Genome-wide linkage mapping of root system architecture-related traits in common wheat ( Triticum aestivum L.).

Identifying loci for root system architecture (RSA) traits and developing available markers are crucial for wheat breeding. In this study, RSA-related traits, including total root length (TRL), total root area (TRA), and number of root tips (NRT), were evaluated in the Doumai/Shi4185 recombinant inbred line (RIL) population under hydroponics. In addition, both the RILs and parents were genotyped using the wheat 90K single-nucleotide polymorphism (SNP) array. In total, two quantitative trait loci (QTLs) each for TRL ( QTRL.caas-4A.1 and QTRL.caas-4A.2 ), TRA ( QTRA.caas-4A and QTRA.caas-4D ), and NRT ( QNRT.caas-5B and QNRT.caas-5D ) were identified and each explaining 5.94%-9.47%, 6.85%-7.10%, and 5.91%-10.16% phenotypic variances, respectively. Among these, QTRL.caas-4A.1 and QTRA.caas-4A overlapped with previous reports, while QTRL.caas-4A.2 , QTRA.caas-4D , QNRT.caas-5B , and QNRT.caas-5D were novel. The favorable alleles of QTRL.caas-4A.1 , QTRA.caas-4A , and QTRA.caas-5B were contributed by Doumai, whereas the favorable alleles of QTRL.caas-4A.2 , QTRA.caas-4D , and QTRA.caas-5D originated from Shi 4185. Additionally, two competitive allele-specific PCR (KASP) markers, Kasp_4A_RL ( QTRA.caas-4A ) and Kasp_5D_RT ( QNRT.caas-5D ), were developed and validated in 165 wheat accessions. This study provides new loci and available KASP markers, accelerating wheat breeding for higher yields.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2023 Jin, Wang, Liu, Wang, Qiu and Liu.)