A multi-reference parent nested-association mapping population to dissect the genetics of quantitative traits in durum wheat

Abstract

Durum wheat (Triticum turgidum L.) breeding programs face many challenges surrounding the development of stable varieties with high quality and yield. Therefore, researchers and breeders are focused on deciphering the genetic architecture of biotic and abiotic traits with the aim of pyramiding desirable traits. These efforts require access to diverse genetic resources, including wild relatives, germplasm collections, and mapping populations. Advances in accelerated generation technologies have enabled the rapid development of mapping populations with signi cant genetic diversity. Here, we describe the development of a durum Nested Association Mapping (dNAM) population, which represents a valuable genetic resource for mapping the effects of different alleles on trait performance. We created this population to understand the quantitative nature of drought-adaptive traits in durum wheat. We developed 920 F 6 lines in only 18 months using speed breeding technology, including the F 4 generation in the eld. Large variation in above-and belowground traits was observed, which could be harnessed using genetic mapping and breeding approaches. We genotyped the population using 13,393 DArTseq markers. Quality control resulted in 6,785 high-quality polymorphic markers used for structure analysis, linkage disequilibrium decay, and marker-trait association analyses. To demonstrate the effectiveness of dNAM as a resource for elucidating the genetic control of quantitative traits, we took a genomewide mapping approach using the FarmCPU method for plant height and days to owering. These results highlight the power of using dNAM as a tool to dissect the genetics of durum wheat traits, supporting the development of varieties with improved adaptation and yield.

Seminal root angle is associated with root system architecture in durum wheat

“…Previously, a durum NAM population was developed by crossing eight ICARDA ‘founder’ lines with two Australian durum ‘reference’ varieties Jandaroi and DBA Aurora (Alahmad et al, 2022). For this study, 11 genotypes including the reference parent DBA Aurora and 10 NAM lines, based on the SRA screenings by Alahmad et al (2019), were selected for divergent SRAs (wide and narrow) (Table 1).…”

Phosphorus management is key to effective deployment of root ideotypes in complex soil environments

“…The two durum wheat lines, QAF0512 (Narrow) and QAF0411 (Wide) were selected from a set of F 6 generation durum lines from a nested association mapping population that were previously characterised by Alahmad et al (2019), in which they were observed to express contrasting seminal root angles (QAF0512 = 41° and QAF0411 = 82). These lines have also been included in a series of further screenings and targeted studies that confirmed their contrasting seminal root angles and relationship with RSA, whilst also displaying similarities in root system biomass, tiller number, growth rate, and time to flowering (Alahmad et al 2022;van der Bom et al 2023). The two sorghum lines, B35 (narrow) and SC999-14E (wide) were selected from a previously characterised set of inbred lines (Mace et al 2012) in which they were observed to express contrasting nodal root angles (B35 = 28° and SC999 = 46° for the first flush of nodal roots, relative to a vertical plane).…”

“…genotypes (wide and narrow root angle) to combinations of starter-P and deep P bands. Previous studies on these crops have focused on genetic variability and control (Alahmad et al 2019(Alahmad et al , 2022Mace et al 2012;Singh et al 2010Singh et al , 2011Singh et al , 2012. Building on these, the aim of the current study was to understand how contrasting genotypes respond to complex target environments.…”

Exploring the genetic variability in yield, nutritional and digestibility traits in oat grains through ruminant nutrition

“…Moving forward, pinpointing specific genetic markers linked to these traits could revolutionize oat breeding programs. Furthermore, diverse parents can be used to develop mapping population and investigate the genetics of yield and quality traits [ 13 ]. Given the understanding above and recognizing a research gap regarding the absence of an appropriate variety of oat grains that comprehensively addresses both nutritional and animal health aspects, this study aims to analyze different types of oats to understand how they vary genetically in terms of how much they produce, their physical characteristics, and what nutrients they contain.…”