NATURAL AND ARTIFICIAL ALLOPLOIDS WITH 22 PAIRS OF CHROMOSOMES IN THE GENUSCARTHAMUS(COMPOSITAE)

Publisher Website
Google Scholar
Abstract
In order to determine which of the diploid Carthamus species (n = 10 and n = 12) were the ancestors of the alloploid species C. lanatus L.(n = 22) a genome analysis was conducted. The types of interspecific hybrids obtained within the genus Carthamus were n = 10 x n = 12 chromosome species, n = 10 chromosome species x C. lanatus and n = 12 chromosome species x C. lanatus. Morphological and chromosome pairing data were collected for these hybrids. Artificial amphidiploids with n = 22 chromosomes were derived from the n = 10 x n = 12 chromosome species hybrids by treatment with colchicine. These were studied morphologically and cytologically. The amphidiploids were crossed to each other and to C. lanatus. Chromosome pairing was studied in hybrids obtained from these crosses. On the basis of morphology and chromosome pairing in the above hybrids it was concluded that none of the artificial alloploids was homologous to C. lanatus and that none of the n = 10 chromosome species investigated in this study was the ancestor of C. lanatus. Possible alternate ancestors are discussed. On the basis of a 15:1 F2 ratio from a cross of yellow x white flowered C. lanatus it is proposed that both parents of C. lanatus had yellow flowers.