Since 1938 there have been annual breeding studies with corn at this institution and in this contribution to Maize Co‑op News Letter it may be useful for other workers to have a brief history of what we have been doing and what are some of our future aims.
Although corn had been used at the John Innes from
time to time for genetical investigations, it was not until C.D.R. Dawson
commenced a sweet corn breeding programme just before the war started that corn
breeding began here in earnest. As a result of his tests, Dawson released to
the seed trade two top crosses, known as the John Innes Hybrids.
However, during the war a number of staff changes
took place and a new breeding programme was initiated by K. Mather who found
that, owing to the differences in climate of southern England and those States
where sweet corn is more commonly grown, even such types as Golden Bantam and
Golden Cross Bantam failed to germinate fully here in sowings made before June.
The first essential was, therefore, to obtain cold‑hardy lines which
would germinate in cold soil. This work has been continued annually, the
principle being to breed from plants of different strains which survived
February and/or March sowings in the field. On the whole, the results are
gratifying and we are now multiplying stocks from our selections of Canada Gold
and Golden Early Market. In addition, we hnve a strain of Golden Standard
Maize, a dent originally imported from Holland, which has been improved to
withstand the rigours of early field sowings.
For several years we have been running an
experimental determination of the influence of sowing times on the behaviour of
various strains of sweet corn and it now seems likely that sowings earlier than
the beginning of June are more advantageous as the seedlings my have a better
chance of avoiding frit fly (Orcinella frit) attacks.
Similarly, K. Mather has conducted numerous varietal
trials of samples of sweet corn that have reached him from the U.S.A. Numerous
crosses have been made and the new combinations tested, but, on the whole, few
proved better than the lines we already had. Perhaps because of our cooler
climate the ears of the different varieties tested have ripened unevenly, and
it was decided that our best chances of producing an improved type of sweet
corn for southern England would be to use the methods now so widely established
in the U.S.A., namely, to inbreed and select those inbred lines which had the
best combining ability later on. A small experiment along these lines was
initiated.
Another series of investigations were conducted by
A. J. Bateman in his studies of the spatial isolation required by seed crops in
order to prevent their contamination with foreign pollen. He used corn as one
example of a wind‑pollinated species.
During the last year, through a grant from the
Agricultural Research Council, I was able to work with W. R. Singleton at the
Connecticut Agricultural Experiment Station so that I could see at first hand
the methods of sweet corn breeding practised in New England, and it is hoped to
introduce some American methods into our future work at the John Innes. In
addition, I was fortunate enough to make a tour of the corn belt and hear some
of the current problems of corn geneticists, many of whom have generously
supplied lines of sweet corn for our cold‑hardiness experiments.
Our programme for 1948 includes a continuation of
the February selections which will include not only the John Innes selected
lines, but also a series of inbreds and their hybrids obtained from W. R. Singleton
and from the Central Experimental Farm in Ottawa; also a large trial of the
stocks I brought back with me to see which behave well enough under our
conditions initially before starting our inbreeding campaign and to study the
reaction under field conditions of some of my cold‑room selections.
Finally we are proposing to see how our previously selected lines behave in
various parts of this area of England.
G. Haskell