Classification and diversity of sacred and American Nelumbo species: the genetic relationships of flowering lotus cultivars in Japan using SSR markers

2009 ◽  
Vol 7 (03) ◽  
pp. 260-270 ◽  
Author(s):  
Nakao Kubo ◽  
Masashi Hirai ◽  
Akio Kaneko ◽  
Daizo Tanaka ◽  
Kumaji Kasumi

The water lotus, genusNelumbo, contains two species, the sacred (Nelumbo nucifera) and American lotuses (Nelumbo lutea). Hundreds of flowering lotus cultivars are currently known. However, their classification is unclear. For the classification ofNelumbocultivars, in addition to 35 simple sequence repeat (SSR) markers recently developed, we have developed 17 and 16 of newNelumboSSR markers from SSR-enriched genomic libraries and expressed sequence tag (EST) data, respectively. Out of these 68 SSRs, along with SSRs recently published by others, 52 showed clear polymorphisms in 98Nelumbosamples. A total of 300 alleles were observed, ranging from 2 to 11 alleles per locus, with an average of 5.77. Alleles specific for the American lotus-derived cultivars and a cluster of the American lotus-derived cultivars on a neighbour-joining tree confirmed genetic differences betweenN. luteaandN. nucifera. In addition, a possible differentiation between Chinese and Japanese cultivars was also suggested. Parentage analysis using the SSR markers confirmed four known parentages and predicted currently-unknown parentages of six cultivars. The present data have demonstrated that site-specific, co-dominant SSR markers enable more accurate classification, identification and comparison ofNelumbospecies.

2021 ◽  
Vol 12 ◽  
Author(s):  
Haftom Brhane ◽  
Teklehaimanot Haileselassie ◽  
Kassahun Tesfaye ◽  
Cecilia Hammenhag ◽  
Rodomiro Ortiz ◽  
...  

Finger millet (Eleusine coracana (L.) Geartn.) is a self-pollinating amphidiploid crop cultivated with minimal input for food and feed, as well as a source of income for small-scale farmers. To efficiently assess its genetic diversity for conservation and use in breeding programs, polymorphic DNA markers that represent its complex tetraploid genome have to be developed and used. In this study, 13 new expressed sequence tag-derived simple sequence repeat (EST-SSR) markers were developed based on publicly available finger millet ESTs. Using 10 polymorphic SSR markers (3 genomic and 7 novel EST-derived), the genetic diversity of 55 landrace accessions and 5 cultivars of finger millet representing its major growing areas in Ethiopia was assessed. In total, 26 alleles were detected across the 10 loci, and the average observed number of alleles per locus was 5.6. The polymorphic information content (PIC) of the loci ranged from 0.045 (Elco-48) to 0.71 (UGEP-66). The level of genetic diversity did not differ much between the accessions with the mean gene diversity estimates ranging only from 0.44 (accession 216054) to 0.68 (accession 237443). Similarly, a narrow range of variation was recorded at the level of regional states ranging from 0.54 (Oromia) to 0.59 (Amhara and Tigray). Interestingly, the average gene diversity of the landrace accessions (0.57) was similar to that of the cultivars (0.58). The analysis of molecular variance (AMOVA) revealed significant genetic variation both within and among accessions. The variation among the accessions accounted for 18.8% of the total variation (FST = 0.19; P < 0.001). Similarly, significant genetic variation was obtained among the geographic regions, accounting for 6.9% of the total variation (P < 0.001). The results of the cluster, principal coordinate, and population structure analyses suggest a poor correlation between the genetic makeups of finger millet landrace populations and their geographic regions of origin, which in turn suggests strong gene flow between populations within and across geographic regions. This study contributed novel EST-SSR markers for their various applications, and those that were monomorphic should be tested in more diverse finger millet genetic resources.


2008 ◽  
Vol 133 (6) ◽  
pp. 810-818 ◽  
Author(s):  
John McCallum ◽  
Susan Thomson ◽  
Meeghan Pither-Joyce ◽  
Fernand Kenel ◽  
Andrew Clarke ◽  
...  

Bulb onion (Allium cepa L.) is a globally significant crop, but the structure of genetic variation within and among populations is poorly understood. We broadly surveyed genetic variation in a cultivated onion germplasm using simple sequence repeat (SSR) markers and sequenced regions flanking expressed sequence tag (EST)-SSRs to develop single-nucleotide polymorphism (SNP) markers. Samples from 89 inbred and open-pollinated (OP) bulb onion populations of wide geographical adaptation and four related Allium L. accessions were genotyped with 56 EST-SSR and four genomic SSR markers. Multivariate analysis of genetic distances among populations resolved long-day, short-day, and Indian populations. EST-SSR markers frequently revealed two major alleles at high frequency in OP populations. The median proportion of single-locus polymorphic loci was 0.70 in OP and landrace populations compared with 0.43 in inbred lines. Resequencing of 24 marker amplicons revealed additional SNPs in 17 (68%) and five SNP assays were developed from these, suggesting that resequencing of EST markers can readily provide SNP markers for purity testing of inbreds and other applications in Allium genetics.


2008 ◽  
Vol 133 (6) ◽  
pp. 794-800 ◽  
Author(s):  
Chunxian Chen ◽  
Jude W. Grosser ◽  
Milica Ćalović ◽  
Patricia Serrano ◽  
Gemma Pasquali ◽  
...  

Somatic hybridization is a powerful tool for the genetic improvement of citrus rootstocks, and it is part of an efficient in vitro-based breeding system described here. An essential component of the system is the requirement of confirming tetraploidy and the combination of the two donor genomes. Expressed sequence tag–simple sequence repeat (EST-SSR) markers provide a means to accomplish both of these objectives, and their application to a population of pummelo [Citrus grandis (L.) Osbeck] + mandarin (C. reticulata Blanco) somatic hybrids developed for the specific purpose of providing alternative rootstocks for sour orange (Citrus aurantium L.) is detailed. Nineteen new somatic hybrids were produced from various mandarin and pummelo parents, and their ploidy level and the complementation of their nuclear genomes were confirmed using four EST-SSR markers. These markers were selected from markers previously mapped in sweet orange [C. sinensis (L.) Osbeck] and trifoliate orange [Poncirus trifoliata (L.) Raf.] and prescreened for suitable allelic polymorphism within the mandarin and pummelo lines used. After polymerase chain reaction amplification of sequences from the parents and putative hybrids, the products were separated on a genetic sequencer and visualized electronically. Additionally, EST-SSR markers identified the unexpected zygotic origin of a presumed nucellar embryogenic callus line. Integration of EST-SSR techniques for high-throughput genotyping with previously developed approaches to somatic hybrid creation increases substantially the effectiveness and efficiency of this in vitro-based breeding system for citrus rootstock improvement.


2010 ◽  
Vol 29 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Chengcheng Tan ◽  
Yanqi Wu ◽  
Charles M. Taliaferro ◽  
Michael P. Anderson ◽  
Chuck Tauer ◽  
...  

2009 ◽  
Vol 134 (3) ◽  
pp. 337-347 ◽  
Author(s):  
David Jesús Gil-Ariza ◽  
Iraida Amaya ◽  
José Manuel López-Aranda ◽  
José Federico Sánchez-Sevilla ◽  
Miguel Ángel Botella ◽  
...  

Unlike other important crops analyzed so far for genetic diversity and population structure, the brief history and particularities of the genetics of the cultivated strawberry (Fragaria ×ananassa Duchesne) have limited its genetic characterization. The genomic composition and the pattern of inheritance have not been fully elucidated, although a number of studies have suggested a highly diploidized genome. In this study, the similarity relationships and structure of 92 selected strawberry cultivars with widely diverse origins have been established using simple sequence repeat (SSR) markers derived from expressed sequence tags (EST-SSR markers). Genetic analysis performed by the unweighted pair group method with arithmetic mean clustering revealed a distribution according to both date of cultivar release and breeding for a specific climatic adaptation. Additionally, a model-based clustering approach identified three populations among the strawberry cultivars with an overall FST value of 0.15 to 0.16. Both analyses support a limited differentiation of modern cultivars, most probably as a consequence of the methodology of strawberry breeding. Interestingly, the collection of strawberry cultivars here analyzed showed comparable genetic differentiation to that observed in natural populations of Fragaria chiloensis (L.) Mill., one of its wild ancestors. Our results suggest that breeding has produced a small but significant reduction on the genetic diversity of F. ×ananassa. The panel of 10 EST-SSRs described in this work provided an extremely low probability of confusion (less than 10−11), offering an efficient and accurate method for cultivar identification.


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