Floral Development And Sexual Chromosome Deletions In An Asexual Mutant K034 And A Hermaphroditic Mutant R025 In Silene latifolia

Abstract

K034 that is an asexual mutant of the dioecious plant, Silene latifolia has asexual and female-like flowers in the ratio of 9:1. The asexual flower lacks a mature gynoecium and stamens while the female-like flower has an imperfect but fertile gynoecium to bear seeds. K034 is presumed to derive from male since the fourth whorl is smaller than that of a female flower. R025 has been obtained by heavy-ion beam accelerated by RIKEN Ring Cyclotron. R025 has bisexual flowers on most branches and normal male flowers on a few branches. Its genetic stability has been examining with individuals propagated by selfing and cutting. The bisexual flower has mature stamens like a wild-type male and a mature gynoecium fused five carpels like a wild-type female. K034 has the Y chromosome carrying two deletions in gynoecium-suppressing and stamen-promoting functional regions. We are now examining some deletion on the Y chromosome of R025.