Mertens, T. R.
Lines 018 and 003 of L. esculentum and 206 and 226 of L. pimpinellifolium provided by A. D. Burdick were irradiated at Brookhaven National Laboratory and germination studies were then made. In the table below percent survival is expressed in terms of the number of seeds planted.
Effect of thermal neutrons and X-rays on germination of
irradiated tomato-seeds
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Line Hours N\th\*
0 10 20 30 40 50
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Percent Germination
206 99 95 89 90 93 67
226 100 97 97 23 0 0
018 94 98 98 96 90 62
003 90 83 83 77 21 2
Percent Survival
206 - - - - - -
226 100 93 93 23 0 0
018 94 98 98 96 82 40
003 90 83 83 54 4 0
Mean Days to Germinate
206 6.0 6.0 6.7 8.8 9.0 10.3
226 6.5 6.6 7.0 8.3 - -
018 6.0 6.2 6.6 6.9 8.5 9.9
C03 - - - - - -
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Line 1000r X-ray
6 12 18 24 36 48 60
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Percent Germination
206 - - - - - - -
226 100 100 100 87 47 13 3
018 96 98 100 96 94 98 96
003 - - - - - - -
Percent Survival
206 - - - - - - -
226 100 100 100 87 43 10 0
018 96 98 100 96 94 98 96
003 - - - - - - -
Mean Days to Germinate
206 - - - - - - -
226 6.4 6.2 6.5 7.3 8.5 10.0 8.0
018 5.7 5.7 5.7 6.0 6.4 6.1 6.5
003 - - - - - - -
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* at flux of Ca 8xlO^8 N\th\ /sq. cm./sec.
The table shows different responses of lines within and between species when
the dormant seeds were irradiated as specified. Line 018 was especially
remarkable in its ability to survive high doses of both types of irradiation.
Furthermore, fruit was set and seed obtained from all treatments of 018 when
the irradiated plants were crossed to the unirradiated controls. The
irradiated plants were used successfully as both pollen and seed parents in
these crosses. It is clear that increasing doses of thermal neutrons tend to
delay germination, but delayed germination of X-irradiated seed occurs only
when higher doses are used.