Characterization and Fine Mapping of qRPR1-3 and qRPR3-1, Two Major QTLs for Rind Penetrometer Resistance in Maize

Abstract

Stalk strength is one of the most important traits in maize, which affects stalk lodging resistance and, consequently, maize harvestable yield. Rind penetrometer resistance (RPR) as an effective and reliable measurement for evaluating maize stalk strength is positively correlated with stalk lodging resistance. In this study, one F2 and three F2:3 populations derived from the cross of inbred lines 3705I (the low RPR line) and LH277 (the high RPR line) were constructed for mapping quantitative trait loci (QTL), conferring RPR in maize. Fourteen RPR QTLs were identified in four environments and explained the phenotypic variation of RPR from 4.14 to 15.89%. By using a sequential fine-mapping strategy based on the progeny test, two major QTLs, qRPR1-3 and qRPR3-1, were narrowed down to 4-Mb and 550-kb genomic interval, respectively. The quantitative real-time PCR (qRT-PCR) assay was adopted to identify 12 candidate genes responsible for QTL qRPR3-1. These findings should facilitate the identification of the polymorphism loci underlying QTL qRPR3-1 and molecular breeding for RPR in maize.

Meta-QTL analysis and candidate genes identification for lodging resistance in maize: Ⅰ. stalk related traits

“…Quantitative trait locus (QTL) analysis provides information on molecular markers associated with speci c traits in chromosomal regions that can be applied for marker-assisted selection (MAS) breeding (Scheben et al 2018). Hundreds of QTLs for stalk-lodging-related traits, including plant height (PH) and ear height (EH), plant diameter (PD), internode length (IL), and rind penetrometer resistance (RPR), have been identi ed in maize (Flint-Garcia et al 2003;Fei et al 2022;Hou et al 2022; Ku et al 2015; Yang et al 2015). However, because of large con dence intervals (CI) for any given QTL, and differences in the positions of QTLs that have the same effect in different mapping populations and environments, QTL ne mapping and gene validation is di cult and timeconsuming.…”

Genetic basis of maize stalk strength decoded via linkage and association mapping

“…QTL mapping studies have been carried out to identify QTLs associated with RPR using different QTL mapping methods in various bi‐parent populations to dissect the genetic architecture of RPR in maize (Flint‐Garcia, Jampatong, et al., 2003; Hou et al., 2022; Hu et al., 2012; Li et al., 2014; Liu et al., 2022; Liu, Hu, et al., 2020; Meng et al., 2016; Peiffer et al., 2013; Zhang et al., 2019, 2020; Zhang, Liu, et al., 2018). These studies mapped hundreds of single QTLs, as well as a few pairs of epistatic QTLs, that contribute to the genetic basis of RPR variation in these bi‐parent populations.…”

Integrating biochemical and anatomical characterizations with transcriptome analysis to dissect superior stem strength of ZS11 (Brassica napus)

“…The mechanical strength of the stem is intimately related to lodging resistance since this serves as the main mechanical support tissue for the aboveground plant. Numerous studies have shown that rind penetrometer resistance (RPR) and stem breaking strength (SBS) are reliable indicators for evaluating stalk lodging resistance (Hu et al, 2012;Hu et al, 2013;Liu et al, 2020;Zhang et al, 2020;Hou et al, 2022). Genetic analysis of the RPR trait in maize showed that it is affected by several minor QTL loci, some of which perform regulatory roles during multiple growth periods (Liu et al, 2020).…”

“…Genetic force analysis indicates that F max contributed the most to the mechanical strength of the stem (Hu et al, 2012;Hu et al, 2013). Several studies have revealed that some genetic loci in SBS and RPR shared the same flanking markers or overlapping confidence intervals with lignin or cellulose concentration-related loci, suggesting that these traits may be influenced by some common genetic factors (Hu et al, 2012;Hou et al, 2022;Shao et al, 2022).…”