2004 年 39 巻 1 号 p. 163-169
For development of an F1 hybrid of lettuce cultivars, an efficient pollinator must be found. To evaluate pollination effects of a candidate pollinator, Lasioglossum villosulum trichopse, the foraging behavior and pollination ability of this sweat bee were investigated on the flowers of male-fertile (MF) and genic male-sterile (GMS) lettuce. Females of the sweet bee visited three lettuce cultivars for a short time corresponding to each cultivar's full blooming time and showed unique foraging behavior on the MF lettuce flower. The flower heads thus visited by a single pollen-gathering female sweat bee indicated a seed set as high as that of self-pollinated flower heads on a fine day. On the GMS lettuce, the rate of seed set was significantly lower in the bee-pollinated flower heads than that of hand-pollinated flower heads which bloomed on fine days. The low seed set was considered to be associated with weather conditions during the experimental period. This is the first report of successful F1 hybrid seed production of lettuce using a pollinator insect.
