Mutation induction with ion beam irradiation of lateral buds of chrysanthemum and analysis of chimeric structure of induced mutants

Abstract

We compared the eVects of ion beam and gamma ray irradiation on mutation induction in axillary buds of chrysanthemum, and analyzed the chimeric structure of the resulting mutants. Axillary buds were irradiated with carbon ions at 2 Gy (mean linear energy transfer 122 keV/ m), helium ions at 10 Gy (mean 9 keV/ m), and gamma rays at 80 Gy, all of which have the similar eVects on survival. The lower Wve nodes of the shoots elongating from the irradiated buds were cut one by one, and new shoots were allowed to grow from the axillary buds. This procedure was repeated twice, and Xower color mutation was investigated. Chimeric structure was analyzed by comparing the Xower color of mutants to that of plants regenerated from the roots. Flower color mutants emerged at a high frequency (17.4-28.8%), and there were no signiWcant diVerences in the mutation frequency between the treatments. All the Xower color mutants induced with gamma rays were periclinal chimeras. In contrast, some mutants obtained with ion beams had the same Xower color as that of the plants derived from the roots. This suggests that they were solid mutants, where both LI and LIII tissues were derived from the same mutated cell. Solid mutants were also obtained when irradiated with 5 Gy of helium ions, which had less eVect on survival and mutation than other treatments. Factors for obtaining solid mutants only with ion beams are also discussed.

The Methylation of the PcMYB10 Promoter Is Associated with Green-Skinned Sport in Max Red Bartlett Pear

“…The color change of plant tissue is one of the commonly observed phenotypes of natural mutation. The mechanisms of color change in some plants have been studied extensively (Tegopati, 2001;Li et al, 2005;Yamaguchi et al, 2009;Palai and Rout, 2011), but not in the sport varieties of the European pear. In this paper, we studied the mechanism of the formation of green-skinned MRB-G fruit and demonstrated that hypermethylation of the PcMYB10 promoter was probably the causative factor.…”

Promotion of somatic embryo production from embryogenic calluses of monocotyledonous and dicotyledonous plants by heavy-ion beam irradiation

“…In general, growth and differentiation of cultured tissues are inhibited by heavy-ion beam irradiation and the degree of inhibition increases as the irradiation dose increases (Miyazaki et al 2002;Ishii et al 2003;Okamura et al 2003;Miyazaki et al 2006;Zhou et al 2006;Godo et al 2007;Kanaya et al 2008;Sugiyama et al 2008;Sasaki et al 2008;Yamaguchi et al 2008). In the present study, growth of embryogenic calluses of both T. hirta and D. carota was also inhibited by heavy-ion beam irradiation.…”

“…Heavy-ion beam irradiation has often been combined with tissue culture for efficient induction and selection of mutants, establishment of solid mutants from chimerical tissues and organs, and/or propagation of valuable mutants (Miyazaki et al 2002;Ishii et al 2003;Okamura et al 2003;Miyazaki et al 2006;Zhou et al 2006;Godo et al 2007;Kanaya et al 2008;Sugiyama et al 2008;Sasaki et al 2008;Yamaguchi et al 2008).…”

Morphogenetic response of shoot tips to cryopreservation by encapsulation-dehydration in a solid mutant and periclinal chimeras of Chrysanthemum × grandiflorum /Ramat./Kitam.

“…Since the nineteenth century, they are used in horticultural production as a source of new phenotypes (Stewart et al 1972;Zonneveld 2007). Moreover, chimeras are also useful in evaluating the interactions between cells during plant development (Szymkowiak and Sussex 1996;Yamaguchi et al 2009). However, these plants are problematic in propagation and storage.…”