Evening star. [volume] (Washington, D.C.) 1854-1972, 1926-12-24
FUNGUS SEXUAL
HYBR|DS PRODUCED
Development at Plant Indus
try Bureau Called First
Successful Test.

Spores Of a hybrid fungus fruit
body have been developed at a labo-
ratory of the Bureau Of Plant Indus.
try here by DR.. c. L. Sheare and DIR.
B. o. Dodge.
They are believed by Washington
botanists to be the first true sexual
hybrids between distinct fungi species
ever produced experimentally. The
work promises to throw much new
light on the origin of new strains OF
fungus disease in plants, such as
rusts and molds, which may have q
far-reaching effect on agriculture.
1t frequently happens that the De.
partment of Agriculture Is called
upon to fight q hitherto unknown
mosaic or rust which Is wiping out
a crop which has been considered i'm
mune. Such a disease may seem
different than any previously encoun-
tered anywhere In the world and will
seem to have dropped out OF clear
sky. The experiments tend to show
that these new parasites really have
resulted from combinations of forms
long known to science. With their
origin and life history determined, 1t
will be much, easier to devise means
of combating them.
OidSSuuCbtlOu Vi II uHSts
The classification of the fungi in.
cludes a large group of parasitic plant
forms ranging from giant toadstools
to microscopic forms such as produce
wheat rust, black spot on rose leaves
and mold on jellies and bread. They
are closely allied with the bacteria,
although not Of the same family.
Propagation of fungi has been gen.
orally by asexual spores. That is,
the distribution apparently has been
provided for and the life Of the race
continued by spores shot forth by
individuals and. of course, continues
indefinitely of the same variety and
species. There has been no cross
fertilization of spores. The. same
type of wheat rust or jelly mold
has continued through countless
generations. Most of the higher
varieties of plant life continually are
producing new varieties by hybridi-
cation, but in the fungi new forms,
although suspected, have not actu-
ally been demonstrated to have
arisen by crossing two different
species.
The present experiments, which
were described before the Botanical
Society of Washington meeting at
ShO SOSiilOS SIuD ucSudy ny
DR.. Sheare and DIR. Dodge, were
made in the course of an investiga-
ton of the life history Of a red bread
mold. and 1t is hoped that they will
result in the development of new
forms of the fungi by crosses.
Causes Fruit Decay.
This red mold has appeared in
bakeries In various countries in the
world and 1t also causes fruit decay.
Unless the dough Is heated to an
unusual degree In baking, this red
mold appears in a day or so and
renders the loaf unfit for sale or
for the table. Ordinary baking does
not kill the mold, which soon in
fects the whole loaf.
The fungus responsible was isolated
and named early in the present CEN
tury in France, but no effort was
made to trace it any further. Later
a fungus of similar type was found
on trunks Of burned trees in Japan
and Brazil, but it was not at first
connected with the bread mold. 1t
was not until the experiments were
undertaken here that the sexual and
aSexual types were brought together.
Then it was found that when the two
forms are grown together they unite,
producing spores Of a different type
black instead Of red.
This In itself was not new. Fungus
varieties have been crossed in the
past and produced a type which lasted
for one generation. but which has not
been proved capable of reproducing
itself. The spores simply would burst
into powder as soon as they We're shot
forth, and that would be the end of
that type.
But in this case the hybrid seems
to be producing perfect spores, thus
assuring the new family of perpetual
ton. 1t is not merely a. new variety,
say DR.. Sheare and DIR. Dodge, but
has all the earmarks Of a new species
in the fungi group.
Progress Far Apart.
Here were two species Of plant life
which had continued their progress in
the world far apart for thousands Of
generations. Neither had been known
to have shown the slightest inclina-
ton to mate with any of the numertus
forms with which they must have
come in contact in nature. Suddenly
they are brought together and recog-
nize each other at once as destined
mates for whom they have been seek
ing through the countless centuries.
1t Is a botanical love romance, say the
botanists, which deserves to become a
classic.
If these things happen in the lab.
oratory. 1t Is held, they must also
happen in nature when favorable
circumstances arise. 1t may illustrate
a curious working of evolution in re-
lation to the law of survival. An eX-
ample cited was that Of two pear
trees growing side by side. One is
of variety which is subject to some
rust disease which soon strips 1t of
its leaves, and, of course, renders 1t
worthless. The other pear tree is of
an immune variety. But with all
the leaves off the first tree the fungi
have nothing to live on.
A new type must be produced ca
pable of living on the other pear tree
or they will perish. And quite fire.
Quently, to the mystification of