# Genetic insights into superior grain number traits: a QTL analysis of wheat-Agropyron cristatum derivative pubing3228

## TL;DR

This study identifies genetic regions in a wheat-Agropyron hybrid linked to higher grain numbers, aiding in improving wheat yield through targeted breeding.

## Contribution

The study identifies novel QTLs and candidate genes in a wheat-Agropyron hybrid associated with high grain number per spike.

## Key findings

- 40 QTLs across 16 chromosomes were identified, explaining 4.25–17.17% of phenotypic variation in grain number per spike.
- Five QTLs explained over 10% of phenotypic variation in multiple environments, with most beneficial alleles from Pubing3228.
- Eleven candidate genes were identified, including a senescence-associated gene linked to a significant SNP on chromosome 7D.

## Abstract

Agropyron cristatum (L.) is a valuable genetic resource for expanding the genetic diversity of common wheat. Pubing3228, a novel wheat-A. cristatum hybrid germplasm, exhibits several desirable agricultural traits, including high grain number per spike (GNS). Understanding the genetic architecture of GNS in Pubing3228 is crucial for enhancing wheat yield. This study aims to analyze the specific genetic regions and alleles associated with high GNS in Pubing3228.

The study employed a recombination inbred line (RIL) population derived from a cross between Pubing3228 and Jing4839 to investigate the genetic regions and alleles linked to high GNS. Quantitative Trait Loci (QTL) analysis and candidate gene investigation were utilized to explore these traits.

A total of 40 QTLs associated with GNS were identified across 16 chromosomes, accounting for 4.25–17.17% of the total phenotypic variation. Five QTLs (QGns.wa-1D, QGns.wa-5 A, QGns.wa-7Da.1, QGns.wa-7Da.2 and QGns.wa-7Da.3) accounter for over 10% of the phenotypic variation in at least two environments. Furthermore, 94.67% of the GNS QTL with positive effects originated from Pubing3228. Candidate gene analysis of stable QTLs identified 11 candidate genes for GNS, including a senescence-associated protein gene (TraesCS7D01G148000) linked to the most significant SNP (AX-108,748,734) on chromosome 7D, potentially involved in reallocating nutrients from senescing tissues to developing seeds.

This study provides new insights into the genetic mechanisms underlying high GNS in Pubing3228, offering valuable resources for marker-assisted selection in wheat breeding to enhance yield.

The online version contains supplementary material available at 10.1186/s12870-024-04913-z.