Segregation Distortion Through Female Gametophytes in Interspecific Hybrids of Tetraploid Wheat as Revealed by RAPD Analysis

Abstract

Interspecific crosses were made among five tetraploid wheat species including three endemic species in Transcaucasia to study chromosome marker segregation. A reciprocal cross between Triticum turgidum and T. tirnopheevi produced sterile F1s, while three reciprocal F1s obtained from cross combinations of T. durum/T. persicurn, T. durum/T. paleocolchicum and T. turgidum/T. puleocolchicum were fertile and produced euploid F2 progeny after self fertilization. Twenty RAPD markers were is nuclear markers specific to one or two species by determining the genotypes of the three fertile reciprocal F1s, and six were assigned to individual chromosomes using the D genome chromosome substitution lines. Segregation analysis in the F2s showed that five among the 20 nuclear markers were almost completely or preferentially transmitted from single parents. A complete transmission through the female gametes of one T. durum marker on chromosome 3A was shown by the analysis of BC1 progeny from the cross combination of T. durum/T. persicum. This complete segregation distortion through the female gametes was correlated with markedly reduced selfed seed set in the F1s. Preferential transmission of a T. puleocolchicum marker associated with the cytoplasm was also detected in a cross of T. paleocolchicurn x T. turgidum.

Segmental allotetraploidy and allelic interactions in buffelgrass (Pennisetum ciliare(L.) Link syn.Cenchrus ciliarisL.) as revealed by genome mapping

“…This behavior is similar to that reported in maize (Maguire 1963), wheat (Scoles and Kibirge-Sebunya 1983;Manabe et al 1999), and barley (Konishi and Fukushima 1992). Because the four SDRFs (cDNAs) involved in these allelic interactions were mapped in both parents, genome rearrangements in these regions were identified between the parents.…”

“…Deviations from the expected ratio would indicate that one of the allelic alternatives is transmitted to the progeny at higher frequencies. Physiological and (or) environmental factors may be involved, but evidence of allelic interactions has been reported in different species (Maguire 1963;Rick 1966;Sano 1990;Manabe et al 1999).…”

Molecular Genetic Analysis of Domestication Traits in Emmer Wheat. I: Map Construction and QTL Analysis using an F2Pupulation

“…one cluster found on chromosome 5B consists of four markers all favoring the DcM1001 alleles, while another cluster found on chromosome 6B consists of five markers all favoring the Dcc63 alleles ( Table 3). Segregation distortion of molecular markers has been documented in a wide range of organisms including wheat (14,20,21,25,26). As reviewed by Xu et al (36), aberrant segregation ratios in plants may arise from a variety of physiological or genetic causes and may be manifested as differential transmission in either the male or female germ line or may result from postzygotic selection prior to genotypic evaluation.…”

Intraparental Gamete Competition Provides a Selective Advantage for the Development of Hybrid Sterility via Meiotic Drive

“…This environment should change with hybridization, and indeed segregation distortion often emerges in interspecific or distant intraspecific hybrids (Hedrick 1981;Harushima et al 1996;Faris et al 1998) although distant hybrids may also show little distortion (Coyne 1986). Two cases of segregation distorters have been established as causes of interspecies sterility (Pilder et al 1991;Manabe et al 1999), although other types of genes have been implicated as well. As predicted, the distorters are detectable only in distant outcrosses.…”