Diversity in Landraces of Cereal and Legume Crops

Teshome, Awegechew; Brown, A. H. D.; Hodgkin, T.

doi:10.1002/9780470650196.ch6

Cited by 31 publications

(21 citation statements)

References 119 publications

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“…The extent of genetic divergence among populations was of a similar order for S-SAP (F ST = 0.18) as for allozymes (G ST = 0.16) (Papa et al 1998). Considerable genetic marker diversity is present within traditional varieties of barley (Jaradat and Shahid 2006) and in other selWng cereals such as rice (Thomson et al 2007;Pusadee et al 2009), as might be expected from the many factors aVecting diversity in landraces (Teshome et al 2001). No relevant diVerences were observed between the two groups of genotypes collected in 1990 and 1999, suggesting that one decade was insuYcient for any signiWcant genetic temporal diVerentiation among these populations to arise.…”

Section: Discussionmentioning

confidence: 66%

Genetic structure and linkage disequilibrium in landrace populations of barley in Sardinia

et al. 2012

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Multilocus digenic linkage disequilibria (LD) and their population structure were investigated in eleven landrace populations of barley (Hordeum vulgare ssp. vulgare L.) in Sardinia, using 134 dominant simple-sequence amplified polymorphism markers. The analysis of molecular variance for these markers indicated that the populations were partially differentiated (F(ST) = 0.18), and clustered into three geographic areas. Consistent with this population pattern, STRUCTURE analysis allocated individuals from a bulk of all populations into four genetic groups, and these groups also showed geographic patterns. In agreement with other molecular studies in barley, the general level of LD was low (13% of locus pairs, with P < 0.01) in the bulk of 337 lines, and decayed steeply with map distance between markers. The partitioning of multilocus associations into various components indicated that genetic drift and founder effects played a major role in determining the overall genetic makeup of the diversity in these landrace populations, but that epistatic homogenising or diversifying selection was also present. Notably, the variance of the disequilibrium component was relatively high, which implies caution in the pooling of barley lines for association studies. Finally, we compared the analyses of multilocus structure in barley landrace populations with parallel analyses in both composite crosses of barley on the one hand and in natural populations of wild barley on the other. Neither of these serves as suitable mimics of landraces in barley, which require their own study. Overall, the results suggest that these populations can be exploited for LD mapping if population structure is controlled.

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Section: Discussionmentioning

confidence: 66%

Genetic structure and linkage disequilibrium in landrace populations of barley in Sardinia

et al. 2012

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Section: Description Of Actionsmentioning

confidence: 97%

“…Other studies have examined the diversity of adaptive and ecophysiological traits within the production system (Teshome et al, 2001;Weltzien et al, 2006;Thinlay et al, 2000;Hue et al, 2006). The diversity of quality and nutritional traits (Duch-Gary, 2004;CazarezSanchez, 2004) has also been described, as has the relationship of levels of crop genetic diversity to geographical regions Bouzeggaren et al, 2002;Teshome et al, 2001). Brown and Hodgkin (2007) reviewed some of the molecular methods available to assess the extent and distribution of diversity, including single nucleotide polymorphisms (SNPs), phylogentic analysis (Clegg, 1997;Brown and Brubaker, 2000) and functional genomics (Aharoni and Vorst, 2001;Peacock and Chaudhar, 2002).…”

Section: Description Of Actionsmentioning

confidence: 97%

An Heuristic Framework for Identifying Multiple Ways of Supporting the Conservation and Use of Traditional Crop Varieties within the Agricultural Production System

Jarvis

Hodgkin

Sthapit³

et al. 2011

Critical Reviews in Plant Sciences

174

117

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“…Some landraces maybe highly valued but their use is constrained by poor access to quality and quantity of seeds or planting materials (Tripp 2001;Almekinders et al 2007;Sperling et al 2008;Hodgkin et al 2007). Landrace populations may, themselves, not be uniform in their adaptive or quality traits, having significant variation both within and among populations (Teshome et al 2001;Harlan 1975;Mariac et al 2006; Barry et al 2007). One way of distinguishing those varieties that provide high public value, i.e., varieties that are high in diversity of crop genetic resources from which people residing elsewhere and in the future may benefit (Smale 2006), is to classify varieties in terms of their immediate and future plant breeding benefits (Smale et al 2004).…”

Section: Introductionmentioning

confidence: 99%

Participatory crop improvement and formal release of Jethobudho rice landrace in Nepal

Gyawali¹,

Sthapit²,

Bhandari³

et al. 2010

Euphytica

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Jethobudho is an aromatic rice landrace of the Pokhara valley in middle hills of Nepal. Although local consumers are willing to pay a high price for its purchase, the landrace has a problem with quality variation. Decentralized participatory population improvement for specific market-identified traits was conducted on ''Jethobudho'' populations collected from farmers' fields in seven geographic regions of the valley in Nepal. The preferred post harvest quality traits, field tolerance to blast and lodging, and superior post harvest quality traits of Jethobudho were established by a consumer market survey. These traits were used for screening the materials. 338 sub-populations of Jethobudho were evaluated for yield, disease, lodging resistance, and post harvest quality traits. Significant variation was found for culm strength, neck blast tolerance, awn characteristics, panicle length, number of grains per panicle, test grain weight and post harvest quality traits, whereas no significant variation was found in grain yield, plant height, tiller number, maturity period and leaf blast. Based on these identified traits and micro-milling evaluations, 183 populations were screened in on-farm and on-station nurseries, and in succeeding years populations were further screened by plant breeders and expert farmers in research trials, resulting in the selection of 46 populations for post harvest quality traits. Six accessions with similar agronomic traits, field tolerance to blast and lodging, and superior post harvest quality traits, were bulked and evaluated on-farm using participatory variety selection (PVS). The enhanced Jethobudho accessions were also evaluated for aroma using simple sequence repeat (SSR) and found to have unique aromatic genetic constitution. Community based seed production groups were formed, linked to the Nepal District Self Seed Sufficiency Programme (DISSPRO), and trained to produce basic seeds (truthfully labeled) of Jethobudho. The National Seed Board of Nepal released the enhanced landrace in the name of ''Pokhareli Jethobudho'' in 2006, as the first bulk variety of traditional high quality aromatic rice improved through participatory plant breeding to be formally released in Nepal for general cultivation under the national seed certification scheme. Landrace improvement is shown as an important option for supporting programmes for in situ conservation of landraces on-farm.

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Diversity in Landraces of Cereal and Legume Crops

Cited by 31 publications

References 119 publications

Genetic structure and linkage disequilibrium in landrace populations of barley in Sardinia

Genetic structure and linkage disequilibrium in landrace populations of barley in Sardinia

An Heuristic Framework for Identifying Multiple Ways of Supporting the Conservation and Use of Traditional Crop Varieties within the Agricultural Production System

Participatory crop improvement and formal release of Jethobudho rice landrace in Nepal

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