1966 Volume 35 Issue 4 Pages 413-421
1. Following varieties of Camellia were used for the present chromosome survey: each one variety of Camellia assimilis, C. granthamiana and of C. hiemalis, 14 varieties of C. japonica, 3 varieties of C. japonica subsp. rusticana, each one of C. salicifolia and of C. saluenensis and 3 of C. spp. (not identified). The karyotype analysis was also carried out with several representative forms.
2. Following different karyotypes were clearly discriminated:
C. japonica K(2n)=16V+8J+2Jt+4v
C. japonic subsp. rusticana (a wild variety) K(2n)=16V+8J+J1t+J2t+4v
C. salicifolia K(2n)=16V+8J+2Jt+4v
C. saluenensis var. Seiôbo K(2n)=17V+7J+J1t+J2t+4v
A wild form of C. japonica subsp. rusticana and a cultivated form, “Seiôbo”, of C. saluenensis were considered presumably to be either structural chromosome hybrids or true hybrid forms.
3. Result of the present chromosome survey was compiled in Table 1 and whole the data hitherto reported by many workers were represented on the list in appendix. The present authors could reveal following new facts: (i) C. assimilis was considered to be a diploid species. (ii) A hypo-triploid (3x-1) and a pentaploid forms were first discovered in C. japonica. (iii)“Otani-totsubaki”, a variety of C. reticulate, was composed of 91 somatic chromosomes including a small supernumerary chromosome. (iv) Horticultural varieties, “Tamuke-yama”and“Umegaka”, were of tetraploid chromosome constitution.
4. The polyploid series in Camellia ranged between 2x(2n=30) and 8x(2n=120) forms. More than half of species studied were the polyploid species or the species showing intraspecific differentiation of polyploidy. There could be noticed remarkable prevalence of 3x and 6x forms in clearcut contrast to the rather slight occurrence of 4x forms, and such situation would strongly suggest that the triploidy had an important role for the evolution of polyploid series in Camellia.
The discovery of 5x and 4x forms in Japonica-camellias, the latter forms being duly considered to be of hybrid origin, will give a great hope for the practical breeding on polyploid level of valuable new forms.