Ralf G. Kynast

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All 10 chromosomes of maize (Zea mays, 2n = 2x = 20) were recovered as single additions to the haploid complement of oat (Avena sativa, 2n = 6x = 42) among F(1) plants generated from crosses involving three different lines of maize to eight different lines of oat. In vitro rescue culture of more than 4,300 immature F(1) embryos resulted in a germination(More)
The possibility of controlling wheat scab (caused by Fusarium graminearum Schw.) was explored by engineering wheat plants for constitutive expression of pathogenesis-related (PR) protein genes. A rice thaumatin-like protein (TLP) gene (tlp) and a rice chitinase gene (chi11) were introduced into the spring wheat cultivar ’Bobwhite’ by co-transformation of(More)
The terminal heterochromatic segments of the long arms of 20 rye B-chromosomes were isolated by means of laser microdissection technology. Also the remaining portions of the long arms, along with the short arms of the same chromosomes were isolated. Each sample was used for degenerate oligonucleotide primer-polymerase chain reaction (DOP-PCR) amplification(More)
We report a neocentromere event on maize chromosome 3 that occurred due to chromosome breakage. The neocentromere lies on a fragment of the short arm that lacks the primary centromere DNA elements, CentC and CRM. It is transmitted in the genomic background of oat via a new centromere (and kinetochore), as shown by immunolocalization of the oat CENH3(More)
Understanding the processes underlying the origin of species is a fundamental goal of biology. It is widely accepted that speciation requires an interruption of gene flow between populations: ongoing gene exchange is considered a major hindrance to population divergence and, ultimately, to the evolution of new species. Where a geographic barrier to(More)
A new gametocidal (Gc) factor was identified on chromosome 4Mg of Aegilops geniculata Roth. When transferred to Chinese Spring wheat, monosomic and disomic Triticum aestivum–Ae. geniculata chromosome 4Mg addition plants undergo regular first and second meiotic divisions. Male gametogenesis in disomic 4Mg addition plants also is normal. However, chromosome(More)
Sexual hybrids between distantly related Solanum species can undergo endosperm failure, a post-zygotic barrier in inter-species hybridizations. This barrier is explained by the endosperm balance number (EBN) hypothesis, which states that parents must have corresponding EBNs for viable seed formation. Tests for inter-crossability were made involving the(More)
The gametocidal factor on the Aegilops cylindrical chromosome 2Cc was used to induce and analyze the nature of chromosomal rearrangements in rye chromosomes added to wheat. For this purpose we isolated plants disomic for a given rye chromosome and monosomic for 2Cc and analyzed their progenies cytologically. Rearranged rye chromosomes were identified in 7%(More)
Oat- (Avena sativa) maize (Zea mays) chromosome additions are produced by crossing maize and oat. During early embryo development maize chromosomes are preferentially eliminated, and oat plants are often recovered that retain a single maize chromosome. Each of the 10 maize chromosomes recently has been isolated as a separate oat-maize addition. We describe(More)
We have developed from crosses of oat (Avena sativa L.) and maize (Zea mays L.) 50 fertile lines that are disomic additions of individual maize chromosomes 1-9 and chromosome 10 as a short-arm telosome. The whole chromosome 10 addition is available only in haploid oat background. Most of the maize chromosome disomic addition lines have regular transmission;(More)