AUTHOR=Wang Yanzhen , Cao Qiang , Zhang Junjie , Wang Siwen , Chen Chunhuan , Wang Changyou , Zhang Hong , Wang Yajuan , Ji Wanquan 

TITLE=Cytogenetic Analysis and Molecular Marker Development for a New Wheat–Thinopyrum ponticum 1Js (1D) Disomic Substitution Line With Resistance to Stripe Rust and Powdery Mildew

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.01282

DOI=10.3389/fpls.2020.01282

ISSN=1664-462X

ABSTRACT=<p><italic>Thinopyrum ponticum</italic> (2<italic>n</italic> = 10<italic>x</italic> = 70), a member of the tertiary gene pool of wheat (<italic>Triticum aestivum</italic> L.), harbors many biotic and abiotic stress resistance genes. CH10A5, a novel disomic substitution line from a cross of <italic>T. aestivum</italic> cv. 7182 and <italic>Th. ponticum</italic>, was characterized by cytogenetic identification, <italic>in situ</italic> hybridization, molecular marker analysis, and morphological investigation of agronomic traits and disease resistance. Cytological observations showed that CH10A5 contained 42 chromosomes and formed 21 bivalents at meiotic metaphase I. Genome <italic>in situ</italic> hybridization (GISH) analysis indicated that two of its chromosomes came from the J<sup>s</sup> genome of <italic>Th. ponticum</italic>, and wheat 15K array mapping and fluorescence <italic>in situ</italic> hybridization (FISH) revealed that chromosome 1D was absent from CH10A5. Polymorphic analysis of molecular markers indicated that the pair of alien chromosomes belonged to homoeologous group one, designated as 1J<sup>s</sup>. Thus, CH10A5 was a wheat–<italic>Th. ponticum</italic> 1J<sup>s</sup> (1D) disomic substitution line. Field disease resistance trials demonstrated that the introduced <italic>Th. ponticum</italic> chromosome 1J<sup>s</sup> was probably responsible for resistance to both stripe rust and powdery mildew at the adult stage. Based on specific-locus amplified fragment sequencing (SLAF-seq), 507 STS molecular markers were developed to distinguish chromosome 1J<sup>s</sup> genetic material from that of wheat. Of these, 49 STS markers could be used to specifically identify the genetic material of <italic>Th. ponticum</italic>. CH10A5 will increase the resistance gene diversity of wheat breeding materials, and the markers developed here will permit further tracing of heterosomal chromosome fragments in the future.</p>