genetic variation has also been applied to determine whether breeding for white pine blister rust ( Cronartium ribicola ) has affected diversity in western white pine ( Pinus monticola ) ( Kim et al., 2003 ). A previous microsatellite analysis of wild A
Myounghai Kwak, Jeong-Ki Hong, Eun Sil Lee, Byoung Yoon Lee, Min Hwan Suh, and Bert Cregg
Michael J. Havey and Daniela Lopes Leite
Hybrid leek is more uniform and higher yielding than open-pollinated cultivars and is presently produced by asexual propagation of a genic male-sterile plant. A cheaper method to produce hybrid leek seed would be a system of cytoplasmic-genic male sterility (CMS). Restriction fragment length polymorphisms (RFLPs) in the organellar genomes have correlated with CMS in many crops. We undertook gel-blot analyses of the chloroplast and mitochondrial DNAs to assess cytoplasmic diversity among 62 accessions of the major cultivated forms of Allium ampeloprasum L. (leek, kurrat, and great-headed garlic). No polymorphisms were detected in the chloroplast genome of leek and kurrat. Three accessions of leek and one of kurrat possessed one or two of seven polymorphic mitochondrial probe-enzyme combinations. Great-headed garlic differed from leek and kurrat for six polymorphisms in the chloroplast genome and for many mitochondrial probe-enzyme combinations. Our analyses revealed few organellar polymorphisms among accessions of leek and kurrat, reducing the probability that selection of polymorphic cytoplasms will reveal CMS in leek.
D.L. Leite and M.J. Havey
Hybrid leek (Allium ampeloprasum) is significantly more uniform and higher yielding than open-pollinated populations. Because leek has perfect flowers, a male-sterility system is required to produce hybrid seed economically. No cytoplasmic male sterility (CMS) has been described in leek. Restriction fragment length polymorphisms (RFLPs) in the chloroplast and mitochondrial genome have correlated with the expression of CMS in many crops. We undertook restriction-enzyme analyses of the chloroplast and mitochondrial DNAs to identify polymorphic organellar genomes among 65 accessions of cultivated leek. Polymorphisms were detected in the chloroplast and mitochondrial genomes. Reciprocal crosses were generated to establish the transmission of the organellar genomes of leek.
Yuan Yu, Chunxian Chen, Ming Huang, Qibin Yu, Dongliang Du, Matthew R. Mattia, and Frederick G. Gmitter Jr.
Luro, F. Gatto, J. Costantino, G. Pailly, O. 2011 Analysis of genetic diversity in Citrus Plant Genet. Resources 9 218 221 Mosjidis, J.A. Yermanos, D.M. 1984 Maternal effects and cytoplasmic inheritance of oleic and linoleic-acid contents in sesame
Patrick P. Moore
Cultivated raspberries may include North American red raspberry (Rubus idaeus strigosus Michx), European red raspberry (R. idaeus vulgatus Arrhen.) or black raspberry (R. occidentalis in their pedigrees. Twenty-one raspberry clones were investigated using chloroplast restriction fragment length polymorphisms to determine the cytoplasm type and the amount of cytoplasmic diversity among these selected clones. The raspberry clones were selected representing North American red raspberry, European red raspberry, black raspberry and cultivars with divergent maternal lineages. Total cellular DNA was probed with two 32P-labelled fragments of tomato chloroplast DNA. Probe-restriction enzyme combinations were selected which discriminated between representatives of the two red raspberry subspecies. Raspberry clones were grouped according to the chloroplast restriction fragment patterns. The composition of the groups was compared with their pedigrees.
Ali Fuat Gökçe, John McCallum, Yutaka Sato, and Michael J. Havey
Cytoplasmic-genic male sterility (CMS) is used to produce hybrid onion (Allium cepa L.) seed. For the most widely used source of onion CMS, male sterility is conditioned by the interaction of the male-sterile (S) cytoplasm and the homozygous recessive genotype at a nuclear male-fertility restoration locus (Ms). Maintainer lines are used to seed propagate male-sterile lines, possess normal (N) male-fertile cytoplasm, and are homozyous recessive at the Ms locus. Due to the biennial nature of onion, it takes 4 to 8 years of crossing and scoring of progeny phenotypes to establish if maintainer lines can be extracted from an uncharacterized population or family. Identification of nuclear markers tightly linked to the Ms locus would allow for molecular-facilitated selection of maintainer lines. We evaluated testcross progenies from a segregating family for nuclear restoration of male fertility over at least three environments. Although segregations in the F2 family fit the expected 1:2:1 ratio (P = 0.973), the proportion of male-sterile testcross progenies showed significant (P < 0.01) year effects and it is therefore imperative to score male-fertility restoration over environments. Too many male-sterile testcross progenies were often observed, indicating that the dominant allele conditioning male-fertility restoration for S cytoplasm may not show complete penetrance. Segregations of amplified fragment length polymorphisms and restriction fragment length polymorphisms (RFLPs) revealed RFLPs flanking the Ms locus at 0.9 and 8.6 cM. An onion cDNA showing highly significant homology to the aldehyde dehydrogenase conditioned by the rf2 locus of maize was identified and mapped to linkage group I, independent of the Ms locus. A sample of commercial onion germplasm was evaluated for putative allelic diversity at the RFLP loci linked to Ms. The genomic region corresponding to the cDNA (AOB272) revealing the closest RFLP to Ms was sequenced to reveal numerous single nucleotide polymorphisms. Single-stranded conformational polymorphisms and single nucleotide extensions were developed that revealed genomic variation at AOB272-EcoRI. The use of these molecular markers to select maintainer lines in onion is discussed.
Michael J. Havey and Sunggil Kim
top-setting onion “Pran” ( Havey, 1993 ). Another possibility is that S and N cytoplasms existed as sympatric cytoplasmic variants in the progenitor of onion, and were maintained during domestication and dispersal of onion from its center of origin in
Amnon Levi, Judy A. Thies, Alvin M. Simmons, Howard Harrison, Richard Hassell, and Anthony Keinath
USVL-220 is a novel watermelon [ Citrullus lanatus (Thunb.) Matsum. & Nakai] breeding line containing the nuclear genome of watermelon cultivars ( Citrullus lanatus var. lanatus ) and cytoplasmic background (chloroplast and mitochondrial genomes
Derek W. Barchenger, Joseph I. Said, Yang Zhang, Mingzhou Song, Franchesca A. Ortega, Yeasong Ha, Byoung-Cheorl Kang, and Paul W. Bosland
polypeptide 270 amino acids long. CaPPR6_48 had six nonsynonymous mutations, and one was an insertion that resulted in a premature stop codon for AVPP0605. Despite the high diversity in sequences found across these candidate Rf genes, no unique
Meryem Ipek, Ahmet Ipek, Douglas Senalik, and Philipp W. Simon
such as rate of crop maturity, bulb size and color, clove size and number, leaf number and color, and bolting habit. Variation observed in genetic diversity studies using molecular markers is as wide as that observed for phenotypic variation among the