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David M. Czarnecki II, Madhugiri Nageswara Rao, Jeffrey G. Norcini, Frederick G. Gmitter Jr, and Zhanao Deng

” (presence of bands) for each individual plant was analyzed using population genetics computer programs to calculate the genetic diversity within populations, genetic differentiation among populations, genetic relationships among populations, and historical

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S. Jorge, M.C. Pedroso, D.B. Neale, and G. Brown

Random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic similarities between Portuguese Camelliasinensis (L.) O. Kuntze (tea plant) accessions and those obtained from the germplasm collections from the Tea Research Foundation of Kenya and from the National Research Institute of Vegetables, Ornamental Plants, and Tea of Japan. The accessions studied are taxonomically classified as C. sinensis, var. sinensis, var. assamica, or ssp. lasiocalyx. A set of 118 ten-base arbitrary primers was tested, of which 25 produced informative, reproducible, and polymorphic banding patterns. These primers were used to amplify DNA from 71 tea plant accessions and produced a total of 282 bands, of which 195 were polymorphic. The phenotypic frequencies were calculated using Shannon's Index and employed in estimating genetic diversity within tea plant populations. Our study demonstrates that tea plant populations, including the Portuguese tea plants, show considerable genetic variability. From the UPGMA cluster analysis based on a matrix using the Jaccard coefficient, it was possible to distinguish the Portuguese tea plants from the remaining accessions. The RAPD markers discriminated the three C. sinensis varieties. Moreover, within each variety cluster, subclusters formed according to geographic distribution. The RAPD analysis also separated the commercially cultivated tea plants from the Taiwanese wild tea plants. The present results show that RAPD analysis constitutes a good method to estimate genetic diversity within C. sinensis, and to differentiate C. sinensis accessions according to taxonomic variety and geographical distribution.

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Yu Zong, Ping Sun, Xiaoyan Yue, Qingfeng Niu, and Yuanwen Teng

recombination ( Schaal et al., 1998 ). These features can lead to relatively high population differentiation because of the lower dispersal potential in seeds than pollen, greater genetic drift of the haploid genome in small refugial populations, or both

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Audrey M. Sebolt and Amy F. Iezzoni

selected as the genetic marker because over 35 different S -alleles have been identified in cherry to date ( Bošković and Tobutt, 2001 ; Choi et al., 2000 ; Hauck et al., 2001 ; Sonneveld et al., 2001 ; Tao et al., 1999 ; Tsukamoto et al., 2006

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Hongwen Huang, Desmond R. Layne, and Don E. Riemenschneider

As a new National Clonal Germplasm Repository for Asimina species at Kentucky State University (KSU), of major concern to us is the genetic variation within our germplasm collection. The present study investigated the extent of genetic diversity for the pawpaw germplasm in our collection and the geographical pattern of genetic diversity among populations using isozyme markers. Allozyme diversity was high in Asimina triloba (L.) Dunal (Annonaceae) collected from all nine different states, as is typical for temperate woody perennial, widespread and outcrossing plant species. Averaged across populations, mean number of alleles per locus (A), percent polymorphic loci (P), effective number of alleles per locus (Ae), and expected heterozygosity (He) were 1.54, 43.5, 1.209, and 0.172, respectively. Significant deviations from Hardy-Weinberg equilibrium were found in nine populations at an average of 4.8 loci. Observed heterozygosity was higher than expected. Partitioning of genetic diversity showed that 88.2% resided within populations. The proportion of genetic diversity among populations (Gst = 0.118; FST = 0.085) was either lower than or within the range of those species with similar ecological and life-history traits. The mean genetic identity among populations was high (I = 0.988). An analysis using UPGMA clustered most populations as one major group, with the southernmost (Georgia) and the westernmost (Illinois) populations readily separated from the main group. The relationships discovered by principal component analysis (PCA) were similar to those revealed by UPGMA. In addition, PCA separated the northernmost population (New York) from the major group. Sampling strategies for future germplasm collection of A. triloba are also discussed.

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Dong Liu, Ping Li, Jiulong Hu, Kunyuan Li, Zhenyu Zhao, Weiyan Wang, Jinyuan Zhang, Xu Ding, and Zhimou Gao

( H t ), and genetic diversity within groups ( H s ) of P. sojae were computed with POPGENE 1.3.1 software ( Yeh et al., 1999 ). The genetic differentiation coefficient ( G ST ), gene flow coefficient ( N m ), genetic identity (I), and genetic

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Xiangli Ma, Min Tang, Yufen Bi, and Junbo Yang

the two matrices. Genetic diversity ( H S ), the total genetic diversity ( H T ), and the genetic differentiation coefficients ( G ST and N ST ) were calculated using Permut version 2.0 software ( Pons and Petit, 1996 ), G ST and N ST were

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Jana Murovec

pairwise comparisons of population genetic differentiation (F ST ) between 0.030 (accessions “07-Gleisdorfer Opal” and “08-Gleisdorfer Diamant”) and 0.760 (accessions “32-PI 364240-Gribovskaja 14” and “48-PI 267664-Yellow Long”). AMOVA revealed that 37

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Samuel G. Obae, Mark H. Brand, and Richard C. Kaitany

. Additionally, morphological characteristics can be influenced by variation in environmental and growing conditions making it difficult to accurately identify and differentiate B. thunbergii cultivars. Modern technology using molecular markers offers a

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Rohollah Karimi, Ahmad Ershadi, Kourosh Vahdati, and Keith Woeste

within-population genetic diversity generally decreased from south to north. Population genetic structure. The genetic analyses revealed high levels of differentiation among populations ( Table 2 ). The coefficient of hierarchical F ST ( Table 3