Academic literature on the topic 'Cassava Cassava Cassava Cassava Cassava Cassava as food Cassava Plant breeding Starch. Theses'
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Journal articles on the topic "Cassava Cassava Cassava Cassava Cassava Cassava as food Cassava Plant breeding Starch. Theses"
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Toae, Sriroth, Rojanaridpiched, Vichukit, Chotineeranat, Wansuksri, Chatakanonda, and Piyachomkwan. "Outstanding Characteristics of Thai Non-GM Bred Waxy Cassava Starches Compared with Normal Cassava Starch, Waxy Cereal Starches and Stabilized Cassava Starches." Plants 8, no. 11 (October 24, 2019): 447. http://dx.doi.org/10.3390/plants8110447.
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Waxy cassava roots of nine varieties successfully developed in Thailand by a non-genetic modification (non-GM), conventional breeding method were used for extracting starches and their starch physico-chemical properties were evaluated and compared with normal cassava starches, commercial waxy starches (i.e., waxy maize starch and waxy rice starch) and commercial stabilized starches (i.e., acetylated starch and hydroxypropylated starch). All waxy cassava varieties provided starches without amylose while normal cassava starches contained 18%–20% amylose contents. As determined by a Rapid Visco Analyzer (RVA) at 5% (dry basis), waxy cassava starches had the highest peak viscosity and the lowest setback viscosity. Cooked paste of waxy cassava starches had the greatest clarity and stability among all starches during storage at 4 ℃ for 7 days as evidenced by its high light transmittance (%T) at 650 nm. No syneresis was detected in waxy cassava starch gels after subjecting to four freeze-thaw cycles (4 weeks) indicating high potential use of waxy cassava starches, free from chemicals, to replace stabilized starches as thickening and texturing agents in food products.
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Ayetigbo, Oluwatoyin, Sajid Latif, Adebayo Abass, and Joachim Müller. "Comparing Characteristics of Root, Flour and Starch of Biofortified Yellow-Flesh and White-Flesh Cassava Variants, and Sustainability Considerations: A Review." Sustainability 10, no. 9 (August 30, 2018): 3089. http://dx.doi.org/10.3390/su10093089.
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Cassava is a significant food security and industrial crop, contributing as food, feed and industrial biomass in Africa, Asia and South America. Breeding efforts have led to the development of cassava variants having desirable traits such as increased root, flour, and starch yield, reduced toxicity, reduced pest/disease susceptibility and improved nutrient contents. Prominent among those breeding efforts is the development of colored-flesh cassava variants, especially biofortified yellow-fleshed ones, with increased pro-vitamin A carotenoids, compared to the white-flesh variants. The concept of sustainability in adoption of biofortified yellow-flesh cassava and its products cannot be fully grasped without some detailed information on its properties and how these variants compare to those of the white-flesh cassava. Flour and starch are highly profitable food products derived from cassava. Cassava roots can be visually distinguished based on flesh color and other physical properties, just as their flours and starches can be differentiated by their macro- and micro-properties. The few subtle differences that exist between cassava variants are identified and exploited by consumers and industry. Although white-flesh variants are still widely cultivated, value addition offered by biofortified yellow-flesh variants may strengthen acceptance and widespread cultivation among farmers, and, possibly, cultivation of biofortified yellow-flesh variants may outpace that of white-flesh variants in the future. This review compares properties of cassava root, flour, and starch from white-flesh and biofortified yellow-flesh variants. It also states the factors affecting the chemical, functional, and physicochemical properties; relationships between the physicochemical and functional properties; effects of processing on the nutritional properties; and practical considerations for sustaining adoption of the biofortified yellow-flesh cassava.
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LESTARI, TRI, and RION APRIYADI. "Genetic potential of cassava biodiversity in Bangka Island, Indonesia." Cell Biology and Development 1, no. 2 (December 1, 2017): 41–45. http://dx.doi.org/10.13057/cellbioldev/v010201.
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Lestari T, Apriyadi R. 2017. Genetic potential of cassava biodiversity in Bangka Island, Indonesia. Cell Biol Dev 2: 41-45. Cassava is potential as a mixture ingredient of flour in the Bangka’s food industry. This study aimed to discover the biodiversity of local cassava in Bangka. This research was conducted in experimental field of the Faculty of Agriculture, University of Bangka Belitung, Indonesia from July 2015 to July 2016. The experimental design was randomized block design with 10 local cassavas of Bangka that consisted of upang, sekula, bayel, mentega, kuning, batin, pulut, sutera, rakit, and Selangor. Isozyme analysis performed using starch gel electrophoresis with horizontal models. Analysis for five Bangka local cassava varieties and one National cassava variety used RAPD group OP A and OP B. The results showed that the phenotypic performance was different on the type of plant, the morphology of leaves, stems, and tubers of local cassava of Bangka. Isozyme analysis showed polymorphic banding pattern, while the eight RAPD primers used did not produce polymorphic. This research showed Bangka local cassava morphologically different based on visual observation. Morphological character of Bangka local cassava leaf was divided into three shapes of lobe: ellipse (upang, sekula, bayel, mentega, batin, pulut, rakit, Selangor), linear (kuning) and lanceolate (sutera). This research data showed that the genetic diversity of local cassava in Bangka relatively high. Bangka local cassava has genetic potential as plant propagation material for plant breeding.
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Subekti, Isnani, Nurul Khumaida, Sintho Wahyuning Ardie, and Dan Muhamad Syukur. "Evaluasi Hasil dan Kandungan Pati Mutan Ubi Kayu Hasil Iradiasi Sinar Gamma Generasi M1V4." Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) 46, no. 1 (April 27, 2018): 64. http://dx.doi.org/10.24831/jai.v46i1.17610.
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<em>Cassava is one of the important starch producer crops. Although Indonesia ranks as the third largest cassava producer country, Indonesia still imports cassava starch to meet the domestic demand in food and non-food industries. Gamma ray irradiation has been implemented to generate cassava mutants in order to support development of superior cassava variety, especially high yield and high starch content, especially high yield and high starch content. The objectives of this research were to evaluate the yield potential and the starch content of gamma irradiated 40 putative cassava mutants at M1V4 generation. This research was arranged in randomized complete block design with three replications and conducted at Cikabayan Experimental Field, IPB, Bogor, from May 2016 to March 2017. The starch content was measured using gravimetric methods. The results showed that five mutants, G2142, G3151, G2141, G1143, and G3111, had higher tuber weight per plant (6-7 kg per plant) compared to the background ‘Gajah’ genotype (4.7 kg per plant). ‘G2112’ mutant genotype showed higher starch content (23.86%) compared to the background ‘Gajah’ genotype (17.65%). The specific gravity (SG) was positively correlated with starch content (r = 0.905), indicated that the higher the SG, the higher the starch content of cassava.<br /><br />Keywords: gravimetric, mutant, specific gravity (SG), yield</em>
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Rossitto De Marchi, Bruno, Tonny Kinene, Renate Krause-Sakate, Laura M. Boykin, Joseph Ndunguru, Monica Kehoe, Elijah Ateka, Fred Tairo, Jamisse Amisse, and Peter Sseruwagi. "Genetic diversity and SNP’s from the chloroplast coding regions of virus-infected cassava." PeerJ 8 (March 2, 2020): e8632. http://dx.doi.org/10.7717/peerj.8632.
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Cassava is a staple food crop in sub-Saharan Africa; it is a rich source of carbohydrates and proteins which currently supports livelihoods of more than 800 million people worldwide. However, its continued production is at stake due to vector-transmitted diseases such as Cassava mosaic disease and Cassava brown streak disease. Currently, the management and control of viral diseases in cassava relies mainly on virus-resistant cultivars of cassava. Thus, the discovery of new target genes for plant virus resistance is essential for the development of more cassava varieties by conventional breeding or genetic engineering. The chloroplast is a common target for plant viruses propagation and is also a potential source for discovering new resistant genes for plant breeding. Non-infected and infected cassava leaf samples were obtained from different locations of East Africa in Tanzania, Kenya and Mozambique. RNA extraction followed by cDNA library preparation and Illumina sequencing was performed. Assembling and mapping of the reads were carried out and 33 partial chloroplast genomes were obtained. Bayesian phylogenetic analysis from 55 chloroplast protein-coding genes of a dataset with 39 taxa was performed and the single nucleotide polymorphisms for the chloroplast dataset were identified. Phylogenetic analysis revealed considerable genetic diversity present in chloroplast partial genome among cultivated cassava of East Africa. The results obtained may supplement data of previously selected resistant materials and aid breeding programs to find diversity and achieve resistance for new cassava varieties.
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Sukara, E., and H. W. Doelle. "Cassava starch fermentation pattern ofRhizopus oligosporus." MIRCEN Journal of Applied Microbiology and Biotechnology 4, no. 4 (1988): 463–71. http://dx.doi.org/10.1007/bf00940173.
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Olayide, Priscilla, Annabel Large, Linnea Stridh, Ismail Rabbi, Susanne Baldermann, Livia Stavolone, and Erik Alexandersson. "Gene Expression and Metabolite Profiling of Thirteen Nigerian Cassava Landraces to Elucidate Starch and Carotenoid Composition." Agronomy 10, no. 3 (March 20, 2020): 424. http://dx.doi.org/10.3390/agronomy10030424.
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The prevalence of vitamin A deficiency in sub-Saharan Africa necessitates effective approaches to improve provitamin A content of major staple crops. Cassava holds much promise for food security in sub-Saharan Africa, but a negative correlation between β-carotene, a provitamin A carotenoid, and dry matter content has been reported, which poses a challenge to cassava biofortification by conventional breeding. To identify suitable material for genetic transformation in tissue culture with the overall aim to increase β-carotene and maintain starch content as well as better understand carotenoid composition, root and leaf tissues from thirteen field-grown cassava landraces were analyzed for agronomic traits, carotenoid, chlorophyll, and starch content. The expression of five genes related to carotenoid biosynthesis were determined in selected landraces. Analysis revealed a weak negative correlation between starch and β-carotene content, whereas there was a strong positive correlation between root yield and many carotenoids including β-carotene. Carotenoid synthesis genes were expressed in both white and yellow cassava roots, but phytoene synthase 2 (PSY2), lycopene-ε-cyclase (LCYε), and β-carotenoid hydroxylase (CHYβ) expression were generally higher in yellow roots. This study identified lines with reasonably high content of starch and β-carotene that could be candidates for biofortification by further breeding or plant biotechnological means.
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Oyadiran, TF, and JA Osakwe. "Effect of African cassava mosaic disease on morphological characteristics of cassava, Manihot esculenta (Crantz)." Journal of Agriculture, Forestry and the Social Sciences 11, no. 2 (February 18, 2015): 258–65. http://dx.doi.org/10.4314/joafss.v11i2.30.
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Field trials were conducted with 10 improved clones of cassava to study the effect of ACMD on their morphological characteristics. The clones used were: 97 / 4763, 97/2205, 91/02324, 98/0505, M98/0068, 96/1089A, 96/1632, M98/0040, 99/2123 and 97/0162. The parameters measured were plant height, leaf area, number of branches and petiole length. The research revealed differences within the clones for the parameters studied, these differences seemed to be mainly genetic, as they were not positively correlated to the disease incidence and severity. Based on the findings in this research the following recommendations were made. On the basis of their branching pattern, highly branched clones 97 / 2205, 97/4763 and 98 /0505 are recommended for selection. The heavy branches bear a lot of leaves or produce a thick canopy which helps to reduce the need for weeding, and also reduce the effect of loss of leaves that occur due to disease incidence. However, for industrial / mechanized agriculture, clones that are less branched should be selected as they are easier to harvest mechanically. Though there is disadvantage with their small leaf areas; the crops would have to be highly resistant to fungal attack which tends to cause leaf drop that will reduce leaf material for food / starch production (examples of less branching clones are, M98 / 0068, 96/1632,91/02324).Key Word: African Cassava Mosaic Disease (ACMD), Cassava Mosaic Virus.(CMV)
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Njoku, Damian Ndubuisi, and Emmanuel Ukaobasi Mbah. "Assessment of yield components of some cassava (Manihot esculenta Crantz) genotypes using multivariate analysis such as path coefficients." Open Agriculture 5, no. 1 (September 8, 2020): 516–28. http://dx.doi.org/10.1515/opag-2020-0051.
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AbstractCassava, which is a tropical storage root crop, serves as a veritable source of carbohydrate for people living in Sub-Saharan Africa. It is also an important source of industrial starch, biopolymers, animal feeds and ethanol. However, the genetic improvement of the crop is impeded by dearth in information on its genetic variability. A field experiment was carried out at the National Root Crops Research Institute, Umudike (05° 29′ N; 07° 33′ E; 122 m a.s.l.), Nigeria, aimed at assessing the interrelationship between fresh root yield and thirteen quantitative yield-related characters of twenty-eight (28) newly developed cassava genotypes. The rain-fed experiment was laid out in a randomized complete block design with dual replications in 2016/2017 cropping seasons. The results indicated that the newly developed cassava genotypes [2] NR110315 followed by [20] B1-5 and [1] NR110238 exhibited (P < 0.05) highest fresh root yield among the twenty-eight genotypes tested. The fresh root yield of [2] NR110315 (18.77 Mt ha−1) was relatively higher compared with [18] NR050080, which gave the least root yield of 5.38 Mt ha−1. The correlation coefficients obtained from the associations among the variables were positive and exhibited highly significant (P ≤ 0.01) association, especially between leaf area index (LAI) and root diameter as well as with fresh root yield of cassava. Among the nine variables subjected to the path analysis, LAI, starch content, above ground dry matter (AGDM), weight of fresh marketable roots per plant and root length that contributed positively and directly to higher fresh root yield require greater attention during selection and breeding in cassava studies. The direct effect of the variables indicating their magnitudes in decreasing order showed that LAI exhibited the greatest effect followed by starch content, AGDM, weight of fresh marketable roots plant−1, root length, % cassava bacterial blight incidence and % Cassava mosaic disease incidence, which had the lowest direct effect on root yield of cassava. Cyanide potential exhibited a direct, weak and negative effect on fresh root yield. The results further suggested that cassava improvement could be achieved through these characters that have positive and highly significant magnitude effect on fresh root yield.
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Khumaida, Nurul, Sintho Wahyuning Ardie, and Mira Sri Astuti. "Characterization of Irradiation Induced Mutants of Cassava (Manihot esculenta Crantz) Generated from Jame-jame and Adira-4 Genotypes at M1V2 Generation." KnE Life Sciences 2, no. 6 (November 26, 2017): 22. http://dx.doi.org/10.18502/kls.v2i6.1016.
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Cassava (Manihot esculenta Crantz., Euphorbiaceae) is an important dietary carbohydrate source for approximately 800 million people in the tropics. It is a potential crop for food, feed, and industry. Cassava breeding through conventional approaches are hampered with some limitations which resulted in a low number of superior varieties. The objective of this research was to generate several mutant lines with higher yield and starch content. This research intended to identify the second generation (M1V2) Jame-jame and Adira-4 variant cassava mutants from gamma ray irradiation. Jame-jame is a local genotype from Halmahera (local high yielding genotype, sweet, and potential) and Adira-4 is an Indonesia national variety of cassava. Mutant diversity appears on the plant height, plant branching, and plant tubers that harvested at 10 months after planting (MAP). Our results showed the positive correlation between plant height, first branching height, tuber weight, number of roots, and number of economic roots. Based on tuber weight and number of economic tuber there were 9 potential mutants (putative). Based on the stability test, there were 6 potential stable mutants (putative) by first branching height, tuber weight, total number of tubers, and total number of economies tuber, namely: V5D1-(2), V5D1-2(2), V5D1-3(2), V5D1-4(3), V5D2-2(2), and V5D2-6(2). Keywords: local genotype, M1V2, storage root, characters, stability.
Dissertations / Theses on the topic "Cassava Cassava Cassava Cassava Cassava Cassava as food Cassava Plant breeding Starch. Theses"
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Mtunda, Kiddo J. "Breeding, evaluation and selection of Cassava for high starch content and yield in Tanzania." Thesis, 2009. http://hdl.handle.net/10413/750.
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Kamau, Joseph Wainaina. "Participatory-based development of early bulking cassava varieties for the semi-arid areas of Eastern Kenya." Thesis, 2006. http://hdl.handle.net/10413/4091.
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Cassava (Manihot esculenta Crantz) is an important food security crop in the semi-arid
areas of Eastern Kenya. It provides food for more days in a calendar year than any other
crop grown. Kenya has relied on varieties bred in other countries and because of this,
local breeding methodologies and expertise are lacking. Access to appropriate varieties
and adequate planting materials are major limiting factors to cassava production.
Farmers grow late bulking landraces that take up to 18 mo to harvest. Efforts to introduce
early bulking genotypes from IITA failed because of poor end-use quality. Local cassava
breeding is necessary to alleviate the production constraints. Before a local breeding
program can be established, farmers' preferences and production constraints must be
identified and methodology appropriate to the Kenyan environment must be developed.
The aims of this study were to identify farmer production constraints and preferences, to
develop methods appropriate for cassava breeding in the semi-arid areas of Kenya,
develop a population segregating for bulking period to estimate genetic variances that
would explain the gene effects controlling yield components, and through participatory
selection identify varieties that combine early bulking and preferred end-user traits.
PRA tools, focus groups and individual interviews were used to identify production
constraints and farmer preferences for cassava varieties. The PRA found that farmers
grow 13 landraces in the area and 11 production constraints were identified and
prioritised. The four most limiting in the order of importance were drought, lack of
planting material, pests and diseases.
Crosses between cassava varieties often do not produce much seed and the seed
produced does not germinate well. Germination studies were done with open pollinated
seeds to identify conditions favourable for seed germination in Kenya. The highest
germination of the seeds was at 36°C. The control seeds had a higher germination
percent (77%) compared to the seeds which were pre-heated at 36°C (57%).
Crosses were made between selected IITA and local Kenyan genotypes following the
NC 11 mating design to develop new genotypes which combine early bulking along with
other farmer/end-user preferred characteristics. The hybrid progenies were evaluated in
a seedling trial and clone genotypes advanced to a clonal trial and performance trial. The
clonal trial was destroyed by red spider mites and cassava green mites, and only the tolerant 225 genotypes were planted in a performance trial that was harvested at 6, 7
and 8 mo after planting. The SCA effects were estimated to be 57% to 75% for most of
the traits, except root number, which was mainly controlled by GCA effects (55%).
Participatory selection of genotypes that combined early bulking and end-user qualities
at the 7 and 8 mo after planting was done by farmers. Thirty genotypes that combined
early bulking and end-user qualities were identified and ranked according to their
performance in both agronomic and end-use traits using a selection index. A number of
selected genotypes yielded more than three times the yield of the best parents, showing
strong progress in breeding. Combining the farmers' preference aggregate score and the
selection index based on the agronomic data, assisted in the final identification of the
best genotypes developed in the breeding process. These results clearly demonstrated
that it is possible to breed early bulking varieties with good end-use quality in the semiarid
areas.Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
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Chikoti, Patrick Chiza. "Development of cassava (Manihot esculenta Crantz) cultivars for resistance to cassava mosaic disease in Zambia." Thesis, 2011. http://hdl.handle.net/10413/8402.
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Despite the increasing number of farmers growing cassava in Zambia, yield per hectare has
remained low at 5.8 t ha-1. The major constraints contributing to low yields are pests and
diseases of which cassava mosaic disease (CMD) caused by East Africa cassava mosaic virus
(EACMV), Africa cassava mosaic virus (ACMV) and South Africa mosaic virus (SACMV) is the
most important. Breeding of cassava is restricted by limited information on viruses and
associated satellites, and farmer preferences. Most of the farmers cannot manage to institute
control strategies that require buying of chemicals. The most feasible option remains improving
existing cultivars through resistance breeding. The study therefore was conducted to: i)
establish farmers’ perception and knowledge of CMD; ii) to identify viruses of cassava occurring
in Luapula province; iii) evaluate the performance of local and improved cultivars for agronomic
traits; iv) evaluate the performance of F1 progenies for CMD resistance; and v) determine
general combining ability and specific combining ability for CMD resistance. The studies were
carried out between 2008 and 2011 at different locations in Zambia. The information generated
was important in formulating a local breeding strategy for CMD resistance.
A participatory rural appraisal and a structured survey was conducted in Mansa, Samfya and
Mwense districts in Luapula province involving farmers to ascertain farmers’ perceptions of
CMD. The results of the study showed that the majority of the respondents (97.6%) were not
aware of CMD. Most of the farmers grew landraces on small pieces of land. Although, the
cultivars (local and improved) were widely grown, they were susceptible to CMD. The farmers
preferred cultivars with high yielding and early bulking characteristics among others.
A CMD survey conducted between April and May 2009 in Samfya, Mansa, Mwense,
Kawambwa and Nchelenge districts in Luapula province established East Africa cassava
mosaic virus (EACMV), and Africa cassava mosaic virus (ACMV) as the most prominent viruses
in the area. Symptoms of satellites were also observed in the farmers’ fields in most of the areas
visited. Satellite II and III were detected in leaf samples. The CMD incidence (59.1%) and
severity (2.4) was moderate across the districts surveyed. The CMD symptoms on the cassava
plants were variable with plants showing mild and severe symptoms characterised with
narrowing and reduced leaf blades. The transmission of CMD infections was mainly through
cuttings rather than via whitefly infection which means that most of the planting materials used
by the farmers were infected.
Evaluation of cassava cultivars for CMD resistance was conducted in 2009/2010 and 2010/11
seasons at Mansa Research Station in Luapula province using a 4 x 4 α lattice design. Both
introduced and locally grown cultivars had significant (P<0.001) differences in their reaction to
CMD. Bangweulu, Namuyongo, Kalaba, Chikula, Mwakamoya, Chila7 and Chila11 were the
most susceptible genotypes. Mweru, Tanganyika, and Nalumino were moderately tolerant to
CMD.
Eight hundred F1 genotypes developed using a North Carolina II mating design were evaluated
in a 4 x 5 α lattice design in 2011 at Mansa Research Station, Luapula province to determine
combining ability for reaction to CMD, yield and yield components. The plants were harvested 7
months after planting (MAP). Significant (P<0.001) general combining ability and specific
general combining ability were recorded for CMD. The SCA effects were more important for
CMD than GCA effects suggesting that non-additive gene action was more prominent than the
additive gene action in determining CMD reaction. Parent lines with desired significant, negative
GCA effects for reaction to CMD were Bangweulu, Kampolombo, Nalumino and TME2.
In general, the survey and participatory rural appraisal established CMD as one of the
constraints to cassava production and created a basis for the research study. The findings
indicate opportunities that exist in creating genotypes with tolerance to CMD. The study
identified cassava lines with resistance to CMD. The lines that expressed the above trait should
be selected and tested further for release to the farmers in Zambia. Since the clonal evaluation
trial was harvested at 7 MAP, there is need to investigate further for earliness trait in best
performing lines in different locations.Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
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Munga, Theresia Luvuno. "Breeding for Cassava brown streak resistance in coastal Kenya." Thesis, 2008. http://hdl.handle.net/10413/205.
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Cassava (Manihot esculenta Crantz ssp. esculenta) is the second most important food crop and a main source of income for the rural communities with potential for industrial use in the coastal region of Kenya. However, its productivity of 5 to 9 t ha-1 is low due to the low yield potential of the local cassava landraces caused by cassava brown streak disease (CBSD) among other biotic and abiotic constraints. Breeding for CBSD resistant varieties with farmer desired characteristics is hampered by limited information on the current status of the disease and farmers’ preferred characteristics of new CBSD resistant genotypes. In addition, there is a lack of an effective inoculation technique for cassava brown streak virus (CBSV) for screening genotypes for CBSD resistance. Information about the general combining ability (GCA) and specific combining ability (SCA) for CBSD above and below ground symptoms, fresh biomass yield (FBY) and fresh storage root yield (FSRY) (kg plant-1), harvest index (HI), dry matter % (DM %) and picrate score (PS) is limited and conflicting especially for the cassava germplasm in Kenya. These studies were carried out to update information on the status of CBSD, farmer’s preferences for cassava genotypes, and identify the most effective CBSV inoculation technique. In addition, the studies aimed to: determine the GCA and SCA for, and gene action controlling, the incidence and severity of above ground CBSD, root necrosis, FBY, FSRY, HI, DM %, and PS; and identify CBSD resistant progeny with farmers’ desired characteristics. A survey carried out in three major cassava-growing divisions in Kilifi, Kwale and Malindi Districts indicated that there was potential to increase production and productivity by increasing the area under cassava production and developing CBSD resistant genotypes that are early maturing, high yielding and sweet. In addition, CBSD was widely distributed, being present in 98.0% of the farms surveyed at a mean incidence of 61.2%. However, 99.0% of farmers interviewed lacked awareness and correct information about the disease. The genetic variability of cassava within the farms was low as the majority of farmers grew one or two landraces. Highly significant differences (P < 0.01) were observed among inoculation techniques for CBSV for which the highest infection rate of up to 92.0% was observed in plants inoculated by wedge grafting infected scion. Highly significant differences (P < 0.01) were observed among genotypes, between sites and their interaction for incidence of CBSD and root necrosis, while the differences among genotypes and the interaction between genotypes and the period of ratings were highly significant (P < 0.01) for the severity of CBSD and root necrosis. Above ground CBSD symptoms were not always associated with below ground CBSD symptoms and below ground CBSD symptoms were more severe at 12 months after planting (MAP) than at 6 MAP. Therefore, selecting cassava genotypes with resistance to below ground CBSD is more important than selection based on resistance to above ground CBSD and should be done after 12 months. Genotypes 5318/3 (exotic) followed by Msa140 and Plot4 (both local) had high resistance and can be used as new sources of resistance to root necrosis. Both GCA and SCA effects were highly significant with GCA sums of squares (SS) predominant over the SCA SS for most traits evaluated except for DM % at the clonal stage. These results indicate that although additive and non-additive genetic effects are involved in the inheritance of these traits, the additive genetic effects are more important except for DM %. Therefore breeding for CBSD-resistant genotypes that have characteristics desired by farmers in the coastal region of Kenya can be achieved through recurrent selection and gene pyramiding followed by participatory selection or use of a selection index that incorporates characteristics considered important by farmers.Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
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Chalwe, Able. "Manipulating morphological traits of cassava to enhance host plant resistance and biological control of cassava green mite in Zambia." Thesis, 2013. http://hdl.handle.net/10413/10056.
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Understanding direct and indirect defense mechanisms that enhance host plant resistance (HPR) and biological control is critical for successful development of an integrated pest management (IPM) approach. Cassava green mite (CGM) (Mononychellus tanajoa Bondar (Acari: Tetranychidae)) is a major arthropod pest of cassava (Manihot esculenta Crantz) in Africa. Strategies to control CGM include HPR and biological control by use of exotic natural enemies particularly the predatory mite Typhlodromalus aripo DeLeon (Acari: Phytoseiidae). The success of the latter depends on continuous survival of the natural enemy which requires suitable host plants and weather conditions. Various plant morphological traits have been recognized as indirect defense mechanisms that enhance HPR to CGM, and/or attract T. aripo in cassava. It was envisaged that integration of HPR and classical biological control approaches through manipulation of such indirect defense traits would lead to a more sustainable management of CGM in view of anticipated climate change. Lack of information on farmers’ perception of CGM and preferred varietal attributes, and gene action controlling the inheritance of CGM resistance also limits success of resistance breeding and adoption of varieties. This research was undertaken to gather information on farmers’ perceptions of cassava varietal attributes and cultural practices in relation to CGM resistance, identify suitable sources of resistance and environments for future breeding; and to determine the nature of gene action controlling CGM resistance and the inheritance of plant morphological traits that enhance the ability of cassava to host and support continuous survival of natural enemies.
High fresh storage root yield (FSRY), high storage root dry mass percentage (SRDM%), earliness combined with extended underground storability, and resistance to foliar pests and diseases are the major factors that influence adoption and retention of genotypes by farmers. Moles, termites and CGM are the most widespread and most damaging pests. However, due to the non-conspicuous nature of CGM, its effects are under-estimated and are given limited attention by farmers. The majority of the farmers are familiar with CGM leaf damage symptoms but they cannot associate them with the actual pest. Participation of farmers in field training and field research activities helps them to know CGM. Crop rotation, intercropping, removal of shoot tips, selective pruning of infested shoots, and burning of cassava fields are some of the ways used by farmers to manage CGM. Farmers associate hairy broad-leaved, tall cassava genotypes and pink leaf pigmentation (anthocyanin) with low CGM damage.
There is substantial genetic variability in the Zambian cassava germplasm for CGM resistance and associated plant morphological traits such as leaf pubescence (Pbs), leaf retention (LR), stay green (SG), tip size (TS), tip compactness, and plant height (PH), stem diameter (StD), SRDM% and FSRY. Genotypes with wide or specific adaptability for these traits have been identified, and should be recommended for general or localized production and for use as sources of desired genes in crop improvement. Genotypes L9.304/147, 92/000, TME2, 4(2)1425, I60/42 and L9.304/175 combine wide adaptability with high levels of resistance to CGM. Genotypes Kapeza, L9.304/147 and 4(2)1425 are able to produce 13-15 t ha ¯¹ at 9 months after planting suggesting their potential for early bulking.
This study has shown that both additive and non-additive gene effects play a role in the expression of CGM resistance and associated plant morphological traits. The best combinations of parents for resistance against CGM were 4(2)1425 x L9.304/147 and Mweru x L9.304/147, while L9.304/147 x I92/000 displayed combined resistance to CGM and cassava mosaic disease (CMD). The resistance of cassava to CGM is positively correlated with Pbs, LR, and TS, SG, PH, StD. Overall, the study has shown that there is wide diversity in the expression of valuable indirect defense traits among genotypes, indicating that there is scope for integration of biological control and host plant resistance for CGM in Zambia. The release of genotypes that exhibit high level of intra-season and inter-season stability for enhanced expression of LR, SG, and Pbs will minimize the impact of CGM on FSRY and SRDM% that results from seasonal effects. Such genotypes should also provide habitat for and thus help to ensure the survival of T. aripo in cassava fields. The study has contributed to the promotion of food security through identification of early-bulking genotypes which also have good potential for extended underground storability of roots. Early-bulking, high FSRY and SRDM% and SRR resistance are farmer-preferred traits. Therefore, enhancement of such traits through plant breeding is likely to increase the adoption of new genotypes by farmers.Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
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Were, Woyengo Vincent. "Cassava breeding through complementary conventional and participatory approaches in western Kenya." Thesis, 2011. http://hdl.handle.net/10413/8573.
Full textAbstract:
Participation of farmers in plant breeding programmes has been reported to increase
breeding efficiency. Farmers’ participation bridges the gap between variety development and
dissemination and provides an opportunity for farmers to select varieties they prefer. The
breeders on the others hand learn more about the farmers’ preferences and the environment
in which the new varieties will be grown. However, the advantages of participatory breeding
can best be realized when farmers’ indigenous technical knowledge (ITK) and experience
complement the breeder’s scientific knowledge and skills. Cassava (Manihot esculenta
Crantz) is a clonally propagated crop grown in diverse environments by small scale farmers
for subsistence. Information on the roles of farmers and breeders at various stages of
breeding and their ability to effectively participate in breeding programmes is limited. The
objectives of this study were to determine: (1) cassava farmers’ preferences, production
constraints and systems; (2) farmers’ selection criteria of cassava varieties; (3) genetic
inheritance of farmer preferred traits; (4) how farmers and breeders complement each other
at all stages and activities of cassava breeding.
Participatory rural appraisal was conducted in three purposefully sampled districts of western
Kenya based on ethnicity and agro-ecology. The results reveal that cassava is
predominantly grown by small scale farmers with mean land size of 1.6 ha mainly under
mixed cropping system for subsistence. The storage roots are eaten either after boiling or
processing to flour. The majority of farmers (over 60%) are aware of the improved varieties
but adoption rate is low (18% in some districts). The effects of pests and diseases, and the
lack of high yielding varieties, capital, land, and disease free planting material are the most
important constraints to cassava production. Farmers prefer tall, high yielding varieties that
are resistant to diseases and pests, early maturing and long underground storability of
harvestable storage roots. The districts surveyed significantly differed in popularity of
utilization methods, traits preferences and relative ranking of the production constraints
indicative of differences in ethnicity and agro-ecology.
Three farmer groups from the three districts selected in western Kenya were used to study
farmers’ variety selection criteria based on their own indigenous technical knowledge (ITK).
The groups evaluated 15 (10 landraces and five improved) popular cassava varieties with
concealed identities on their farms. The results revealed that farmers have effective methods
of selecting varieties for most of their preferred traits. However, ITK alone cannot be used to
evaluate all the important traits, such as cyanide content.
The genetic inheritance of farmer preferred traits was determined through a genetic study.
Six landraces and four improved varieties popular in western Kenya were crossed using the
North Carolina mating design II to generate 24 full-sib families. The 24 families, represented
by 40 siblings each, were evaluated at two sites, Kakamega and Alupe research station
farms, in a 24 x 40 a-lattice design. General combining ability (GCA) and specific combining
ability (SCA) mean squares were significant (P<0.05) for all traits evaluated except dry
matter content and cyanide content. However, non-additive gene action predominated over
additive gene for cassava mosaic disease (CMD) resistance, height to first branching, total
number of storage roots per plant and fresh storage root yield in all environments. The best
crosses were not necessarily obtained from parents with high general combining ability
confirming the presence of non-additive gene action. The best performing parents per se did
not necessarily have high GCA effects implying that selection based on the per se
performance of parents may not always lead to development of superior hybrids.
The clonal evaluation trial (CET) was established at Alupe research station and evaluated by
the breeder and farmers from two districts independently. Three selection criteria were
tested to determine the most appropriate approach to selection of varieties that meet both
farmers’ and breeder’s preferences. The selection criteria were; farmers’ independent
selection index (SI) derived from farmers’ selection criteria from each district, breeder’s
negative selection and independent SI, and a participatory SI which combines farmers’ and
breeder’s selection criteria. There was 14% overlap among the top 100 varieties selected by
farmers from all districts and the breeder when independent SI were used. However, there
was 49% overlap among the top 100 varieties selected by farmers using participatory SI and
the breeder’s SI. The farmers and the breeder have a role to play in the variety development
process. Varieties with traits preferred by both the farmers and the breeder are likely to
enhance breeding efficiency and effectiveness.Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
Books on the topic "Cassava Cassava Cassava Cassava Cassava Cassava as food Cassava Plant breeding Starch. Theses"
Book chapters on the topic "Cassava Cassava Cassava Cassava Cassava Cassava as food Cassava Plant breeding Starch. Theses"
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Sharma, Binny, and Asha Kumari. "Role of Post-Harvest Physiology in Evolution of Transgenic Crops." In Plant Breeding - Current and Future Views [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.94694.
Full textAbstract:
The increasing world population over few decades has led to increase in demand of food grains or agricultural commodities, thus possessing great impact on food security. Conventional farming approaches has been traditionally practiced but a lot of effort is required to make to enhance agricultural production. With changing climatic conditions plants are vulnerable to several stress factors. In order to combat such conditions, the agricultural systems are needed to be contemporary with advance and recent technologies. Crops after harvest are liable to a lot of changes which ultimately affect quality and quantity of produce, thus reducing economic value. Postharvest losses are decisive factors in reducing loss of produce and agricultural commodities. Thus in order to achieve maximum production, it is therefore essential to reduce postharvest losses and ensures proper management of postharvest products. Postharvest physiology is the science which deals with quantitative and qualitative study of physiology of agricultural products after harvesting. Biotechnological and transgenic approaches are the recent and emerging technologies that possess great impact on agricultural production. Transgenic technology like genome editing, CRISPR/Cas9, TILLING are successfully used in various species to enhance production, possess resistance to abiotic and biotic stresses, enhance shelf life and improve nutritional quality. Transgenic crops or Genetically modified crops (GMO) like tomato, brinjal, soybean, cassava etc are cultivated globally. These techniques therefore are promising means in establishing food security, increasing crop production, reducing postharvest losses, production of secondary metabolites, hormones and plantibodies.
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Smith, David G. "People and Plants in the Precontact Caribbean." In Cuban Archaeology in the Caribbean. University Press of Florida, 2016. http://dx.doi.org/10.5744/florida/9781683400028.003.0004.
Full textAbstract:
Research work at the site of Canímar Abajo in northern Cuba, one of the rare Cuban sites investigated through systematic, large scale excavations, has yielded exciting new data that contribute to our understanding of two major themes in circum-Caribbean archaeology: 1. the timing of first migration to the Greater Antilles as well as the origins of the first settlers; and 2. the nature and timing of the origins of resource production in the Caribbean. The discovery of starch grains of maize (Zea mays), common bean (Phaseous sp.), sweet potato (Ipomoea batatas) and cassava (Manihot esculenta) in dental calculus from burials at this site have important implications for discussions on food production in the Neotropics. Research results indicate that a community of people practicing a subsistence regime of fishing, gathering, hunting and plant cultivation was already established in the area of the Canímar River estuary by 1200 BC. It is argued that the first migrants most likely crossed to the Greater Antilles from mainland Central America well before 1200 BC, and brought cultivated species originating in Mexico (maize and beans) and in Central America (sweet potato) with them.
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"nose family of sugars [178]. Total free sugar content of rye from tubers and roots, particularly potato, sweet potato, and was reported as 3.2%, with sucrose (1.9%), raffinose tapioca (cassava). Isolated starch can be modified physical-(0.4%), fructose (0.1%), and glucose (0.08%) [120]. ly and/or chemically to alter its functional properties. Starches and modified starches have an enormous number Ill. STARCH of food uses, including adhesive, binding, clouding, dust-ing, film forming, and thickening applications [20]. Starch is found in a number of plant sources, and the plant relies on starch for its energy requirements for growth and reproduction. For humans, starch is extremely important as A. Starch Content of Cereals a macronutrient, because it is a complex carbohydrate and The most important sources of starch are cereal grains an important energy source in our diet. (40-90% of their dry weight), pulses (30-70%), and tubers The commercial and technological uses of starch are (65-85%). Of the common starches, regular corn, waxy numerous; this arises from its unique character, because it corn, and high-amylose corn are by far the most important can be used directly as intact granules, in the dispersed sources. The starch content of corn may vary from about form, as a film dried from a dispersion, as an extruded 54% in sweet corn to 64-78% in dent [194]. Corn is large-powder, or after conversion to a mixture of oligosaccha-ly used as stock feed but nevertheless supplies the bulk, by rides or via hydrolysis and isomerization. far, of the world's starch production. Corn starch is manu-When starch is heated in water, it absorbs water and factured by traditional wet-milling process. Only about 5% swells. This is the process of gelatinization, a process that of the annual world maize crop is used for the manufacture cause a tremendous change in rheological properties of the of maize starch. About 70% of the maize starch produced starch suspension. The crystalline structure is destroyed is converted into corn syrups, high-fructose corn syrup, during gelatinization. The ability of starch molecules to and dextrose. Corn starch has a wide variety of industrial crystallize after gelatinization is described by the term of applications, with uses ranging from thickening and retrogradation. Although some retrogradation of amylose gelling agents in puddings and fillings to molding for con-seems to be a prerequisite for the formation of a normal fections [72]. bread crumb, long-term retrogradation usually causes Potato starch is a variable commodity, sensitive to vari-gradual deterioration of bread quality during the products' ety, climate, and agricultural procedure. Potato starch, shelf life [55]. however, is presently second only to corn and comparable Starch occurs as discrete granules in higher plants. Two to wheat in terms of quantity produced and especially pop-major polymers, amylose and amylopectin, are contained in ular in Europe. About 3% of the world crop of potatoes is the granule. Cereal starch granules may also contain small used for the production of potato starch. Potato starch is amounts of proteins, lipids, and minerals [118]. Cereal used in food, paper, textile, and adhesive industries. starches are widely used in foods, where they are important The starch content of wheat has been reported to be in functionally and nutritionally. Commercial starches are ob-the range of 63-72% [147] (Table 2). Wheat starch, found tained from cereal grain seeds, particularly from corn, waxy in the endosperm of the wheat kernel, constitutes approxi-corn, high-amylose corn, wheat, and various rites, and mately 75-80% of the endosperm on a dry basis. The TABLE 2 Carbohydrate Composition of Some Cereal Grains' Sample Starch (%) Amylose (%) Pentosan (%) P-Glucan (%) Total dietary fiber Wheat 63-72 (147) 23.4-27.6 (133) 6.6 (81) 1.4 (151) 14.6 (32) Barley 57.6-59.5 (87) 22-26 (27) 5.9 (82) 3-7 (139) 19.3-22.6 (87) Brown rice 66.4 (104) 16-33 (124) 1.2 (81) 0.11 (102) 3.9 (32) Milled rice 77.6 (104) 7-33 (102) 0.5-1.4 (104) 0.11 (104) 2.4 (32) Sorghum 60-77 (194) 21-28 (127) 1.8-4.9 (127) 1.0 (151) 10.1 (160) Pearl Millet 63 (123) 17 (11) 2-3 (12) 8.5 (32) Corn 64-78 (194) 24 (132) 5.8-6.6 (194) 13.4 (32) Oats 43-61 (143) 16-27 (120) 7.7 (81) 3.9-6.8 (198) 9.6 (32) Rye 69 (168) 24-31 (168) 8.5 (81) 1.9-2.9 (151) 14.6 (32) Triticale 53 (22) 24-26 (40) 7.1 (81) 1.2 (151) 18.1 (32) aSources shown in parentheses." In Handbook of Cereal Science and Technology, Revised and Expanded, 403–4. CRC Press, 2000. http://dx.doi.org/10.1201/9781420027228-40.
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