Transgenerational effect of maternal growth environment on flowering date in rice (Oryza sativa L.)

Flowering date reflects the adjustment of a plant's growth period to a given environment. This is true of rice, which is a major food source around the world. We tested whether rice plants can recognize and record natural variation in their growth environments and thus control flowering in their progeny. We grew seedlings of two japonica cultivars from the same seed stock at two locations, in cool and warm climates, in Japan until they produced seeds. We then tested their progeny at the same locations. The progeny of mother plants of both cultivars grown in a cool climate flowered significantly earlier (by 1 to 6 days) than the progeny of mother plants grown in a warm climate. This transgenerational effect was partially explained by water temperatures during the vegetative growth stage. This is the first study to show the effect of transgenerational effect of natural environments on flowering date in rice.