Cassava - Science topic

Dear @Collethy Jaru

I have attached one pdf, and shared useful links; hope, these will be useful to you.

can you represent other result similat to your result and compare between them

Dear @Ernest Samuel Impact factor (Clarivate analytics) is the widely accepted indicator to assess the importance of journals. You can choose journals based on the quality and quantity of data generated across years and locations, suitability of your article to specific journals, publication options ( open access/subscription based), and the like.

Dear @Ancel Rei Salazar Acuña You can access the below mentioned link, and the attached pdf; hope, these would be useful to you.

Also check https://www.tandfonline.com/doi/pdf/10.1080/10942910902934090

You can check the paper below for more information:

Regards,

K

Dear @Emmanuel Oladeji Alamu Please also verify the attached PDF; hope, it may be useful.

In India, one institute "ICAR-CTCRI" has been working on root and tuber crops; you can contact the relevant scientist.

I agree with Sylvester Ochwo.

Hi Michael!

Thank you for your answer!

After the DNA clonning , I will make the DNA sequencing... With that I can Identify the Cis- regulatory elements (CRE´s)

Pakop Sovo

The 2 likely diseases of cassava are necrosis and anthracnose (the canker, like you called it). And from the close-up view, I would go with your diagnosis (the latter).

Regarding the possible mode of transmission, the anthracnose disease is a fungal one, and is air-borne. The existence of infected stems or leaves is enough to spread the fungal spores, irrespective of whether the infected vegetative part is dead or not. Infected soil could as well be threatening. In your case, wind could have spread the disease during the drought season, if your soil is innocent.

I recommend you completely eradicate (destroy by burning) old/infected stems, and practice shifting cultivation; bearing in mind that the same fungal spp. can attack other crops like paw-paw and pepper.

Kind regards

@ Williams F. Hansen, thanks for the insight.

In the ethanol prduction process from cassava starch, two main steps are involved: Hydrolysis and Fermentation. Hydrolysis converts cassava starch to glucose using acids or enzymes. Fermentation produces ethanol from glucose by ethanologenic organisms. Both acid and enzymatic methods have their own merits and demerits.

First of all, I would like to focus on merits and demerits of acid hydrolysis. In terms of merits, acid hydrolysis produces higher yield of glucose if the process is pefoemed at optimized conditions of acid concentration, solid to liquid ratio, reaction temperature, reaction time and agitation speed. Cost of acid is cheaper than enzymes. Process conditions may not be harsh. In terms of demerits, degradation products of glucose form during hydrolysis. It happens sometime, which is beyond experimenter's control. In such case, glucose yield decreased. Also, to everyone's knowledge, stoichiometrically, at 100% recovery, only 1.11 gram of glucose can be produced per gram of starch.

Next, let's discuss about enzyme hydrolysis. In terms of advantages, enzymes are specific, versatile and produce enhanced yield at optimum conditions of pH, temperature, time, mixing, concentrations of substrate, enzyme and inhibitor. In terms of disadvantages, cost of enzymes are expensive than acids. A single enzyme is not sufficient to produce glucose from starch. A mixture of amylases and amyloglucosiodases (or glucoamylases) are required for hydrolysis. In enzymatic hydrolysis itself, three steps are involved: Gelatinization, liquefaction and hydrolysis. Again, experimenter should keep stoichiometry in mind.

Thank you for this question which openend up my mind to provide elaborate answer,

This link I found interesting

You can use clustering and/or PCA

Thank you very much

Please look at the following below links which may help you in your analysis:

Thanks

Kindly see the following RG link.

hello

i dont know

Hi

Which model to use is according to your research question.

Need to clarify the statement:" every 24 hours and 48 hours for every week for a period of one month . " this will affect how the measurements are organized.

Hope that it is of benefit.

Yours,

Thank you for the insight (@Pratapsingh Khapte)

The technology of producing ethanol from starch is internationally well developed. Waste stream of cassava - ethanol can be used for biogas production. For detail information consult https://www.probos.nl and https://www.jstor.org and https://www.academicjournals.org

Hey Astrid,

I agree with Abhijeet. Try out the kit that is favoured in your country, if you have enough DNA to work with, that's all you want. Just put it out in the methods when you publish. Cheers!

In order to assess the development of Fusarium oxysporum in roots and stems of cucumber plants, I cut the tissues in circa 1-2 mm slices with a scalpel or cutter before suspending in sterile water, blending for10 sec, check that all slices remain in the suspension, followed by 60 sec blending at high speed. One ml samples of the macerate and serial dilutions (1ml +9ml water in sterile test tubes) are poured in sterile Petri dishes and suspended in autoclaved 1.5% agar medium at 45°C.

The size of the blender will depend on the size of your sample and degree of colonisation. If you are planning dilutions you could already blend with a larger amount than 1ml.

The duration of blending probably requires adjustment. You can compare number of colonies developing for sub samples blended for various durations and so determine the duration which gives you the maximum number of fungal and/or bacterial colonies. For the bacteria you may spread 0.1 ml. of the suspension on the surface of the medium rather than incorporating it in the medium.

It is prepared by taking 9.16 gm of picric acid and volume is made upto 1000ml with 1N sodium hydroxide

Thanks Vitor.

So, does this mean that in my study I should concentrate on analysing the cassava varieties rather than basing on the ecological zones?

The most recent study shows that there are 217 cassava varieties grown in the 6 agro-ecological zones of Uganda (Nakabonge et al., 2017). How can I be able to zero onto particular varieties like 6 to base my study? 217 is alot and I am sure each variety has a different composition and hence the peel compositions too are different.

Hello,

Did you get the correct band size after PCR amplification?

Which restriction sites did you opt for?

Did you go for sequencing of the clone you used before the expression of protein?

It will help in understanding the situation better. Also, can you show me the gel picture?

it is a good method for measurement of PH

Thanks for the references but they don't say how to collect and establish spiralling whiteflies in the lab for research.

The inherent variation among plants needs also to be considered and this depends to a large extent on the variation in soil water content. Proper randomisation is of huge importance, especially if measuring outdoors as water potential will track changes in wind and irradiation. If you use paired measurements in time (one from each treatment) then you will minimise bias. Leaves are not replicates, just samples. Be aware of what are the true replicates in your experimental design (pots, plots, etc) and take mean or median of all leaves/plant measured within a single experimental unit. With a careful sampling strategy and well controlled conditions you will need fewer that 300-400 leaves per treatment. With a sampling strategy that does not control for bias, you will not get reliable estimates with any number of leaves.

Other important points: timing of measurements, traditionally, either pre-dawn or midday. In either case, the measuring period should not extend for more than one or two hours unless you include time in your data analysis. If outdoors, try to measure under clear sky conditions, and avoid days with changing cloud cover in the case of midday measurements. Handling of leaves: be very fast, the shortest the time between leaf excision and enclosing it into the chamber, the better. Try to keep this time to less than one minute, be even faster at midday if stomata are open.

Youngest fully expanded leaves are frequently used. If measuring at midday, make sure to avoid shaded leaves. Use a stereo microscope or magnifier and make sure you can easily see when the cut surface gets wet. Increase the pressure slowly enough so that you can record the exact balancing pressure value. Discard any leaf that is broken, especially in the petiole or veins as this will allow N2 to enter the xylem directly.

Hello Francis Anosike ,

You can enrich / fortify cassava with protein-rich food material as described in the attached article. In this work optimum (daily nutritional requirement for a balanced diet) protein content in carbohydrate-rich cassava was sought.

Soybean was preferred over several others, such as groundnut due to its exceptionally rich protein content with less lipid; to enable manipulation of nutritional composition without offset. Feel free to contact me if you need anything extra.

Liquid biofuel (bio-oil) can be produced by pyrolizing cassava peel. It is cost effective method.

Kindly see here too..

thanks, it is true, we can use cassava for both, human and animals (because animal will give food too for us!!). In times of climate challenges cassava is and will be an important crop that we need to take in account

you can go through

Climate change and on farm conservation of crop landraces in centres of diversity

How social organization shapes crop diversity: an ecological anthropology approach among Tharaka farmers of Mount Kenya

Evolutionary response of landraces to climate change in centers of crop diversity

If you want to work on FAOSTAT data in a GIS, you can use the QGIS. This program has a FAOSTAT plugin and you can spatialize the data.

Dear Salvador,

many thanks for your reply and clarification, your suggestions will be more helpful for me in the continuation

you can use mitochondrial DNA sequence (cytochrome ) to generate cassava specific primers.

Hi Okunlola,

I do not know if cassava chip would be interesting for you. Check papers on cassava chip effects on milk production due to its content in malate (papers published in 2006and 2007 by Wanapat if I am not wrong).

In this sense, also the attached article could help you.

Regards.

Thank you all.

The most reliable techniques are photo-optical methods:

- Several publications show, that photooptical analysis (either SOPAT - www.sopat.eu, PVM or any other in-situ microscope or endoscope probes) gives reliable data opposed to laser or ultrasonic based in-situ devices [Boxall et al. 2010, Hu et al. 2006, Maaß et al. 2011, Pacek et al. 1994 ]

- Especially the transformation from chord lenght distributions into real particle size distribution is difficuilt

- Photooptical devices are the only ones able to differentiate between for example the ice crystals and a fat droplet in the same sample, FBRM or the like will always try to average across the different components

- I know only one photooptical device which offers an image analysis software capable to investigate highly concentrated samples fully automated

Literature

Hu, B., et al., Evaluation of drop size distribution from chord length measurements. AIChE Journal, 2006. 52(3): p. 931-939.

Boxall, J.A., et al., Measurement and calibration of droplet size distributions in water-in-oil emulsions by particle video microscope and a focused beam reflectance method. Industrial & Engineering Chemistry Research, 2010. 49(3): p. 1412-1418.

Maaß, S., et al., Experimental comparison of measurement techniques for drop size distributions in liquid/liquid dispersions. Experiments in Fluids, 2011. 50(2): p. 259-269.

Pacek, A.W., et al., Video technique for measuring dynamics of liquid-liquid dispersion during phase inversion. AIChE Journal, 1994. 40(12): p. 1940-1949.

you can contact

Research Assistant-African Cassava Whitefly Project

Organisation: Root Crops Research Program, National Crops Resources Research Institute (NaCRRI), National Agricultural Research Organization (NARO), 

Contact Information: ocittipatrick@gmail.com T|

Hi,

you can use the single fiber tensile test to determine the mechanical properties of fibers using the single filament tensile tests procedure described in ASTM D-3322-01 standard test method.

Regards,

BELOUADAH Zouheyr

Leonardus,

If you want to quantify the amount of fermentable sugars, such as glucose and maltose, please refer to the following publication (HPAEC-PAD). 

If you do not avail of chromatography, you can calculate the free glucose using a simple colorimetric assay. Please, refer to the second article (GOPOD assay kit from Megazyme). 

If you want to determine the DE, i.e. reducing sugars in the dry solids, Somogyi-Nelson will suit you very well.

Firstly, I would like to suggest you to double check the bait vector, and ensure the bait protein could be translated properly. Since all control experiments were good, there's not any technical problem here. So screen again confidently and carefully, and make sure everything in good condition, including yourself. Good luck.

A5 is a nauplius larvae of a cyclopid copepod.

A4 and A6 are not organisms. They are pieces of detritus.

A2 is a filamentous algae.

Parts of cassava plant especially roots, leaves and peels have been tested for non-ruminant feeding especially in pigs and poultry (see Livestock Research for Rural Development Journal). However, little has been done on  stems/stump. It could be argued that stems are of low/little nutritional value (roughage/cellulose etc.) for non-ruminants (have no capacity like ruminants to digest roughage EXCEPT rabbits, which have specialized caecum combined with copraphogia/caecotrophy). However, you could try the efficacy of using stems but first determine the nutritional composition and ascertain whether it is worth conducting research on this kind of alternative feedstuff for non-ruminants.

The loss of pigment is the defective state for chlorophyll and can result from a genetic mutation due to propagation conditions. Make sure you have good light with 12 hr photoperiod and if possible have day and night temperatures which are constant. When mutations occur they can be stimulated by hormones in use they may mean that you need to lower them. Also when plants become habituated to sugar in media they may not continue to depend on photosynthesis providing a mutation favorable environment. Lowering sugar might be helpful.  When people have issues like these many revert to coconut water rather than synthetic cytokinin.

Dear Keisha Njenga

Bacterial pathogens generally need a wound in order to infect their host. If your are microprogating cassava plantlets and testing for tolerance or resistance you will want to keep the progeny clearly identified and separated. For your bacterial inoculation you will need a standard population which can be measured according to optical density of your suspension. Once you have your hardened plantlets you can take your standard inoculum and dip a cluster of pins into it and wound a leaflet. If your plantlets are in pots I would place a bag over the pot to maintain high humidity and after that I would transplant into the field and see the adult plant reaction. You will want to take data on bacterial incidence and the severity of the disease. Good Luck. 

We hybridizing crops like cassava you may have pigmented and nonpigmented strains.

Generally the nonpigmented plants are due to recessive genes. The highly colored condition such as purple plants are due to a dominant gene for anthocyanin production.

Use you nonpigmented strain as females and the colored strains as males in your crosses. The idea is the any seed from noncolored female having a seedling which is colored is a successful cross. The non pigmented female strain is demasculated before stigmas are receptive. Pollen ready purple plants are used as an anther pollen source and the tweezer used to collect pollen which is brushed on the stigma of the female when it is a receptive maturity. 

Breeders use a pod to row technique to evaluate and follow in a progeny breeding scheme with evaluation and culling of unwanted reactions and types.

Could you contact me by e-mail .. my feeling is that you are doing several things wrong (jos@ing.puc.cl); please send me the question text in word and I will answer it

You may try Dr.Dipjyoti answer.

my opinion, some strain of LAB has a ability to produce alpha galactosidase,that produce some sugars i.e GOS (galacto oligosaccharide) as we all know that GOS has a prebiotic effect and can utilize by several strains bifido and lactobacilli since growol fermented by lactobacillus plantarum

What is the best management approach for Chromolaena odorata?

I am planning to use a Traditional Morphometric Analysis to determine the quantitative measurement of morphological parts. If I already get a morphometric data, is it applicable to undergo a phylogenetic analysis to determine the evolutionary relationship of a different cultivars of Cassava?

Hi Grace,

I think your suggestion is good.

Hi Hammad,

Thanks for the information. It was for information search, to avoid plagiarism. A paper on this topic we be sent for publication soon by me and other co-authors.

Guillaume, you might want to look at NASA power to see if they have data for your location (see power.larc.nasa.gov, under the section Access Data, select Agroclimatology); and also the improved Bristow-Campbell approach to estimating solar radiation based on temperature and rainfall. I'll send you some references. Best

Simple and practical suggestion.  Discard the experiment.  Grow the Casava in new pot with fresh soil outside the green house and then take them in to see if it is the green house problem.  If the experiment can be done outside the green house in normal soil using leaves or buds, that may be easier as Casava grows in almost any type of environment.  All the best.

It depends on many factors.  Starch is paracrystaline.  So, lack of birefringence is an indicator of gelatination.  You could make a slurry and observe under polarized light.  Compare this to standard flour.  If only 20% or less granules exhibit the polarization cross, it is considered gelatinized.

Dear Tennsion, Please see the attached paper which describes simple procedure for the determination of cyanides in cassava. The only disadvantage of this protocol is that it involves picric acid but on the other hand it is commonly used among farmers in the country.

Dear Dr. Hajar,  

I believe that this review of Dr Navas Castillo and colleagues will be very useful and will bring some new information about this virus complex and other emerging viruses in the world.

Navas-Castillo et al. Emerging virus diseases transmitted by whiteflies. Ann. Rev. Phytopathol, 2011. 49:219-248.

Fernando Sanhueza Salas

The physico-chemical parameters (pH, DO, BOD, COD, K, P, N, oil and grease, metal contents etc.) of POME & CME need to be determined b4 ur study their effects on E. crassipes & P. stratiotes. The physico-chemical characteristics of the soil/sediment where they grow is also important if u have the required funds. lastly, the effects on plant growth parameters shd be determined

When I used to work with cassava I applied a test kit as described in the attached paper. I subjected cassava bagasse to fermentation and I quantified the content of cyanides following method. It gives reliable results and it is good for frequent measurements. You may also consider gas chromatography but it is more expensive solution and it requires handling of potassium cyanide which is very toxic.

Best regards.

1) Collect samples of diseased plants from different farms/regions.  Record location coordinates, weather conditions at the site of collection, make photo of  the leaves, keep plant material dry for herbarium.

2) Isolate yellow-pigmented bacteria using semi-selective medium (better to use 2 or 3 different ones) - at least 100 isolates

3) Subculture the bacteria on YDC and prove that you have pure culture

4) Store the bacteria at -80 or in sterile water at room temperature

5) Test the bacteria identity as Xanthomonas and as Xanthomonas axonopodis pv. manihotis using IFA or specific PCR primers published elsewhere.

6) Test the proved Xanthomonas strains for virulence by HR on tobacco, Pelargonium or Plectrantus, and on young Cassava plants in controlled conditions (glasshouse, climatic chamber).

7) Use only virulent strains of Xanthomonas to isolate DNA in 2-3 replications - at least 100 ng/mkl. for  at least 30 strains in your study + type strains for the pathogen Xanthomonas axonopodis pv. manihotis and related species, obtained from international collections and used in other studies (reference strains for species, genetic groups , etc.)

8) Use BOXA PCR or single-adapter AFLP to group the strains and remove from your collection obviously different strains of other species.

9) Use AFLP, AP-PCR for fingerprinting and grouping strains based on their genetic similarity. 

10) Use  MLST for type strains of your groups to show relation of your collection to previously studied bacteria from Cassava. 

 Rastilav is Ok.

The introduction of 1 molecula of water per every  bond hydrolized, increase  the mass of the hydrylisis system. The factor is aprox. 1.1

Nigeria produces an estimated 38.2 million tonnes of cassava annually (data from 2007). This represents about 37 % of world output. So you see it is very important tuber crop in Nigeria. There hasn't been any reported case of serious pest or diseases affecting cassava production in Nigeria. Apparently the farmers have mastered the art of growing the crop.

It can be indicating the presence of hydrogen cyanide (HCN) in high level, which is toxic. Cassava naturally contain cyanogenic glycosides, named Linamarin and Lotaustralin, that can be removed by washing intensively. 

Dear Randall

Except for the salt, are there any other reasons? Our wild type cassava and other GM ones grow well in the MS medium, and only the new one grows slowly. Thanks.

 

Hi,

Titer is expressed as

-infectious unit/mL.

-viral protein pg/mL (p24 core protein for HIV-1),

-RNA copies/mL

Madhu Lin thats great. I am greatly encouraged by the answer and the paper sent. Thanks. Hope to be with u in India as my Institute is having some understanding with yours to do more research collaborations. Madu thanks again

Thanks for this important and food-security-relevant question. While IITA Ibadan and others have done a lot for breeding against virus-diseases and palatabilty, more and more areas get under cassava again after being lost for decades. The theoretical and partly practically high yield-potential of cassava is one of THE challenges for the years to come, also considering the strong move of agronomy towards improving the availability of industrial raw-materials as well as energy-crops.....in addition to the highest priority FOOD and food-security. In crop-husbandry matters I see enormous further potentials in a) planting cassava in contour-line-oriented landscaping for better rain-harvesting; b) planting cassava in alley-systems, mixed cropping, esp. with leguminous soil-cover and Nitrogen-suppliers; c) Using all sorts of organic mulching-materials for weed-suppression, water-retention and nutrient-supply. Note: mulching can reduce water-loss by evaporation in the range of up to 50% !; d) Integrating cassava into perma-culture systems which were the predominant land-use manner before "man-made negativ impacts"; e) Allowing commercial large-scale mechanized cassava-plantations only with a wise eco-system, socio-system and minimum crop-rotation or alley-cropping-systems. e) Establishing a permanent system of variety-testing in farmers' fields and not only behind 3-m-high research-station-fences.

Hello, Nguyen,

Actually I don't know what caused the colorization of cassava ethanol wastewater. But I think the pollution should come from the starting material - that is, the organic molecules with chromopores in cassava. These molecules normally are much bigger than ethanol and I think any adsorbent with developed mesopores can remove the color effectively. In addition, catalytic degradation should also be a promosing approach to decolorization. You can consult our publications for further information. Hope my answer will help you.

Chen, X.G., Lv, S.S., Liu, S.T., Zhang, P.P., Zhang, A.B., Sun J., and Ye, Y.* (2012): Adsorption of methylene blue by rice hull ash. Separation Science and Technology. 47, 147-156. doi: 10.1080/01496395.2011.606865

Zhang, A.B., Pan, L., Zhang, H.Y., Liu, S.T., Ye, Y., Xia, M.S., Chen, X.G.*(2012): Effects of acid treatment on the physico-chemical and pore characteristics of halloysite. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 396, 182-188. doi:10.1016/j.colsurfa.2011.12.067

Lv, S.S.1, Chen, X.G.1, Ye, Y.*, Yin, S.H., Cheng, J.P., and Xia, M.S. (2009): Rice hull/MnFe2O4 composite: Preparation, characterization and its rapid microwave-assisted COD removal for organic wastewater. Journal of Hazardous Materials 171, 634-639. doi: 10.1016/j.jhazmat.2009.06.039