Genetic analysis of maize shank length by QTL mapping in three recombinant inbred line populations

Meiling Liu; Wenshu He; Ao Zhang; Lijun Zhang; Daqiu Sun; Yuan Gao; Pengzun Ni; Xinglin Ma; Zhenhai Cui; Yanye Ruan

doi:10.1016/j.plantsci.2020.110767

Genetic analysis of maize shank length by QTL mapping in three recombinant inbred line populations

Plant Sci. 2021 Feb:303:110767. doi: 10.1016/j.plantsci.2020.110767. Epub 2020 Nov 22.

Authors

Meiling Liu¹, Wenshu He², Ao Zhang¹, Lijun Zhang¹, Daqiu Sun¹, Yuan Gao¹, Pengzun Ni¹, Xinglin Ma³, Zhenhai Cui⁴, Yanye Ruan⁵

Affiliations

¹ College of Biological Science and Technology, Liaoning Province Research Center of Plant Genetic Engineering Technology, Shenyang Key Laboratory of Maize Genomic Selection Breeding, Shenyang Agricultural University, Shenyang, 110866, China.
² College of Biological Science and Technology, Liaoning Province Research Center of Plant Genetic Engineering Technology, Shenyang Key Laboratory of Maize Genomic Selection Breeding, Shenyang Agricultural University, Shenyang, 110866, China; Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio Center, Av. Alcalde Rovira Roure, Lleida, 25198, Spain.
³ Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China.
⁴ College of Biological Science and Technology, Liaoning Province Research Center of Plant Genetic Engineering Technology, Shenyang Key Laboratory of Maize Genomic Selection Breeding, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: zhcui@syau.edu.cn.
⁵ College of Biological Science and Technology, Liaoning Province Research Center of Plant Genetic Engineering Technology, Shenyang Key Laboratory of Maize Genomic Selection Breeding, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: yanyeruan@syau.edu.cn.

PMID: 33487352
DOI: 10.1016/j.plantsci.2020.110767

Abstract

In maize, the shank is a unique tissue linking the stem to the ear. Shank length (SL) mainly affects the transport of photosynthetic products to the ear and the dehydration of kernels via regulated husk morphology. The limited studies on SL revealed it is a highly heritable quantitative trait controlled by significant additive and additive-dominance effects. However, the genetic basis of SL remains unclear. In this study, we analyzed three maize recombinant inbred line (RIL) populations to elucidate the molecular mechanism underlying the SL. The data indicated the SL varied among the three RIL populations and was highly heritable. Additionally, the SL was positively correlated with the husk length (HL), husk number (HN), ear length (EL), and ear weight (EW) in the BY815/K22 (BYK) and CI7/K22 (CIK) RIL populations, but was negatively correlated with the husk width (HW) in the BYK RIL population. Moreover, 10 quantitative trait loci (QTL) for SL were identified in the three RIL populations, five of which were large-effect QTL. The percentage of the total phenotypic variation explained by the QTL for SL was 13.67 %, 20.45 %, and 30.81 % in the BY815/DE3 (BYD), BYK, and CIK RIL populations, respectively. Further analyses uncovered some genetic overlap between SL and EL, SL and ear row number (ERN), SL and cob weight (CW), and SL and HN. Unlike the large-effect QTL qSL BYK-2-2, which spanned the centromere, the other four large-effect QTL were delimited to a single peak bin via bin map. Furthermore, 2, 5, 6, and 12 genes associated with SL were identified for qSL BYK-2-1, qSL CIK-2-1, qSL CIK-9-1, and qSL CIK-9-2, respectively. Five of the candidate genes for SL may contribute to the hormone metabolism and sphingolipid biosynthesis regulating cell elongation, division, differentiation, and expansion. These results may be relevant for future studies on the genetic basis of SL and for the molecular breeding of maize based on marker-assisted selection to develop new varieties with an ideal SL.

Keywords: Bin map; Genetic overlap; Hormone; Maize (Zea mays); QTL mapping; Shank length.

MeSH terms

Genes, Plant / genetics
Genetic Association Studies
Genetic Linkage / genetics
Plant Breeding
Quantitative Trait Loci / genetics*
Quantitative Trait, Heritable
Zea mays / anatomy & histology
Zea mays / genetics*