noun
heliotropism; phototropism
Scientific term for the directional growth of a plant toward sunlight. In broader biology, it can refer to movement toward any light source.
ヒマワリの向光性はよく知られている。
The heliotropism of sunflowers is well known.
植物の向光性は、光の方向に成長する
Phototropism in plants is the property of growing toward the light.
背光性 is negative phototropism (growth away from light), the opposite of 向光性.
Compound of 向 (toward), 光 (light), and 性 (property/nature). A straightforward Sino-Japanese scientific term.