ORCID Profile
0000-0003-4957-9386
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Publisher: Springer Science and Business Media LLC
Date: 07-01-2021
DOI: 10.1186/S12284-020-00449-6
Abstract: African rice ( Oryza glaberrima Steud) is one of the two independently domesticated rice species, the other one being Asian rice ( Oryza sativa L.). Despite major progress being made in understanding the evolutionary and domestication history of African rice, key outstanding issues remain controversial. There appears to be an underlying difficulty in identifying the domestication centre and number of times the crop has been domesticated. Advances in genomics have provided unprecedented opportunities for understanding the genetic architecture of domestication related traits. For most of the domestication traits, the underlying genes and mutations have been identified. Comparative analysis of domestication genes between Asian and African rice has revealed that the two species went through an independent but convergent evolution process. The genetic and developmental basis of some of the domestic traits are conserved not only between Asian and African rice but also with other domesticated crop species. Analysis of genome data and its interpretation is emerging as a major challenge facing studies of domestication in African rice as key studies continue giving contradictory findings and conclusions. Insights obtained on the domestication of this species are vital for guiding crop improvement efforts.
Publisher: Springer Science and Business Media LLC
Date: 24-10-2018
Publisher: Public Library of Science (PLoS)
Date: 17-03-2014
Publisher: Wiley
Date: 11-07-2018
DOI: 10.1111/PBI.12752
Publisher: Frontiers Media SA
Date: 09-04-2018
Publisher: Informa UK Limited
Date: 21-08-2009
Publisher: Cambridge University Press (CUP)
Date: 28-03-2016
DOI: 10.1017/S147926211600006X
Abstract: Identification and characterization of the farmers’ named crop varieties cultivated around the world is a major issue for conservation and sustainable use of plant genetic resources. Intraspecific ersity is strongly determined by farmers’ socio-cultural environment, but this has little been documented. In this paper, we tested, on a contact zone among three ethnolinguistic groups located on the Mount Kenya region, whether farmers’ socio-cultural differences have an impact on the morphological characteristics of the farmers’ named sorghum varieties. Eighteen qualitative morphological traits of the panicles were measured. We first compared the morphological ersity of the named varieties among ethnolinguistic groups using multivariate analysis of homogeneity of groups’ dispersion and tested their differentiation using permutational multivariate analysis of variance. Discriminant analysis of principal components was then used to categorize the morphological ersity without a priori , and this classification was compared with farmers’ local taxonomy (vernacular names) in the three ethnolinguistic groups. Our results show that some morphotypes are peculiar to some ethnolinguistic groups and that a morphotype can bear different variety names while the same variety name can be used to identify different morphotypes. Morphological differentiation that was explained by ethnolinguistic groups was higher for local landraces than for improved varieties. Our findings imply that socio-cultural ersity of farmers and the criteria they use to identify and maintain landraces need to be considered in studying and s ling crop ersity for in situ as well as for ex situ conservation.
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.CARBPOL.2015.04.035
Abstract: The molecular structure and gelatinization properties of starches from domesticated African rice (Oryza glaberrima) and its wild progenitor (Oryza barthii) are determined and comparison made with Asian domesticated rice (Oryza sativa), the commonest commercial rice. This suggests possible enzymatic processes contributing to the unique traits of the African varieties. These have similar starch structures, including smaller amylose molecules, but larger amounts of amylose chains across the whole amylose chain-length distribution, and higher amylose contents, than O. sativa. They also show a higher proportion of two- and three-lamellae spanning amylopectin branch chains (degree of polymerization 34-100) than O. sativa, which contributes to their higher gelatinization temperatures. Fitting amylopectin chain-length distribution with a biosynthesis-based mathematical model suggests that the reason for this difference might be because O. glaberrima and O. barthii have more active SSIIIa and/or less active SBEIIb enzymes.
Publisher: MDPI AG
Date: 26-09-2019
Abstract: African rice (Oryza glaberrima) has a pool of genes for resistance to erse biotic and abiotic stresses, making it an important genetic resource for rice improvement. African rice has potential for breeding for climate resilience and adapting rice cultivation to climate change. Over the last decade, there have been tremendous technological and analytical advances in genomics that have dramatically altered the landscape of rice research. Here we review the remarkable advances in knowledge that have been witnessed in the last few years in the area of genetics and genomics of African rice. Advances in cheap DNA sequencing technologies have fuelled development of numerous genomic and transcriptomic resources. Genomics has been pivotal in elucidating the genetic architecture of important traits thereby providing a basis for unlocking important trait variation. Whole genome re-sequencing studies have provided great insights on the domestication process, though key studies continue giving conflicting conclusions and theories. However, the genomic resources of African rice appear to be under-utilized as there seems to be little evidence that these vast resources are being productively exploited for ex le in practical rice improvement programmes. Challenges in deploying African rice genetic resources in rice improvement and the genomics efforts made in addressing them are highlighted.
Publisher: Springer Science and Business Media LLC
Date: 10-09-2015
DOI: 10.1038/SREP13957
Abstract: Rice is the most important crop in the world, acting as the staple food for over half of the world’s population. The evolutionary relationships of cultivated rice and its wild relatives have remained contentious and inconclusive. Here we report on the use of whole chloroplast sequences to elucidate the evolutionary and phylogenetic relationships in the AA genome Oryza species, representing the primary gene pool of rice. This is the first study that has produced a well resolved and strongly supported phylogeny of the AA genome species. The pan tropical distribution of these rice relatives was found to be explained by long distance dispersal within the last million years. The analysis resulted in a clustering pattern that showed strong geographical differentiation. The species were defined in two primary clades with a South American/African clade with two species, O glumaepatula and O longistaminata , distinguished from all other species. The largest clade was comprised of an Australian clade including newly identified taxa and the African and Asian clades. This refined knowledge of the relationships between cultivated rice and the related wild species provides a strong foundation for more targeted use of wild genetic resources in rice improvement and efforts to ensure their conservation.
Publisher: Springer Science and Business Media LLC
Date: 29-10-2013
Abstract: Africa contains a huge ersity 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 ersity 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.
Publisher: Routledge
Date: 27-11-2012
Publisher: Oxford University Press (OUP)
Date: 23-04-2018
DOI: 10.1093/BFGP/ELY014
Publisher: Informa UK Limited
Date: 30-11-2010
Location: Kenya
No related grants have been discovered for Peterson Wambugu.