To understand the cytogenetic behaviors and pollen resource potentialities, meioses and pollen fertility were examined in the 16 cultivars of Higo chrysanthemum (Dendran-thema ×grandiflorum (Ramat.) Kitam.).
Bivalent formation was highly regular at metaphase I in the pollen mother cells of all the cultivars although univalents and quadrivalents were also sporadically distributed. Considerable abnormalities such as lagging chromosomes and chromosome bridges at telophase I and II, and unequal sizes and abnormal numbers of microspores at tetrad stage were observed in the succeeding stages of microsporogenesis in all the cultivars. Pollen fertility varied from 0.4 to 97.7% among the cultivars and they could be grouped into 3: high (71100%), 8 cultivars; intermediate (3170%), 5 cultivars; and, low (030%), 3 cultivars.
It is indicative from the above results that majority of the cultivars of Higo chrysan-themum are potential pollen resources for the improvement of modern chrysanthemums.