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Dario J. Chavez, Thomas G. Beckman, and José X. Chaparro

- Padus group, were recovered by Lee and Wen’s (2001) phylogenetic analysis using ITS sequences of ribosomal DNA. These results were not congruent with Rehder’s (1940) taxonomic treatment. Bortiri et al. (2001) supported the genus Prunus monophyly

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Beibei Li, Jianfu Jiang, Xiucai Fan, Ying Zhang, Haisheng Sun, Guohai Zhang, and Chonghuai Liu

instead switched to modern cultivars or recently bred cultivars. Therefore, many germplasm resources that were not preserved were lost permanently. DNA molecular marker technique showing polymorphism at the DNA level is a powerful tool for the

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Justin A. Porter, Hazel Y. Wetzstein, David Berle, Phillip A. Wadl, and Robert N. Trigiano

individual based on its developmental stage or even different stress factors at the time of sampling ( Lee et al., 2002 ). With the advent of DNA methodologies, a number of methods have been developed to evaluate genetic relatedness in species including RAPD

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Júlia Halász, Attila Hegedűs, Zoltán Szabó, József Nyéki, and Andrzej Pedryc

first S -genotype ( S a S b ) of a japanese plum cultivar (‘Sordum’) was described by Yamane et al. (1999) . Later, Beppu et al. (2002 , 2003) demonstrated the diversity of S -haplotypes in japanese plum by molecular cloning of genomic DNAs

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Victor Luk and John Carlson

DNA fingerprinting is a potentially powerful molecular genetic technique that can be used to distinguish subtle differences in genome structure among closely related genotypes, such as many horticultural varieties. A DNA fingerprinting project is currently in progress at the Univ. of British Columbia (UBC) Biotechnology Laboratory to produce a set of DNA markers and an easy, reliable, and legally recognized analysis protocol that will enable the UBC Botanical Garden Plant Introduction Scheme (PISBG) to unambiguously identify any of their released varieties, even in dormant or juvenile form, wherever it is being propagated or sold. High-quality genomic DNA was isolated from the leaf samples of six PISBG species (Anagallis monellii, Artemesia stelleriana, Clematis, Genista pilosa, Microbiota decussata, and Penstemon fruticosa) using a modified CTAB DNA isolation protocol, and further purified by cesium chloride/ethidium bromide gradient. Samples of these genomic DNA preparations (10 ng) were then amplified by a 45-cycle polymerase chain reaction (PCR) protocol using 1.5-μm 10-nucleotide primers of arbitrary nucleotide sequence that amplify a variety of sites distributed across the genome. Following the amplification, PCR products [random amplified polymorphic DNA (RAPD) markers] were separated by agarose gel electrophoresis and visualized by ethidium bromide staining. More than 70% of the 51 primers tested so far generated distinctive banding patterns (2–11 bands) with DNA samples from each species. Subtle changes in the genome or differences between genotypes can be detected by screening a series of such primers against DNA samples from the genotypes in question. Once a RAPD primer has been identified that consistently generates a different banding pattern between genotypes, it can be used as an identification tool for discriminating between those genotypes at any time in the future.

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Mohammed Elsayed El-Mahrouk, Yaser Hassan Dewir, and Yougasphree Naidoo

, protein marker, and DNA-based molecular markers. Therefore, DNA markers have been reported as an important tool to evaluate the genetic homogeneity and true-to-type nature of micropropagated plants ( Cheruvathur et al., 2013 ). Among them, RAPD is a

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Sima Taheri, Thohirah Lee Abdullah, Nur Ashikin Psyquay Abdullah, and Zaiton Ahmad

markers can reveal differences among irradiated and non-irradiated individual plants at the DNA level and thus provide a more direct, reliable, and efficient tool for germplasm conservation and management ( Kumar et al., 2006 ). Several molecular markers

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Eric J. Votava and Paul W. Bosland

Random amplified polymorphic DNA (RAPD) analysis can provide a means of evaluating and comparing genetic variability within cultivars. The purpose of this study was to evaluate the relative genetic variability between accessions of two open-pollinated bell pepper cultivars: 'California Wonder', an heirloom cultivar, and 'Jupiter', a modern cultivar. RAPD molecular markers were used to assess the genetic variability between accessions of these two cultivars. The high levels of genetic variability found among accessions of 'California Wonder' may preclude its use as a standard cultivar in research.

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Amnon Levi and Claude E. Thomas

triploid seeds ( Shimotsuma and Matsumoto, 1957 ). Still, DNA markers can be useful in quality assurance tests to confirm sufficient production of triploid seeds in isolation plots. DNA markers have been used in genetic studies and in breeding programs of

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Naomi R. Smith and Robert N. Trigiano

Flowering dogwood (Cornus florida L.) is an important tree of forests and urban landscapes in the eastern United States. Currently, there are over 100 cultivars of flowering dogwood commercially available. An identification process based on genotype would be of use to researchers, breeders, and nurserymen, as many cultivars are similar phenotypically. Molecular markers offer a promising way of definitively identifying flowering dogwood cultivars. Amplified fragment length polymorphism (AFLP) is a technique that can be used to generate DNA fingerprints. DNA was isolated from leaves of 17 common cultivars of dogwood and AFLP fingerprints were generated by a Beckman Coulter CEQ™ 8000. Fingerprints were converted to binary data and verified manually. Two drafts of a cultivar identification key were generated based on the corrected, verified binary data and cultivar-specific peaks. Six primer combinations were used to construct all keys and were tested with seven unknown dogwood cultivar samples. Six unknown samples were correctly identified using the keys. Only one unknown, `Cherokee Brave', was unidentifiable with any key. In all cases, some intracultivar variation was observed. A similarity index was calculated and visualized with a tree of genetic relatedness using NTSYSpc. Intracultivar variation was observed in the similarity index as well. This database for cultivar-specific molecular markers will serve as a starting point to which other cultivars can be added and also can be used in breeding applications, patent application and other projects, such as mapping the C. florida genome.