scholarly journals Rich diversity in cultivated Finnish potato onions (Allium cepa var. aggregatum G. Don)

Author(s):  
Terhi Suojala-Ahlfors ◽  
Maarit Heinonen ◽  
Pirjo Tanhuanpää ◽  
Kristiina Antonius

AbstractPotato onion (Allium cepa var. aggregatum G. Don) remained the most widely grown onion type in Finland up to the 1950’s, after which the more productive cultivars of common onion replaced this vegetatively propagated onion type. The Finnish accessions have been maintained in two national plant genetic resources (PGR) collections since 1990’s but new samples have been obtained still later. In this research, we analysed the genetic diversity of potato onions and shallots, grown in home gardens and in PGR collection, and compared the uniformity of the two PGR collections. One hundred ten onion samples were analysed using eight microsatellite loci, which amplified 83 alleles in total. There was a large number of genetically different samples, forming four major groups in the dendrogram. The results show that there is still a lot of genetic diversity among the Finnish potato onions, even though they are propagated vegetatively. The rich diversity in the samples obtained from citizens reflects a valuable source of genetic resources maintained by home gardeners. The national collection has been updated on the basis of the results. To ensure the preservation of the rich onion heritage, efforts are needed to increase the availability of potato onion to home gardeners and commercial growers.

Author(s):  
Paula Bramel ◽  

This chapter reviews the key issues and challenges facing genebanks in preserving crop genetic diversity ex situ. Local crop genetic diversity is challenged with changes in land use, urbanization, land degradation, changes in agricultural practises, availability of improved varieties, changes in market preference, and the impact of climate change. Efforts have been made to secure plant genetic resources ex situ for future use but there are significant issues related to cost effective, efficient, secure, rational, and sustainable long-term ex situ conservation. It begins by addressing issues for the composition of ex situ collections and moves on to discuss issues for routine operations for conservation. The chapter also highlights issues for the use of conserved genetic resources, before concluding with a summary of why the development of sustainable genebank systems is so important.


2010 ◽  
Vol 8 (2) ◽  
pp. 171-181 ◽  
Author(s):  
C. C. M. van de Wiel ◽  
T. Sretenović Rajičić ◽  
R. van Treuren ◽  
K. J. Dehmer ◽  
C. G. van der Linden ◽  
...  

Genetic variation in Lactuca serriola, the closest wild relative of cultivated lettuce, was studied across Europe from the Czech Republic to the United Kingdom, using three molecular marker systems, simple sequence repeat (SSR, microsatellites), AFLP and nucleotide-binding site (NBS) profiling. The ‘functional’ marker system NBS profiling, targeting disease resistance genes of the NBS/LRR family, did not show marked differences in genetic diversity parameters to the other systems. The autogamy of the species resulted in low observed heterozygosity and high population differentiation. Intra-population variation ranged from complete homogeneity to nearly complete heterogeneity. The highest genetic diversity was found in central Europe. The SSR results were compared to SSR variation screened earlier in the lettuce collection of the Centre for Genetic Resources, the Netherlands (CGN). In the UK, practically only a single SSR genotype was found. This genotype together with a few other common SSR genotypes comprised a large part of the plants sampled on the continent. Among the ten most frequent SSR genotypes observed, eight were already present in the CGN collection. Overall, the CGN collection appears to already have a fair representation of genetic variation from NW Europe. The results are discussed in relation to sampling strategies for improving genebank collections of crop wild relatives.


2004 ◽  
Vol 2 (3) ◽  
pp. 143-151 ◽  
Author(s):  
I.S. Bisht ◽  
K.V. Bhat ◽  
S. Lakhanpaul ◽  
B.K. Biswas ◽  
M. Pandiyan ◽  
...  

Sesame (Sesamum indicum L.) is one of the world's oldest oil crops and has been cultivated in Asia from ancient times. India has a rich diversity of this crop and a landrace collection is maintained at the National Genebank at the National Bureau of Plant Genetic Resources (NBPGR). The breeding potential of this germplasm has been hardly exploited to date. The major hindrance for the utilization of these resources is the transfer of diversity into a form that can be easily used by breeders and farmers. As part of a core collection strategy, a selection was made of 24 of the most diverse and unadapted parental lines, including one accession of the wild species S. mulayanum, and these were intercrossed in various combinations to maximize genetic diversity and to develop locally adapted pools of genetic resources. A weak and decentralized selection regime was maintained at four selected target sites on the progeny of 103 crosses. The range of variation in the selected F4 progenies was assessed, and promising types with desired plant characteristics and high seed yield were selected. Realized genetic gains, especially for yield-related traits, were also assessed. Only a limited fraction of the existing diversity held in the genebank was used in the present study and there is much more diversity available for large-scale genetic enhancement of sesame in the future.


2003 ◽  
Vol 1 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Toby Hodgkin ◽  
V. Ramanatha Rao ◽  
Angélica Cibrian-Jaramillo ◽  
Samy Gaiji

AbstractPlant genetic resources are conserved so that they can be used to improve crop plant pro- duction and in other ways. However, it is often asserted that use of ex situ conserved germplasm is inadequate and that genetic diversity maintained in genebanks is underutilized. In part, this reflects an incomplete recognition of what constitutes use of plant genetic resources, and of the many different ways in which material from genebanks contributes to improved agricultural production. Based on recent information from surveys of distribution of germplasm from genebanks, and from surveys of users, we suggest that the evidence indicates that there is substantial use of ex situ conserved materials for a wide range of different uses. We suggest that barriers to use of ex situ conserved germplasm may often result from a lack in numbers of users, and from limitations in capacity to effectively utilize the genetic diversity present in genebanks to reduce genetic vulnerability and increase sustainability in modern production systems.


Author(s):  
Jones Abrefa Danquah ◽  
Mark Appiah ◽  
Adam Osman ◽  
Ari Pappinen

Mahogany is the collective international trade name for the high-value tropical and subtropical timber tree species of the family Meliaceae. Mahogany species are noted for their deep red-brown heartwood and are widely used in the construction, boat building, interior decoration (particularly paneling and floor tiles), and in the manufacture of furniture. Across their natural geographical distribution range, many rural communities depend for their livelihoods on the genetic resources of the species as they provide natural products and services. However, mahogany populations across their native range are threatened by deforestation, habitat fragmentation, excessive logging and genetic erosion. In addition, climate change may bring about a shift in the distributional range of the native species. To safeguard the rich diversity of mahogany requires a conscientious effort in policy formulation and the enforcement of existing laws in regard to the management and conservation of the species. In addition, it is imperative that mahogany is used as an integral component in agroforestry systems and in reforestation efforts, as well as in the restoration of degraded forest ecosystems in order to protect the genetic resources of the species. The aim of this review was to highlight the threats to the sustainability of the species. We conducted literature review to examine the geographic distributional range of a mahogany complex (Khaya spp, Entandrophragma spp, Cedrela spp, Toona spp, Swietenia spp) at global, regional and ecosystem scales. We used maps as annotated diagrams to show the probable geographic global distribution range of the mahogany complex. The Khaya spp. and Entandrophragma spp. are native to Africa, Cedrela spp. and Swietenia spp. are native to Central and South America, whereas, Toona spp. are found primarily in southeast Asia.


2021 ◽  
Author(s):  
HALIL IBRAHIM OZTURK ◽  
Veysel Dönderalp ◽  
Hüseyin Bulut ◽  
Recep Korkut ◽  
Arash HOSSEINPOUR ◽  
...  

Abstract Background Plant genetic resources constitute the most valuable assets of countries. It is of great importance to determine the genetic variation among these resources and to use the data in breeding studies. Cucurbita maxima species in the cucurbitaceae family have high genetic diversity, but its genetic diversity at the molecular level is inadequately characterized. Methods and Results To determine the genetic diversity among genotypes of Cucurbita maxima species of squash, which is widely grown in Erzincan, 14 different squash genotypes collected were examined based on the morphological parameters and molecular characteristics. SSR (Simple sequence repeat) markers were used to determine genetic diversity at the molecular level. The analysis of morphological characterization within genotypes showed a wide variability in morphological traits of plant, flower, fruit, and leaf. Seven SSR markers yielded a total of 23 polymorphic bands, the number of alleles per marker ranged from 2 to 5, and the mean number of alleles was 3.286. Polymorphic information content (PIC) ranged from 0.00 (GMT-M61) to 0.202 (GMT-P25), and the mean PIC value per marker was 0.130. Cluster analysis using Nei's genetic distance determined that 14 genotypes were divided into 3 major groups. Conclusions The SSR markers used were effective in distinguish among similar winter squash or pumpkin and therefore can be beneficial for consideration of Cucurbita maxima species diversity, screening of genetic resources and their selection.


Author(s):  
M. Ehsan Dulloo ◽  
◽  
Prishnee Bissessur ◽  
Jai Rana ◽  
◽  
...  

This chapter reviews the methodologies developed to assess the extent of diversity of PGRFA at species, variety, and genetic level and examines the efforts made at global level in monitoring them at different scales. Efforts have been made to halt the loss of biodiversity (including genetic diversity) by United Nations Organizations (FAO, UNEP, UN) at setting of global targets (second Global Plan of Action on conservation and sustainable use of PGRFA, Aichi Targets and Sustainable Development Goals) and indicators have been established to monitor progress towards them. Yet none of the targets on genetic diversity have been achieved, due to a lack of implementable monitoring system that would allow progress to be accurately monitored. Further research is needed to improve the methodologies for monitoring plant genetic resources, particularly at the varietal and genetic level. The chapter discusses the opportunities and challenges as well as provides recommendations for future conservation and monitoring strategies that may safeguard PGRFA for posterity.


2008 ◽  
Vol 5 (3) ◽  
pp. 183-187
Author(s):  
Li Hui-Fang ◽  
Song Wei-Tao ◽  
Zhu Wen-Qi ◽  
Xu Wen-Juan ◽  
Tang Qing-Ping

AbstractUsing microsatellite markers, the genetic structure of nine domestic duck (Anas platyrhynchos) populations in eastern China was analysed. The results showed that the heterozygosity was high in these populations, ranging from 0.5137 to 0.6055, with an average heterozygosity of 0.5523, reflecting the rich diversity. Considerable breed differentiation was observed and 25.65% of the total genetic variation came from breed differences; this low differentiation result affirmed that each breed has its own genetic diversity. The DA genetic distances suggested that greater differentiation existed between populations. The duck populations were clustered into four groups based on neighbour joining (NJ) clustering, and the clustering results showed relationships with duck breed distributions and economic utilization.


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