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result(s) for
"Nyamongo, Desterio"
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Role of Seed Banks in Supporting Ecosystem and Biodiversity Conservation and Restoration
by
Wambugu, Peterson W.
,
Kirwa, Everlyne C.
,
Nyamongo, Desterio O.
in
Anthropogenic factors
,
assets
,
Banking industry
2023
The world is witnessing massive land degradation caused by climate change and various anthropogenic activities. There has been a significant increase in habitat restoration efforts, with demand for seeds to restore these degraded ecosystems in some cases outstripping supply. Traditionally, seeds for restoration activities have mainly been sourced through collections from the wild, but with the growing seed demand, this is increasingly becoming unsustainable. In order to ensure responsible restoration practice, restoration practitioners need to explore other options of economical, ethical and sustainable sourcing of seeds. Ex situ seed banks can leverage their technical and infrastructural capacity to play a greater and more direct role in supporting biodiversity and ecosystem conservation and restoration, particularly through the supply of quality ecologically and genetically suitable seed. In this paper, we review whether ex situ seed banks possess the capacity and competence for supporting habitat restoration and the challenges they are likely to face in these efforts. The review focuses on seed collecting, field-based seed bulking, seed handling and storage, seed quality control as well as experience and capacity in facilitating germplasm exchange. The availability of high-quality germplasm collections of documented provenance and with broad genetic diversity is arguably the greatest resource and asset that seed banks have in supporting habitat restoration.
Journal Article
Genotypic Variation in Cultivated and Wild Sorghum Genotypes in Response to Striga hermonthica Infestation
2021
Striga hermonthica is the most important parasitic weed in sub-Saharan Africa and remains one of the most devastating biotic factors affecting sorghum production in the western regions of Kenya. Farmers have traditionally managed Striga using cultural methods, but the most effective and practical solution to poor smallholder farmers is to develop Striga -resistant varieties. This study was undertaken with the aim of identifying new sources of resistance to Striga in comparison with the conventional sources as standard checks. We evaluated 64 sorghum genotypes consisting of wild relatives, landraces, improved varieties, and fourth filial generation (F 4 ) progenies in both a field trial and a pot trial. Data were collected for days to 50% flowering (DTF), dry panicle weight (DPW, g), plant height (PH, cm), yield (YLD, t ha −1 ), 100-grain weight (HGW, g), overall disease score (ODS), overall pest score (OPS), area under Striga number progress curve (ASNPC), maximum above-ground Striga (NS max ), and number of Striga -forming capsules (NSFC) at relevant stages. Genetic diversity and hybridity confirmation was determined using Diversity Arrays Technology sequencing (DArT-seq). Residual heterosis for HGW and NS max was calculated as the percent increase or decrease in performance of F 4 crossover midparent (MP). The top 10 best yielding genotypes were predominantly F 4 crosses in both experiments, all of which yielded better than resistant checks, except FRAMIDA in the field trial and HAKIKA in the pot trial. Five F 4 progenies (ICSVIII IN × E36-1, LANDIWHITE × B35, B35 × E36-1, F6YQ212 × B35, and ICSVIII IN × LODOKA) recorded some of the highest HGW in both trials revealing their stability in good performance. Three genotypes (F6YQ212, GBK045827, and F6YQ212xB35) and one check (SRN39) were among the most resistant to Striga in both trials. SNPs generated from DArT-seq grouped the genotypes into three major clusters, with all resistant checks grouping in the same cluster except N13. We identified more resistant and high-yielding genotypes than the conventional checks, especially among the F 4 crosses, which should be promoted for adoption by farmers. Future studies will need to look for more diverse sources of Striga resistance and pyramid different mechanisms of resistance into farmer-preferred varieties to enhance the durability of Striga resistance in the fields of farmers.
Journal Article
Conservation and utilization of African Oryza genetic resources
by
Henry, Robert J
,
Furtado, Agnelo
,
Waters, Daniel LE
in
Africa
,
Agriculture
,
Biomedical and Life Sciences
2013
Africa contains a huge diversity of both cultivated and wild rice species. The region has eight species representing six of the ten known genome types. Genetic resources of these species are conserved in various global germplasm repositories but they remain under collected and hence underrepresented in germplasm collections. Moreover, they are under characterized and therefore grossly underutilized. The lack of in situ conservation programs further exposes them to possible genetic erosion or extinction. In order to obtain maximum benefits from these resources, it is imperative that they are collected, efficiently conserved and optimally utilized. High throughput molecular approaches such as genome sequencing could be employed to more precisely study their genetic diversity and value and thereby enhance their use in rice improvement.
Oryza sativa
was the first crop plant to have its reference genome sequence released marking a major milestone that opened numerous opportunities for functional characterization of the entire rice genome. Studies have however demonstrated that one reference genome sequence is not enough to fully explore the genetic variation in the
Oryza
genus, hence the need to have reference sequences for other species in the genus. An overview of the state of conservation and utilization of African
Oryza
is hereby presented. Progress in the release of reference genome sequences for these species is also highlighted.
Journal Article
The Role of Gender and Institutional Dynamics in Adapting Seed Systems to Climate Change: Case Studies from Kenya, Tanzania and Uganda
by
Marimo, Pricilla
,
Nyamongo, Desterio Ondieki
,
Mollel, Margaret
in
Access to information
,
Adaptation
,
Agriculture
2021
We explore how seed systems enhance access to seeds, and information for climate-change adaptation in farming communities in Kenya, Tanzania and Uganda, as well as how gender-driven roles and institutional dynamics influence the process. Men and women farmers equally experience climate-change related effects, including drought, short rainy seasons and increased pest and disease incidence. Our study relies on exploratory data analysis of 1001 households surveyed in four sites in 2016. Farmers surveyed preferred early-maturing, heat-tolerant, high-yielding, and pest- and disease-resistant varieties, all important climate-adaptive traits. Seed systems of the focus crops studied are largely informal—overall, 68% women and 62% men use their own seed, indicating women’s higher reliance on ‘informal’ seed and information sources. Only 21% of respondents reported interacting with seed experts who are affiliated with formal organizations. Both formal and informal organizations play a key role in providing access to climate-adapted seed/information, with access for men and women varying across the countries studied. There is a need to support further development of those connections, building on existing social networks. We conclude that inclusive and gender-responsive context- and country-specific seed interventions will ensure equitable outcomes, increase women’s empowerment and strengthen both formal and informal seed systems for more effective climate-change adaptation.
Journal Article
Whole-genome resequencing of a global collection of Napier grass (Cenchrus purpureus) to explore global population structure and QTL governing yield and feed quality traits
by
Muktar, Meki Shehabu
,
Pereira, Jorge Fernando
,
Teshome, Abel
in
Drought
,
Genetic diversity
,
Genomes
2025
Napier grass (Cenchrus purpureus) is a C4 perennial grass species native to Sub-Saharan Africa and widely used as livestock feed in the region. In this study, we sequenced the genomes of 450 Napier grass individuals from 18 countries, identifying over 170 million DNA variants (SNPs and Indels). Approximately 1% of these SNPs were informative and used to assess genetic diversity within the collection. Our resequencing study provided valuable insights into the global genetic diversity of Napier grass. Additionally, a genome-wide association study on 2 independent populations identified multiple quantitative trait loci significantly associated with key agronomic traits, including biomass yield, nitrogen and cellulose content. These findings serve as a crucial resource for preserving and understanding Napier grass genetic diversity in the context of climate change. Moreover, they will support genomics-based breeding programs aimed at developing high-yielding and drought-tolerant varieties for forage and biofuel production.Napier grass (Cenchrus purpureus) is a perennial grass species native to Sub-Saharan Africa (SSA), primarily used to feed cattle in SSA. The authors’ resequencing study provided valuable insights into the genetic diversity across a global Napier grass collection. Furthermore, a genome-wide association study on two independent populations, identified multiple quantitative trait loci (QTL) that were significantly associated with desirable agronomic traits. Therefore, their results will serve as a valuable resource to spearhead genomics-based breeding programs to develop high-yielding and drought-tolerant varieties.
Journal Article
Adapting Agriculture to Climate Change: A Synopsis of Coordinated National Crop Wild Relative Seed Collecting Programs across Five Continents
2022
The Adapting Agriculture to Climate Change Project set out to improve the diversity, quantity, and accessibility of germplasm collections of crop wild relatives (CWR). Between 2013 and 2018, partners in 25 countries, heirs to the globetrotting legacy of Nikolai Vavilov, undertook seed collecting expeditions targeting CWR of 28 crops of global significance for agriculture. Here, we describe the implementation of the 25 national collecting programs and present the key results. A total of 4587 unique seed samples from at least 355 CWR taxa were collected, conserved ex situ, safety duplicated in national and international genebanks, and made available through the Multilateral System (MLS) of the International Treaty on Plant Genetic Resources for Food and Agriculture (Plant Treaty). Collections of CWR were made for all 28 targeted crops. Potato and eggplant were the most collected genepools, although the greatest number of primary genepool collections were made for rice. Overall, alfalfa, Bambara groundnut, grass pea and wheat were the genepools for which targets were best achieved. Several of the newly collected samples have already been used in pre-breeding programs to adapt crops to future challenges.
Journal Article
Adapting Agriculture to Climate Change: A Synopsis of Coordinated National Crop Wild Relative Seed Collecting Programs across Five Continents
2022
The Adapting Agriculture to Climate Change Project set out to improve the diversity, quantity, and accessibility of germplasm collections of crop wild relatives (CWR). Between 2013 and 2018, partners in 25 countries, heirs to the globetrotting legacy of Nikolai Vavilov, undertook seed collecting expeditions targeting CWR of 28 crops of global significance for agriculture. Here, we describe the implementation of the 25 national collecting programs and present the key results. A total of 4587 unique seed samples from at least 355 CWR taxa were collected, conserved ex situ, safety duplicated in national and international genebanks, and made available through the Multilateral System (MLS) of the International Treaty on Plant Genetic Resources for Food and Agriculture (Plant Treaty). Collections of CWR were made for all 28 targeted crops. Potato and eggplant were the most collected genepools, although the greatest number of primary genepool collections were made for rice. Overall, alfalfa, Bambara groundnut, grass pea and wheat were the genepools for which targets were best achieved. Several of the newly collected samples have already been used in pre-breeding programs to adapt crops to future challenges
Journal Article
Climate resilience conserved in global germplasm repositories: Picking the most promising parents for agile plant breeding
2024
Crop diversity is an essential resource for national and international breeding programs aimed at preparing global agriculture for a changing climate to ensure global food security. To do this there are related risks that need to be evaluated (1) does the genetic diversity needed for climate adaptation exist somewhere? And (2) is such genetic diversity accessible? To evaluate these risks, we consider the test case of publicly available genotyped and georeferenced sorghum landraces (n = 1,937) to ask if diversity is sufficient to support breeding for climate change adaptation. Answering these questions allows for characterization of the best potential parents and the geographies that harbor the most potentially promising genetypes for crop improvement. We subset this data into national, regional, and global geographic regions, and complete/mini core collections to understand the potential for climate adaptation in regional germplasm. Study accessions were given a future climate resilience score based on future climatic projections and a genomic adaptive capacity score using genomic estimated adaptive values (GEAVs) generated from environmental genomic selection - EGS) to ask whether this accessible diversity stored in germplasm repositories is potentially sufficient to meet forecasted changes in growing environments under climate change. We find that genomic resilience capacity is highly variable among countries and regions. High geographical variability was also found for climate resilience. To equitably adapt agriculture to future climate conditions, increased accessibility to plant genetic resources is essential.