Genetic diversity of American wild rice species

Veasey, Elizabeth Ann; Bressan, Eduardo de Andrade; Zucchi, Maria Imaculada; Vencovsky, Roland; Cardim, Daruska Cavalcante; Silva, Rainerio Meireles da

doi:10.1590/s0103-90162011000400008

Cited by 15 publications

(9 citation statements)

References 26 publications

(34 reference statements)

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“…Mesoamerican populations have not yet been analyzed; genetic diversity studies have primarily been conducted in Brazil ( Karasawa et al, 2007b ). These studies have consistently found a larger degree of genetic diversity structured among populations in different rivers, likely due to limited gene flow ( Akimoto, Shimamoto & Morishima, 1998 ; Buso, Rangel & Ferreira, 1998 ; Karasawa et al, 2007b ; Veasey et al, 2008 ; Veasey et al, 2011 ). Populations within a river system are less likely to show differences in allele frequencies.…”

Section: Introductionmentioning

confidence: 91%

Genetic diversity inOryza glumaepatulawild rice populations in Costa Rica and possible gene flow fromO. sativa

Fuchs

Martínez

Calvo

et al. 2016

PeerJ

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Wild crop relatives are an important source of genetic diversity for crop improvement. Diversity estimates are generally lacking for many wild crop relatives. The objective of the present study was to analyze how genetic diversity is distributed within and among populations of the wild rice species Oryza glumaepatula in Costa Rica. We also evaluated the likelihood of gene flow between wild and commercial rice species because the latter is commonly sympatric with wild rice populations. Introgression may change wild species by incorporating alleles from domesticated species, increasing the risk of losing original variation. Specimens from all known O. glumaepatula populations in Costa Rica were analyzed with 444 AFLP markers to characterize genetic diversity and structure. We also compared genetic diversity estimates between O. glumaepatula specimens and O. sativa commercial rice. Our results showed that O. glumaepatula populations in Costa Rica have moderately high levels of genetic diversity, comparable to those found in South American populations. Despite the restricted distribution of this species in Costa Rica, populations are fairly large, reducing the effects of drift on genetic diversity. We found a dismissible but significant structure (θ = 0.02 ± 0.001) among populations. A Bayesian structure analysis suggested that some individuals share a significant proportion of their genomes with O. sativa. These results suggest that gene flow from cultivated O. sativa populations may have occurred in the recent past. These results expose an important biohazard: recurrent hybridization may reduce the genetic diversity of this wild rice species. Introgression may transfer commercial traits into O. glumaepatula, which in turn could alter genetic diversity and increase the likelihood of local extinction. These results have important implications for in situ conservation strategies of the only wild populations of O. glumaepatula in Costa Rica.

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Section: Introductionmentioning

confidence: 91%

Genetic diversity inOryza glumaepatulawild rice populations in Costa Rica and possible gene flow fromO. sativa

Fuchs

Martínez

Calvo

et al. 2016

PeerJ

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“…However the genetic diversity and structure, as well as the in situ conservation status of these species remains severely understudied, jeopardizing the conservation and future use of their genetic resources. To date most studies have focused on O. glumaepatula (Akimoto et al 1998 ; Buso et al 1998 ; Brondani et al 2005 ; Karasawa et al 2007a ; Karasawa et al 2007b ; Veasey et al 2008b ; Karasawa et al 2012 ), and much less on the other three species (Quesada et al 2002 ; Arrieta-Espinoza et al 2005 ; Veasey et al 2008b ; Veasey et al 2011 ).…”

Section: Introductionmentioning

confidence: 99%

Distribution, genetic diversity and potential spatiotemporal scale of alien gene flow in crop wild relatives of rice (Oryza spp.) in Colombia

Thomas

Tovar

Villafañe

et al. 2017

Rice

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BackgroundCrop wild relatives (CWRs) of rice hold important traits that can contribute to enhancing the ability of cultivated rice (Oryza sativa and O. glaberrima) to produce higher yields, cope with the effects of climate change, and resist attacks of pests and diseases, among others. However, the genetic resources of these species remain dramatically understudied, putting at risk their future availability from in situ and ex situ sources. Here we assess the distribution of genetic diversity of the four rice CWRs known to occur in Colombia (O. glumaepatula, O. alta, O. grandiglumis, and O. latifolia). Furthermore, we estimated the degree of overlap between areas with suitable habitat for cultivated and wild rice, both under current and predicted future climate conditions to assess the potential spatiotemporal scale of potential gene flow from GM rice to its CWRs.ResultsOur findings suggest that part of the observed genetic diversity and structure, at least of the most exhaustively sampled species, may be explained by their glacial and post-glacial range dynamics. Furthermore, in assessing the expected impact of climate change and the potential spatiotemporal scale of gene flow between populations of CWRs and GM rice we find significant overlap between present and future suitable areas for cultivated rice and its four CWRs. Climate change is expected to have relatively limited negative effects on the rice CWRs, with three species showing opportunities to expand their distribution ranges in the future.ConclusionsGiven (i) the sparse presence of CWR populations in protected areas (ii) the strong suitability overlap between cultivated rice and its four CWRs; and (iii) the complexity of managing and regulating areas to prevent alien gene flow, the first priority should be to establish representative ex situ collections for all CWR species, which currently do not exist. In the absence of studies under field conditions on the scale and extent of gene flow between cultivated rice and its Colombian CWRs, effective in situ conservation might best be achieved through tailor-made management plans and exclusion of GM rice cultivation in areas holding the most genetically diverse CWR populations. This may be combined with assisted migration of populations to suitable areas where rice is unlikely to be cultivated under current and future climate conditions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12284-017-0150-9) contains supplementary material, which is available to authorized users.

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“…In Brazil four species of wild rice have been identified and among them Oryza glumaepatula Steud (Poaceae) is now indicated as a potential gene source to transfer to rice cultivars by crop breeding, due their similarity in genomic structure (Rangel et al 2006, Rosa et al 2006, Veasey et al 2011. Although the potential of O. glumaepatula as a genetic resource was shown, the interaction of this species with soil microorganisms remains largely unknown and must be investigated.…”

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confidence: 99%

Diazotrophic bacteria isolated from wild rice <i>Oryza glumaepatula</i> (Poaceae) in the Brazilian Amazon

Fernandes‐Júnior

Pereira

Perin³

et al. 2013

RBT

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Bacterias diazotróficas aisladas de arroz silvestre Oryza glumaepatula (Poaceae) en la Amazonia brasileña. The association of wild grasses with diazotrophic bacteria in Brazilian biomes is poorly understood. The isolation and characterization of bacteria associated with wild grasses can contribute to understand the diazotrophic ecology as well as to identify bacteria with biotechnological applications. In this study, we isolated and characterized diazotrophic bacterial isolates from Oryza glumaepatula collected in Cerrado and Forest areas of the Amazon in Roraima State, Brazil. Healthy O. glumepatula plants were collected at five sampling sites at Forest and seven at Cerrado, respectively. The plants were collected at the Cerrado areas in September 2008 while the Forest plants were collected in June/2008 and April/2009. The plants and the soil adhering to the roots were transferred to pots and grown for 35 days in greenhouse conditions. During the harvest, the shoots and the roots were crushed separately in a saline solution; the suspension was diluted serially and inoculated in Petri dishes containing Dyg's medium. All distinct bacterial colonies were purified in the same medium. The diazotrophic capacity of each bacterium in microaerophilic conditions was assessed in semisolid BMGM medium. In addition, the pellicles forming bacterial isolates were also evaluated by PCR amplification for nifH gene. The diversity of nifH + bacteria was analyzed by Box-PCR fingerprinting. For selected strains, the growth promoting capacity of O. sativa as a model plant was also evaluated. A total of 992 bacterial isolates were obtained. Fiftyone bacteria were able to form pellicles in the semisolid medium and 38 also positively amplified the 360bp nifH gene fragment. Among the 38 nifH + isolates, 24 were obtained from the shoots, while 14 originated from the roots. The Box-PCR profiles showed that the bacterial isolates obtained in this study presented a low similarity with the reference strains belonging to the Herbaspirillum, Azospirillum and Burkholderia genus. The growthpromoting ability was confirmed for at least five isolates. For these bacteria, the root and shoot growing results showed higher increases when compared to those observed in plants inoculated with the evaluated reference strains. These results indicate that O. glumaepatula is colonized by a high diverse diazotrophic community in

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Genetic diversity of American wild rice species

Cited by 15 publications

References 26 publications

Genetic diversity inOryza glumaepatulawild rice populations in Costa Rica and possible gene flow fromO. sativa

Genetic diversity inOryza glumaepatulawild rice populations in Costa Rica and possible gene flow fromO. sativa

Distribution, genetic diversity and potential spatiotemporal scale of alien gene flow in crop wild relatives of rice (Oryza spp.) in Colombia

Diazotrophic bacteria isolated from wild rice <i>Oryza glumaepatula</i> (Poaceae) in the Brazilian Amazon

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