Cacao - Science topic

Is there any data in the current literature (from the last 10 years) that reports how much biomass is stored in the wood of the cacao tree? Is there any estimate of how many cubic meters of wood a cacao plant produces? I have been searching the literature but have not found anything yet. This information is crucial to determine how much biomass a cacao plantation yields at the end of its cycle.

I have read some articles about oleaginous yeasts isolation but I haven't found a research which explains that these yeasts are isolated from fermented cacao beans. Is that possible to oleaginous yeast to be found in fermented cacao beans? What are the factors?

I'm doing research on Cacao swollen shoot virus. but right now I'm facing a problem that primers I use can't detect the virus. I have tried using several primers such as those described by Hoffman et al (1997), Kouakou et al (2012), Oro et al (2008), and Quainoo et al (2008). Is there any solution for the problem? thank you

Due Covid-19 I personally cannot visit a rural site for the collection of samples. But have found some great people who are happy to do the extractions on my behalf. I need to provide them with an RNA extraction protocol but personally don't have any experience with it. Your suggestions will be highly appreciated.

ISARA is coordinating the education part of Cacao Forest Initiative (http://www.cacaoforest.org/english) supporting local universities to reinforce education on Agroforestry.

We are looking for any expert (fluent in spanish) for this task

my sample is cacao (theobroma cacao),

I need some tips about extraction

Hi,

I am conducting an experiment for reisolate Verticillium dahliae from cacao. I am thinking to grind my sample in phosphate buffer and PVP (15 g/l). I am adding PVP because my samples are quite rich in polyphenols that could impact the reisolation success. I want to use a buffer at a molarity of 1M or 2 M because they are also quite rich in polysaccharides and so they are viscous. Does this could impact the reisolation success?

Hi,

I want to measure –(-)Epicatechin from cacao by fluorimetry. I have used acetone, water, acetic acid (70%, 29.5%, 0.5%) and sonication for the extraction. I have to let the sample evaporate to get rid of the acetone. But, I have noticed that the degradation of the epicatechin is quite fast (loss of approx. 20% after 3 hours).

How could I prevent it? Increasing the concentration of acetic acid and/or adding ascorbic acid could help?

Hi,

I have phenotypic data for disease scoring (1-5) over three years for 184 cacao lines. The scoring was done in single environment over a period of three years. To calculate the mean, do I just average the score in excel or I shall calculate BLUPs? I want to perform GWAS analysis to look disease resistance QTLs.

Hi,

I want to extract DNA from dried cacao leaves. In the kit DNeasy Plant Pro it is recommanded to add a buffer in the tube for the disruption with the TissueLyser. Meanwhile it is not recommended in the documentation of the TissurLyser to add a buffer for the disruption for dried leaves.

When I have tried with the buffer, no disruption has happened.

What could you advise for extraction of DNA with dried leaves ? Buffer or no buffer ? TissueLyser or FastPrep ?

I have extracted DNA from cacao leaf tissue (freeze dried).

I used CTAB buffer (5%) along with 1% B-mercaptoethanol and 3% PVP. I did the DNA extraction overseas and transported it as a pellet to Australia. When they arrived in Australia I stored them at 4 C after resuspending them in TE buffer. However, when I checked the quality on agarose gel surprisingly all of my samples have degraded DNA.

Could anyone pls advice me what can I do to prevent the degradation of the DNA? The downstream application of the DNA will be DarT analysis.

I have attached the gel picture as well.

Regards

Gurpreet

I will be collecting cacao leaves and thinking of preserving the leaf samples in 96% ethanol for 3-4 weeks. I am concerned it will cause any degradation of the DNA. Do I need to maintain the temperature of the samples (for example at 4 C) or they will be fine at room temperature.

I have DNA extracted from Cacao plant. I am wondering if I need to get rid of RNA contamination. The samples are gonna be used for DArT analysis.

I have extracted DNA from Cacao leaf tissue using CTAB, chloroform isoamyl alcohol method. When I quantified my samples on Nandodrop they show a conc. of 300-800 (ng/ul) in 50 ul of TE buffer. The ratios of 260/280 are good and 260/230 are fair.

However, when I ran my samples on 1% agarose gel electrophoresis at 70 V, I do not see any bands of DNA but only RNA. I have attached the picture of both gel and nanodrop results.

What must have gone wrong? Can you please advice me on what to do?

Regards

Gurpreet

I am analyzing one paper Deheuvelsa et al. 2010 Vegetation structure and productivity in cocoa-based agroforestry systems in

Talamanca, Costa Rica. I have a lot of questions since I am going to characterize the Cacao Agroforest System in Sodconusco Chiapas in other to make a study of Bird diversity and environmental services.

Deheuvelsa and colaborador use a methodology to search the relation between different Cacao Agroforest Clusters (Diversity and Vegetation Structure) and the productivity of Cacao.

They measure cacao productivity as a function of three components.

1) Counting The number of healthy pods in an area of 50mx20m in the center of the cacao Agroforest.

2) They collect 30 cacao pods in 2 seasons before the harvesting, in order to get the dray cacao comercial yield, they weight the fresh beans and applied the 56% discount to the average weight fresh.

3)Finally they estimated the Fresh above the ground plant volume, based on the function basal area x total height.

I am sure those measures are so important and determinant to get very precise data, but I wonder and some colleges suggest that, I could measure just the total dry weight asking the cacao smallholder, and I will get a direct measure of the total productivity of the plantation. But I am sure that I will miss valuable information with such simple method.

Deheuvelsa et al never explains what is the relevance to get those detailed measurements

I am a PhD student in Australia. I am going to collect leaf samples from cacao tree in Indonesia. Can any one suggest me how can I ship the leaf samples while retaining the viability. Purpose of bringing the leaf samples is performing a DNA extraction.

I have been working with cacao (Theobroma cacao) crops and the small scale farmers in developing countries cannot access to the Cd analytical extraction methods for Cd detection in soils due to their cost.

Is there a way to design a bio-indicator to detect Cd in soils as a good approximation of the analytical methods? Or is it possible to detect Cd in soils with a colorimetric method?

Is the cadmium uptake in cacao (Theobroma cacao L.) greater as the tree grows? I am planning to develop a pot experiment with cacao seedlings and I will evaluate Cd just in leaves after 90 days. I am not sure if I can extrapolate my results to a tree. Thanks.

Dear researchers,

I am starting in the Raspberry Pi and Arduino world. I am doing my masters in soil science and I was wondering if I can use (or construct) a cheap sensor with one of these devices to detect Cd (or Zn) in agricultural soils. There is a new EU regulation regarding Cd in cacao based products and the Colombian cacao farmers do not have access to a XRF and rarely made a soil test.

Is it a waste of time?

Best regards,

I´m currently making some trials in cacao fermentation, and cotyledon pH is a variable i need to measure as well as pulp pH. Literature mentions some protocols but i´m uncertain about it's applicability in this part of the process.

During the analysis of the observations from a complete diallel cross of cacao clones at CATIE in Costa Rica it turned out to be impossible to determine for a number of traits their inheritance at the diploid level whereas this was possible using tetraploidy as the prevailing ploidy level. In correspondence with Dr. Allan in Ecuador during the 1980ies this view was supported. The 'discovery' of the publication of Opeke and Jacob (1967) in which the formation of quadrivalents in 36.6% of pollen mother cells of the Nanay clone and the fact that this clone can be regarded primarily as an autotretraploid did make me think of using tetraploid inheritance to explain the genetics of a number of traits. This worked and makes me think that cacao is a relatively 'primitive' crop that is 'in transition' from a tetraploid into a diploid species. For more details see my thesis 'The systematic description of cacao clones and its significance for taxonomy and plant breeding (Engels, 1986).

The suggestion of tetraploid rather than diploid inheritance might be one of the (main?) reasons why breeding new cacao varieties with specific traits is so difficult!?

Hello, I am writing up for my data analysis for a comparison of forest structure and composition between forest and cacao agroforest in the tropics. I have decided to use first-order jackknife to estimate species richness, shannon and simpson index to study the alpha diversity and soerensen index to study the beta diversity. I have being reading about the pielou equitability index, ordination analysis. can someone help explain these please? and is there anymore useful analysis I might add?

Thank you

I have been conducted research about artificial nest for predatory ant Oecophylla smaragdina (Hymenoptera : Formicidae) in cacao field. They are a potential predator for cocoa pod borer (Conopomorpha smaragdina). In my research, the ants reject artificial nests from bamboo and dried cacao leaves inside. It makes me surprised, they prefer artificial nest from bamboo and dried banana leaves inside it. I think it similar dried leaves?what happen?