Cytological Studies on Iris (Preliminary Note)

Abstract

The diploid number of chromosomes of several species of Iris have been determined as follows: Iris Kaempferi var. hortensis 24, I. Kaempferi var. spontanea 24, I. sibirica var. orientaris 28, I. laevigata 32, I. gracilipes 36, I. florentina 48, I. japonica 54. Among these species, Iris japonica and I. florentina form trivalent chromosomes in the prophase of the heterotypic nuclear division in their pollen-mother-cells. Therefore their chromosomes must be considered as triploid. It is a remarkable fact that all the individuals of a distinct species have triploid chromosomes.