| Roegneria ciliaris（Trin.）Nevski（2n=4x=28,ScScYcYc）,a perennial tetraploid wild relative of wheat,possess many useful traits for wheat improvement,such as resistances to wheat streak mosaic virus,barley yellow dwarf virus,Fusarium head blight,and tolerances to drought and cold,etc.For mining useful genes from more R ciliaris collections,different accessions were collected from different areas.The genetic diversity and phylogenetic relationship of partial collections were analyzed using Oligo-FISH,ITS,and marker analysis using intron targeting（IT）markers.Based on the powdery mildew resistance evaluation of partial R.ciliaris accessions,F1 hybrids were obntained and confirmed.This will be used for mapping powdery mildew resistance genes from R.In previous study,a complete set of wheat-R.ciliaris addition lines have been created by chromosome engineering.A standard FISH-based karyotype of R ciliaris was established,and molecular markers specific to each chromosome of R.ciliaris were developed for accurately identification of R.ciliaris chromosomes.In the present research,for identifying and utilizing alien genes on chromosome 6Sc,chromosomal abberrations involving 6Sc were developed by using wheat-R.ciliaris addition line DA6Sc as initial materials through irradiation and Chinese spring ph1b mutant.The contribution of 6Sc for the powdery mildew resistance of DA6Sc was clarified.The main results obtained in this research are as follows:1、The genetic diversity of R.ciliaris collectionPart of the R.ciliaris collection were selected for evaluate their genetic diversity and phylogenetic relationship.FISH karyotypes base of oligo-FISH showed different accessions were quite different for their FISH patterns,however the homologous chromosomes within each accession had high homozygosity.ITS sequence comparison showed they were highly similar,and IT molecular marker analysis show they could be classified into different subgroups.We also found the genetic diversity of R.ciliaris accessions had no significant correlation with their geographical origin,and the accession 2019In-504 from Inner Mengolia was a unique genetic resource.2、Construction of R.ciliaris mapping population for powdery mildew resistancePart of the R.ciliaris accessions were evaluated for powdery mildew resistance.11 accessions（20171-145,146,150,152,176,182,183,184,185,231,305）were highly resistant in two years,12 accessions（20171-145,146,150,152,176,182,183,184,185,231,285,305）were highly resistant in year 2018 at Jiangpu and 11 accessions（20171-145,146,150,152,176,182,183,184,185,231,305）were highly resistant in year 2019 at Zhenjiang.Three resistant accessions and three susceptible accessions were used to make cross for the construction of mapping population.Using marker analysis,true hybrids for seven combinations were obtained.3、Phenotyping of the（DA6Sc × NAU06Y86）F2 population for powdery mildew resistance and other agronpmic traitsTo evaluate the contribution of the introduced 6Sc to powdery mildew resistance and agronomic traits,a（DA6Sc × NAU06Y86）F2 population was constructed and used for genotyping for the presence or absence of 6Sc using specific molecular markers.Followed by phenotyping for their powdery mildew resistance,spike length,etc.The results showed that there was no significant difference for plants carring 6Sc and plants without 6Sc for all the tested traits except spike length.This indicated that the introduction of 6Sc inhibited spike length in wheat background.4、Development of wheat-R.ciliaris 6Sc chromosome structural aberrantionsTwo approaches were used to induce chromosomal abberrations.Molecular marker analysis of the（DA6Sc × CS phlb）BC1F3 population identified 71 structural aberrantions.FISH and marker analysis of the（DA6Sc × Alondra’s）M4/BC1F3 population identified 5 different types of structural aberrantions.These abberrations include large fragment translocation,terminal translocation and complex structural translocation.Their chromosome identities from wheat side need to be further characterized. |
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