Mapping QTL for flowering time-related traits under three plant densities in maize
Liwei Wang,
Zhiqiang Zhou,
Ronggai Li,
Jianfeng Weng,
Quanguo Zhang,
Xinghua Li,
Baoqiang Wang,
Wenying Zhang,
Wei Song,
Xinhai Li
Affiliations
Liwei Wang
The Key Laboratory of Crop Genetics and Breeding of Hebei Province, Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050035, Hebei, China; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Zhiqiang Zhou
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Ronggai Li
The Key Laboratory of Crop Genetics and Breeding of Hebei Province, Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050035, Hebei, China
Jianfeng Weng
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Quanguo Zhang
The Key Laboratory of Crop Genetics and Breeding of Hebei Province, Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050035, Hebei, China
Xinghua Li
The Key Laboratory of Crop Genetics and Breeding of Hebei Province, Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050035, Hebei, China
Baoqiang Wang
The Key Laboratory of Crop Genetics and Breeding of Hebei Province, Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050035, Hebei, China
Wenying Zhang
The Key Laboratory of Crop Genetics and Breeding of Hebei Province, Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050035, Hebei, China
Wei Song
The Key Laboratory of Crop Genetics and Breeding of Hebei Province, Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050035, Hebei, China; Corresponding authors.
Xinhai Li
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Corresponding authors.
Flowering time is an indicator of adaptation in maize and a key trait for selection in breeding. The genetic basis of flowering time in maize, especially in response to plant density, remains unclear. The objective of this study was to identify maize quantitative trait loci (QTL) associated with flowering time-related traits that are stably expressed under several plant densities and show additive effects that vary with plant density. Three hundred recombinant inbred lines (RIL) derived from a cross between Ye 478 and Qi 319, together with their parents, were planted at three plant densities (90,000, 120,000, and 150,000 plants ha−1) in four environments. The five traits investigated were days to tasseling (DTT), days to silking (DTS), days to pollen shed (DTP), interval between anthesis and silking (ASI), and interval between tasseling and anthesis (TAI). A high-resolution bin map was used for QTL mapping. In the RIL population, the DTT, DTS, and DTP values increased with plant density, whereas the ASI and TAI values showed negligible response to plant density. A total of 72 QTL were identified for flowering time-related traits, including 15 stably expressed across environments. Maize flowering time under different densities seems to be regulated by complex pathways rather than by several major genes or an independent pathway. The effects of some stable QTL, especially qDTT8-1 and qDTT10-4, varied with plant density. Fine mapping and cloning of these QTL will shed light on the mechanism of flowering time and assist in breeding early-maturing maize inbred lines and hybrids.
