PNL Volume 14
1982
RESEARCH REPORTS 39
THE INHERITANCE OF THE ABILITY TO REGENERATE PLANTS FROM CELL CULTURES
OF PISUM SATIVUM L. — A PRELIMINARY ANALYSIS
Malmberg, R. L. Cold Spring Harbor Lab, Cold Spring Harbor, NY USA
Previously we had reported that certain wild or primitive forms of
peas had some ability to regenerate from callus cultures (1, 2).
Specifically, two lines obtained from G. A. Marx (B77-259 and B77-276)
were found to be able to give rise to whole plants when epicotyl derived
callus was shifted to shoot inducing medium after as long as six months
in culture; however, these lines showed an increasing difficulty in ob-
taining regeneration as a function of time, requiring progressively
longer incubations on shoot medium to give rise to regeneration events.
Also, because the pea callus grew very slowly, with doubling times on
the order of three to four weeks, the six months regeneration window did
not reflect very many cell divisions. Thus the ability to regenerate
from cultures was very limited. In this note we report some preliminary
results of crosses between one of the regenerating lines (B77-259) and a
non-regenerating multiply marked line (A1078-234-0) also kindly provided
by G. A. Marx. A partial genetic characterization of these lines is as
follows:
By standard crossing methods we constructed F1, F2, and backeross
generations. As previously described (1, 2) seeds to be tested for
their callus/regeneration ability were surface sterilized and germinated
on an agar medium. The epicotyls were dissected out two to three days
later and cultured on callus medium for four to six months, after which
they were transferred to shoot inducing medium. Successfully
regenerated shoots were then rooted and transferred to soil and growth
chamber conditions with a great deal of care at initially keeping the
humidity high. Two problems with this experimental design seem
unavoidable. First, the assay for regeneration potential can require as
much as twelve months, e.g. six months in culture, four months to
regenerate shoots, two months to obtain roots plus transplant to soil.
This is before any linkage data could be obtained by monitoring the
growth of the plants and scoring the markers. Second, non-regenerating
calli cannot be scored at all for the whole plant markers, thus we lost
a substantial portion of the linkage data that was present in the seeds.
Initial data indicated that there was no maternal effect so subsequent
data have been pooled.