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Min Wang and Irwin L. Goldman

Genetic relationships among 37 accessions of Beta vulgaris, including 21 table beet, 14 sugar beet, and two Swiss chard (Beta vulgaris ssp. cicla) accessions, were evaluated using randomly amplified polymorphic DNA (RAPD). Genetic distance was estimated based on the presence or absence of polymorphic RAPD bands. Multidimensional scaling plots of genetic distance values revealed that table beet inbred lines from the University of Wisconsin Table beet Breeding Program clustered in an intermediate position between sugar beet breeding lines and standard table beet germplasm, likely because of their origin from an introgression program designed to incorporate sugar beet genes.

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Jan Tiväng, Jim Nienhuis, and O.S Smith

The sampling method was applied to a data-set generated by RFLP molecular marker analysis, representing 37 Zea maize cultivars. A total of 251 enzyme probe-combinations were used yielding a total of 1,205 scores per genotype. Genetic distance was calculated among all 37 entries from subsets of arbitrary and increasing sample size. Each score entry in the subset was selected at random from all possible scores with replacement following each selection. The variance for genetic distance was calculated among all subsets of equal size for all possible cultivar pairs. The pooled pair variance was plotted and compared to random simulation models. Additional comparisons were made contrasting closely vs. distantly related cultivars.

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Jan E. Paul Debaene and Laren Robison

Tepary beans (Phaseolus acutifolius A. Gray) are considered drought and heat tolerant, desirable characteristics for arid regions. Knowing the genetic distances among tepary lines can indicate both compatibility for intraspecific crosses and potential for Interspecific P. acutifolius × P. vulgaris hybrids. Fifteen tepary lines, including cultivars and landraces, were compared to two pinto bean varieties using random amplified polymorphic DNA's (RAPDs). At the present time polymorphisms have been clearly identified between wild and cultivated teparies and the pinto bean. An ammo acid profile is also being determined using HPLC. More work needs to be completed before relationships among cultivated teparies can be established.

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Jane M. Marita, José Luis Pires, W. Martin Aitken, and James Nienhuis

An increased need to understand the genetic relationships among cacao (Theobroma cacao) germplasm exists to identify cultivars that possess resistance to witches' broom disease (caused by Crinipellis perniciosa). Loss of production due to witches' broom disease in important cacao-growing areas, such as Bahia, Brazil, has generated a strong demand for disease-resistant varieties. Varieties based on single sources of resistance have been released; however, other genotypes are needed to enlarge the genetic diversity of cultivars in breeding programs. A core collection has been created to represent the range of genetic diversity available among the more than 600 cacao accessions at Centro de Pesquisa do Cacau (CEPEC). The cacao core facilitates access to the collection and is intended to enhance its use. This core collection was created from RAPD marker-based estimates of genetic distance among a subset of 270 accessions from the entire collection. The subset was sampled based on 1) witches' broom disease resistance data, 2) random sampling of the collection, and 3) random sampling of recently acquired accessions. Differences in RAPD marker frequencies were used to identify accessions in a witches' broom disease breeding program that contribute to the genetic diversity of the collection as a whole. In addition, differences in RAPD marker frequency allowed the comparison between accessions in the original collection and those acquired from new geographic regions that may expand the collection's genetic diversity.

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Njung’e Vincent Michael, Pamela Moon, Yuqing Fu, and Geoffrey Meru

into C. pepo is difficult because of wide genetic distances between the species that require resource-intensive techniques, such as embryo rescue and bridge crossing ( Rakha et al., 2012 ; Zhang et al., 2012 ). In an effort to identify sources of

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Xianping Qu, Jiang Lu, and Olusola Lamikanra

Two morphologically distinct types of grapes belonging to the subgenera Euvitis and Muscadinia in the genus Vitis are cultivated in the United States. The former is commonly called bunch grapes while the latter is usually called muscadine. Genetic diversity among these grapes was investigated using RAPD markers. Sixteen grape cultivars, with parentage including V. rotundifolia Michx., V. vinifera L., and several American Vitis species, were used for the RAPD analysis. A total of 156 RAPD markers was produced from 19 random primers, over 90% of which was polymorphic among the muscadine and the bunch grapes. Polymorphisms were lower within each subgenus. Relationships between these two subgenera were estimated based on band-sharing and cluster analysis. The average genetic distance between the bunch and the muscadine grape cultivars was 0.45. The results based on DNA analysis agree with isozyme data obtained from a separate study, which demonstrated that muscadine grapes share very few common alleles with American bunch grapes and European grapes.

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S.E. Gardiner, H.C.M. Bassett, C. Madie, and D.A.M. Noiton

Information about a rare allele of phosphoglucomutase (PGM) that is shared by `Braeburn' and 16% of cultivars in the New Zealand Cultivar Collection was combined with historical information about cultivar distribution to select a set of 15 cultivars for a more detailed genetic analysis of their relatedness to the key New Zealand apple (Malus domestica Borkh.) `Braeburn'. DNA from all 16 cultivars was examined by RFLP analysis using 41 probe-enzyme combinations and also by RAPD analysis with 39 selected primers. The RFLP and RAPD data excluded a proposal that `Lady Hamilton' and `Braeburn' are genetically identical. All cultivars except `Lady Hamilton' were excluded as potential parents for `Braeburn' based on incompatible RFLP banding. Assessment of genetic distances between `Braeburn' and the other 15 cultivars from RFLP and RAPD data demonstrated that `Lady Hamilton' was more closely related to `Braeburn' than all others. We conclude that there is a high likelihood that `Lady Hamilton' is one of the parents of `Braeburn'.

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Yeun-Kyung Chang, Richard E. Veilleux, and Muhammad Javed Iqbal

peaks. NTSYS-pc software version 2.20 ( Rohlf, 2005 ) was used to calculate the genetic distance or similarity between the samples. A cluster analysis was performed using unweighted pair group method with arithmetic mean (UPGMA) based on the Dice index

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Jack E. Staub, Isabelle Y. Delannay, and Jin-Feng Chen

). Description Multivariate analyses using Rogers ( Rogers, 1972 ) genetic distances (GD) modified by Wright (1978) were used employing 32 codominant markers to define phenotypic and genotypic relationships between the IBL and their parents ( Delannay, 2009

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Michael J. Havey and Farhad Ghavami

needed to produce the most accurate genotyping results. Clustering and genotype calls were proofed by a second person to eliminate any miscalling of the markers (standard protocol of Eurofins-BioDiagnostics). Genetic distances among A. vavilovii and the