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THE CYTOGEOGRAPHY OF THE LORANTHACEOUS MISTLETOES
Author(s) -
Barlow B. A.,
Wiens D.
Publication year - 1971
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.2307/1218882
Subject(s) - temperate climate , southern hemisphere , biology , northern hemisphere , tropics , taxon , temperate rainforest , ecology , climatology , ecosystem , geology
Summary Known chromosome numbers in the Loranthaceae are reviewed and 102 new records added. The basic number of the family is x = 12 and there has been progressive aneuploid reduction to x = 8. The early development of the family has been under temperate conditions in the Southern Hemisphere, where stocks with x = 12 and 11 became established in temperate South America and Australasia. Rapid aneuploid reduction continued after the establishment of strong continental isolation, establishing numbers of x = 9 and 8 in the Old and New Worlds respectively. Massive secondary radiation in the tropics has followed, involving the 12‐, 9‐ and 8‐paired stocks. Increase in chromosome size occurred during the tropical radiation, perhaps compensating for loss of recombination potential due to aneuploid reduction. Polyploidy is a rare and recent phenomenon in the history of the family, being documented in only two Central American taxa. One of these may be an autoploid.