A rare SNP mutation in Brachytic2 moderately reduces plant height and increases yield potential in maize.
Plant height has long been an important agronomic trait in maize breeding. Many plant height QTLs have been reported, but few of these have been cloned. In this study, a major plant height QTL, qph1, was mapped to a 1.6kb interval in Brachytic2 (Br2) coding sequence on maize chromosome 1. A naturally occurring rare SNP in qph1, which resulted in an amino acid substitution, was validated as the causative mutation. QPH1 protein is located in the plasma membrane and polar auxin transport is impaired in the short near-isogenic line RIL88(qph1). Allelism testing showed that the SNP variant in qph1 reduces longitudinal cell number and decreases plant height by 20% in RIL88(qph1) compared to RIL88(QPH1), and is milder than known br2 mutant alleles. The effect of qph1 on plant height is significant and has no or a slight influence on yield in four F2 backgrounds and in six pairs of single-cross hybrids. Moreover, qph1 could reduce plant height when heterozygous, allowing it to be easily employed in maize breeding. Thus, a less-severe allele of a known dwarf mutant explains part of the quantitative variation for plant height and has great potential in maize improvement.
National Maize Improvement Centre of China, China Agricultural University, Beijing 100193, China.
Anqi
A
Xing
National Maize Improvement Centre of China, China Agricultural University, Beijing 100193, China.
Yufeng
Y
Gao
College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Lingfeng
L
Ye
National Maize Improvement Centre of China, China Agricultural University, Beijing 100193, China.
Weiping
W
Zhang
National Maize Improvement Centre of China, China Agricultural University, Beijing 100193, China.
Lichun
L
Cai
DuPont Co., Agricultural Biotechnology, 200 Powder Mill Road, Wilmington, DE 19805, USA.
Ada
A
Ching
DuPont Co., Agricultural Biotechnology, 200 Powder Mill Road, Wilmington, DE 19805, USA.
Victor
V
Llaca
Pioneer Hi-Bred Intl, 1501 Road P, York, NE 68467-8234, USA.
Blaine
B
Johnson
College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Lin
L
Liu
National Maize Improvement Centre of China, China Agricultural University, Beijing 100193, China.
Xiaohong
X
Yang
College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China kdm@pku.edu.cn yjianbing@mail.hazu.edu.cn lijiansheng@cau.ed.cn.
Dingming
D
Kang
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China kdm@pku.edu.cn yjianbing@mail.hazu.edu.cn lijiansheng@cau.ed.cn.
Jianbing
J
Yan
National Maize Improvement Centre of China, China Agricultural University, Beijing 100193, China kdm@pku.edu.cn yjianbing@mail.hazu.edu.cn lijiansheng@cau.ed.cn.
Jiansheng
J
Li
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics; D001692:Biological Transport; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D056726:Genetic Association Studies; D006824:Hybridization, Genetic; D007178:Inbreeding; D007210:Indoleacetic Acids / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D020161:Physical Chromosome Mapping; D010940:Plant Proteins / Q000378:metabolism; D018547:Plant Stems / Q000166:cytology / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D015203:Reproducibility of Results; D012639:Seeds / Q000254:growth & development*; D013347:Subcellular Fractions / Q000378:metabolism; D014170:Transformation, Genetic; D003313:Zea mays / Q000033:anatomy & histology* / Q000166:cytology / Q000235:genetics* / Q000254:growth & development
D007210:Indoleacetic Acids; D010940:Plant Proteins
Brachytic2; maize (Zea mays); major QTL; mild mutation; plant height; rare allele.