by cherelle wilt. Lastly, the chapter will discuss whether there is a clear link between cherelle wilt and frosty pod rot caused by Moniliophthora roreri.

The worldwide threat to cacao production from the major pests and diseases continues to overshadow other problems of local or sporadic importance. Since the introduction of cacao (Theobroma cacao, L.) from its center of diversity in the Amazon forest into other regions of the world, several diseases, often regarded as minor pests, affects production of the crop in various cacao-producing regions and countries. These diseases may not be globally important, but may have very great local impact on production wherever they are found. Among these minor diseases are pink diseases caused by Erythricium salmonicolor, charcoal pod rot, caused by Lasiodiplodia theobromae, warty pod, a disease of unknown etiology, mealy pod caused by Trachysphaera fructigena, thread blight caused by Marasmius species, brown root rot caused by Phellinus noxious, and anthracnose of cacao caused by Colletotrichum species. Most often, the symptoms of cacao pod diseases are similar, and this often confuses farmers and extension personnel, resulting in either the overestimation or underestimation of these diseases in the field. This chapter discusses the situation and outlook, taxonomy, distribution, symptoms, modes of spread, and impact of these diseases on cacao. It also discusses control measures available for these diseases and future prospects for their management.

The C-biotype of Moniliophthora perniciosa is the causal agent of witches’ broom disease of Theobroma cacao L. While this disease is of major economic importance, the pathogenicity mechanisms and plant responses underlying the disease are difficult to study given the cacao tree’s long life cycle and the limited availability of genetic and genomic resources for this system. The S-biotype of M. perniciosa infects solanaceous hosts, particularly pepper (Capsicum annuum) and tomato (Solanum lycopersicum). These species are much more amenable for performing studies of mechanisms underpinning host-pathogen interactions as compared to cacao. A phylogenetic analysis performed in this study demonstrated that S-biotype strains clustered with C-biotype strains, indicating that these biotypes are not genetically distinct. A comparative analysis demonstrated that disease progression in tomato infected with the S- biotype is similar to that described for cacao infected with the C- biotype. The major symptoms observed in both systems are swelling of the infected shoots and activation and proliferation of axillary meristems. Cellular changes observed in infected tissues correspond to an increase in cell size and numbers of xylem vessels and phloem parenchyma along the infected stem. Observations revealed that fungal colonization is biotrophic during the first phase of infection, with appearance of calcium oxalate crystals in close association with hyphal growth. In summary, despite different host specificity, both biotypes of M. perniciosa exhibit similar disease-related characteristics, indicating a degree of conservation of pathogenicity mechanisms between the two biotypes.

The small resupinate genus Pseudolagarobasidium (Polyporales, Basidiomycota) presently comprises less than five species, all of which were described from tropical to subtropical regions, and two of which are root parasites on leguminous trees. The genus has recently been synonymized with Radulodon on morphological grounds, and the present study evaluates this proposal in a molecular context. Pseudolagarobasidium was found to constitute a well supported, monophyletic group excluding Radulodon and this synonymy is rejected. The ecological range of the genus spans saprotrophy to parasitism, and this study presents evidence that at least one lineage in Pseudolagarobasidium is endophytic in the cacao tree ( Theobroma cacao L.).

Cocoa butterfat and cocoa powder are key economic products from the seeds of the cacao tree (Theobroma cacao L.). In this study, 323 accessions (comprised mainly of Upper Amazon Forasteros and Refractarios) from the International Cocoa Genebank, Trinidad were characterized for one biochemical and five morphological seed-derived traits. The data were analysed using non-parametric statistics including correlation analysis to identify promising parental candidates for future cacao breeding programmes. The Upper Amazon Forastero group had the greatest proportion of accessions with high butterfat content in cotyledons, whereas Refractario and Trinitario groups tended to contain more accessions with high butterfat content per fruit. The correlation of butterfat content of cotyledons with the dry mass of cotyledons was inconsistent in significance and direction. However, consistent significant positive correlations between butterfat content per fruit, cotyledon size and dry mass of cotyledons were found. The results suggested that butterfat content is a likely trait for independent selection but that selection for increased cotyledon size could lead to the selection of genotypes for high butterfat yield. Several promising accessions exhibited favourable levels of multiple traits and MATINA 1/7, CRU 51, AM 2/91 [POU], CRU 133, EET 58 [ECU] and POUND 18/A [POU] could be recommended as good choices for parental stock in breeding programmes for improving cacao butterfat content.

Moniliophthora roreri, the cause of moniliasis or frosty pod rot, occurs on the neotropical rainforest genera Theobroma and Herrania. While this basidiomycete has had devastating effects on the cacao tree (T. cacao) in tropical America, where it is confined, little is known of its biogeography and intraspecific genetic variability. Here, AFLP and ISSR profiles of 94 isolates of M. roreri from across its geographic range in Central/South America were analyzed. The study provided limited evidence to support the hypothesis that M. roreri is capable of sexual reproduction. The highest levels of genetic diversity occurred in Colombia and not in Ecuador as originally believed. The fungus was broadly divided into five genetic groups. Two of these have a wide geographic range: Bolivar group (north of Santander in Colombia, eastern Venezuela, peripheral Ecuador, Peru), and Co-West group (western Colombia, central Ecuador, Central America). The other groups are all apparently endemic to Colombia (Co-East and Co-Central groups) or north-western Ecuador (Gileri group). We speculate that central/north-eastern Colombia may represent the centre of origin for M. roreri. Sequence data from the internal transcribed spacer region of the nuclear rDNA repeat were congruent with the AFLP/ISSR results, dividing M. roreri into two broad groups: the Orientalis group, comprising most isolates from the Co-East, Co-Central and Bolivar groups, and the Occidentalis group, comprising isolates from the Co-West and Gileri groups. The spread of M. roreri into new areas and countries mediated by human activity is discussed.

Theobroma cacao is a tropical understory tree that is one of the most important perennial crops in agriculture. Treasured by ancient civilizations in Mesoamerica for over 3,000 years, the cocoa bean now supports a multibillion-dollar industry that is involved in the production and commercialization of chocolate, a treat appreciated worldwide. The cacao tree is originally from the Amazon rainforest and is currently grown in more than 50 countries throughout the humid tropics, serving as a major source of income for over 40 million people. Each year, more than 3 million tons of cocoa beans are produced, mostly by smallholder farmers in areas of high biodiversity. Notably, the cacao tree does not require direct sunlight and naturally grows under the canopy of other, taller trees. This characteristic often encourages farmers to preserve existing forests and to plant additional trees to shelter their cacao plants [1], thereby reducing the environmental impacts of cacao cultivation. Despite its great importance, the cacao tree is affected by a number of untreatable diseases that reduce fruit production and threaten our global supply of cacao. Among them, witches’ broom disease (WBD) stands out as one of the most severe problems that affect this crop, accounting for production losses of up to 90%.

Oxidative stress plays a key role in the pathogenesis of different serious chronic diseases such as cancer, diabetes, cardiovascular and neurodegenerative disorders, etc. Recent research has been focused on the beneficial role of dietary antioxidants against oxidative stress both under in vitro and in vivo conditions. Theobroma cacao L. (cacao tree) is an evergreen tree which is native to South America. It is a plant of great economic importance and its seeds are commonly used to produce cocoa powder and chocolate. In addition to its uses in food industry, cocoa is a rich source of polyphenolic antioxidants. There is a plethora of in vitro and in vivo studies that report cocoa antioxidant capacity. The protective activity of cocoa seems to be due to its phytochemical constituents, especially catechins. However, bioavailability of cocoa polyphenolic constituents following oral administration is very low (nanomolar concentrations). In the present paper, we critically reviewed the available literature on the antioxidant and free radical scavenging activities of cocoa and its polyphenolic constituents. In addition to these, we provide brief information about cultivation, phytochemistry, bioavailability and clinical impacts of cocoa.

Black pod rot, caused by Stramenopiles of the genus Phytophthora, leads to serious production losses in all cocoa growing zones. In order to reduce the impact of these pests, preference is given to genetic control using resistant varieties, and sources of resistance are actively being sought, particularly in wild cacao trees. Surveys were undertaken in the natural cacao tree populations of south-eastern French Guiana between 1985 and 1995 and an abundant amount of plant material belonging to a particular genetic group, the "Guiana" group, was collected. A great deal of work has shown the merits of this genetic group as a source of resistance to Phytophthora palmivora and megakarya. We describe here the results of a global study to assess the resistance of the 186 clones in the "Guiana" group "core collection" to a Guianese strain of Phytophthora capsici (strain Reg 2-6). This study, which used an efficient methodology (fifteen series of tests on leaf discs and a statistical test adapted to the ordinal nature of the basic data), showed that the "Guiana" genetic group is a major source of resistance to P. capsici. Strain Reg 2-6 proves to be particularly virulent, as the Scavina 6 control, an international reference for resistance to Phytophthora, is not resistant to it. However, 24 clones of the "Guiana" group are, and 92 have proved to be more resistant than Scavina 6, thereby showing the interest of the group in genetically controlling P. capsici. Thus, of the clones in the Guiana group that are more resistant to P. capsici than Scavina 6, some, which are also resistant to P. palmivora and/or Phytophthora megakarya, and also displaying some other notable qualities, could be incorporated into cocoa genetic improvement programmes in countries where P. capsici is rife on cacao trees. (Resume d'auteur)

Trichoderma theobromicola and T. paucisporum spp. nov. are described. Trichoderma theobromicola was isolated as an endophyte from the trunk of a healthy cacao tree (Theobroma cacao, Malvaceae) in Amazonian Peru; it sporulates profusely on common mycological media. Trichoderma paucisporum is represented by two cultures that were obtained in Ecuador from cacao pods partially infected with frosty pod rot, Moniliophthora roreri; it sporulates sporadically and most cultures remain sterile on common media and autoclaved rice. It sporulates more reliably on synthetic low-nutrient agar (SNA) but produces few conidia. Trichoderma theobromicola was reintroduced into cacao seedlings through shoot inoculation and was recovered from stems but not from leaves, indicating that it is an endophytic species. Both produced a volatile/diffusable antibiotic that inhibited development of M. roreri in vitro and on-pod trials. Neither species demonstrated significant direct in vitro mycoparasitic activity against M. roreri.

The current evidence on the vasculoprotective effects of flavonoid-rich cocoa and chocolate is reviewed. Cocoa flavonoids are derived from the cacao bean, found in the fruit pod of the cacao tree, Theobroma cacao . There is growing evidence that dietary supplementation with flavonoid-rich cocoa and chocolate may be cardioprotective because of their interference in many pathophysiological mechanisms associated with atherosclerosis. Possible beneficial effects by cocoa flavonoids include: antioxidant properties, improvement in endothelial function, blood pressure lowering, decreased platelet activation and function, and modulation of immune function and inflammation. Larger, long-term clinical trials investigating the potential beneficial effects of purified flavonoids and food sources rich in flavonoids, including cocoa and chocolate, are certainly warranted.

Witches' broom disease, caused by Crinipellis perniciosa, is one of the major fungal diseases causing severe losses to cacao tree (Theobroma cacao L.) plantations in South America. One of the challenges associated with the understanding of the cacao and Crinipellis interaction in genomic studies is the isolation of intact nucleic acids. In this report, we describe a new, successful, and reliable procedure for the isolation of RNA from tissues of cacao tree, both infected and uninfected by Crinipellis. This protocol overcomes the problems associated with the very high amount of polyphenols and polysaccharides present in cacao organs that are not easily removed by conventional extraction procedures. The protocol requires few reagents, uses ultracentrifugation and inexpensive consumables, and can be easily applied in any laboratory. This method produced high-quality RNA that was suitable for subsequent purposes, such as reverse transcription PCR and cDNA library construction. We also report the first evidence of RNA isolation from cacao organs infected by C. perniciosa such as meristems and fruits.

It is increasingly recognized that microbiota affect host health and physiology. However, it is unclear what factors shape microbiome community assembly in nature, and how microbiome assembly can be manipulated to improve host health. All plant leaves host foliar endophytic fungi, which make up a diverse, environmentally acquired fungal microbiota. Here, we experimentally manipulated assembly of the cacao tree ( Theobroma cacao ) fungal microbiome in nature and tested the effect of assembly outcome on host health. Using next-generation sequencing, as well as culture-based methods coupled with Sanger sequencing, we found that manipulating leaf litter exposure and location within the forest canopy significantly altered microbiome composition in cacao. Exposing cacao seedlings to leaf litter from healthy conspecific adults enriched the seedling microbiome with Colletotrichum tropicale , a fungal endophyte known to enhance pathogen resistance of cacao seedlings by upregulating host defensive pathways. As a result, seedlings exposed to healthy conspecific litter experienced reduced pathogen damage. Our results link processes that affect the assembly and composition of microbiome communities to their functional consequences for host success, and have broad implications for understanding plant–microbe interactions. Deliberate manipulation of the plant–fungal microbiome also has potentially important applications for cacao production and other agricultural systems in general.

Cocoa is derived from the seeds of the fruit of the Theobroma cacao tree and has a complex chemical composition. A number of compounds found in cocoa have documented physiological effects. In particular, a significant body of literature supports the role of cocoa polyphenols in maintaining cardiovascular health. Future studies on cocoa should be aimed at elucidating the mechanisms whereby cocoa polyphenols modulate cardiovascular function and at identifying individual polyphenolic compounds within cocoa that are efficacious.

Moniliophthora perniciosa is a fungus that causes witches' broom disease (WBD) in the cacao tree (Theobroma cacao). The M. perniciosa genome contains different transposable elements; this promp- ted an evaluation of the use of its retrotransposons as molecular markers for population studies. The inter- retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymor- phism (REMAP) techniques were used to study the variability of 70M. perniciosa isolates from different geographic origins and biotypes. A total of 43 loci was amplified. Cluster analysis of different geo- graphical regions of C biotype revealed two large groups in the state of Bahia, Brazil. Techniques using retrotransposon-based molecular markers showed advantages over previously used molecular techniques for the study of genetic variability in M. perniciosa.

The cacao tree, Theobroma cacao L., a diploid fruit tree species (2n = 20) is the source of dried cocoa beans used as the main raw material in the manufacture of chocolate, confectioneries and some cosmetics product. Although native to the humid tropical regions of the northern parts of South America and the northern parts of Central America (Bartley 2005; Cheesman 1944; Cuatrecasas 1964, Motamayor 2008), the largest cultivation of cacao, an under-storey forest tree species takes place in West and Central Africa. Originally designated a member of the Sterculiaceae family (Purseglove, 1974), Theobroma cacao was recently re-classified into the Malvaceae plant family (Alverson et al., 1999). Since its first introduction in the early 19th century by the Portuguese and the Spaniards, the West and Central African region has become the largest producer accounting for some 70% of the world’s cocoa output (Figure 1) of more than 3.632 million metric tons (ICCO, 2010). The main producing countries are Cote d’Ivoire (43 % of global production), Ghana (14 %), Nigeria (6 %) and Cameroon (5 %) followed by Togo, Gabon, Sao Tome, Equatorial Guniea, Sierra Leone, Congo and Liberia. The major market for cocoa beans include The Netherlands, United States of America, United Kingdom, France, Germany, Spain, Italy, Japan, China and India.

BackgroundThe fermented dried seeds ofTheobroma cacao(cacao tree) are the main ingredient in chocolate. World cocoa production was estimated to be 3 million tons in 2010 with an annual estimated average growth rate of 2.2%. The cacao bean production industry is currently under threat from a rise in fungal diseases including black pod, frosty pod, and witches' broom. In order to address these issues, genome-sequencing efforts have been initiated recently to facilitate identification of genetic markers and genes that could be utilized to accelerate the release of robustT. cacaocultivars. However, problems inherent with assembly and resolution of distal regions of complex eukaryotic genomes, such as gaps, chimeric joins, and unresolvable repeat-induced compressions, have been unavoidably encountered with the sequencing strategies selected.ResultsHere, we describe the construction of a BAC-based integrated genetic-physical map of theT. cacaocultivar Matina 1-6 which is designed to augment and enhance these sequencing efforts. Three BAC libraries, each comprised of 10× coverage, were constructed and fingerprinted. 230 genetic markers from a high-resolution genetic recombination map and 96 Arabidopsis-derived conserved ortholog set (COS) II markers were anchored using pooled overgo hybridization. A dense tile path consisting of 29,383 BACs was selected and end-sequenced. The physical map consists of 154 contigs and 4,268 singletons. Forty-nine contigs are genetically anchored and ordered to chromosomes for a total span of 307.2 Mbp. The unanchored contigs (105) span 67.4 Mbp and therefore the estimated genome size ofT. cacaois 374.6 Mbp. A comparative analysis withA. thaliana, V. vinifera, andP. trichocarpasuggests that comparisons of the genome assemblies of these distantly related species could provide insights into genome structure, evolutionary history, conservation of functional sites, and improvements in physical map assembly. A comparison between the twoT. cacaocultivars Matina 1-6 and Criollo indicates a high degree of collinearity in their genomes, yet rearrangements were also observed.ConclusionsThe results presented in this study are a stand-alone resource for functional exploitation and enhancement ofTheobroma cacaobut are also expected to complement and augment ongoing genome-sequencing efforts. This resource will serve as a template for refinement of theT. cacaogenome through gap-filling, targeted re-sequencing, and resolution of repetitive DNA arrays.

Vascular Streak Dieback (VSD) disease of cacao (T heobroma cacao ) in Southeast Asia and Melanesia is cause d by a basidiomy cete ( Ceratobasidiales ) fungus Oncobasidium theobromae (syn. Thanatephorus theobromae). The most characteristic symptoms of the disease are green-spotted leaf chlorosis or, commonly since about 2004, necrotic blotches, followed by senescence of leaves beginning on the second or third ???ush behind the shoot apex, and blackening of infected xylem in the vascular trace s at the leaf scars resulting from the abscission of infected leaves. Eventually the shoot apex is killed and infected branches die. In susceptible cacao the fungus may grow through the xylem down into the main stem and kill a mature cacao tree. Infections in the stem of young plants prior to the formation of the ???rst 3 - 4 lateral branches usually kill the plant. Basidiospores released from corticioid basidiomata developed on leaf scars or along cracks in the main vein of infected leaves infect young leaves. The pathogen commonly infects cacao but there are rare reports from avocado. As both crops are introduced to the region, the pathogen is suspected to occur asymptomatically in native vegetation. The pathogen is readily isolated but cultures cannot be maintained. In this study, DNA was extracted from pure culture s of O. theobromae obtained fro m infected cacao plants sampled from Indonesia. The internal transcribed spacer regi on (ITS), consisting of ITS1, 5.8S ribosomal RNA and ITS2, and a portion of nuclear large subunit (L SU) were sequenced. Phylogenetic analysis of ITS sequences placed O. theobromae sister to Ceratobasidium anastomosis groups AG-A, AG-Bo, and AG-K with high posterior probability. Therefore the new combination Ceratobasidium theobromae is proposed. A PCR-based protocol was developed to detect and identify C. theobromae in plant tissue of cacao enabling early detection of the pathogen in plants. A second species of Ceratobasidium , Ceratobasidium ramicola, identi???ed through ITS sequence analysis, was isolated from VSD-affected cacao plants in Java, and is widespread in diseased cacao collected from Indonesia.

International audience; We sequenced and assembled the draft genome of Theobroma cacao, an economically important tropical-fruit tree crop that is the source of chocolate. This assembly corresponds to 76% of the estimated genome size and contains almost all previously described genes, with 82% of these genes anchored on the 10 T. cacao chromosomes. Analysis of this sequence information highlighted specific expansion of some gene families during evolution, for example, flavonoid-related genes. It also provides a major source of candidate genes for T. cacao improvement. Based on the inferred paleohistory of the T. cacao genome, we propose an evolutionary scenario whereby the ten T. cacao chromosomes were shaped from an ancestor through eleven chromosome fusions.

A importância econômica do cacaueiro se deve, principalmente, à produção de frutos, dos quais se extraem sementes que servem como matéria prima para a fabricação do chocolate. Vários fatores podem interferir na produção, porém as características reprodutivas do cacaueiro e sua influência na frutificação não têm sido intensamente estudadas. Além disso, alguns genótipos são autoincompatíveis, mas clones autocompatíveis são encontrados em populações comerciais. Com o objetivo de comparar a performance do pólen e o modo de reprodução entre clones autocompatíveis CCN51 e autoincompatíveis TSH1188, foram realizadas estudos de germinação in vitro (utilizando-se dois testes) e da razão pólen-óvulo (P:O). O Teste 1 (meio de cultura sem alguns elementos essenciais e com maior concentração de sacarose) proporcionou melhores resultados de germinação do pólen, com médias acima de 77%, enquanto que com o Teste 2 o máximo de pólen germinado foi, em média, de 39,95%. O percentual de pólen germinado in vitro foi maior em plantas autoincompatíveis. Com base na razão P:O, ambos os clones foram classificados como autógamos obrigatórios, o que foi considerado um desvio da classificação de Cruden. An adequate level of pollinization is necessary for abundance in fruit production. The economic importance of the cacao trees is mainly found in its fruit production from which the seeds are extracted and used as raw material in chocolate manufacturing. Several factors can interfere with the production, but the reproductive characteristics of the cacao tree and their influence on the fructification have not been extensively studied. Moreover, some genotypes are self-incompatible, but self-compatible clones are also found in the commercial populations. In order to compare the pollen performance and the reproduction process between the self-compatible clones CCN51, and the self-incompatible clones TSH1188 clones, were made studies of germination in vitro (using two tests) and the pollen grain-ovule ratio (P:O). Test 1 (media without some essential elements but with a higher concentration of sacarose) gave better results for pollen germination, with averages higher than 77%, while in test 2 the highest was 39.95%. The percentage of pollen germinated in vitro was higher in self-incompatible plants. Based on the P:O ratio, both clones were classified as obligate autogamous, which was considered a deviation from Cruden classification.

Les cacaoyers spontanés (Theobroma cacao L.) du sud-est de la Guyane française représentent une part notable de la diversité génétique de l'espèce. Plusieurs prospections ont permis la collection de nombreuses accessions, permettant l'étude de la structuration de la diversité dans les populations naturelles. Cent quatre-vingt-neuf cacaoyers spontanés, issus de 18 populations, ont été génotypés grâce à un séquenceur capillaire. Les profils obtenus avec 15 marqueurs SSR ont permis d'analyser les variations intra et inter populations, et leurs relations avec des clones témoins. La richesse allélique globale est de 4,87 allèles par locus, mais de 2,4 en moyenne dans les populations; la diversité génique est de 0,368 et l'hétérozygotie observée est faible (0,160). Une importante structuration existe dans la métapopulation de cacaoyers spontanés Guyanais, avec un Fst de 0,20, qui pourrait s'expliquer par les caractéristiques biologiques du cacaoyer et les événements climatiques ayant affecté les forêts guyanaises au Quaternaire.

Rainwater and throughfall water were evaluated nutrient sources for a cacao (Theobroma cacao L.) ecosystem in Ilheus, Bahia, Brazil. Rainwater was collected for 35 months in an open area. Throughfall was collected on shaded and unshaded cacao plots. The shade trees were Erythrina and some species of Ficus. In evaluating the results, the agricultural year was subdivided into winter (April–September) and summer (October–March). It was found that the concentrations of N, P, K, Ca and Mg, in both rainwater and throughfall varied between and for periods within years. The nutrient concentrations in the throughfall also varied with the presence or absence of shade trees in the cacao plantation. The rainwater contributions of N, Ca, Mg, K, and P reached averages of 43, 21, 9, 9 and nearly 1 kg ha−1 year−1, respectively. The averages of annual throughfall recycling to the soil in the unshaded and shaded plots, respectively, were 141 and 47 kg K ha−1, 28.4 and 21 kg Ca ha−1, 21 and 12.2 kg Mg Ha−1, and 13 and 8 kg P ha−1. The throughfall K and P appears to be rapidly absorbed by the cacao roots, whilst most of the Mg, Ca, and N are retained in the soil. The throughfall and leaf fall constitute the most important nutrient recycling processes in the cacao ecosystem, which appears to be self-sufficient in terms of its nutrient requirements.

Endophytic isolates of Trichoderma species are being considered as biocontrol agents for diseases of Theobroma cacao (cacao). Gene expression was studied during the interaction between cacao seedlings and four endophytic Trichoderma isolates, T. ovalisporum-DIS 70a, T. hamatum-DIS 219b, T. harzianum-DIS 219f, and Trichoderma sp.-DIS 172ai. Isolates DIS 70a, DIS 219b, and DIS 219f were mycoparasitic on the pathogen Moniliophthora roreri, and DIS 172ai produced metabolites that inhibited growth of M. roreri in culture. ESTs (116) responsive to endophytic colonization of cacao were identified using differential display and their expression analyzed using macroarrays. Nineteen cacao ESTs and 17 Trichoderma ESTs were chosen for real-time quantitative PCR analysis. Seven cacao ESTs were induced during colonization by the Trichoderma isolates. These included putative genes for ornithine decarboxylase (P1), GST-like proteins (P4), zinc finger protein (P13), wound-induced protein (P26), EF-calcium-binding protein (P29), carbohydrate oxidase (P59), and an unknown protein (U4). Two plant ESTs, extensin-like protein (P12) and major intrinsic protein (P31), were repressed due to colonization. The plant gene expression profile was dependent on the Trichoderma isolate colonizing the cacao seedling. The fungal ESTs induced in colonized cacao seedlings also varied with the Trichoderma isolate used. The most highly induced fungal ESTs were putative glucosyl hydrolase family 2 (F3), glucosyl hydrolase family 7 (F7), serine protease (F11), and alcohol oxidase (F19). The pattern of altered gene expression suggests a complex system of genetic cross talk occurs between the cacao tree and Trichoderma isolates during the establishment of the endophytic association.

Combining crop plants with other plant species in agro-ecosystems is one way to enhance ecological pest and disease regulation mechanisms. Resource availability and microclimatic variation mechanisms affect processes related to pest and pathogen life cycles. These mechanisms are supported both by empirical research and by epidemiological models, yet their relative importance in a real complex agro-ecosystem is still not known. Our aim was thus to assess the independent effects and the relative importance of different variables related to resource availability and microclimatic variation that explain pest and disease occurrence at the plot scale in real complex agro-ecosystems. The study was conducted in cacao (Theobroma cacao) agroforests in Cameroon, where cocoa production is mainly impacted by the mirid bug, Sahlbergella singularis, and black pod disease, caused by Phytophthora megakarya. Vegetation composition and spatial structure, resource availability and pest and disease occurrence were characterized in 20 real agroforest plots. Hierarchical partitioning was used to identify the causal variables that explain mirid density and black pod prevalence. The results of this study show that cacao agroforests can be differentiated on the basis of vegetation composition and spatial structure. This original approach revealed that mirid density decreased when a minimum number of randomly distributed forest trees were present compared with the aggregated distribution of forest trees, or when forest tree density was low. Moreover, a decrease in mirid density was also related to decreased availability of sensitive tissue, independently of the effect of forest tree structure. Contrary to expectations, black pod prevalence decreased with increasing cacao tree abundance. By revealing the effects of vegetation composition and spatial structure on mirids and black pod, this study opens new perspectives for the joint agro-ecological management of cacao pests and diseases at the plot scale, through the optimization of the spatial structure and composition of the vegetation.

For centuries, elite people in ancient Mesoamerica drank a foaming beverage made from the ground beans of the tropical Theobroma cacao tree. Served in cylindrical jars and spouted pitchers in grand cities and temples, this was a chocolate drink steeped in ritual. North America had its great prehistoric cities, too—for example, ancient Cahokia near St. Louis, Missouri, or Chaco Canyon in New Mexico—but for years most archaeologists assumed little contact between the cultures. Chocolate may change that picture, with the recent discovery of subtle residues of it in pots from Cahokia. Added to similar evidence from the Southeast and Southwest, the findings suggest regular trade in cacao—and movements of the people who imbued it with significance—between ancient Mesoamericans and their northern neighbors, says Dorothy Washburn, an archaeologist at the University of Pennsylvania Museum of Archaeology and Anthropology and co-author of a new paper. But the new work also reveals the complexities of such residue analysis, she says: Low levels of a certain alkaloid of T. cacao may be due to modern contamination.

The study of interactions between cacao (Theobroma cacao) and coconut (Cocos nucifera) in Lampung, Indonesia, examined different combinations of age, plant lay-out, planting chronology and choice of planting material under changing environmental conditions. Four coconut-cacao intercropping trials were used to assess the performance of each intercrop under limiting or non-limiting environmental conditions. In intercropping experiments with young cacao trees and young coconut palms, delayed cacao tree development and reduced yields were observed. When coconut palms were aged five years or over, coconut and cacao growth were satisfactory under virtually normal environmental conditions; death rates remained reasonable and yield percentages differed little from those of the monocultures for each crop. The performance of both plants, however, changed when water became a limiting factor.

The seeds of the cacao tree, Theobroma cacao L. (Sterculiaceae), provide the basis of the multibillion dollar chocolate industry. A native of the Neotropics, cacao grows as an understory tree in the rainforest. Flowers and fruit are produced directly from the stem, with pods attaining lengths of approximately 15–25 cm, each containing 30–40 seeds (Pence 1989).