7 research outputs found
A Behavioral Change Perspective of Maroon Soil Fertility Management in Traditional Shifting Cultivation in Suriname
In Suriname, the Maroons have practiced shifting cultivation for generations, but now the increasing influence of modern society is causing a trend of decreasing fallow periods with potentially adverse effects for the vulnerable tropical soils. Adoption of appropriate soil fertility management (SFM) practices is currently slow. Combining methods from cultural ecology and environmental psychology, this study identifies two groups with divergent behavioral intentions which we term semi-permanent cultivators and shifting cultivators. Semi-permanent cultivators intend to practice more permanent agriculture and experiment individually with plot-level SFM. Shifting cultivators rely on traditional knowledge that is not adequate for their reduced fallow periods, but perceive constraints that prevent them practicing more permanent agriculture. Semi-permanent cultivators act as a strong reference group setting a subjective norm, yet feel no need to exchange knowledge with shifting cultivators who are in danger of feeling marginalized. Drawing on a political ecology perspective, we conclude that cultural ecological knowledge declined due to negative perceptions of external actors setting a strong subjective norm. Semi-permanent cultivators who wish to enter the market economy are most likely to adopt SFM. We conclude that any future SFM intervention must be based on an in-depth understanding of each group’s behavior, in order to avoid exacerbating processes of marginalization
Conventional and Molecular Breeding Approaches for Biofortification of Pearl Millet
Pearl millet [Pennisetum glaucum (L.) R. Br.] is an essential diet of more than 90
million people in the semi-arid tropics of the world where droughts and low fertility
of soils cause frequent failures of other crops. It is an important nutri-rich grain
cereal in the drier regions of the world grown on 26 mha by millions of farmers
(IFAD 1999; Yadav and Rai 2013). This makes pearl millet the sixth most important
crop in the world and fourth most important food crop of the India, next to rice,
wheat, and maize with annual cultivation over an area of ~8 mha. Pearl millet is also
primary food crop in sub-Saharan Africa and is grown on 15 mha (Yadav and Rai
2013). The significant increase in productivity of pearl millet in India is attributed
to development and adoption of hybrids of early to medium duration maturity. More
than 120 diverse hybrids/varieties have been released till date for various production
environments. The heterosis breeding and improved crop management technologies
increased productivity substantially achieving higher increased production of
9.80 mt in 2016–2017 from 2.60 mt in 1950–1951 in spite of declined of area under
the crop by 20–30% over last two decades (Yadav et al. 2012)
Novel measures of linkage disequilibrium that correct the bias due to population structure and relatedness
UMR 1334 AGAP : Equipe AFEF ‘Architecture et Fonctionnement des Espèces fruitières’ ; Team AFFS ‘Architecture and Functioning of Fruit Species’Among the several linkage disequilibrium measures known to capture different features of the non-independence between alleles at different loci, the most commonly used for diallelic loci is the r(2) measure. In the present study, we tackled the problem of the bias of r(2) estimate, which results from the sample structure and/or the relatedness between genotyped individuals. We derived two novel linkage disequilibrium measures for diallelic loci that are both extensions of the usual r(2) measure. The first one, r(S)(2), uses the population structure matrix, which consists of information about the origins of each individual and the admixture proportions of each individual genome. The second one, r(V)(2), includes the kinship matrix into the calculation. These two corrections can be applied together in order to correct for both biases and are defined either on phased or unphased genotypes. We proved that these novel measures are linked to the power of association tests under the mixed linear model including structure and kinship corrections. We validated them on simulated data and applied them to real data sets collected on Vitis vinifera plants. Our results clearly showed the usefulness of the two corrected r(2) measures, which actually captured 'true' linkage disequilibrium unlike the usual r(2) measure
Genomic Designing of Pearl Millet:A Resilient Crop for Arid and Semi-arid Environments
Pearl millet [Pennisetum glaucum (L.) R. Br.; Syn. Cenchrus americanus
(L.) Morrone] is the sixth most important cereal in the world. Today, pearl
millet is grown on more than 30 million ha mainly in West and Central Africa and
the Indian sub-continent as a staple food for more than 90 million people in agriculturally
marginal areas. It is rich in proteins and minerals and has numerous
health benefits such as being gluten-free and having slow-digesting starch. It is
grown as a forage crop in temperate areas. It is drought and heat tolerant, and a
climate-smart crop that can withstand unpredictable variability in climate. However,
research on pearl millet improvement is lagging behind other major cereals mainly
due to limited investment in terms of man and money power. So far breeding
achievements include the development of cytoplasmic male sterility (CMS),
maintenance counterparts (rf) system and nuclear fertility restoration genes (Rf) for
hybrid breeding, dwarfing genes for reduced height, improved input responsiveness,
photoperiod neutrality for short growing season, and resistance to important
diseases. Further improvement of pearl millet for genetic yield potential, stress
tolerance, and nutritional quality traits would enhance food and nutrition security
for people living in agriculturally dissolute environments. Application of molecular
technology in the pearl millet breeding program has a promise in enhancing the
selection efficiency while shortening the lengthy phenotypic selection process ultimately improving the rate of genetic gains. Linkage analysis and genome-wide
association studies based on different marker systems in detecting quantitative trait
loci (QTLs) for important agronomic traits are well demonstrated. Genetic
resources including wild relatives have been categorized into primary, secondary
and tertiary gene pools based on the level of genetic barriers and ease of gene
introgression into pearl millet. A draft on pearl millet whole genome sequence was
recently published with an estimated 38,579 genes annotated to establish
genomic-assisted breeding. Resequencing a large number of germplasm lines and
several population genomic studies provided a valuable insight into population
structure, genetic diversity and domestication history of the crop. Successful
improvement in combination with modern genomic/genetic resources, tools and
technologies and adoption of pearl millet will not only improve the resilience of
global food system through on-farm diversification but also dietary intake which
depends on diminishingly fewer crops