The soybean [Glycine max (L.) Merr.] line B739 has the high linolenic
acid content in its seed oil. This line was identified from Bay in a m
utation breeding program conducted in 1985 at Saga University. The obj
ective of this study was to determine the genetic control of the high
linolenic acid content in B739. The line B739 was crossed reciprocally
with Bay. There was no maternal and cytoplasmic effects for linolenic
acid content in these crosses. For total oil content, no maternal and
cytoplasmic effects were also observed. The linolenic acid of F2 plan
ts of B739 X Bay was segregated in bimodal pattern into normal and hig
h contents which satisfactorily fitted to a 3 : 1 ratio. This result w
as consistent with segregation of major gene at a single locus. The al
lele in B739 was designated lin(h) and the genotype for B739 as lin(h)
lin(h) and for Bay as Lin-Lin. The oil content of F2 plants had an inv
erse relationship with linolenic acid and when the oil was segregated
in bimodal pattern into normal and low contents which satisfactorily f
itted to a 3 : 1 ratio. Thus, it was assumed that the low oil content
in B739 was also controlled by this allele. However, linolenic acid is
the major component in the diet for some mammals, and consequently th
is allele would be effective to improve the lines with high linolenic
acid content.