scholarly journals Genetic Analysis of Yield and Quality Characteristics in Provitamin A Hybrid Cassava Families in Ghana

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1911
Author(s):  
Bright Boakye Peprah ◽  
Elizabeth Yaa Parkes ◽  
Peter Kulakow ◽  
Angeline van van Biljon ◽  
Maryke Tine Labuschagne

Cassava is the most widely cultivated and consumed crop in Ghana. Malnutrition is endemic in cassava-producing regions of Africa, partly due to the low micronutrient content of this crop. The aim of this study was to generate genetic information on characteristics such as total carotenoid content, dry matter content, root weight and number, and cassava mosaic disease (CMD), and their possible combination in cassava clones, using a North Carolina II breeding scheme. Five genetically diverse yellow-fleshed clones at advanced selection stages, with CMD resistance, were used as females and two high dry matter content white-fleshed clones, selected from farmers’ fields in Ghana, were used as males. Ten F1 families were generated, and evaluated at two locations in Ghana. General combining ability (GCA) mean squares were larger than specific combining ability (SCA) mean squares for harvest index, CMD, and carotenoid content, indicating additive genetic effects. The positive significant correlations that were observed between pulp color and carotenoid content; carotenoid content and CMD; pulp color and CMD; and pulp color and cortex color, make the screening of large numbers of progenies possible in the cassava breeding program. This could allow breeders to combine carotenoid content and CMD at the early breeding stages through visual assessment of pulp color and CMD symptoms. Large numbers of genotypes can be evaluated and a few can be selected to be quantified for carotenoid content at later stages of the breeding program, to save costs. One of the parents (P6), showed positive GCA effects for carotenoid content, dry matter content, CMD and storage root weight, hence could be used as a parent to generate clones that combine carotenoid content and dry matter content.

2021 ◽  
Vol 11 (4) ◽  
pp. 1714
Author(s):  
Wilfred Abincha ◽  
Ugochukwu N. Ikeogu ◽  
Robert Kawuki ◽  
Chiedozie Egesi ◽  
Ismail Rabbi ◽  
...  

The use of standard laboratory methods for trait evaluation is expensive and challenging, especially for low-resource breeding programs. For carotenoid assessment, rather than the standard HPLC method, these programs mostly rely on proxy approaches for quantitative total carotenoid content (TCC) assessment. To ensure data transferability and consistency, calibration models were developed using TCC iCheck and Chroma Meter proxy methods for the adoption of the alternative near-infrared phenotyping method in cassava. Calibration was developed for dry matter content (DMC) using a simple and inexpensive sampling procedure associated with the proxy TCC protocols. The partial least square (PLS) and random forest (RF) models were compared for the two traits, and the correlation (r) between the actual and predicted values in the training and validation (in bracket) sets of r = 0.85 (0.76) and r = 0.98 (0.82) with PLS and RF, respectively, for iCheck, and r = 0.99 (0.96) and r = 0.99 (0.96) with PLS and RF, respectively, for Chroma Meter, was obtained. The calibration result of r = 0.93 (0.83) and r = 0.99 (0.81) using PLS and RF, respectively, was obtained for DMC. This effort is valuable in carotenoids improvement and supports the ongoing effort in adopting portable spectrometers for rapid and cheap phenotyping in cassava.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1850
Author(s):  
Elizabeth Parkes ◽  
Olufemi Aina ◽  
Akuwa Kingsley ◽  
Peter Iluebbey ◽  
Moshood Bakare ◽  
...  

Cassava is an important root crop in sub-Saharan Africa, largely cultivated for its starchy edible roots. Biofortified cassava varieties with enhanced provitamin A carotenoid content (PVAC) developed through conventional breeding provide a solution for vitamin A deficiency among vulnerable communities. The aim of this study was to use diallel analysis of six provitamin A cassava genotypes to determine the combining ability, genetic components, heritability, and heterosis of the most important yield characteristics and total carotenoids. Genetic variability for measured characteristics were evident. Fresh root yield was mainly determined by non-additive genetic effects, while dry matter content and total carotenoids were determined by additive effects. Total carotenoids were negatively correlated with fresh root yield, indicating that selection for higher provitamin A content could reduce yield. Mid and higher parent heterosis was seen in some of the crosses for fresh root yield, dry matter content, and total carotenoids. Narrow sense heritability was moderate for fresh root yield and dry matter content, and was high for total carotenoids. This study indicated that yield and dry matter content can be improved in provitamin A cassava but that increased provitamin A content may carry a yield penalty.


Author(s):  
Eduardo O. Leidi-Montes ◽  
Youssef Ech-Liach ◽  
Sabina Rossini-Oliva ◽  
Marten Sørensen

Among the many neglected underutilized species, tuberous Andean root crops like the ahipas (Pachyrhizus ahipa) constitute a promising alternative for increasing diversity in nutrient sources and food security at a regional level. In this study, we present the content of some functional compounds in tuberous roots from several ahipa accessions and the progenies of the interspecific hybrid X207 (P. ahipa × P. tuberosus). A significant objective was to determine protein and free amino acids in the roots to evaluate their food quality as protein supply. The interspecific hybrids have been found to possess the root quality to provide the crop with a higher dry matter content. The high dry matter content of the P. tuberosus Chuin materials is retained in the root quality of the hybrids. Food functional components like carbohydrates, organic acids, and proteins were determined in several ahipa accessions and a stable (non-segregating) progeny of the interspecific hybrid, X207. The X207 roots showed a significantly higher dry matter content and a lower content in soluble sugars, but no significant differences were found in starch content or organic acids compared to the ahipa accessions. About the root mineral contents, Fe and Mn concentrations in X207 were significantly raised compared to the average of ahipa accessions. Among the ahipa and the hybrid, no prominent differences in protein content or protein amino acids were found, being both partially defective in providing sufficient daily intake of some essential amino acids. Root weight, a central component of root yield, was significantly higher in X207, but thorough field studies are required to substantiate the hybrid’s superior yield performance..


2017 ◽  
Author(s):  
Ismail Y. Rabbi ◽  
Lovina I. Udoh ◽  
Marnin Wolfe ◽  
Elizabeth Y. Parkes ◽  
Melaku A. Gedil ◽  
...  

ABSTRACTCassava (Manihot esculenta (L.) Crantz) is a starchy root crop cultivated in the tropics for fresh consumption and commercial processing. Dry matter content and micronutrient density, particularly of provitamin A – traits that are negatively correlated – are among the primary selection objectives in cassava breeding. This study aimed at identifying genetic markers associated with these traits and uncovering the potential underlying cause of their negative correlation – whether linkage and/or pleiotropy. A genome-wide association mapping using 672 clones genotyped at 72,279 SNP loci was carried out. Root yellowness was used indirectly to assess variation in carotenoid content. Two major loci for root yellowness was identified on chromosome 1 at positions 24.1 and 30.5 Mbp. A single locus for dry matter content that co-located with the 24.1 Mbp peak for carotenoid content was identified. Haplotypes at these loci explained a large proportion of the phenotypic variability. Evidence of mega-base-scale linkage disequilibrium around the major loci of the two traits and detection of the major dry matter locus in independent analysis for the white- and yellow-root subpopulations suggests that physical linkage rather that pleiotropy is more likely to be the cause of the negative correlation between the target traits. Moreover, candidate genes for carotenoid (phytoene synthase) and starch biosynthesis (UDP-glucose pyrophosphorylase and sucrose synthase) occurred in the vicinity of the identified locus at 24.1 Mbp. These findings elucidate on the genetic architecture of carotenoids and dry matter in cassava and provides an opportunity to accelerate genetic improvement of these traits.CORE IDEASCassava, a starchy root crop, is a major source of dietary calories in the tropics.Most varieties consumed are poor in micronutrients, including pro-vitamin A.These two traits are governed by few major loci on chromosome one.Genetic linkage, rather than pleiotropy, is the most likely cause of their negative correlation.


2021 ◽  
Vol 39 (3) ◽  
pp. 299-304
Author(s):  
Lucimeire Pilon ◽  
Jaqueline S Guedes ◽  
Bruna S Bitencourt ◽  
Raphael Augusto de C Melo ◽  
Larissa PC Vendrame ◽  
...  

ABSTRACT Sweetpotato (Ipomoea batatas) is a root crop grown in many countries. This tuberous root is a source of energy, nutrients, and phytochemicals. In this study, bioactive compounds and physical and physicochemical qualities of sweetpotato genotypes were evaluated. Eight new genotypes of sweetpotato produced by Embrapa Hortaliças (orange-fleshed: MD09026-OF and MD09024-OF; cream-fleshed: MD09011-CF, MD09004-CF, MD10039-CF, and MD10004-CF; yellow-fleshed: MD09017-YF and MD12002-YF) and two cultivars used as controls (Beauregard and Brazlândia Roxa) were evaluated for color, soluble solids, dry matter, phenolic compounds, total carotenoids and β-carotene. Hue angles differed even between those sweetpotatoes with the same flesh color. The orange-fleshed genotypes MD09024-OF, MD09026-OF, and Beauregard, had the lowest L*, showing to be darker than the others. These sweetpotatoes also had the brightest flesh colors with higher C*. The orange-fleshed genotypes MD09026-OF and MD09024-OF were sweeter (10.55oBrix and 9.23oBrix) than Beauregard (5.12oBrix). Brazlândia Roxa had the highest dry matter content (38.05%), followed by the genotypes MD10004-CF, MD09017-YF, MD09026-OF MD10039-CF, and MD09011-CF, which showed similarity, ranging from 32.33% to 29.12%. The highest contents of total carotenoids were found for the orange-fleshed genotypes MD09026-OF (80.06 mg g-1) and MD09024-OF (70.56 mg g-1) and Beauregard (73.12 mg g-1). These same genotypes showed the highest total phenolic compounds (0.815 mg g-1 and 0.686 mg g-1, respectively). MD09026-OF showed the highest content of β-carotene (46.47 mg g-1). MD09026-OF was the most prominent genotype among those evaluated, as it showed the highest total carotenoid, β-carotene, phenolic compounds, and soluble solids content, in addition to a high dry matter content.


2010 ◽  
Vol 10 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Henry Fred Ojulong ◽  
Maryke Tine Labuschagne ◽  
Liezel Herselman ◽  
Martin Fregene

The cassava breeding scheme currently used is long, because initial stages concentrate mainly on improving yield, with root quality selection following later. To shorten the scheme, yield and root quality should be selected simultaneously, starting at the seedling nursery. In this study, a nursery comprising of eight cassava families and 1885 seedlings developed from parents adapted to three major agro-ecologies, were evaluated for yield related traits in Colombia. Percentage dry matter content (DMC) and harvest index produced similar ranking of the parents. Tuber yield, weight, and number showed potential of increasing yield through conventional breeding. A selection index including fresh root yield, percentage DMC, root weight and roots per plant, with heavier weights being assigned to root weight and roots per plant, should be used.


1976 ◽  
Vol 87 (2) ◽  
pp. 443-446 ◽  
Author(s):  
O. A. Denton ◽  
W. J. Whittington

SummaryThe mean total yield and mean fresh weight of seven swede varieties and their F1 hybrids was increased primarily by nitrogen and also by phosphorus fertilizer. There was no evidence of genotype × environment interaction for characters concerned with yield except for dry-matter content where two varieties, Best-of-All and Reform, were less stable to fertility environments than the others. Heterosis was common amongst F1 hybrids and this suggests their use in swede improvement: the inheritance pattern of root weight showed overdominance, shoot weight showed partial dominance and drymatter content showed additivity, with no evidence of gene interaction. Segregation for root fresh weight and dry-matter content occurred in F2 populations and although an overall negative correlation was found there was evidence that progeny from certain crosses gave reasonable prospects of combining both characters.


2007 ◽  
Vol 132 (5) ◽  
pp. 729-738 ◽  
Author(s):  
Lucia E. Villavicencio ◽  
Sylvia M. Blankenship ◽  
G. Craig Yencho ◽  
Judith F. Thomas ◽  
C. David Raper

Sweetpotatoes [Ipomoea batatas (L.) Lam.] often experience significant epidermal loss during harvest and postharvest handling. Skin loss causes weight loss, shriveling of the root surface, and increased susceptibility to pathogen attack as well as poor appearance. It is not known if sweetpotatoes show variation in skin adhesion, cell wall enzyme activity and components, and growth parameters with growth temperature or if skin loss can be explained on the basis of variation among these variables. Skin adhesion, polygalacturonase (PG) and pectin methylesterase (PME) activity, lignin, anthocyanin, and dry matter content were measured in the periderm of ‘Beauregard’ roots grown at various temperatures under controlled conditions. Biomass dry matter content, storage root yield, root length, diameter, and weight at harvest were recorded. Histochemical and anatomical characteristics of periderm of roots were studied. Growth temperature affected skin adhesion, PG and PME activity, periderm and biomass dry matter content, yield, storage root weight, and diameter. High temperatures (34/31 °C day/night) yielded roots that were smaller and more resistant to skin loss. These roots had a periderm composed of more cell layers with a lower dry matter content than roots grown at lower and intermediate temperatures (27/24 °C and 20/17 °C). In cured roots, the correlation between skin adhesion and PG activity was negative (r = 0.544, P = 0.0006) and positive between skin adhesion and PME (r = 0.319, P = 0.05). For most of the variables studied, the interaction between growing temperature and curing was significant. Curing improved skin adhesion, but the effect of curing was dependent on the root growth temperature. The periderm of roots grown at higher temperatures was thicker and had more layers than that of roots grown at lower temperatures. Histochemical studies of the periderm of sweetpotato showed that the anatomical and structural composition of the cell walls differ depending on growth temperature.


2021 ◽  
Author(s):  
Ravena Rocha Bessa Carvalho ◽  
Massaine Bandeira e Sousa ◽  
Luciana Alves de Oliveira ◽  
Eder Jorge Oliveira

Abstract Increasing carotenoid content and improving other root quality traits has been the focus of cassava biofortification. This study aimed to i) evaluate the genetic variability for total carotenoid content (TCC), as well as for root yield and root quality attributes; ii) estimate potentially useful correlations for selection; and iii) select parents for breeding and estimate the genetic gain. Data from 2011 to 2020 of 265 cassava genotypes with cream and yellow roots were analyzed for dry matter content (DMC), shoot yield, fresh root yield (FRY), dry root yield (DRY), harvest index, average number of roots per plant, starch content, root pulp color, cyanogenic compounds, and TCC. The best linear unbiased predictions showed great phenotypic variation for all traits. Six distinct groups were formed for productive characteristics of root quality, mainly TCC, DMC and FRY. Only TCC showed high broad-sense heritability (\({h}^{2}\)= 0.72), while the other traits had low to medium magnitude (0.21 ≤ \({h}^{2}\) ≤ 0.60). TCC was strongly correlated with pulp color (r = 0.70), but null significance for DMC. The network analysis identified a clear separation between the agronomic and quality attributes of cassava roots. The selection of the 30 genotypes for recombination in the breeding program has the potential to raise TCC by 37.1% and reduce the cyanogenic compounds content by 19.4%, in addition to increasing FRY and DRY by 37.7% and 40.2%, respectively. This is the first consolidated study on the potential of germplasm for the development biofortified cassava varieties in Brazil.


Author(s):  
Ina Alsiņa ◽  
Anita Anševica ◽  
Laila Dubova ◽  
Inta Dudare ◽  
Maiga Niedrīte ◽  
...  

Pot experiments were carried out to investigate the effectiveness of six Rhizobium leguminosarum strains stored at the collection of Latvia University of Agriculture. Three of them are included at international Rhizobium data base. The obtained results showed that all Rhizobium strains were active and inoculated plants formed nodules on the roots. Inoculation with Rhizobium strains increased the proportion between shoots and root weight. The dry matter content of inoculated plants increased in comparison with untreated ones. The negative correlation between the plant weight and nitrogen content in the dry mater of shoots was observed. The host plant specificity was observed for tested Rhizobium leguminosarum strains.


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