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Xinwang Wang, Phillip A. Wadl, Cecil Pounders, Robert N. Trigiano, Raul I. Cabrera, Brian E. Scheffler, Margaret Pooler, and Timothy A. Rinehart

sizes using pedigree-based analyses. Alleles associated with important horticultural traits could be used to accelerate future crapemyrtle breeding through molecular marker-assisted selection (MAS). SSRs were used to DNA fingerprint 93 crapemyrtle

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Enrique I. Sánchez-González, Adriana Gutiérrez-Díez, and Netzahualcóyotl Mayek-Pérez

Mendelian laws of inheritance from one generation to the next one. SSRs, also known as microsatellites, are tandemly arranged repeats of mono, di-, tri, tetra-, and pentanucleotides with different lengths of repeat motifs ( Bhat et al., 2010 ). SSR markers

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R.E. Veilleux, L.Y. Shen, and M.M. Paz

RAPD and SSR analyses were used to characterize the genetic composition of anther-derived plants of a diploid potato clone, CP2 (S. chacoense 80-1 × S. phureja 1-3). The ploidy of anther-derived plants was first determined by flow cytometry. A total of 44 decamer primers was screened for polymorphism. The loci that segregated were selected and scored. The monoploids had only half as many loci carrying RAPD markers compared to the anther donor. Among the 13 anther-derived diploids, four were identified as homozygous by marker frequency similar to monoploids and nine as heterozygous. Five of seven SSRs obtained from published potato sequences were polymorphic in CP2. CP2 was found to be heterozygous with two alleles at four SSR loci (TC/TA, AAG, AGA, CTT), and three alleles at an ACTC locus. Primer pairs flanking each of the five polymorphic SSRs revealed that monoploids had only the allele contributed by chc 80-1. Homozygous diploids had only one band per SSR locus, whereas heterozygous diploids displayed more than one allele for at least one SSR locus. Results of the SSR analysis supported the findings based on RAPD markers; the same diploid clones were characterized as homozygous by both SSR and RAPD markers.

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R.L. Jarret, S. Kresovich, T. Holms, Janelle Evans, and Z. Liu

Simple sequence repeats (SSRs) were isolated from a size-fractionated genomic DNA library of watermelon (Citrullus lanatus L. cv. New Hampshire Midget). Screening of the library with five oligonucleotide probes, including (GT)11, (AT)11, (CT)11, (GC)11, and (TAA)8, detected the occurrence of 96 positive colonies among ≈8000 recombinants. Automated DNA sequencing revealed the presence of SSRs. PCR primer pairs homologous to the regions flanking the SSR loci were synthesized commercially and used to screen 56 watermelon genotypes for the occurrence of SSR polymorphisms. Amplification products were separated using nondenaturing PAGE. Eighty percent of the primer pairs produced amplification products of the expected size and detected polymorphisms among the genotypes examined. The use of SSRs for watermelon germplasm characterization is discussed.

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Kim S. Lewers*, Eric T. Stafne, John R. Clark, Courtney A. Weber, and Julie Graham

Some raspberry and blackberry breeders are interested in using molecular markers to assist with selection. Simple Sequence Repeat markers (SSRs) have many advantages, and SSRs developed from one species can sometimes be used with related species. Six SSRs derived from the weed R. alceifolius, and 74 SSRs from R. idaeus red raspberry `Glen Moy' were tested on R. idaeus red raspberry selection NY322 from Cornell Univ., R. occidentalis `Jewel' black raspberry, Rubus spp. blackberry `Arapaho', and blackberry selection APF-12 from the Univ. of Arkansas. The two raspberry genotypes are parents of an interspecific mapping population segregating for primocane fruiting and other traits. The two blackberry genotypes are parents of a population segregating for primocane fruiting and thornlessness. Of the six R. alceifolius SSRs, two amplified a product from all genotypes. Of the 74 red raspberry SSRs, 56 (74%) amplified a product from NY322, 39 (53%) amplified a product from `Jewel', and 24 (32%) amplified a product from blackberry. Of the 56 SSRs that amplified a product from NY322, 17 failed to amplify a product from `Jewel' and, therefore, detected polymorphisms between the parents of this mapping population. Twice as many detected polymorphisms of this type between blackberry and red raspberry, since 33 SSRs amplified a product from NY322, but neither of the blackberry genotypes. Differences in PCR product sizes from these genotypes reveal additional polymorphisms. Rubus is among the most diverse genera in the plant kingdom, so it is not surprising that only 19 of the 74 raspberry-derived SSRs amplified a product from all four of the genotypes tested. These SSRs will be useful in interspecific mapping and cultivar development.

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Yunyan Sheng, Feishi Luan, Faxing Zhang, and Angela R. Davis

using simple sequence repeat length polymorphisms (SSRs). Subsequently, codominant simple sequence repeat markers were used to detect genetic diversity in watermelon ( Patcharin et al., 2011 ). Recently, two types of molecular markers (RAPD and SSR) were

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Zuguo Cai, Wenfang Zeng, Liang Niu, Zhenhua Lu, Guochao Cui, Yunqin Zhu, Lei Pan, Yifeng Ding, and Zhiqiang Wang

peach cultivars and accessions ( Cao et al., 2014 ; Verde et al., 2012 ). SSR (microsatellites) are tandem repeat DNA sequences with a core unit of 1–6 bps, which are abundant in prokaryotic and eukaryotic genomes and are ubiquitously distributed in

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R.L. Jarret, N. Bowen, S. Kresovich, and Z. Liu

Simple sequence repeats (SSRs) were isolated from a size-fractionated genomic DNA library of sweetpotato [Ipomoea batatas (L.) Lam.]. Screening of the library with five oligonucleotide probes, including; (GT)11, (AT)11, (CT)11, (GC)11, and (TAA)8, detected the occurrence of 142 positive colonies among ≈12,000 recombinants. Automated DNA sequencing revealed the presence of simple, compound, perfect, and imperfect SSRs. Five homologous PCR primer pairs were synthesized commercially and used to screen 30 sweetpotato clones for the occurrence of SSR polymorphisms. All primer pairs produced an amplification product of the expected size and detected polymorphisms among the genotypes examined. The potential for the use of SSRs as genetic markers for sweetpotato germplasm characterization is discussed.

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Cecilia McGregor, Vickie Waters, Savithri Nambeesan, Dan MacLean, Byron L. Candole, and Patrick Conner

). Breeders wanting to introduce new P. capsici resistance genes into their programs probably want to use a source that is not genetically closely related to CM-334. The use of SSR markers to determine genetic variation and uniformity within and between

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Nader R. Abdelsalam, Hayssam M. Ali, Mohamed Z.M. Salem, Elsayed G. Ibrahem, and Mohamed S. Elshikh

, mango germplasm has been collected and analyzed using simple sequence repeat (SSR) markers in numerous studies ( Dillon et al., 2013 ; Tsai et al., 2013 ). Microsatellite markers were developed by Kundapura et al. (2011) to calculate the genetic