Cacao Plants Research Articles

Topical Antioxidant Cocoa Polyphenol Skin Penetration.

Cocoa powder derived from the Theobroma cacao plant is rich in polyphenols, such as catechin and epicatechin. These polyphenols are strong antioxidants when consumed orally; however, their ability to enter the stratum corneum following the topical application has never been demonstrated. The objective of this study was to demonstrate the deposition of catechin and epicatechin in the stratum corneum following the topical application of 6% aqueous cocoa powder 1 and 2 h after application. Five healthy female subjects aged 25-60 years were enrolled. A 6% aqueous cocoa powder solution was prepared and applied to two randomized designated spots on the left forearm. 2 cc of the solution was applied under a ¼-inch gauze square covered with plastic wrap and held in place with a Coban dressing. The 15 d-squame 7/8-inch circular tape strips were applied to the predetermined area on the forearm 1 h and 2 h after application of the 6% cocoa powder solution. The tape strips were immediately placed in a -80°C freezer for storage until extraction in preparation for LC-MS evaluation for catechin and epicatechin levels. More catechin and epicatechin were detected at 2 h than 1 h for both compounds, although the difference was not statistically significant. Higher epicatechin levels than catechin levels were detected from the cocoa powder at both time points. This is consistent with published data from food-grade cocoa powder. It is detected that 6% aqueous cocoa powder delivers the antioxidants catechin and epicatechin to the stratum corneum 1 h and 2 h after topical application.

Landscape forest cover and local vegetation structure mediate multitrophic relationships but not the leaf damage in cacao trees

Cacao is the most important agricultural product in the southern region of Bahia state, Brazil, with 70 % of its production occurring under the traditional agroforestry where cacao is mostly shaded by native trees. This traditional system allows to reconcile the production with the maintenance of the portion of original biodiversity. However, increased deforestation and intensified agroforestry management aimed at boosting productivity may impact the diversity of native species and the services they provide. In this context, our aim was to disentangle the role of landscape forest cover and the local vegetation complexity on predation of caterpillars and herbivory of cacao plants located in agroforestry systems. The study was conducted across 18 cacao agroforest sites in southern Bahia located in landscapes with different amounts of forest cover. We assessed predation rate using dummy caterpillars, sampling understory birds and arthropods and collected leaves of cacao trees to analyze damage by herbivory. We also measured shading levels and the abundance of cacao trees in each agroforestry. Predation pressure on dummy caterpillars was positively influenced by the abundance of total predators and the level of landscape forest cover and negatively by the number of cacao trees. Even so, we found no evidence that landscape, local features or the actual invertebrate assemblages (predators or herbivores) influenced the cacao leaf damage. The findings highlight the multifaceted interactions between ecological factors, predation pressure, and leaf damage within cacao agroforestry systems.

The morphological performance of indonesian cacao plant as a result of mutation using gamma-ray

Abstract The diversity of cacao (Theobroma cacao L.) genetic resources can be increased through mutation breeding. The study aimed to determine the LD20 and LD50 information of gamma-ray irradiation on cacao seeds. The research was conducted from January to December 2020 in the greenhouse and the Integrated Laboratory of The Indonesian Industrial and Beverage Crops Research Institute (IIBCRI). The cacao seeds were obtained from a prospective mother garden belonging to the IIBCRI. Seeds were applied at the Isotope and Radiation Application Center (PAIR) BATAN. Five bulk cacao clone seeds, including Sulawesi 1, Sulawesi 2, MCC 01, MCC 02, and SCA 6, were irradiated at doses of 0, 20, 40, 60, 80, and 100 Gy. The observed characteristics include the percentage of germination, root length, number of leaves, leaf length, leaf width, petiole length, plant height, and leaf shape. Each clone exhibited different LD20 and LD50 values based on the percentage of germination. The LD20 ranged from 5.83 Gy (Sulawesi 1) to 11.79 Gy (SCA 6) and LD50 ranged from 19.58 Gy (Sulawesi 1) to 25.07 Gy (SCA 6). Morphological changes in leaf shape were also observed. Increasing the dose of gammarays decreased the average values of root length, number of leaves, leaf length, leaf width, petiole length, and plant height of five cacao clones. The optimal dose of gammaray irradiation for cacao seeds was found to be 20Gy. In the future, cacao mutants will be used as parents in a plant breeding program.

In-vitro test of five cacao (Theobroma cacao L.) F1 hybrids to Phytophthora palmivora

Abstract Phytophthora palmivora causes black pod diseases (BPD) in cacao pods and reduces up to 25% of cacao yield. Cacao plant breeding aims to produce superior plants resistant to BPD. This research intended to confirm the pathogen through morphological characteristics and molecular identification, as well as evaluate the resistance level of five cacao F1 hybrids against P. palmivora in-vitro. The morphology of colonies was observed visually and microscopically, while sequencing analysis was performed using primer-specific pairs YPh1F/2R, followed by phylogenetic analysis. Resistance studies were using five cacao F1 hybrids: 8-7 (1), 9-7 (1), 1-11 (1), 5-1 (2), 2-8 (3), and BL 50 as the comparison variety using leaf disc methods. The research findings were Phytophthora sp. colonies on carrot medium showed faster growth than on potato dextrose agar. The microscopic observation showed the presence of pear-shaped spores. Likewise, the phylogenetic analysis confirmed that this pathogen was P. palmivora, with a high similarity of 98.78%. In the in-vitro study, two clones categorized as resistant, with clones 2-8 (3) having the lowest severity score. Other clones, including comparison varieties, have moderately resistant levels. The results are important information in assembling superior cacao clones resistant to P. palmivora.

Association between bacterial community and cadmium distribution across Colombian cacao crops.

Cadmium (Cd) content in cacao crops is an issue that generates interest due to the commercialization of chocolate for human consumption. Several studies provided evidence about the non-biological factors involved in its translocation into the cacao plant. However, factors related to this process, including soil bacterial community composition (SBCC), still need to be addressed. It is well known that soil microbiome could impact compounds' chemical transformation, including Cd, on the field. Here, we found the first evidence of the link between soil bacterial community composition and Cd concentration in cacao soils and seeds. It highlights the importance of including the variation of bacterial communities to assess the factors driving the Cd translocation into cacao seeds. Moreover, the results highlight the relevance of the spatial heterogeneity within and across cacao farms, influencing the variability of Cd concentrations.

Comparative assessment of copper pollution, bioavailability, and ecological risks in soil-cacao systems under organic versus conventional management

The continuous use of fertilizers and fungicides has triggered copper (Cu) contamination in cacao soils in Ghana, which is a critical issue for the ecological risk and health safety of cacao products. In this study, we investigated Cu pollution, bioavailability, and ecological risk in soil and determined the Cu levels in the cacao nib, shell, and pod husk. Soils were collected at two soil depths (0–15 ​cm and 15–30 ​cm) from 20 cacao farms, under conventional (CCM: chemical-based fertilizers) and organic (OCM: organic-based fertilizers) management practices together with pods. The total Cu concentration ranged from 67.6 to 96.8 ​mg ​kg−1 in OCM and 28.5–33.9 ​mg ​kg−1 in CCM soil, which decreased with soil depth. The enrichment factor revealed minimal Cu enrichment, which was attributed to anthropogenic activity (fungicide and fertilizer applications). The contamination factor and geoaccumulation index values were low for the CCM soils, and moderate for the OCM soils. Both management systems pose a low potential ecological risk to soil biota activity. Bioavailable Cu extracted with CaCl2, NH4OAc, and DTPA was dominant in CCM soil and decreased with soil depth. The Cu concentration in cacao plants decreased in the order of shell > pod husk > nib, with nib-Cu being below the threshold (50.0 ​mg ​kg−1) of contamination. The results from the pairwise correlation analysis show that CaCl2-available Cu is better for evaluating the Cu content in cacao plants. This study reveals the pollution levels associated with cacao management practices, thus providing valuable insights for developing appropriate mitigation strategies.

Successful shoot tip grafting of cacao (Theobroma cacao L.) due to the application of plant growth regulators on various concentrations

Cacao plays an important role in the Indonesia economy. Therefore, its production and area expansion have to increase to achieve maximum cacao productivity by the quality and superior cacao clones. Shoot tip grafting is one of the propagation methods to obtain superior cacao plants by applying Plant Growth Regulators (PGRs). Research on the effect of several PGRs with various concentrations on cacao (Theobroma cacao L.) shoot tip grafting was conducted at the Integrated Innovation Farmer Group, Belubus, Sungai Talang Village, Guguak District, Lima Puluh Kota Regency, West Sumatra from February until June 2022. This study aimed to determine the interaction between PGR type and concentration on the grafting success and growth of cacao shoot tip grafted seedling. The research was designed by a Factorial Completely Randomized Design with three replications. The first factor was the type of PGR, i.e., synthetic PGR (BAP), young corn seed extract, shallot extract, and young coconut water. The second factor was the concentration of PGR, i.e., 0%, 25%, 50%, 75% and 100%. The results showed an interaction between PGRs with some concentrations on the number of shoots, shoot length, and leaf length on the grafted cacao seedling. The natural PGR from young coconut water at a concentration of 75% gave the best effect on the number of shoots (3.33 shoots) and shoot length (24.50 cm) of cacao seedling.

Evaluation of homeopathic treatments for the control of moniliasis (Moniliophthora roreri Samson & Benny), in cacao (Theobroma cacao L.)

Objective: To evaluate low- and high-dilution homeopathic products in the incidence of Moniliophthora roreri in cacao plants. Design/Methodology/Approach: The plantation was studied using a randomized block design with three repetitions and six treatments: Homeopathic nosode 12C and 200C, Cacao homeopathic combination remedy 12C and 200C, water control, and control sample, with applications every 15 days. The studied variables were: Number of flowers, number of healthy and diseased cherelles, number of healthy and diseased pods, ripe pod weight, fresh grain weight, and leaf color. Results: A significant difference was observed in the number of flowers with Cacao combined remedy 200C during November-December 2018. A significant difference was observed in leaf color with Cacao combined remedy 200C during October 2018-January 2019 and with Cacao combine remedy 12C in October 2018. No significant difference was found in treatments for number of healthy and diseased cherelles, number of healthy and diseased pods, ripe pod weight, and fresh grain weight. Study limitations/Implications: The treatment application period was short. In order to obtain more convincing results, a one-year application period prior to evaluation is suggested. Findings/Conclusions: The Cacao combined remedy 200C had a positive effect on the number of flowers during the period in which flowering decreases due to environmental conditions and on leaf greenness during four consecutive months of evaluation. Cacao homeopathic combination remedy 12C showed a significant difference for the latter variable only in October 2018. This suggests that the low-dose homeopathic medication and a high centesimal potency promotes a better response of the cacao plant to an acute disease such as moniliasis.

Morphology, phylogeny and pathogenicity of fungal species associated with leaf blight and stem canker of Theobroma cacao in Malaysia

AbstractMalaysia stands prominently among Asia's key cocoa‐producing countries. In the cocoa season of 2022–2023, Malaysia demonstrated its contribution to the industry, with an estimated production of around 364,000 tonnes of cacao bean grindings. Nonetheless, fungal diseases pose undeniable challenges to the cocoa sector. Extensive sampling conducted between September 2018 and March 2019 across multiple states in Malaysia revealed concerning symptoms of leaf blight and stem canker affecting Theobroma cacao plants. The aim of this study was to identify and characterize fungal species associated with leaf blight and stem canker of T. cacao in Malaysia through morphological, molecular and pathogenicity analyses. Morphological and molecular phylogenetic analyses using multiple DNA regions (rDNA internal transcribed spacer [ITS], TEF1 and TUB2) were performed and identified 40 fungal isolates found in this study as Diaporthe tulliensis (17 isolates), Fusarium solani (seven isolates), Fusarium proliferatum (six isolates) and Neopestalotiopsis clavispora (10 isolates). Pathogenicity tests with mycelial plugs and wound treatments showed that D. tulliensis and N. clavispora were responsible for causing leaf blight whereas D. tulliensis, F. solani and F. proliferatum caused stem canker of T. cacao. The present study provides insights into disease aetiology and symptomatology that may be useful in planning effective disease management for the host plant.

Population Abundance and Frequency of Visits Forcipomyia spp. (Diptera: Ceratopogonidae) on Cocoa Plantations in Lima Puluh Kota District, Indonesia

Forcipomyia spp. is a pollinator insect on cacao plants that belongs to the Ceratopogonidae Family, Diptera Order. The objectives of this research were to determine the abundance of the insect population of Forcipomyia spp. in Lima Puluh Kota District and to determine the frequency of visits of those insects to cacao flowers. This research was conducted on a small smallholder plantation in Sungai Talang Village, Lima Puluh Kota District. Then, the samples obtained were identified at the Andalas University Laboratory. This research was conducted using a survey method and purposive sampling technique. Five cacao plants were selected in each plot of land, and then three flower beds per plant were selected to bloom. Sampling was carried out by installing yellow sticky traps. The insects obtained were put into a collection bottle filled with 96% alcohol to preserve those insects, and then the abundance of Forcipomyia spp. Insects were calculated. The research results showed that the highest insect abundance was in Jorong Guguak Nunang: 1.260 individuals, then in Jorong Bukik Apik: 1.061 individuals and the lowest was in Jorong Boncah: 1.045 individuals. The highest frequency of visits was in the morning, with an average of 648 individuals/60 minutes. The insect diversity index based on the Shannon-Wienner Diversity Index in Jorong Guguak Nunang was 1,97; in Jorong Boncah, it was 2,21; in Jorong Bukik Apik was 1,88, and all of it is in the medium diversity level category.

Description and Pathogenicity of Colletotrichum kapreanum sp. nov, a Cherelle Wilt Pathogen Belonging to the Gigasporum Species Complex.

Similar to cacao pod rot, cherelle wilt decreases production from cacao fields. Among all known fungal pathogens of the cacao, Colletotrichum spp. are common infectious agents that affect the cherelles and pods of cacao; thus, cacao diseases are often classified by stage. Therefore, knowing whether these pathogens are common in both fruit stages is necessary for implementing disease control measures. Symptoms of cherelle wilt were found in cacao plants in Pangasinan, Philippines, in 2022. The fungal strain obtained from the lesion was found to be pathogenic towards cherelles, but not towards pods. The strain was classified as an unknown species belonging to the gigasporum species complex, based on the morphological and molecular phylogenetic analyses of ITS, GAPDH, CHS1, ACT, and TUB2. We propose Colletotrichum kapreanum sp. nov. as a causal agent of cacao cherelle wilt, but not pod rot.

Cacao sustainability: The case of cacao swollen-shoot virus co-infection.

The cacao swollen shoot virus disease (CSSVD) is among the most economically damaging diseases of cacao trees and accounts for almost 15-50% of harvest losses in Ghana. This virus is transmitted by several species of mealybugs (Pseudococcidae, Homoptera) when they feed on cacao plants. One of the mitigation strategies for CSSVD investigated at the Cocoa Research Institute of Ghana (CRIG) is the use of mild-strain cross-protection of cacao trees against the effects of severe strains. In this study, simple deterministic, delay, and stochastic ordinary differential equation-based models to describe the dynamic of the disease and spread of the virus are suggested. Model parameters are estimated using detailed empirical data from CRIG. The modeling outcomes demonstrate a remarkable resemblance between real and simulated dynamics. We have found that models with delay approximate the data better and this agrees with the knowledge that CSSVD epidemics develop slowly. Also, since there are large variations in the data, stochastic models lead to better results. We show that these models can be used to gain useful informative insights about the nature of disease spread.

Using ddRADseq to assess the genetic diversity of in-farm and gene bank cacao resources in the Baracoa region, eastern Cuba, for use and conservation purposes.

The Baracoa region, eastern Cuba, hosts around 80 % of the country cacao (Theobroma cacao L.) plantations. Cacao plants in farms are diverse in origin and propagation, with grafted and hybrid plants being the more common ones. Less frequent are plants from cuttings, TSH progeny, and traditional Cuban cacao. A national cacao gene bank is also present in Baracoa, with 282 accessions either prospected in Cuba or introduced from other countries. A breeding program associated with the gene bank started in the 1990s based on agro-morphological descriptors. The genetic diversity of cacao resources in Baracoa has been poorly described, except for traditional Cuban cacao, affecting the proper development of the breeding program and the cacao planting policies in the region. To assess the population structure and genetic diversity of cacao resources in Baracoa region, we genotyped plants from both cacao gene bank (CG) and cacao farms (CF) applying a new ddRADseq protocol for cacao. After data processing, two SNPs datasets containing 11,425 and 6,481 high-quality SNPs were generated with 238 CG and 135 CF plants, respectively. SNPs were unevenly distributed along the 10 cacao chromosomes and laid mainly in noncoding regions of the genome. Population structure analysis with these SNP datasets identified seven and four genetic groups in CG and CF samples, respectively. Clustering using UPGMA and principal component analysis mostly agree with population structure results. Amelonado was the predominant cacao ancestry, accounting for 49.22 % (CG) and 57.73 % (CF) of the total. Criollo, Contamana, Iquitos, and Nanay ancestries were detected in both CG and CF samples, while Nacional and Marañon backgrounds were only identified in CG. Genetic differentiation among CG (FST ranging from 0.071 to 0.407) was higher than among CF genetic groups (FST: 0.093-0.282). Genetic diversity parameters showed similar values for CG and CF samples. The CG and CF genetic groups with the lowest genetic diversity parameters had the highest proportion of Amelonado ancestry. These results should contribute to reinforcing the ongoing breeding program and updating the planting policies on cacao farms, with an impact on the social and economic life of the region.

Tingkat Pengetahuan Petani dalam Pengendalian Hama dan Penyakit Tanaman Kakao di Kecamatan Masamba Luwu Utara

Masamba Regency, North Luwu, is one of the largest cocoa-producing centers in South Sulawesi Province. Almost every region has a cocoa plant (Theobroma cacao L.), and it is relatively easy to grow in climatic conditions suitable for cocoa plants, so it is essential to do the right way for pest and disease control aimed at increasing production. This study aims to determine how much knowledge there is about controlling pests and diseases in cocoa plants. Using a quantitative analysis approach, this research was conducted using a survey technique from November to December 2022. Data obtained from interviews and questionnaire-filling results were used to conduct this research. The population used in this study is a group of farmers in Pandak Village and Pongo Villages. The population used as the targets in this study are the Masagena Farmer Group, the Limbong Dewata Farmer Group, and the Rante Sipulung Farmer Group, each of which is the target of this study. The purposive sampling technique used 50 samples per person. The Structural Equation Modeling (SEM) model uses variance-based statistical tests. Smart Partial Least Squares (Smart PLS) software is used for SEM data analysis to show farmers' knowledge level about pest and disease control of cacao plants. Motivation (X1), role of farmer groups (X2), extension (X3), and knowledge (Y) are the variables analyzed in this study. Based on the analysis results, it is known that X1, X2, and X3 affect Y by 40.9%, while other variables not observed in this study affect 45.7%. This indicates that the level of knowledge in controlling pests and diseases in cacao plants in Masamba District, North Luwu, has an influence, although not significant.

Identification of self- and pathogen-targeted miRNAs from resistant and susceptible Theobroma cacao variety to black pod disease

Cacao (Theobroma cacao) is a highly valuable crop with growing demand in the global market. However, cacao farmers often face challenges posed by black pod disease caused by Phytophthora spp., with P. palmivora being the most dominant. Regulations of various gene expressions influence plant resistance to pathogens. One mechanism involves targeting the mRNA of virulence genes in the invading pathogens, suppressing their infection. However, resistance also could be suppressed by plant-derived miRNAs that target their own defence genes. The objective of this study is to identify differentially expressed miRNAs in black pod-resistant and susceptible cacao varieties and to predict their targets in T. cacao and P. palmivora transcripts. Extracted miRNA from resistant and susceptible varieties of T. Cacao was sequenced, identified, and matched to host and pathogen mRNA. In total, 54 known miRNAs from 40 miRNA families and 67 novel miRNAs were identified. Seventeen miRNAs were differentially expressed in susceptible variety compared to resistant one, with 9 miRNAs upregulated and 8 miRNAs downregulated. In T. cacao transcripts, the upregulated miRNAs were predicted to target several genes, including defence genes. The suppression of these defense genes can lead to a reduction in plant resistance against pathogen infection. In P. palmivora transcripts, the upregulated miRNAs were predicted to target several genes, including P. palmivora effector genes. In the future, limiting expression of miRNAs that target T. cacao’s defence genes and applying miRNAs that target P. palmivora effector genes hold promise for enhancing cacao plant resistance against P. palmivora infection.

Phyllosphere to Ferment: Site Conditions Structure Cacao Pod and Fermentation Microbiomes in Hawaiʻi

Microbial fermentation is crucial to the development of flavors in cacao-based products, but how the abiotic environment and pod surface microbiomes can contribute to these different sensory profiles is underdeveloped. To better understand the connections between environment, plant variety, associated pod phyllosphere microbiomes, and the fermentation microbiome, we characterized the fungi and bacteria on pod surfaces and early fermentations of two cacao varieties across wet and dry sites on the island of O‘ahu, Hawai‘i. We showed that site (and the environmental conditions linked to those sites) significantly influenced the microbiomes of both the pod phyllosphere and fermentations but did not significantly explain the differences between cacao varieties. Certain taxa of bacteria and fungi seemingly prefer the wet Kualoa Ranch site compared with the drier Urban Garden Center Site. Rare members of the pod phyllosphere communities became highly enriched during fermentation, where basidiomycetous yeasts ( Filobasidium sp., Hannaella zeae, Rhodotorula mucilaginosa, R. paludigena, and Sporobolomyces carnicolor) became dominant at the wet site, and both ascomycetous and basidiomycetous yeasts ( Hyphopichia burtonii, Meyerozyma sp., Yamadazyma phyllophila, Filobasidium sp., Kwoniella heveanensis, R. mucilaginosa, Sporobolomyces sp., and S. carnicolor) became dominant at the dry site. The agricultural production site where cacao plants are grown should be considered carefully because it is likely important in structuring microbes that are present on pod surfaces and the microbes (mostly yeasts) that will be carried forward into fermentation. These yeasts may contribute to the development of the unique fruity or floral flavors in chocolates produced in Hawai‘i. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Accumulation of cadmium in soils, litter and leaves in cacao farms in the North Sierra Nevada de Santa Marta, Colombia

Cadmium (Cd) accumulation in Colombian cacao is a growing concern due to its potential health impacts and EU regulations on Cd content in chocolate products. Furthermore, cacao plays a significant role as an agricultural commodity and a tool for illegal crop replacement, yet our regional understanding of Cd dynamics in cacao cultivation in the north flank of the Sierra Nevada de Santa Marta is still limited. This research provides the first comprehensive investigation of cadmium biogeochemistry in cacao agroecosystems by analyzing the interactions between subsurface soils, topsoil, rock fragments, litter, and cacao leaf Cd concentrations from 30 farms. Results reveal generally low mean total soil Cd concentrations for topsoil and subsurface soils at 0.12 mg kg−1 and 0.05 mg kg−1, respectively. Leaf and litter Cd concentrations are significantly higher (p < 0.05) than soil Cd, with a mean of 0.42 and 0.4 mg kg−1, respectively. Our results suggest that age dependent surface-level processes such as the bioaccumulation and biocycling of Cd over time through the leaves, litter, and topsoil, govern Cd in the topsoil, leading to older cultivars and trees exhibiting higher Cd concentrations in leaves, litter, and soils. Subsurface soil Cd is primarily driven by geogenic Cd coming from the weathering of the underlying bedrock with a hypothesized contribution from pedogenic Cd being translocated to deeper soil horizons from the topsoil via clay and oxide illuviation. Our research provides insights into the accumulation of Cd in cacao plants and soils, which can lead to long-term preferential accumulation of cadmium on soil layers and thus increase plant uptake through roots.

Comparing the performances of SSR and SNP markers for population analysis in Theobroma cacao L., as alternative approach to validate a new ddRADseq protocol for cacao genotyping.

Proper cacao (Theobroma cacao L.) plant genotyping is mandatory for the conservation and use of the species genetic resources. A set of 15 international standard SSR markers was assumed as universal cacao genotyping system. Recently, different SNPs and SNP genotyping techniques have been exploited in cacao. However, a consensus on which to use has not been reached yet, driving the search for new approaches. To validate a new ddRADseq protocol for cacao genotyping, we compared the performances for population analysis of a dataset with 7,880 SNPs obtained from ddRADseq and the genotypic data from the aforementioned SSR set, using 158 cacao plants from productive farms and gene bank. Four genetic groups were identified with STRUCTURE and ADMIXTURE softwares using SSR and SNP data, respectively. Similarities of cacao ancestries among these groups allowed the identification of analogous pairs of groups of individuals, referred to as: G1SSR/G1SNP, G2SSR/G2SNP, G3SSR/G3SNP, G4SSR/G4SNP, whether SSRs or SNPs were used. Both marker systems identified Amelonado and Criollo as the most abundant cacao ancestries among all samples. Genetic distance matrices from both data types were significantly similar to each other according to Mantel test (p < 0.0001). PCoA and UPGMA clustering mostly confirmed the identified genetic groups. AMOVA and FST pairwise comparison revealed a moderate to very large genetic differentiation among identified groups from SSR and SNP data. Genetic diversity parameters from SSR (Hobs = 0.616, Hexp = 0.524 and PIC = 0.544) were higher than that from SNP data (0.288, 0.264, 0.230). In both cases, genetic groups carrying the highest Amelonado proportion (G1SSR and G1SNP) had the lowest genetic diversity parameters among the identified groups. The high congruence among population analysis results using both systems validated the ddRADseq protocol employed for cacao SNP genotyping. These results could provide new ways for developing a universal SNP-based genotyping system very much needed for cacao genetic studies.

Morphological Characterization of Cacao Plants (Theobroma cacao L.) from Dharmasraya Regency of West Sumatra

Dharmasraya, a regency in West Sumatra Province, has traditionally focused on cultivating oil palm and rubber. However, due to a decline in prices for these commodities, there has been a shift towards cultivating cacao plants. Despite several years of cultivation, cacao production in Dharmasraya Regency remains low. This is attributed to unsuitable land and weather conditions, as well as the use of inferior plant material and uncertain origins of the cacao clone. To address these issues, a research study was conducted to assess the diversity and similarity of cacao plants in Dharmasraya Regency. The study focused on four locations within Sitiung Subdistrict: Siguntur, Sitiung, Gunung Medan, and Sungai Duo. A purposive sampling method was used to select the sample plants. The data was analyzed descriptively, and similarity analysis was performed using the NTSYS 2.02 software. The study identified seven different clones of cacao plants, each with distinct morphological characteristics in terms of leaves, flowers, fruits, and seeds. The phenotypic similarity analysis revealed a coefficient value ranging from 23% to 47%, indicating a moderate level of similarity, and a variability value ranging from 53% to 77%. It was found that qualitative traits exhibited a narrow range of variability, while quantitative traits displayed a broader range of phenotypic variability.

Effects of Different Liming Materials on the Uptake of Cadmium and Mineral Nutrients in Cacao Plants

Effects of Different Liming Materials on the Uptake of Cadmium and Mineral Nutrients in Cacao Plants