Identification of a Wheat-Psathyrostachys huashanica 7Ns Ditelosomic Addition Line Conferring Early Maturation by Cytological Analysis and Newly Developed Molecular and FISH Markers.

Hao Zhang,Yiran Cheng,Dandan Wu,Lingyu Li,Binwen Tan,Houyang Kang,Xing Fan,Wei Zhu,Yi Wang,Haiqin Zhang,Jian Zeng,Lei Zhao,Lina Sha,Lili Xu,Guoyue Chen,Yonghong Zhou

doi:10.3389/fpls.2021.784001

Abstract

Early maturation is an important objective in wheat breeding programs that could facilitate multiple-cropping systems, decrease disaster- and disease-related losses, ensure stable wheat production, and increase economic benefits. Exploitation of novel germplasm from wild relatives of wheat is an effective means of breeding for early maturity. Psathyrostachys huashanica Keng f. ex P. C. KUO (2n=2x=14, NsNs) is a promising source of useful genes for wheat genetic improvement. In this study, we characterized a novel wheat-P. huashanica line, DT23, derived from distant hybridization between common wheat and P. huashanica. Fluorescence in situ hybridization (FISH) and sequential genomic in situ hybridization (GISH) analyses indicated that DT23 is a stable wheat-P. huashanica ditelosomic addition line. FISH painting and PCR-based landmark unique gene markers analyses further revealed that DT23 is a wheat-P. huashanica 7Ns ditelosomic addition line. Observation of spike differentiation and the growth period revealed that DT23 exhibited earlier maturation than the wheat parents. This is the first report of new earliness per se (Eps) gene(s) probably associated with a group 7 chromosome of P. huashanica. Based on specific locus-amplified fragment sequencing technology, 45 new specific molecular markers and 19 specific FISH probes were developed for the P. huashanica 7Ns chromosome. Marker validation analyses revealed that two specific markers distinguished the Ns genome chromosomes of P. huashanica and the chromosomes of other wheat-related species. These newly developed FISH probes specifically detected Ns genome chromosomes of P. huashanica in the wheat background. The DT23 line will be useful for breeding early maturing wheat. The specific markers and FISH probes developed in this study can be used to detect and trace P. huashanica chromosomes and chromosomal segments carrying elite genes in diverse materials.

Highlights

Maturation is an important target in wheat breeding programs
We identified a novel wheat-P. huashanica 7Ns ditelosomic addition line, DT23, from offspring lines that exhibited earlier maturation than the wheat parents by fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH), Fluorescence in situ hybridization (FISH) painting, and PCR-based landmark unique gene (PLUG) marker analyses
These findings suggested that DT23 was a cytogenetically relatively stable wheat-P. huashanica ditelosomic addition line

Summary

Introduction

Maturation is an important target in wheat breeding programs. In recent years, breeding efforts have targeted increase in wheat yield potential to meet the growing food demand resulting from global population explosion, climate change, and reduction in arable land area (Mondal et al, 2013; Chen et al, 2016). Exploitation of new early maturation genes and the breeding of early maturing wheat cultivars are strategies proven to be effective against these emerging threats to agricultural production and are suitable for a double-cropping management system, in which earlier sowing of the following crop improves the probability of its success (Hunger et al, 2014; Su et al, 2018). Such an approach promotes effective utilization of the limited arable land and enhances grain yield. The discovery and identification of additional sources of early maturation in wheatrelated germplasm are an important and long-term objective for breeding early maturing wheat cultivars

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Discussion

Conclusion