Genomic analysis of plant height with molecular marker linkage map
in maize
Jianbing Yan1, Hua Tang1, Yiqin Huang1, Yonggang Shi2, Yonglian Zheng1 and
Jiansheng Li(lijs@163bj.com)3
1
National Key Laboratory of Crop Genetic Improvement, Huanzhong Agricultural University,
Wuhan 430070, China; 2Xiangfan Chia-Tai Agricultural Development Co., LTD., Xiangfan 441104,
China; 3National Maize Improvement Center of China, China Agricultural University, Beijing
100094, China
Plant height is one of important agronomic traits. With the increase of planting density
recently, selecting compatible heights of hybrids has been paid more attention during
breeding. Alternatively, the rapid developments of the molecular markers provide
powerful tools to localize QTLs involved in important agronomic traits at a genomic level.
The purposes of this investigation are to map plant height QTLs with molecular markers
and to analyze their genetic effects in maize. A F2:3 population from an elite hybrid
(Zong3×87-1) was utilized for evaluating plant heights in two locations, Wuhan and
Xiangfan, in South China, using a randomized complete block design respectively. The
mapping population included 266 F2:3 family lines. A genetic linkage map containing 150
SSR and 24 RFLP markers was constructed, which spanned a total of 2531.6cM with an
average interval of 14.5cM. Totally 10 QTLs (LOD>2.5) affecting plant heights were
mapped on 6 different chromosomes with the composite interval mapping. 7 of 10 QTLs
were detected in two locations, all of which showed the same direction to increase plant
heights, while 3 QTLs were detected only in one of the two locations. The contributions
to phenotypic variations for the single QTL varied between 5.29% and 17.12%. A large
number of digenic interactions for plant height were detected by two-way analyses of
variance. 107 and 98 two-locus combinations were found to be significant at a 0.01
probability level among 12,603 possible combinations in two locations respectively. 17
were simultaneously detected in both locations. Some of the QTLs detected by
single-locus analyses were involved in significant interactions, but most significant
interactions occurred between non-QTLs. These results demonstrated that epistatic
interactions might play an important role in the genetic bases of maize plant heights.