Plant Genome II Conference
Town & Country Conference Center, San Diego, CA, January, 1994.
PG-II: RFLP ANALYSIS OF INTROGRESSION IN PEANUT
RFLP ANALYSIS OF INTROGRESSION IN PEANUT.
Gary Kochert, Department of Botany, University of Georgia,
Athens, GA 30602, Gustavo M. Garcia and H. Thomas Stalker,
Department of Crop Science, North Carolina State University,
Raleigh NC 27695.
Forty-six lines derived from a cross between cultivated
peanut (Arachis hypogaea L.), which is an allotetraploid, and a
diploid wild species (A. cardenasii Krap. et Greg.) were analyzed
for introgression using RFLPs and RAPDS. Some of the
introgression lines exhibit valuable agronomic traits, such as
disease and insect resistance, which were apparently introgressed
from the wild species. Our goal was to determine the degree of
introgression and to correlate segments introgressed from the
wild species with agronomic traits. Seventy-two cDNA probes,
which had been previously mapped on the peanut RFLP map, and 70
RAPD primers were used to screen the introgression lines.
Thirty-four RFLP probes and 45 RAPD primers detected introgressed
segments. With RFLP analysis it was possible to map the
introgressed segments and to determine their approximate size.
Nine of the 11 linkage groups on the current peanut RFLP map
exhibited introgressed segments; the smallest introgressed
segment was about 11 cM in size and the largest more than 100 cM.
Segments introgressed from A. cardenasii were found in both
genomes of cultivated peanut, but one genome was usually
preferred for introgression. RAPD primers detected many A.
cardenasii-specific amplification products in the introgression
lines. However, these usually produced patterns typical of
repeated sequences when used as hybridization probes on Southern
blots, and this limited their usefulness as mapping markers.
Several introgressed segments appeared to be associated with the
introgressed agronomic traits.
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