scholarly journals Unravelling the complex story of intergenomic recombination in ABB allotriploid bananas

2020 ◽  
Vol 127 (1) ◽  
pp. 7-20 ◽  
Author(s):  
Alberto Cenci ◽  
Julie Sardos ◽  
Yann Hueber ◽  
Guillaume Martin ◽  
Catherine Breton ◽  
...  
Keyword(s):  
Developing Countries ◽  
Food Security ◽  
Chromosome Structure ◽  
Snp Markers ◽  
Staple Food ◽  
Musa Spp ◽  
Ancestral Origin ◽  
Intergenomic Recombination ◽  
B Genome

Abstract Background and Aims Bananas (Musa spp.) are a major staple food for hundreds of millions of people in developing countries. The cultivated varieties are seedless and parthenocarpic clones of which the ancestral origin remains to be clarified. The most important cultivars are triploids with an AAA, AAB or ABB genome constitution, with A and B genomes provided by M. acuminata and M. balbisiana, respectively. Previous studies suggested that inter-genome recombinations were relatively common in banana cultivars and that triploids were more likely to have passed through an intermediate hybrid. In this study, we investigated the chromosome structure within the ABB group, composed of starchy cooking bananas that play an important role in food security. Methods Using SNP markers called from RADSeq data, we studied the chromosome structure of 36 ABB genotypes spanning defined taxonomic subgroups. To complement our understanding, we searched for similar events within nine AB hybrid genotypes. Key Results Recurrent homologous exchanges (HEs), i.e. chromatin exchanges between A and B subgenomes, were unravelled with at least nine founding events (HE patterns) at the origin of ABB bananas prior to clonal diversification. Two independent founding events were found for Pisang Awak genotypes. Two HE patterns, corresponding to genotypes Pelipita and Klue Teparod, show an over-representation of B genome contribution. Three HE patterns mainly found in Indian accessions shared some recombined regions and two additional patterns did not correspond to any known subgroups. Conclusions The discovery of the nine founding events allowed an investigation of the possible routes that led to the creation of the different subgroups, which resulted in new hypotheses. Based on our observations, we suggest different routes that gave rise to the current diversity in the ABB cultivars, routes involving primary AB hybrids, routes leading to shared HEs and routes leading to a B excess ratio. Genetic fluxes took place between M. acuminata and M. balbisiana, particularly in India, where these unbalanced AB hybrids and ABB allotriploids originated, and where cultivated M. balbisiana are abundant. The result of this study clarifies the classification of ABB cultivars, possibly leading to the revision of the classification of this subgroup.

scholarly journals Unraveling the complex story of intergenomic recombination in ABB allotriploid bananas

2019 ◽  
Author(s):  
Cenci Alberto ◽  
Sardos Julie ◽  
Hueber Yann ◽  
Martin Guillaume ◽  
Breton Catherine ◽  
...  
Keyword(s):  
Developing Countries ◽  
Chromosome Structure ◽  
Snp Markers ◽  
Staple Food ◽  
Good Source ◽  
Ancestral Origin ◽  
Drought Tolerant ◽  
The Right ◽  
New Cultivars

AbstractBackground and AimsBananas (Musa spp.) are a major staple food for hundreds of millions of people in developing countries. The cultivated varieties are seedless and parthenocarpic clones of which the ancestral origin remains to be clarified. The most important cultivars are triploids with an AAA, AAB, or ABB genome constitution, with A and B genomes provided by M. acuminata and M. balbisiana, respectively. Previous studies suggested that inter-genome recombinations were relatively common in banana cultivars and that triploids were more likely to have passed through an intermediate hybrid. In this study, we investigated the chromosome structure within the ABB group, composed of starchy cooking bananas that play an important role in food security.MethodsUsing SNP markers called from RAD-Seq data, we studied the chromosome structure of 36 ABB genotypes spanning defined taxonomic subgroups. To complement our understanding, we search for similar events within nine AB hybrid genotypes.Key ResultsRecurrent Homoeologous Exchanges (HEs), i.e. chromatin exchanges between A and B subgenomes were unraveled with at least 9 founding events at the origin of the ABB bananas prior to the clonal diversification. The discovery of this nine founding events allows discussing the possible routes that led to the creation of the different subgroups and formulate new hypotheses. Based on our observations, we suggest different routes that gave rise to the current diversity in the ABB cultivars. Routes involving primary AB hybrids, routes leading to shared HEs and routes leading to a B excess ratio. Genetic fluxes took place between M. acuminata and M. balbisiana, particularly in India, where these unbalanced AB hybrids and ABB allotriploid originated and where cultivated M. balbisiana are abundant.ConclusionsThe result of this study clarifies the classification of ABB cultivars and leading possibly to the revision of the classification of this subgroup. This is an important step to unravel the origin of polyploid bananas, and contributes to possible scenarios on the origin. ABB bananas are hypothesized to be more drought tolerant. Knowing the origin of our current cultivars and so their potential parents will help breeders to make the right choices for future crosses. The M. balbisiana genome is a good source to create new cultivars able to answer the numerous challenges of banana breeding.

scholarly journals The Impact of Food Price Crises on the Demand for Nutrients in Pakistan

2016 ◽  
Vol 11 (3) ◽  
pp. 305-327
Author(s):  
Nadia Shabnam ◽  
Fabio Gaetano Santeramo ◽  
Zahid Asghar ◽  
Antonio Seccia
Keyword(s):  
Developing Countries ◽  
Food Security ◽  
Nutritional Status ◽  
Economic Crisis ◽  
Food Price ◽  
Price Increase ◽  
Policy Implications ◽  
Time Varying ◽  
Staple Food ◽  
The Impact

The global economic crisis in 2007–2008 resulted in a tremendous food price increase that is likely to have adversely affected the food security and nutritional status in many developing countries. Understanding how nutritional intakes may have changed as a result of the food price crisis is important, especially for Pakistan, the country under scrutiny which, despite of being a large producer of staple food, suffers from severe problems of undernourishment. We used two survey rounds, 2005–2006 and 2010–2011, to investigate how calorie and macronutrient intakes have evolved. The analysis was carried out with the use of a time varying model and is enriched by an in-depth investigation for different quantiles. The results show that food security deteriorated because of the food price crisis. In the light of this outcome, policy implications are discussed.

scholarly journals Heteroalleles in Common Wheat: Multiple Differences between Allelic Variants of the Gli-B1 Locus

2021 ◽  
Vol 22 (4) ◽  
pp. 1832
Author(s):  
Eugene Metakovsky ◽  
Laura Pascual ◽  
Patrizia Vaccino ◽  
Viktor Melnik ◽  
Marta Rodriguez-Quijano ◽  
...  
Keyword(s):  
Common Wheat ◽  
Dna Sequences ◽  
Fragment Length Polymorphism ◽  
Snp Markers ◽  
Group Iv ◽  
Nucleotide Polymorphisms ◽  
High Genetic Diversity ◽  
Single Nucleotide ◽  
Allelic Variants ◽  
B Genome

The Gli-B1-encoded γ-gliadins and non-coding γ-gliadin DNA sequences for 15 different alleles of common wheat have been compared using seven tests: electrophoretic mobility (EM) and molecular weight (MW) of the encoded major γ-gliadin, restriction fragment length polymorphism patterns (RFLPs) (three different markers), Gli-B1-γ-gliadin-pseudogene known SNP markers (Single nucleotide polymorphisms) and sequencing the pseudogene GAG56B. It was discovered that encoded γ-gliadins, with contrasting EM, had similar MWs. However, seven allelic variants (designated from I to VII) differed among them in the other six tests: I (alleles Gli-B1i, k, m, o), II (Gli-B1n, q, s), III (Gli-B1b), IV (Gli-B1e, f, g), V (Gli-B1h), VI (Gli-B1d) and VII (Gli-B1a). Allele Gli-B1c (variant VIII) was identical to the alleles from group IV in four of the tests. Some tests might show a fine difference between alleles belonging to the same variant. Our results attest in favor of the independent origin of at least seven variants at the Gli-B1 locus that might originate from deeply diverged genotypes of the donor(s) of the B genome in hexaploid wheat and therefore might be called “heteroallelic”. The donor’s particularities at the Gli-B1 locus might be conserved since that time and decisively contribute to the current high genetic diversity of common wheat.

scholarly journals Delineating Smallholder Maize Farms from Sentinel-1 Coupled with Sentinel-2 Data Using Machine Learning

2021 ◽  
Vol 13 (9) ◽  
pp. 4728
Author(s):  
Zinhle Mashaba-Munghemezulu ◽  
George Johannes Chirima ◽  
Cilence Munghemezulu
Keyword(s):  
Machine Learning ◽  
Food Security ◽  
Rural Communities ◽  
Machine Learning Algorithms ◽  
Support Vector ◽  
Subsistence Agriculture ◽  
Smallholder Farms ◽  
Main Driver ◽  
Sentinel 2

Rural communities rely on smallholder maize farms for subsistence agriculture, the main driver of local economic activity and food security. However, their planted area estimates are unknown in most developing countries. This study explores the use of Sentinel-1 and Sentinel-2 data to map smallholder maize farms. The random forest (RF), support vector (SVM) machine learning algorithms and model stacking (ST) were applied. Results show that the classification of combined Sentinel-1 and Sentinel-2 data improved the RF, SVM and ST algorithms by 24.2%, 8.7%, and 9.1%, respectively, compared to the classification of Sentinel-1 data individually. Similarities in the estimated areas (7001.35 ± 1.2 ha for RF, 7926.03 ± 0.7 ha for SVM and 7099.59 ± 0.8 ha for ST) show that machine learning can estimate smallholder maize areas with high accuracies. The study concludes that the single-date Sentinel-1 data were insufficient to map smallholder maize farms. However, single-date Sentinel-1 combined with Sentinel-2 data were sufficient in mapping smallholder farms. These results can be used to support the generation and validation of national crop statistics, thus contributing to food security.

Food security in the 21st century and in the role of biotechnology

foresight ◽  
1999 ◽  
Vol 1 (5) ◽  
pp. 399-412 ◽  
Author(s):  
Per Pinstrup‐Andersen ◽  
Marc J. Cohen
Keyword(s):  
Developing Countries ◽  
Food Security ◽  
Food Production ◽  
Supply Side ◽  
Adequate Diet ◽  
The World ◽  
Productivity Gains ◽  
Global Population ◽  
Global Food

Although global food production has consistently kept pace with population growth, the gap between food production and demand in certain parts of the world is likely to remain. More than 800 million people in developing countries lack access to a minimally adequate diet. Continued productivity gains are essential on the supply side, because global population will increase by 73 million people a year over the next two decades. In this article we assess the current global food situation, look at the prospects through to the year 2020, and outline the policies needed to achieve food security for all. Emphasis is on the role that agricultural biotechnology might play in reaching this goal.

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