Molecular mapping of quantitative trait loci for grain moisture at harvest in maize

Abstract

In maize, high grain moisture (GM) at harvest causes problems in harvesting, threshing, artificial drying, storage, transportation and processing. Understanding the genetic basis of GM will be useful for breeding low‐GM varieties. A quantitative genetics approach was used to identify quantitative trait loci (QTL) related to GM at harvest in field‐grown maize. The GM of a double haploid population consisting of 240 lines derived from Xianyu335 was evaluated in three planting seasons and a high‐density genetic linkage map covering 1546.4 cM was constructed. The broad‐sense heritability of GM at harvest was 71.0%. Using composite interval mapping, six QTL for GM at harvest were identified on five chromosomes (Chr). Two QTL located on Chr1, qgm1‐1 and qgm1‐2, explained 5.0% and 10.8% of the phenotypic variation in GM at harvest, respectively. The QTL qgm2, qgm3, qgm4 and qgm5 accounted for 3.3%, 8.3%, 5.4% and 11.0% of the mean phenotypic variation, respectively. Because of their consistent detection over multiple planting seasons, the detected QTL appear to be robust and reliable for the breeding of low‐GM varieties.

Combined linkage mapping and association analysis reveals genetic control of maize kernel moisture content

“…Of them, three (75%) showed negative additive effects on KWC, indicating that the larger KWC was mainly affected by the alleles from Mo17. Moreover, qKMC1 was located in qgm1-1 detected by Song et al (2016), whereas qKMC4-2 overlapped with qgm1-1 as reported previously (Li et al 2019).…”

QTL mapping of three ear traits using a doubled haploid population of maize

“…With the genetic linkage map constructed in our earlier study (Song et al., ), we were able to identify multiple QTLs conditioning EL, ED and CD, based on their overall mean across three environments using the composite interval mapping (Table and Figure ). Two QTLs responsible for EL, designated as qEL1‐1 and qEL1‐2 , were mapped on Chromosome (Chr) 1 across all three growing conditions with the LOD score of 10.9 and 4.8, and they explained 15.7% and 6.6% of the phenotypic variation, respectively.…”

“…The DH population consisting of 240 lines was developed by Maize Research Center, and it was obtained from the single‐cross Xianyu 335 as previously described (Song et al., ). The parental inbred lines, ‘PH4CV’ and ‘PH6WC’, were developed by DuPont Pioneer (Johnston, IA, USA), and they exhibit phenotypic variation in the ear traits tested in this study.…”

“…The genetic linkage map established in our previous study (Song et al., ) was employed for QTL mapping. In particular, the genotyping of the DH population was conducted using MaizeSNP3072 chip (Tian et al., ), and a total of 964 SNPs that are polymorphic between two parents were used for map construction.…”

“…The resulting linkage map was 1546.4 cM with the average marker interval of 1.6 cM. QTLs were detected by the composite interval mapping (CIM) in WinQTL Cartographer 2.5 (Wang, Basten, & Zeng, ), and the parameters were set as previously described (Song et al., ).…”