Mc. Oleary et Th. Boyle, SEGREGATION DISTORTION AT ISOZYME LOCUS LAP-1 IN SCHLUMBERGERA (CACTACEAE) IS CAUSED BY LINKAGE WITH THE GAMETOPHYTIC SELF-INCOMPATIBILITY (S) LOCUS, The Journal of heredity, 89(3), 1998, pp. 206-210
The inheritance of leucine aminopeptidase (LAP), phosphoglucomutase (P
GM), and shikimate dehydrogenase (SKD) isozymes was studied in Schlumb
ergera truncata and S. x buckleyi (Cactaceae). Isozymes were extracted
from phylloclades and separated using polyacrylamide-gel electrophore
sis. F-1, F-2, and BC1 populations were examined to determine the mode
of inheritance. Relatively few families exhibited disturbed segregati
on ratios at Pgm-1 or Skd-1. In contrast, segregation ratios at Lap-1
were distorted in 14 of the 22 families that were examined. Disturbed
segregation at Lap-1 was attributed to linkage with the gametophytic s
elf-incompatibility (S) locus (recombination frequency = 7% +/- 1%). L
ap-1, Pgm-1, and Skd-1 assorted independently of each other. Lap-1 and
S may be useful for assessing linkage conservation among self-incompa
tible taxa In the Cactaceae.