The industrial starch market is undergoing major expansion, but certain specific industrial uses ... more The industrial starch market is undergoing major expansion, but certain specific industrial uses cannot be satisfied by native starches and, therefore, chemical or physical modification is necessary. Mutations in the cassava starch biosynthesis pathways were discovered at CIAT (Cali, Colombia) few years ago. A starch mutation induced by gamma rays radiation resulted in a deeply modified branching pattern of amylopectin as well as other starch characteristics and properties. These modifications include changes in starch granule ultrastructure (e.g. decreased starch crystallinity), a weak organized structure, and increased susceptibility to mild acid and enzymatic raw starch hydrolysis (fastest and most efficient hydrolysis of all studied native starches). This mutation could offer interesting advantages for the production of bioethanol. Surprisingly this mutation also results in increased proportion of amylopectin. Hydrolysis was more dependent on granule morphology than on starch ch...
Significant progress has been made increasing carotenoids content in cassava roots. The informati... more Significant progress has been made increasing carotenoids content in cassava roots. The information was used to test the usefulness of NIRs and the Minolta Chromameter in predicting carotenoids content (and other relevant traits). Quantification was made of fresh root tissue (not lyophilized). The dataset (2129 data points) was first cleaned of outlying or suspicious data points to develop reliable prediction equations. R2 values between NIRs prediction and actual measurements were 0.91 for total carotenoids content (TCC); 0.93 for total ?-carotene (TBC), and 0.95 for dry matter content, but is less efficient for cyanogenic potential (0,81). Standard error of cross validation (SECV) for TCC and TBC were (1.191 and 0.837, respectively) while the residual predictive deviations (RPD) were also acceptable (above 3.0). These results suggest that NIRs can be used to reliably predict different variables based on fresh root samples. The Minolta Chromameter can also be used for pre-selection...
ABSTRACT Summary The cassava starch presents a little variation in its quality. Although induced ... more ABSTRACT Summary The cassava starch presents a little variation in its quality. Although induced mutations are a source of inherited variation for desirable traits, phenotypic expression of mutants is currently difficult to detect due to its heterozygous condition. The objective of this work was to produce M2 populations in order to increase the homozygous level of traits related to starch quality and the phenotypic characterization of irradiated plants (M1) to evaluate the induced variability. Botanical seeds from families CM9331, SM3015, SM3045, GM155, C4, and C127 were irradiated with gamma rays and fast neutrons. Plants were established in an experimental plot in the Research Station of Corpoica-Palmira. Self-pollination was carried out both to eliminate the possible chimerical states as well as to increase the level of homozygosity. In order to identify chimeras and/or useful traits among treatments, a morphological screening were made using 9 quantitative and 18 qualitative parameters. A total of 9707 flowers were self-pollinated. The percentage of surviving plants was 60% and 29% for seeds treated with gamma rays and fast neutrons, respectively. Quantitative descriptors revealed high variability. The main components analysis suggested formation of groups related to ramification and vigor. For qualitative description, chimerical plants in crust color of stem and leaf shape, and remarkable effects on the flower type (e.g., hermaphrodite flower and apomictic behavior) were observed. The multiple correspondence analysis suggested clusters related to the flowering. These results demonstrate the effect of the radiation sources on the phenotypic variability of the population. Future analysis of segregating populations will allow detection of useful variability for traits related with starch quality.
Esta variedad fue obtenida enel programa de mejoramiento delciat a partirde semillas sexuales pro... more Esta variedad fue obtenida enel programa de mejoramiento delciat a partirde semillas sexuales producidas en lote de policruzamiento durante el ano 1997, solamente el parental femenino es conocido: SM 1565-15.la siembrade la Fi se llevo a cabo en 1998. Al ano siguiente, tras haber sido seleccionado en ei F1C1 (1999), este se incluyo en la evaluacion en campo de observacion (2000) y se continuo con su avance hasta cubrir las etapas de ensayo preliminar de rendimiento (2001), ensayo avanzado de rendimiento (2002-2003), pruebas regionales (2003-2009) y pruebas semicomerciales (2013-2017). Conocido experimentalmente como sm 2792-31, este genotipo fue elevado a la categoria de clon elite, pues su desempeno —a traves de anos de evaluacion en distintas localidades— demostro que cuenta concaracteristicas semejantes o superiores, en cuanto a tipo de planta, rendimiento y contenido de materia seca, en comparacion con los testigos Brasilera (mcol 2737), Catumare y Reina. Tales caracteristicas f...
Cassava starch is a functional ingredient largely used in the food industry. This work reported t... more Cassava starch is a functional ingredient largely used in the food industry. This work reported the discovery of the first natural waxy cassava genotype (AM206-5) in CIAT, Cali, Colombia. SDS-PAGE demonstrated abnormality in the GBSS enzyme in the starch AM206-5. No change in starch granule size or shape was observed in comparison with normal cassava starch. Colorimetric and DSC amylose content for AM206-5 showed (3.4%; 0%) in comparison with normal cassava starch (19.7%; 19.0%) respectively. Paste clarity (61% vs 50%). Wavelength of maximum absorption (?max), (535 nm vs 590 nm), Pasting properties (RVA 5%): Pasting temperature (67.4°C vs 63.9°C) ; Maximum viscosity (1119 cP vs 954 cP) ; breakdown (631 cP vs 479 cP). swelling power ( 54.7% vs 40%), solubility(8.8% vs 7.3%), at 90°C. All analysis reported converge to support the hypothesis that genotype AM206-5 has amylose-free (waxy) starch. The evaluation of gel stress resistance was also compared with other industrial roots, tuber...
The Global Cassava Strategy initiative identified weak markets for cassava products as a bottlene... more The Global Cassava Strategy initiative identified weak markets for cassava products as a bottleneck limiting the capacity of the crop to help farmers out of poverty. Identifying or creating genetic variability to make cassava better suited to meet the needs of different industries could help overcoming this bottleneck. This article summarizes the results from traditional approaches (breeding, screening germplasm collections, inbreeding to expose recessive traits, mutagenesis and inter-specific crosses). Significant progress has been attained for different traits recently: 1) Tolerance to post-harvest physiological deterioration was introgressed from #Manihot wakerae# and perhaps found in mutagenized populations. This trait will drastically reduce the marketing costs of cassava; 2) Commercially relevant starch mutations (amylose-free and small-granule/high-amylose) have been identified through inbreeding and induction of mutations. These traits are relevant for the starch and bio-eth...
Vitamin A deficiency (VAD) is a major problem with huge public health implications. One strategy ... more Vitamin A deficiency (VAD) is a major problem with huge public health implications. One strategy to overcome this problem is the development of varieties with increased levels of pro-vitamin A carotenoids. Cassava is a relevant crop in many regions of the world where VAD is prevalent. Significant progress has already been achieved increasing the content of total carotenoids (CTC) in cassava roots. However, little is known on the inheritance of this trait in cassava. In this study the segregations for CTC in several full-sib and self-pollinated (S1) families were analyzed. Parent-offspring regression was used to estimate heritability, which was found to be high (>0.60). The analyses of segregations did not allow for the identification of simple Mendelian patterns that could explain the variation in CTC in every family analyzed. However, enough evidence has been generated for a hypothesis that few (2-3) major genes control most of the variation in CTC but their action is modified b...
The industrial starch market is undergoing major expansion, but certain specific industrial uses ... more The industrial starch market is undergoing major expansion, but certain specific industrial uses cannot be satisfied by native starches and, therefore, chemical or physical modification is necessary. Mutations in the cassava starch biosynthesis pathways were discovered at CIAT (Cali, Colombia) few years ago. A starch mutation induced by gamma rays radiation resulted in a deeply modified branching pattern of amylopectin as well as other starch characteristics and properties. These modifications include changes in starch granule ultrastructure (e.g. decreased starch crystallinity), a weak organized structure, and increased susceptibility to mild acid and enzymatic raw starch hydrolysis (fastest and most efficient hydrolysis of all studied native starches). This mutation could offer interesting advantages for the production of bioethanol. Surprisingly this mutation also results in increased proportion of amylopectin. Hydrolysis was more dependent on granule morphology than on starch ch...
Significant progress has been made increasing carotenoids content in cassava roots. The informati... more Significant progress has been made increasing carotenoids content in cassava roots. The information was used to test the usefulness of NIRs and the Minolta Chromameter in predicting carotenoids content (and other relevant traits). Quantification was made of fresh root tissue (not lyophilized). The dataset (2129 data points) was first cleaned of outlying or suspicious data points to develop reliable prediction equations. R2 values between NIRs prediction and actual measurements were 0.91 for total carotenoids content (TCC); 0.93 for total ?-carotene (TBC), and 0.95 for dry matter content, but is less efficient for cyanogenic potential (0,81). Standard error of cross validation (SECV) for TCC and TBC were (1.191 and 0.837, respectively) while the residual predictive deviations (RPD) were also acceptable (above 3.0). These results suggest that NIRs can be used to reliably predict different variables based on fresh root samples. The Minolta Chromameter can also be used for pre-selection...
ABSTRACT Summary The cassava starch presents a little variation in its quality. Although induced ... more ABSTRACT Summary The cassava starch presents a little variation in its quality. Although induced mutations are a source of inherited variation for desirable traits, phenotypic expression of mutants is currently difficult to detect due to its heterozygous condition. The objective of this work was to produce M2 populations in order to increase the homozygous level of traits related to starch quality and the phenotypic characterization of irradiated plants (M1) to evaluate the induced variability. Botanical seeds from families CM9331, SM3015, SM3045, GM155, C4, and C127 were irradiated with gamma rays and fast neutrons. Plants were established in an experimental plot in the Research Station of Corpoica-Palmira. Self-pollination was carried out both to eliminate the possible chimerical states as well as to increase the level of homozygosity. In order to identify chimeras and/or useful traits among treatments, a morphological screening were made using 9 quantitative and 18 qualitative parameters. A total of 9707 flowers were self-pollinated. The percentage of surviving plants was 60% and 29% for seeds treated with gamma rays and fast neutrons, respectively. Quantitative descriptors revealed high variability. The main components analysis suggested formation of groups related to ramification and vigor. For qualitative description, chimerical plants in crust color of stem and leaf shape, and remarkable effects on the flower type (e.g., hermaphrodite flower and apomictic behavior) were observed. The multiple correspondence analysis suggested clusters related to the flowering. These results demonstrate the effect of the radiation sources on the phenotypic variability of the population. Future analysis of segregating populations will allow detection of useful variability for traits related with starch quality.
Esta variedad fue obtenida enel programa de mejoramiento delciat a partirde semillas sexuales pro... more Esta variedad fue obtenida enel programa de mejoramiento delciat a partirde semillas sexuales producidas en lote de policruzamiento durante el ano 1997, solamente el parental femenino es conocido: SM 1565-15.la siembrade la Fi se llevo a cabo en 1998. Al ano siguiente, tras haber sido seleccionado en ei F1C1 (1999), este se incluyo en la evaluacion en campo de observacion (2000) y se continuo con su avance hasta cubrir las etapas de ensayo preliminar de rendimiento (2001), ensayo avanzado de rendimiento (2002-2003), pruebas regionales (2003-2009) y pruebas semicomerciales (2013-2017). Conocido experimentalmente como sm 2792-31, este genotipo fue elevado a la categoria de clon elite, pues su desempeno —a traves de anos de evaluacion en distintas localidades— demostro que cuenta concaracteristicas semejantes o superiores, en cuanto a tipo de planta, rendimiento y contenido de materia seca, en comparacion con los testigos Brasilera (mcol 2737), Catumare y Reina. Tales caracteristicas f...
Cassava starch is a functional ingredient largely used in the food industry. This work reported t... more Cassava starch is a functional ingredient largely used in the food industry. This work reported the discovery of the first natural waxy cassava genotype (AM206-5) in CIAT, Cali, Colombia. SDS-PAGE demonstrated abnormality in the GBSS enzyme in the starch AM206-5. No change in starch granule size or shape was observed in comparison with normal cassava starch. Colorimetric and DSC amylose content for AM206-5 showed (3.4%; 0%) in comparison with normal cassava starch (19.7%; 19.0%) respectively. Paste clarity (61% vs 50%). Wavelength of maximum absorption (?max), (535 nm vs 590 nm), Pasting properties (RVA 5%): Pasting temperature (67.4°C vs 63.9°C) ; Maximum viscosity (1119 cP vs 954 cP) ; breakdown (631 cP vs 479 cP). swelling power ( 54.7% vs 40%), solubility(8.8% vs 7.3%), at 90°C. All analysis reported converge to support the hypothesis that genotype AM206-5 has amylose-free (waxy) starch. The evaluation of gel stress resistance was also compared with other industrial roots, tuber...
The Global Cassava Strategy initiative identified weak markets for cassava products as a bottlene... more The Global Cassava Strategy initiative identified weak markets for cassava products as a bottleneck limiting the capacity of the crop to help farmers out of poverty. Identifying or creating genetic variability to make cassava better suited to meet the needs of different industries could help overcoming this bottleneck. This article summarizes the results from traditional approaches (breeding, screening germplasm collections, inbreeding to expose recessive traits, mutagenesis and inter-specific crosses). Significant progress has been attained for different traits recently: 1) Tolerance to post-harvest physiological deterioration was introgressed from #Manihot wakerae# and perhaps found in mutagenized populations. This trait will drastically reduce the marketing costs of cassava; 2) Commercially relevant starch mutations (amylose-free and small-granule/high-amylose) have been identified through inbreeding and induction of mutations. These traits are relevant for the starch and bio-eth...
Vitamin A deficiency (VAD) is a major problem with huge public health implications. One strategy ... more Vitamin A deficiency (VAD) is a major problem with huge public health implications. One strategy to overcome this problem is the development of varieties with increased levels of pro-vitamin A carotenoids. Cassava is a relevant crop in many regions of the world where VAD is prevalent. Significant progress has already been achieved increasing the content of total carotenoids (CTC) in cassava roots. However, little is known on the inheritance of this trait in cassava. In this study the segregations for CTC in several full-sib and self-pollinated (S1) families were analyzed. Parent-offspring regression was used to estimate heritability, which was found to be high (>0.60). The analyses of segregations did not allow for the identification of simple Mendelian patterns that could explain the variation in CTC in every family analyzed. However, enough evidence has been generated for a hypothesis that few (2-3) major genes control most of the variation in CTC but their action is modified b...
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