Linkage Relationships of Nine Induced Mutants in Common Bean

Abstract

Nine recessive gamma ray induced bean,
Phaseolus vulgaris
L., mutants were selected for linkage testing in diallel crosses. All mutants had a common genetic background, Florida dry bean breeding line 7-1404. Linkage was calculated using F
2
data, employing Fisher and Balmukand's product ratio method for crosses in repulsion and coupling phases. Repulsion phase linkage tests revealed 2 linkage groups involving 5 genes. Round leaf (
rnd
), stipelless lanceolate leaf (
sl
), and dark green savoy leaf (
dgs
) formed one linkage group, while diamond leaf (
dia
) and progressive chlorosis (
pc
) formed the 2nd linkage group. Recombination values from combined repulsion and coupling phase data were:
rnd
with
sl, p
= 11.51 ± 0.95;
sl
with
dgs, p
= 20.50 ± 1.34; and
rnd
with
dgs, p
= 30.07 ± 1.38.
Dgs
was found to be linked to the yellow wax locus,
y
, thereby tying the
dgs - sl
-
rnd
linkage group into linkage group VII defined by Lamprecht. Also, the
y
locus was found to be independent of
rnd
. Preliminary data suggest that the
dwarf seed
(
ds
) character may be controlled by the same locus as Lamprecht's
tenuis
(
te
), also of linkage group VII, and
ds
was found to be linked to
rnd
. If
te
and
ds
are identical, then the orientation of the
dgs
-
sl - rnd
linkage group with respect to
y
and
te
is determined.