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Karyotype of a David Medicago sativa L. Analyzed from Sporophytic and Gametophytic Mitoses 1
Author(s) -
Buss G. R.,
Cleveland R. W.
Publication year - 1968
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1968.0011183x000800060021x
Subject(s) - biology , ploidy , pollen , karyotype , chromosome , medicago sativa , mitosis , botany , homologous chromosome , pollen tube , b chromosome , genetics , gene , pollination
Idiograms were constructed for the mitotic chromosomes of diploid Medicago sativa L. (2n = 16). Chromosomes were measured in root tip cells and generative nuclei of pollen tubes. Statistical methods applied to the data did not provide a means for identifying homologous chromosomes; however, a pattern of morphology was found by which chromosomes could be matched by inspection. The haploid complement of eight chromosomes was divided into two groups, four long and four short chromosomes. Within each group the arm length ratios (short arm length ÷ long arm length) increased as total lengths decreased. Only minor discrepancies for this pattern existed. In root‐tips the chromosomes ranged from 3.5 to 4.5 microns in length, and ratios ranged from 0.53 to 0.94. The chromosomes were shorter in pollen tubes (lengths: 2.4‐3.1 microns; ratios: 0.64‐0.95). Idiograms from the two sources agreed in essential form except that the satellited chromosome was not recognizable in pollen‐tube nuclei.