Search Results

You are looking at 1 - 10 of 322 items for :

  • All content x
Clear All
Free access

R.G. Fjellstrom, D.E. Parfitt, and G.H. McGranahan

RFLP markers were used to investigate genetic diversity among California walnut (Juglans regia) cultivars and germplasm collected worldwide. Sixteen of 21 RFLP markers were polymorphic in the 48 walnut accessions tested. RFLP markers were useful for identifying walnut cultivars. All genotypes were heterozygous at ≈20% of the loci for both California and worldwide germplasm. California walnut germplasm contained 60% of the worldwide allelic diversity. Cluster analysis of genetic distance between accessions and principal component analysis of allelic genotypes showed two major groups of walnut domestication. California germplasm was associated with germplasm from France, central Europe, and Iran and had less genotypic similarity with germplasm from Nepal, China, Korea, and Japan.

Free access

Mei Guo, David A. Lightfoot, Machteld C. Mok, and David W. S. Mok

142 ORAL SESSION (Abstr. 666-672) CROSS-COMMODITY BIOTECHNOLOGY II/RFLPs

Free access

Mei Guo, David A. Lightfoot, Machteld C. Mok, and David W. S. Mok

142 ORAL SESSION (Abstr. 666-672) CROSS-COMMODITY BIOTECHNOLOGY II/RFLPs

Free access

Wayne Kennard, Arian Dijkhuizen, Michael Havey, and Jack Staub

142 ORAL SESSION (Abstr. 666-672) CROSS-COMMODITY BIOTECHNOLOGY II/RFLPs

Free access

Diane R. Lester, Wayne B. Sherman, and Brian J. Atwell

, CSIRO Division of Horticulture, for support and advice; Bruce Topp, Queensland Dept. of Primary Industry, for leaf and fruit samples; and Zeneca Seeds for advice and facilities for the RFLP work. Use of trade names does not imply endorsement of the

Free access

R. Fjellstrom and D.E. Parfitt

RFLP probes were developed to determine the degree of genetic diversity both within and between 12 walnut species (Juglans spp.), including the widely cultivated English walnut (J. regia). One to three kilobase DNA fragments from Pst I digested J. regia nuclear DNA were cloned using the vector pUC18. Inserts corresponding to low copy number walnut genomic sequences were used to assess the genetic variability among walnut species. Extensive polymorphism was found between species and limited polymorphism within species. The inheritances of the RFLP loci are being analyzed to provide a genetic basis for the polymorphisms detected and to establish a RFLP based linkage map in walnuts

Free access

Hong Lin and M. Andrew Walker

probe and primers used in RFLP and SSR analysis and Doug Adams and Sekar Arulsekar for critiquing this manuscript. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must

Free access

M. Hubbard, J. Kelly, S. Rajapakse, A. Abbott, and R. Ballard

We have identified cloned rose DNA fragments that detect restriction fragment length polymorphisms (RFLP) in rose (Rosa ×hybrida) cultivars. RFLP can be used as genetic markers for identification, certification, and patent protection. By comparing RFLP patterns for each of six probes, we have been able to characterize eight cultivars. These results confirm that RFLP analyses are useful for rose cultivar identification and may provide a means for protecting patent rights to new cultivars.

Free access

L. Eldredge, R. Ballard, W.V. Baird, A. Abbott, P. Morgens, A. Callahan, R. Scorza, and R. Monet

Peach [Prunus persica (L.) Batsch.] is considered the best genetically characterized species of the genus Prunus. We therefore used it as a model in our study of the genome organization in Prunus by means of restriction fragment length polymorphisms (RPLPs). Initial results indicated that 60% of cloned DNA sequences examined occur at low copy number within the peach genome. After selecting and examining these sequences, polymorphisms sufficient for RPLP mapping were found. We determined that ≫33% of our cDNA clones and 20% of our genomic clones detected RPLPs among peach cultivars. Analysis of RPLP segregation in two families, both of which segregate for known morphological characters, revealed segregation in 12 RFLP markers for one family and 16 for the other. Although we have not detected linkage between RFLP and morphological markers, preliminary analyses indicate possible linkage between two RPLP markers.

Free access

Robert G. Fjellstrom and Dan E. Parfitt

32 cloned probes from a walnut (Juglans sp.) PstI random genomic library were used to develop a linkage map for walnut. Low copy number walnut random genomic DNA probes were constructed and hybridized to restriction endonuclease digested DNA from parent walnut trees from a backcross of (J. hindsii × J. regia) with J. regia to identify parental polymorphism. 63 backcross progeny were analyzed to determine the inheritance and linkage of 48 RFLP loci. 66% of the probes detected duplicated, but unlinked loci. 42 of the RFLP loci could be placed on 12 linkage groups. The other 6 loci could not be placed on common linkage groups. (Theoretical maximum number of linkage groups is 16.) A Poisson probability method for estimating genome size was utilized to calculate the approximate walnut genome length as 1660 cm and to estimate that 138 markers would be needed to cover 95% the walnut genome within 20 cM of each marker.