scholarly journals Issues concerning reproductive isolation in a rice hybrid swarm involving Oryza sativa Linn., O. longistaminata A. Chev. et Roehr. and Oryza glaberrima Steud. located in Jebba Nigeria

2014 ◽  
Vol 7 (5) ◽  
pp. 2040 ◽  
Author(s):  
AO Bolaji ◽  
CC Nwokeocha
Keyword(s):  
Oryza Sativa ◽  
Reproductive Isolation ◽  
Oryza Glaberrima ◽  
Hybrid Swarm ◽  
Rice Hybrid

scholarly journals Analysis of mitochondrial DNAs from Oryza glaberrima and its cytoplasmic substituted line for Oryza sativa associated with cytoplasmic male sterility.

1990 ◽  
Vol 65 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Wataru SAKAMOTO ◽  
Koh-ichi KADOWAKI ◽  
Shigemitsu TANO ◽  
Tomosaburo YABUNO
Keyword(s):  
Oryza Sativa ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Oryza Glaberrima ◽  
Mitochondrial Dnas

Interspecific Rice Hybrid of Oryza sativa × Oryza nivara Reveals a Significant Increase in Seed Protein Content

2008 ◽  
Vol 56 (2) ◽  
pp. 476-482 ◽  
Author(s):  
Ahmed A. Mahmoud ◽  
S. Sukumar ◽  
Hari B. Krishnan
Keyword(s):  
Oryza Sativa ◽  
Protein Content ◽  
Seed Protein ◽  
Seed Protein Content ◽  
Oryza Nivara ◽  
Rice Hybrid

scholarly journals Molecular characterization and genetic diversity of different genotypes of Oryza sativa and Oryza glaberrima

2017 ◽  
Vol 30 ◽  
pp. 48-57 ◽  
Author(s):  
Caijin Chen ◽  
Wenchuang He ◽  
Tondi Yacouba Nassirou ◽  
Athanase Nsabiyumva ◽  
Xilong Dong ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa ◽  
Molecular Characterization ◽  
Oryza Glaberrima

Water extraction and root traits in Oryza sativa × Oryza glaberrima introgression lines under different soil moisture regimes

2013 ◽  
Vol 40 (1) ◽  
pp. 54 ◽  
Author(s):  
Abubakary A. Kijoji ◽  
Susan Nchimbi-Msolla ◽  
Zakaria L. Kanyeka ◽  
Stephen P. Klassen ◽  
Rachid Serraj ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Drought Stress ◽  
Water Uptake ◽  
Root Traits ◽  
Genetic Differences ◽  
Introgression Lines ◽  
Sub Saharan Africa ◽  
Future Research ◽  
Oryza Glaberrima ◽  
Soil Drying

Drought is a major constraint to rainfed rice production in some parts of sub Saharan Africa (SSA) because of irregular and low rainfall. Improving root water uptake during progressive soil drying could contribute to terminal drought stress resistance. Two lysimeter experiments were conducted using 200 introgression lines (ILs) derived from Oryza sativa L. × Oryza glaberrima Steud. crosses (IR64/RAM54 and IR64/RAM90) to characterise water uptake and root traits under progressive soil drying and to assess genetic differences among these lines in relation to drought stress. The lysimeter facility setup and protocols for simultaneous monitoring of water uptake rates and leaf area are described. Significant genetic variability for water uptake and root traits among the ILs was observed under drought stress. Water uptake in the drought stress treatments was correlated with root length density (RLD) and root dry matter (RDM) at lower soil depths. The highest RLD values at depth were observed among the RAM90 ILs and genetic differences were observed between RAM90 and RAM54 populations, implying that accession RAM90 could be used as a source for improving drought avoidance in lowland rice. The ILs with greater water uptake identified in this study will be used in future research for improving drought resistance of rice in SSA.

scholarly journals Hybridization drives genetic erosion in sympatric desert fishes of western North America

2019 ◽  
Author(s):  
Tyler K. Chafin ◽  
Marlis R. Douglas ◽  
Bradley T. Martin ◽  
Michael E. Douglas
Keyword(s):  
Reproductive Isolation ◽  
Extinction Risk ◽  
Genetic Erosion ◽  
Sympatric Species ◽  
Habitat Modification ◽  
Genetic Purity ◽  
Hybrid Swarm ◽  
Desert Fishes ◽  
Differential Adaptation ◽  
Anthropogenic Habitat

AbstractMany species have evolved or currently coexist in sympatry due to differential adaptation in a heterogeneous environment. However, anthropogenic habitat modifications can either disrupt reproductive barriers or obscure environmental conditions which underlie fitness gradients. In this study, we evaluated the potential for an anthropogenically-mediated shift in reproductive boundaries that separate two historically sympatric fish species (Gila cypha and G. robusta) endemic to the Colorado River Basin using ddRAD sequencing of 368 individuals. We first examined the integrity of reproductive isolation while in sympatry and allopatry, then characterized hybrid ancestries using genealogical assignment tests. We tested for localized erosion of reproductive isolation by comparing site-wise genomic clines against global patterns and identified a breakdown in the drainage-wide pattern of selection against interspecific heterozygotes. This, in turn, allowed for the formation of a hybrid swarm in one tributary, and asymmetric introgression where species co-occur. We also detected a weak but significant relationship between genetic purity and degree of consumptive water removal, suggesting a role for anthropogenic habitat modifications in undermining species boundaries. In addition, results from basin-wide genomic clines suggested that hybrids and parental forms are adaptively non-equivalent. If so, then a failure to manage for hybridization will exacerbate the long-term extinction risk in parental populations. These results reinforce the role of anthropogenic habitat modification in promoting interspecific introgression in sympatric species by relaxing divergent selection. This, in turn, underscores a broader role for hybridization in decreasing global biodiversity within rapidly deteriorating environments.

scholarly journals Genetic Structure and Diversity of Rice From Certified Cultivars and Farmer’s Fields in Burkina Faso

2021 ◽  
Author(s):  
Mariam BARRO ◽  
Abdourasmane KONATE ◽  
Issa WONNI ◽  
Abalo Itolou KASSANKOGNO ◽  
François SABOT ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa ◽  
West Africa ◽  
Burkina Faso ◽  
Snp Array ◽  
Genetic Data ◽  
Genetic Group ◽  
Oryza Glaberrima ◽  
Rainfed Lowland ◽  
Rice Samples

Abstract Background: In West Africa, two rice species are cultivated, the African rice Oryza glaberrima and the Asian rice Oryza sativa, the second one being much more frequent. Despite its importance for food security in West Africa, the genetic diversity of Oryza sativa in farmer’s fields remains understudied in this region. Documenting the dynamics of diversity in the fields between landraces and improved cultivars is of importance to ensure rice cultivation adaptation to global change.In this study, we genotyped 77 rice samples from Burkina Faso using the C6AIR SNP array from IRRI. Among the studied samples, 27 were certified cultivars and 50 were sampled in rice fields from three geographical zones in western Burkina Faso, each zone comprising one irrigated area and a neighboring rainfed lowland. Obtained data were analyzed in the frame of the worldwide rice genetic diversity by using the 3K genomes as reference.Results: Most of the certified cultivars clustered with the indica genetic group, with a minority (26%) assigned to the japonica group. All except one of the rice samples from farmer’s fields belonged to the indica group. The peculiar one unexpectedly clustered with the Aus genetic group and originated from Tengrela (rainfed lowland in Karfiguela zone). This site, already known to differ in terms of agronomic practices, showed the highest genetic diversity compared to the five other sites, as well as highest genetic differentiation. Obtained genetic data confirmed the high global frequency of one cultivar, in accordance with the data from farmer’s interview. However, at the field level, genetic data rarely corresponded to the cultivar’s names obtained from farmer’s interviews.Conclusions: Overall we found a high genetic diversity in the studied samples from Burkina Faso (certified and field’s samples). We argue on the importance to document and preserve this agro-biodiversity as a prerequisite to face the current challenges of growing rice demand and global change. To this purpose, are required further scientific studies to refine our understanding of the dynamics of diversity in farmers’ fields, as well as a better knowledge of rice agro-biodiversity and awareness of its importance by rice farmers themselves.

scholarly journals Assessment of morphological characteristics among upland rice (Oryza sativa and Oryza glaberrima) germplasm

2018 ◽  
Vol 17 (29) ◽  
pp. 906-914
Author(s):  
Luther Zogbo ◽  
Akromah Richard ◽  
P. Tokpah David ◽  
Page Zipporah
Keyword(s):  
Oryza Sativa ◽  
Upland Rice ◽  
Morphological Characteristics ◽  
Oryza Glaberrima
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