Molecular and genealogical analysis of grain dormancy in Japanese wheat varieties, with specific focus on MOTHER OF FT AND TFL1 on chromosome 3A.
In the wheat (Triticum aestivum L.) cultivar 'Zenkoujikomugi', a single nucleotide polymorphism (SNP) in the promoter of MOTHER OF FT AND TFL1 on chromosome 3A (MFT-3A) causes an increase in the level of gene expression, resulting in strong grain dormancy. We used a DNA marker to detect the 'Zenkoujikomugi'-type (Zen-type) SNP and examined the genotype of MFT-3A in Japanese wheat varieties, and we found that 169 of 324 varieties carry the Zen-type SNP. In Japanese commercial varieties, the frequency of the Zen-type SNP was remarkably high in the southern part of Japan, but low in the northern part. To examine the relationship between MFT-3A genotype and grain dormancy, we performed a germination assay in three wheat-growing seasons. On average, the varieties carrying the Zen-type SNP showed stronger grain dormancy than the varieties carrying the non-Zen-type SNP. Among commercial cultivars, 'Iwainodaichi' (Kyushu), 'Junreikomugi' (Kinki-Chugoku-Shikoku), 'Kinuhime' (Kanto-Tokai), 'Nebarigoshi' (Tohoku-Hokuriku), and 'Kitamoe' (Hokkaido) showed the strongest grain dormancy in each geographical group, and all these varieties, except for 'Kitamoe', were found to carry the Zen-type SNP. In recent years, the number of varieties carrying the Zen-type SNP has increased in the Tohoku-Hokuriku region, but not in the Hokkaido region.
NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
Makiko
M
Chono
NARO Kyushu Okinawa Agricultural Research Center , 496 Izumi, Chikugo, Fukuoka 833-0041 , Japan.
Hitoshi
H
Matsunaka
NARO Agricultural Research Center , 1-2-1 Inada, Jouetsu, Niigata 943-0193 , Japan.
Masako
M
Seki
NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
Masaya
M
Fujita
NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
Chikako
C
Kiribuchi-Otobe
NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
Shunsuke
S
Oda
NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
Hisayo
H
Kojima
NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
Shingo
S
Nakamura
MFT; Triticum aestivum L.; genealogical pedigree; grain dormancy; pre-harvest sprouting