Search Results

You are looking at 11 - 20 of 927 items for :

  • "genetic diversity" x
Clear All
Free access

Timothy A. Rinehart, Brian E. Scheffler and Sandra M. Reed

have been identified (Glyn Church, personal communication). The objectives of this study were to examine ploidy levels of Dichroa selections, evaluate the genetic diversity within the available Dichroa germplasm, determine if naturally occurring

Free access

Emmanouil N. Tzitzikas, Antonio J. Monforte, Abdelhak Fatihi, Zacharias Kypriotakis, Tefkros A. Iacovides, Ioannis M. Ioannides and Panagiotis Kalaitzis

inodorus, reticulates, and cantalupensis) ( Silberstein et al., 1999 ). Various DNA molecular markers have been used to characterize the genetic diversity of melons, including restriction fragment length polymorphism ( Zheng et al., 1999 ), amplified

Free access

Hussam S.M. Khierallah, Saleh M. Bader, Michael Baum and Alladin Hamwieh

sanctions imposed on Iraq have negatively affected both the production and natural genetic diversity of the crop in Iraq and inhibited the much-needed impetus to rebuild the date palm industry. Development of suitable DNA molecular markers for this crop may

Free access

Yiqun Weng

genes into elite cultivated germplasm, it is necessary to understand the genetic diversity and phylogenetic relationships among wild and cultivated Cucumis species. The objective of this study was to assess genetic variation among C. metuliferus

Free access

Xiaoxu Yang, Yinshan Guo, Junchi Zhu, Zaozhu Niu, Guangli Shi, Zhendong Liu, Kun Li and Xiuwu Guo

genetic diversity and population structure in Vitis species. Huang et al. (2011) used 145 SSR primer pairs to compare the loci of ‘Cabernet Sauvignon’ ( Vitis vinifera ) and ‘Riesling’ ( V. vinifera ) grapevines, with the results showing that 70 loci

Free access

Yuan Zhang, Chen Wang, HongZheng Ma and SiLan Dai

morphometric criteria, but very little work has been performed on the molecular characterization of the chrysanthemum genome. It is therefore necessary to develop and use tools to evaluate the genetic diversity among chrysanthemum cultivars to promote the

Free access

K.M. Aradhva, F. Zee and R.M. Manshardt

Fifty-six accessions involving five taxa of Nephelium (N. Iappaceum varieties lappaceum and pallens, N. hypoleucum, N. ramboutan-ake, and N. cuspidatum) were fingerprinted and evaluated for genetic diversity using isozyme polymorphism. All five taxa were polymorphic for most of the enzymes encoded by 10 putative loci. Number of alleles per locus ranged from three for Pgi-1 to nine for Pgi-2 with a total of 57 alleles. Thirty-eight accessions out of 56 possessed unique isozyme genotypes, indicating a high level of diversity in the collection. On average, 80% of the loci were polymorphic and the expected and observed heterozygosities were 0.374 and 0.373, respectively. The cluster analysis of the isozyme data revealed five distinct clusters representing the five taxa included in the study. Genetic differentiation within N. Iappaceum var. Iappaceum was evident from the cluster analysis. Isozyme data indicated that N. ramboutan-ake is the closest relative of N. Iappaceum var. Iappaceum, followed by N. hypoleucum, N. Iappaceum var. pallens, and N. cuspidatum. Interestingly, the varieties of N. Iappaceum exhibited genetic divergence far beyond that of the congenerics, N. hypoleucum and N. ramboutan-ake and may require a taxonomic revision.

Free access

Jelka Šustar-Vozlič, Marko Maras, Branka Javornik and Vladimir Meglič

There is a long tradition of common bean cultivation in Slovenia, which has resulted in the development of numerous landraces in addition to newly established cultivars. The genetic diversity of 100 accessions from the Genebank of the Agricultural Institute of Slovenia (AIS) were evaluated with amplified fragment length polymorphism (AFLP) markers and phaseolin seed protein. Twenty-seven standard accessions of known Mesoamerican and Andean origin, 10 wild Phaseolus vulgaris accessions and two related species, P. coccineus L. and P. lunatus L., were also included. Ten AFLP primer combinations produced 303 polymorphic bands, indicating a relatively high level of genetic diversity. Based on the marker data, unweighted pair group method with arithmethic mean (UPGMA) analysis and principal coordinate analysis (PCoA) all P. vulgaris accessions were separated into three well-defined groups. Two groups consisted of accessions of Mesoamerican and Andean origin, while the third was comprised of only four wild P. vulgaris accessions. A set of Slovene accessions formed a well-defined sub-group within the Andean cluster, showing their unique genetic structure. These data were supported by phaseolin analysis, which also revealed additional variants of “C” and “T” phaseolin types. The results are in agreement with previous findings concerning diversification of common bean germplasm introduced in Europe.

Free access

Nnadozie C. Oraguzie, Sue E. Gardiner, Heather C.M. Basset, Mirko Stefanati, Rod D. Ball, Vincent G.M. Bus and Allan G. White

Four subsets of apple (Malus Mill.) germplasm representing modern and old cultivars from the repository and apple genetics population of the Horticulture and Food Research Institute of New Zealand Limited were used in this study. A total of 155 genotypes randomly chosen from the four subsets were analyzed for random amplified polymorphic DNA (RAPD) variation. Nine decamer primers generated a total of 43 fragments, 42 of which were polymorphic across the 155 genotypes. Pairwise distances were calculated between germplasm subsets using the distance metric algorithm in S-PLUS, and used to examine intra-and inter-subset variance components by analysis of molecular variation (AMOVAR). A phenogram based on unweighted pair group method with arithmetic average (UPGMA) cluster analysis was constructed from the pairwise distances and a scatter plot was generated from principal coordinate analysis. The AMOVAR showed that most of the variation in the germplasm (94.6%) was found within subsets, suggesting that there is significant variation among the germplasm. The grouping of genotypes based on the phenogram and scatter plot generally did not reflect the pedigree or provenance of the genotypes. It is possible that more RAPD markers are needed for determining genetic relationships in apple germplasm. Nevertheless, the variation observed in the study suggests that the current practice of sublining populations in the first generation to control inbreeding may not be necessary in subsequent generations. If these results are confirmed by fully informative molecular markers, germplasm managers should reassess the structure of their genetics populations. There may be a need to combine sublines in order to capture the maximum genetic diversity available and to streamline breeding efforts.

Open access

Qing Shen, Hua Bian, Hai-yan Wei, Li Liao, Zhi-yong Wang, Xiao-yan Luo, Xi-peng Ding, Zhenbang Chen and Paul Raymer

were few reports on genetic diversity of P. vaginatum in recent years. Liu et al. (1994) used random amplified polymorphic DNA (RAPD) to detect the genetic diversity of 46 P. vaginatum ecotypes. The genetic diversity, size, and distribution