Abstract
The chromosome numbers in fifty-eight cultivars of Camellia vernalis MAKINO and fifty-six open-pollinated seedlings from those cultivars were studied in an attempt to understand the process of varietal differentiation of C.vernalis group.
For those cultivars whose chromosome number had already been reported, exactly the same results were obtained. Among the other cultivars, 2 triploids (2n=45), 1 tetraploid (2n=60), and 2 pentaploids (2n=75) were newly obser ved.
Some of the seedlings gave good results, consistent with Tanaka's hypothesis on classification of C.vernalis, for chromosome numbers and morphological characters of flower and leaf, but many others had different chromosome numbers which did not agree with the hypothesis. Various polyploids were also derived from the basic chromosome number (X=15) of the genus Camellia; in particular, a wide variation was observed, from triploid to decaploid (2n=150), within the seedlings from triploids that hardly ever set fruit. As for the seedlings from pentaploid and hexaploid cultivars, they showed to be hexaploids and heptaploids (2n=105), respectively.
These results indicate that the variation of C.vernalis has been extended within the relatively short time since an F1 hybrid was produced between C.sasanqua THUNB. and C.japonica LINN.
