Isolation of a novel lodging resistance QTL gene involved in strigolactone signaling and its pyramiding with a QTL gene involved in another mechanism.
Lodging has been a major roadblock to attaining increased crop productivity. In an attempt to understand the mechanism for culm strength in rice, we isolated an effective quantitative trait loci (QTL), STRONG CULM3 (SCM3), the causal gene of which is identical to rice TEOSINTE BRANCHED1 (OsTB1), a gene previously reported to positively control strigolactone (SL) signaling. A near-isogenic line (NIL) carrying SCM3 showed enhanced culm strength and increased spikelet number despite the expected decrease in tiller number, indicating that SL also has a positive role in enhancing culm strength and spikelet number. We produced a pyramiding line carrying SCM3 and SCM2, another QTL encoding APO1 involved in panicle development. The NIL-SCM2+SCM3 showed a much stronger culm than NIL-SCM2 and NIL-SCM3 and an increased spikelet number caused by the additive effect of these QTLs. We discuss the importance of utilizing suitable alleles of these STRONG CULM QTLs without inducing detrimental traits for breeding.
Bioscience and Biotechnology Center, Nagoya University, Nagoya, Japan.
Kenji
K
Yano
Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan.
Taiichiro
T
Ookawa
Bioscience and Biotechnology Center, Nagoya University, Nagoya, Japan.
Koichiro
K
Aya
Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan.
Yusuke
Y
Ochiai
Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan.
Tadashi
T
Hirasawa
Agricultural Research Institute, Toyama Agricultural, Forestry & Fisheries Research Center, Toyama, Japan.
Takeshi
T
Ebitani
Agricultural Research Institute, Toyama Agricultural, Forestry & Fisheries Research Center, Toyama, Japan.
Takeshi
T
Takarada
National Institute of Agrobiological Sciences, Tsukuba, Japan.
Masahiro
M
Yano
National Institute of Agrobiological Sciences, Tsukuba, Japan.
Toshio
T
Yamamoto
National Institute of Agrobiological Sciences, Tsukuba, Japan.
Shuichi
S
Fukuoka
National Institute of Agrobiological Sciences, Tsukuba, Japan.
Jianzhong
J
Wu
National Institute of Agrobiological Sciences, Tsukuba, Japan.
Tsuyu
T
Ando
Bioscience and Biotechnology Center, Nagoya University, Nagoya, Japan.
Reynante Lacsamana
RL
Ordonio
Bioscience and Biotechnology Center, Nagoya University, Nagoya, Japan.
Ko
K
Hirano
Bioscience and Biotechnology Center, Nagoya University, Nagoya, Japan makoto@agr.nagoya-u.ac.jp.
Makoto
M
Matsuoka
OsTB1; QTL; culm; lodging resistance; strigolactone