The S alleles of 15 Japanese apple cultivars were determined by using the allele-specific polymerase chain reaction amplification and restriction enzyme digestion system developed by Janssens et al. (1995). Both S alleles were identified in eight diploid cultivars, two S alleles in three triploid cultivars, and one S allele in the remaining four diploid cultivars. Two cultivars had S alleles different than those predicted by their parentage, and in one comparison of a cultivar with its sport, an identity problem was discovered. The technique helped to indicate the parent contributing the unreduced gamete in triploids.
The ribosomal genes of the two crab apple (Malus) genotypes White Angel' and `Robusta 5' were characterized to determine the extent of between- and within-genotype heterogeneity. Initial investigations with a cloned sequence of soybean rDNA failed to detect some Malus intergenic spacer region fragments. An alternative probing method that used electrophoretically purified Malus rDNA was developed. Double-digests of total genomic DNA with combinations of 13 restriction endonucleases identified the positions of 35 restriction sites. Restriction site polymorphism was observed both between and within the crab apple genotypes. Ribosomal DNA from White Angel' was cloned in phage and plasmid vectors and mapped with 11 enzymes. The region of the spacer causing length heterogeneity was identified. These clones should be useful as genetic markers and for examining population dynamics and systematic of Malus and closely related taxa.
A study was initiated to investigate the possibility of using RAPD markers in related populations of Vitis. We also sought to design primers that could amplify translation initiation sites (Kozak sequence) as a mean to maximize the production of RAPD markers from single copy DNA sequences in the genome. RAPD bands were labeled and used as probes on blots with either genomic DNA or RAPD products from cvs Aurore, Cayuga White, Horizon and Illinois 547-1. Reamplification of excised RAPD products produced either several bands of smaller size, a single band of smaller size or a single band of the same size as the original band. Among 16 probes hybridized to genomic DNA blots, three probes, including one from the Kozak primer amplification, hybridized to 1-2 bands, 5 probes hybridized to 3-8 bands and 8, including two from a Kozak primer reaction, to more than 10 bands on the genomic DNA blots. Twelve RAPD bands were also probed on RAPD blots derived from the RAPD reaction that produced each probe. Three of those probes hybridized to 1-2 bands, 8 hybridized to 3-8 and one hybridized to more than 10 bands indicating the presence of probe sequences in more than one RAPD band as amplified with the same primers. This result and the observations on reamplification of RAPD bands support the hypothesis that some of the longer RAPD fragments harbor internal priming sites that are either not amplified unless the reaction mixture is saturated with longer other primers indicating amplification from the same sequence but different sized repetitive DNA. RAPD reactions were also run with 16 primers on parental DNA of 2 crosses used in genetic mapping (Cayuga White x Aurore and Horizon x Illinois 547-1). These reactions rated 140 bands; 100 bands were shared by both populations, including 47 polymorphic bands. Ten polymorphic bands in Cayuga White x Aurore and 22 in Horizon x Illinois 547-1 were population specific. The RAPD analysis as well as hybridization of RAPD markers to the genomic blots suggest that linkage analysis could be used in related segregating populations with carefully chosen markers. Tagging single copy regions with Kozak-sequence-derived primers may be possible, but the low number of probes tested and lack of DNA sequence information prevents any definite conclusions.
Journal Article The genetics of chloroplast enzymes Get access NORMAN F. WEEDEN, NORMAN F. WEEDEN Department of Genetics, University of CaliforniaDavis, California 95616 Search for other works by this author on: Oxford Academic PubMed Google Scholar L. D. GOTTLIEB L. D. GOTTLIEB Department of Genetics, University of CaliforniaDavis, California 95616 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Heredity, Volume 71, Issue 6, November 1980, Pages 392–396, https://doi.org/10.1093/oxfordjournals.jhered.a109393 Published: 01 November 1980