. Chromosomes and phylogeny in Crepis. Crepis; Plants; Chromosomes. 1930] Hollingshead-Babcock: Chromosomes and Phylogeny in Crepis 21 decision as to their exact number. The chromosomes of C. biennis and C. ciliata are of the same size order. The group of four species with 2n = 12 (fig. 13), C. mollis, C. Iijrata, C. montana, C. hierosolymitana, gave material on which it was somewhat difficult to make out exact details of chromosome morphology. The chromosome outlines were not quite so clear as in most species and the increased number added to the difficulty. True satellites were found in mont
. Chromosomes and phylogeny in Crepis. Crepis; Plants; Chromosomes. 1930] Hollingshead-Babcock: Chromosomes and Phylogeny in Crepis 21 decision as to their exact number. The chromosomes of C. biennis and C. ciliata are of the same size order. The group of four species with 2n = 12 (fig. 13), C. mollis, C. Iijrata, C. montana, C. hierosolymitana, gave material on which it was somewhat difficult to make out exact details of chromosome morphology. The chromosome outlines were not quite so clear as in most species and the increased number added to the difficulty. True satellites were found in montana and distal constricted ends which often resembled satellites were found on V-shaped chromosomes of lyrata, mollis, and hierosolymitana. Whether there are other small true satellites has not been definitely C. nana C. elegan3 a b Figure 14. The material of C. nana and C. elegans (2« —14, fig. 14«, b) was limited to a few root tips from germinated seeds and the figures available were anything but satisfactory for a study of chromosome morphology though the number was quite clear. The complexes are similar, containing long and medium V's and probably a satellited pair of chromosomes with submedian constrictions. In each of the figures reproduced only one satellite appears, but in C. nana other plates were seen containing two satellites. Extensive study of material from six plants of C. tenuifolia, grown from seed collected from the wild, revealed always a somatic number of fifteen chromosomes. Two of these plants have flowered with the help of artificial light and one produced a number of achenes. Two plants which grew from these achenes were examined and each had 15 chromosomes. Reduction divisions of the plants which flowered were very irregular showing sometimes 15 univalent chromosomes and sometimes both bivalents and univalents. An examination of the somatic chromosomes (fig. 15a) shows no good evidence of hybrid origin since many of the have se
Size: 1507px × 1658px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookpublisherberkeleycalifun, booksubjectplants
