Evening star., 1960-06-29

obviously, the ny was NJ
in fact, no individual fly wa
killed. The method of execu
ton was much more subtle
Radiation from isotopes wa
the weapon, and the attack wa
aimed at a weak point in thC
insects life-cycle.
The female of this specie
mates only once in her lifetime
If this union is with a sterile
male, she dies without produc
ing offspring. If such fruitles
unions happen often enough
the species will die out.
BY radiating the immature
form of the fly with heavy bu
uon-lethal doses of gamma
rays, sterility was induced. A.
they matured, about so millior
of the flies we're released eact
week for almost a year, to q
out into the Florida cattle land,
to seek mates.
The program began in 1857
Today the screw-worm fly il
50 close to extinction in thu
Southeast that it is no Longer
a threat, or even a major pest
in the cattle industry.
Other Uses
The f1y'S life-cycle weakness.
Is an exception in the insecr
World. The housef1y has a diff.
erent pattern, for instance
Thus radiation cannot conquel
all mans pestiferous competi'
tors. But there is hope that 6
few other inSectS-various type.
Of fruit flies and the tsetSe fly
that carries sleeping sickness
may be subject to the same ge.
netic death sentence.
sSDr. Willard Libby, principa
booster of the isotope, believes
its use in agriculture may turr
out to be atomic energy'S great.
est boon to mankind. Certainly
there are areas on the farm
where the radioactive atom Of
fers tremendous promise. One
OF the most hopeful is in de.
veloping new plant varieties
through radioactively induced
genetic mutations.
Scientists take the genera,
position that artiflcially in.
duced changes in species are
harmful, because bad" muta-
tions greatly outnumber good.
Some mutations are beneficial
however.
1t is only where it is prac.
tical to sacrifice a vast number
Of individuals that induced mu.
tations are a feasible means oi
improving the breed. Plants car
be radiated by the millior
while still in the compact, seec
form, and can be planted ano
later culled without fuss, emo.
ton or even much expense.
Already, radioactive muta.
ton Of a plant species has paio
off IN the development of a new
strain of peanuts. This strain
developed at North Carolins
State College, gives unusually
high yields and is resistant tc
a peanut disease called leaf
spot.
p Flowers Benefit
Experimental work at Brook.
haven, L. l., and elsewhere
looks to improving varieties oi
decorative plants, including
flowers. This research is partly
basic genetics and partly prac-
tical, applied Horticulture
Flowers are a big business; g
rose bud just a little more
velvety or longer stemmed thar
the old types could be worth
a million dollars to the florists
Of America.
The most important single
scientific development in the
atoms application to plant
study, however, has been de.
termination of the entire
process of "photosynthesis.
This is the marvellous mechan.
ism by which green plants take
water and carbon dioxide from
their environment and trans.
form them into useful food il
the presence of light. Photo.
synthesis is the basic process ol
life on earth. All animals, from
man on down, are mere
parasites on the chlorophyll.
bearing plants that manufac.
ture food from water, air anc
sunlight.
Until the atomic age, all re.
search into photosynthesis was
based on guesswork. There
were some good guesses, but
others were quite wide of the
marx. Studies under DR.
Melvin Calvin at the University
of. California have now cracked
the secret of photosynthesis
thanks to long Lived radio.
active isotope called carbon-14
Nov we know the whole
carbon reduction cycle" say.
DR.. Calvin. eve have traced the
carbon all the way through
Now we can start with radio.
active hydrogen-3 - tritium -
and start following hydrogen'i
path-"
This work will continue unit
the precise role of every ele
ment in the living plant
understood. 1t will be a lonI
and laboriouS job, to be sure
but one that could not hav,
been undertaken before radio
active tagging was perfected.
-
ChIorophylI Project
Side by side with photosyn
thesis studies are research pro
jects looking toward eventus
manufacture of chlorophyll i
the laboratory. DR.. Calvin
interested-in fact, has a prof