The present invention provides a method and a composition for restoring
pollen fertility by suppressing formation insufficiency in a
pollen formation process due to a high-temperature or low-
temperature stress. The present invention provides a
fertility restorative agent comprising an
auxin as an
active ingredient, and a method for restoring the
fertility of a plants of the family
Poaceae, comprising spreading an
auxin. Moreover, the present invention provides a fertility restorative agent containing as an
active ingredient a substance which inhibits
auxin action, and a method for restoring the fertility of
rice plant, including spreading a substance which inhibits auxin action. Preferably, the auxin is 10−4 M to 10−7 M of indole-3-
acetic acid (IAA), 4-chloroindoleacetic acid,
phenylacetic acid, 2,4-
dichlorophenoxyacetic acid (2,4-D), α-naphthaleneacetic acid (NAA), 2,6-dichlorobenzoic acid,
indolebutyric acid (IBA), 4-chlorophenoxyacetic acid, ethyl 5-chloroindazoleacetate, naphthoxyacetic acid or 2,4,5-trichlorophenoxyacetic acid.