Characterization of the Durum Wheat-Aegilops tauschii 4D(4B) Disomic Substitution Line YL-443 With Superior Characteristics of High Yielding and Stripe Rust Resistance.

Fan Yang,Jie Zhang,Honshen Wan,Yonghong Zhou,Qier Liu,Wuyun Yang,Zehou Liu,Wujun Ma,Xing Fan,Ying Wang,Jun Li,Hang Liu,Qin Wang,Ning Yang,Sujie Yang

doi:10.3389/fpls.2021.745290

Abstract

Durum wheat is one of the important food and cash crops. The main goals in current breeding programs are improving its low yield potential, kernel characteristics, and lack of resistance or tolerance to some biotic and abiotic stresses. In this study, a nascent synthesized hexaploid wheat Lanmai/AT23 is used as the female parent in crosses with its AB genome donor Lanmai. A tetraploid line YL-443 with supernumerary spikelets and high resistance to stripe rust was selected out from the pentaploid F7 progeny. Somatic analysis using multicolor fluorescence in situ hybridization (mc-FISH) revealed that this line is a disomic substitution line with the 4B chromosome pair of Lanmai replaced by the 4D chromosome pair of Aegilops tauschii AT23. Comparing with Lanmai, YL-443 shows an increase in the number of spikelets and florets per spike by 36.3 and 75.9%, respectively. The stripe rust resistance gene Yr28 carried on the 4D chromosome was fully expressed in the tetraploid background. The present 4D(4B) disomic substitution line YL-443 was distinguished from the previously reported 4D(4B) lines with the 4D chromosomes from Chinese Spring (CS). Our study demonstrated that YL-443 can be used as elite germplasm for durum wheat breeding targeting high yield potential and stripe rust resistance. The Yr28-specific PCR marker and the 4D chromosome-specific KASP markers together with its unique features of pubescent leaf sheath and auricles can be utilized for assisting selection in breeding.

Highlights

Tetraploid durum wheat (2n = 28, AABB, Triticum turgidum L. ssp. durum) appears to have been derived from wild emmer wheat (T. turgidum ssp. dicoccoides) about 10,000 years ago in southeast Turkey, most likely through artificial domestication and continuous evolution (Özkan et al, 2011; Tidiane Sall et al, 2019)
Compared with the karyotype of Chinese Spring (CS) (Tang et al, 2014), Lanmai (Figures 2A,E), AT23 (Figures 2B,E), and YL-724 (Figures 2D,E), line YL-443 (Figures 2C,E) clearly showed as a 4D(4B) disomic substitution line that contained a pair of 4D chromosomes plus the other 26 durum wheat chromosomes
There was no significant difference between years based upon the ANOVA results (Figure 3)

Summary

Introduction

About 75% of the global durum wheat production is contributed by the Mediterranean region (Othmeni et al, 2019), where crops are mainly grown under environmental (high temperature, drought, and salinity) and biotic (pests and diseases) stresses (Tidiane Sall et al, 2019). In China, durum wheat cultivation was first started in the 1970s using varieties introduced from European countries such as Italy (Zhao et al, 2002). It was only grown in China sporadically in the beginning. Domestic cultivars with high yield and quality are required in the farming sector, making durum wheat breeding an important task in China

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Discussion

Conclusion